Abstract:[Objective] To analyze the spatio-temporal variation of rainfall erosivity in order to provide the basis for predicting soil erosion and evaluating the effectiveness of conservation measures.[Methods] Based on the daily rainfall records(1970-2010) from 13 rain-gauge stations located in Daning river watershed in the Three Gorges reservoir region, the characteristics of annual and monthly rainfall erosivity were investigated. Meanwhile, by using GIS 10.2 software, spatio-temporal variation of rainfall erosivity was analyzed.[Results] The annual rainfall erosivity(R-factor) was ranged from 3 619.55~11 109.14 MJ·mm/(hm²·h·a), and the mean value was 7 245.55 MJ·mm/(hm²·h·a). The spatial distribution of rainfall erosivity showed a decreasing trend from east and west to the central of the watershed, while there was no significant change from south to north. The distribution of rainfall showed a similar trend. The maximum and minimum rainfall erosivity occurred in Jianlou and Wushan station, respectively. The inner-annual distribution of the rainfall erosivity showed two peaks and highly concentrated in the period from April to October, which accounted for 95% of total annual rainfall erosivity.[Conclusion] The spatio-temporal variation of rainfall erosivity is not only closely related to the distribution of rainfall amount, but also related to the regional rainfall pattern and local topography.

Abstract:[Objective] To analyze the effects of runoff gather engineering on soil moisture conversation in afforestation land converted from cropland in order to provide the basis for improving soil water supply in planted forest.[Methods] With an intensive survey on the runoff gather engineering and afforestation types, we investigated soil moisture conservation and growth and development of tree and grass under different site preparation practices including slope-separate flat terrace(SSFT), slope-separated reversing sloping terrace(SSRST), cone-shape focused fluid pit(CFFP), Swallow-tail-shape focused fluid pit(SFFP) in the region of returning farmland to forest land in Anding district of Dingxi City, Gansu Province.[Results] The runoff gather engineering increased soil moisture and improved water supply to the plants greatly. The total water supply for individual tree reached to 2.54~4.29 m³/a, and it reached to 1.42~1.79 m³/a for an individual bush. Soil moisture within the 2 m soil depth varied from 8.76% to 11.40%, which satisfied the water demand for the growth and development of trees and grasses.[Conclusion] Feasible runoff gather engineering practices combined with suitable tree species, can improve soil water supply in planted forest.

Abstract:[Objective] To investigate the influences of soil erosion on the distribution and properties of soil in order to provide scientific basis for controlling soil erosion and land degradation in Pinus massoniana forestry.[Methods] Soil properties of eroded slope in P. massoniana forestry in the hilly red soil area of Southern China were studied based on statistics and the grey relational degree methods. The data was obtained by field surveying and sampling.[Results] Soil nutrients of the eroded slope were poor. Most of the soil physical and chemical indices were at or below level 4. There were significant differences in the soil index between soil on the slope and soil in the erosion gully. Among eighteen soil indices, ten soil indices of soil erosion gully were better than the corresponding indicators of soil on the slope. Compared with slope, the correlation between erosion gully and soil properties was higher, and the number of significant correlation indices of soil was less in erosion gully.[Conclusion] Soil erosion had a significant impact on the properties and distribution of soil on eroded slope in P. massoniana forest in the hilly red soil area of Southern China. Nevertheless, the mechanisms of the effect of erosion on soil properties needs to be further studied.

Abstract:[Objective] We studied the variation pattern of soil salinity at different layer of GSM(gravel-sand mulched field) and CK in order to provide basis for improvement and utilization of soil salinization in the northwest arid area in China.[Methods] Based on the statistics at different layer of GSM and CK, classical statistics and geo-statistics were used to analyze the statistical characteristic value, semi-variance simulation model and its fitting parameters, and the isocline distribution map of soil salinity in Jingtai County of Gansu Province.[Results] Mean soil salinity of GSM was lower than that of CK, and the result showed:CK > OGM(old gravel-sand mulched field) > NGM(new gravel-sand mulched field) > MGM(middle gravel-sand mulched field). There were significant differences in soil salinity among different layers of GSM and CK, and the result showed:layer Ⅳ(30-50 cm) > layer Ⅲ(20-30 cm) > layerⅡ(10-20 cm) > layerⅠ(0-10 cm). The variations of soil salinity in layerⅡ, Ⅲ, Ⅳ(CK) and MGM were weak, while variations in other layers were moderate. The best semi-variance theory model of layer Ⅱ(CK) was linear model, the optimal model for layerⅠ, Ⅲ(CK), layer Ⅲ(NGM), layer Ⅰ(MGM) and layer Ⅰ, Ⅱ, Ⅲ(OGM) was exponential model, while the best model for other layers was spherical model. The spatial auto-correlation of soil salinity at layer Ⅱ(CK) was lower, while it was high at other layers. The soil salinity in northern area was higher than that in southern area.[Conclusion] Gravel sand on soil surface can reduce soil salt accumulation and control soil secondary salinization, and there is spatial variability and correlation exists in soil salinity among different layer of GSM and CK.

Abstract:[Objective] The spatial distribution of nutrients and bacterial communities in sediments of water resource reservoir were investigated in order to reveal the interrelation between microbes and migration and transformation of nutrient salts.[Methods] Sediment samples were collected in a Tangpu reservoir in low mountain and hilly area of Eastern Zhejiang Province, the content of total organic carbon(TOC), total nitrogen(TN), ammonium-nitrogen(NH₄⁺-N), nitrate-nitrogen(NO₃-N), total phosphorus(TP) and available phosphorous and bacterial community structure were analyzed respectively.[Results] (1) The average TOC content was 14.6 g/kg and the average TN content was 1.6 g/kg in the reservoir sediments. The maximum content of TOC and TN was found in sampling sites H, minimum value was found in sampling site F. The content of TP was in the range of 0.5~1.08 g/kg, the mean value was 0.8 g/kg. Available phosphorus and ammonium nitrogen had a highest content in the river storage section, and showed low levels in central location of the reservoir and dam. (2) In the sediments, microbial population were significantly different. A total of 10 kinds of known phylum were identified, and 4 kinds of phylum(Verru comicrobia. Proteobacteria, Acidobacteria, Chloroflexi, and Verruc omicrobia) were shared among all samples. In all the samples, Proteobacteria predominated about 50%~70.8% of the total bacteria.[Conclusion] Pearson's correlation analysis show a significant negative correlation among Gamma proteobacteria, Delta proteobacteria and TP. While there is a significant positive correlation between Firmicutes and TN (p<0.05).

Abstract:[Objective] To analyze the export characteristics and source of non-point source in order to provide reference basis for the study of the similar agricultural watershed water quality and non-point source pollution control.[Methods] This area was firstly divided into certain catchments with ArcGIS software. The water quality and precipitation was monitored across sections in 2014. Combined with the mean concentration method and export coefficient model, a calculation model was set up to estimate non-point source pollution export, and the sources for various non-point pollutants was analyzed with optimized mathematic method.[Results] The total nitrogen export coefficients of agricultural land, woodland, residential land, domestics and livestock was 15.87 kg/(hm²·a), 6.33 kg/(hm²·a), 6.27 kg/(hm²·a), 0.20 kg/(person·a), 0.83 kg/(anamal·a), respectively, while the total phosphorus export coefficients was 0.46 kg/(hm²·a), 0.39 kg/(hm²·a), 0.67 kg/(hm²·a), 0.10 kg/(person·a), 0.16 kg/(anamal·a), respectively. Nitrate nitrogen was the main form of nitrogen loss in the runoff and a large amount of particulate phosphorus run off in the periods of peak rainfall. In the precipitation, ammonia nitrogen and dissolved phosphorus was main loss form.[Conclusion] In this small catchment, precipitation, woodland and domestic waste are the main pollution sources.

Abstract:[Objective] Taking Meijiang river basin as a case study, this paper investigates the variations of precipitation and runoff in order to provide supports for river regulation, flood control and environmental protection.[Methods] Runoff and precipitation data during 1960-2013 was collected. Mathematical methods including accumulative anomaly, variation coefficient, concentration frequency and concentration period were used to investigate the variations of runoff and precipitation at decadal, annual and seasonal time scales. The hysteresis effect of runoff to precipitation was discussed.[Results] The inter-annual changes of runoff was declined at the rate of 5.79 mm/10 a. The runoff was mainly concentrated in the summer and spring time from April to September. The fluctuation of precipitation showed a slight decreasing trend in the basin. The precipitation mainly concentrated in May to June. Correlation between annual runoff and precipitation was significant(the significant level is more than 0.001, r=0.824>0.428=R_0.001,54). There was a hysteresis effect of runoff to precipitation, the average hysteresis period was about 21 days, and this hysteresis period was expected to increase over time.[Conclusion] Human activity may be the main reason that alters the status of land cover or the change of climate.

Abstract:[Objective] To discuss the motion law and liquefaction effect by analyzing the motion characteristics and its driving factors of loess landslides in order to provide theoretical references for hazard prevention and treatment in landslide areas.[Methods] The loess landslide in South Jingyang plateau was chosen to research the motion law of landslide by site investigating, trench excavating, and statistical analysis. Based on the above works, the influences of liquefaction effects on motion characteristics were discussed.[Results] According to the motion characteristics, the landslide in South Jingyang plateau was classified into two types:flowslide and slide. In the flowslide type, the sliding distance was four times of slope height, while the sliding distance was two times of slope height in the slide type. The minimum landslide volume that was sufficient to produce the greatest degree of liquefaction was about 1.50×10⁵ m³ in study area.[Conclusion] Greater volume and simpler sliding boundary of landslide will improve flow motion, vice versa.

Abstract:[Objective] To analyze the physicochemical properties of the cotton and peanut biochar, and investigate the effects of rainfall on Cu(Ⅱ) leaching quantity under simulated rainfall in natural conditions in order to assess the feasibility of using straw biochars to remediate the Cu(Ⅱ) contaminated soil.[Methods] Cotton and peanut straw was selected as raw materials to produce biochar by using limited oxygen pyrolysis method under 350, 500 and 650℃ conditions. A laboratory simulation test was used to analyze the effects of different biochar amendment on soil buffering capability and the retention capacity of heavy metals. Biochar with 1% carbon/soil dry weight ratio were supplied in Cu(Ⅱ) (200 mg/kg) contaminated brown soil.[Results] The ratio of O/C and H/C in two different kinds of biochar were decreased gradually with the increase of temperature, while the BET surface area of biochar was decreased with the increase of temperature. The pH value of soil leaching solution in biochar added soil was significantly higher than that of the control treatment, and the effect of peanut biochar was more significant. With the increase of leaching times, Cu(Ⅱ) leaching amount in biochar added soil was significantly lower than that in the control treatment. The peanut biochar addition could increase the specific adsorptions of Cu(Ⅱ) in soil, especially at 650℃ condition.[Conclusion] Both of the two straw biochar addition significantly improve the soil buffering capability and the retention capacity of heavy metals in soil, in which the effect of peanut biochar is more obvious.

Abstract:[Objective] To analyze the late settlement of high filled project in Yan'an District of Shaanxi Province in order to provide technological and theoretic support for the design and construction of high filled project.[Methods] A variety of laboratory consolidated drained static lateral pressure coefficient K₀ triaxial creep tests were conducted under different water content, compacted degree and vertical stress by using a refitted K₀ triaxial creepmeter.[Results] The remolded Q₃ loess had an obvious creep properties, and it showed a typical attenuation creep under low stress level. Creep phenomenon showed an increase trend and the deformation of creep enlarged, with higher water content, higher pressure stress and smaller compacted degree. Under low stress level, there was a linear relationship between lateral stress and vertical stress.[Conclusion] Based on the tested data, a user-defined creep model of remolded Q₃ loess about vertical stress was established, and characteristic parameters were obtained by fitting test data. The established model can well describe the properties of remolded Q₃ loess in Yan'an District.

Abstract:[Obiective] Investigating the distribution of soil calcium on natural slope under the influences of integrated factors in order to better understand the structure and evolution of soil in karst area.[Methods] Typical karst peak-cluster in Yanbei Town, Yingde City, Northern Guangdong Province, was selected as the research area. The contents of total calcium, exchangeable calcium, water calcium and organic matter were measured, and correlation analysis were used.[Results] At the peak cluster, the average content of total calcium, exchangeable calcium and water soluble calcium was 4.172, 1.050 and 0.026 g/kg, respectively. Exchangeable calcium accounted for 22.29% of the total calcium, while water soluble calcium accounted for 0.56% of total calcium. The contents of total calcium, exchangeable calcium and organic matter reduced with the decrease of slope gradient. Contents of soil calcium in steep slope were obviously higher than that in the gentle one. The contents of water soluble calcium showed little changes with the slope variation. The correlation analysis showed that the total calcium and exchangeable calcium was positively related with altitude, slope and coverage of rock, while negatively related with soil thickness. There were no significant correlations between water soluble calcium and the topographical factors.[Conclusion] The topographical change and soil development influences the contents of total calcium and exchangeable calcium, while it has no significant influence on the contents of water soluble calcium. On the natural slope of karst peak-cluster, both total calcium and exchangeable calcium migrate with the slope descending, but the vertical migration is not obvious. The migration of water soluble calcium is not obvious, but it is sensitive to local hydrological conditions.

Abstract:[Objective] Studying relationships between forest vegetation and its hydrological effects, and evaluating the water resources potential in the upper reaches of Lijiang river in order to provide scientific basis for water resources management and forest management.[Methods] Changes of soil water content at different soil layers in three typical forests including Phyllostachys pubescens, Schima superba and Cunninghamia lanceolata were studied in Mao'er mountain in the upper reaches of Lijiang River.[Results] (1) Due to the complicated canopy structure, higher water storage was found in S. superba. There was an obvious difference in the vertical variation of soil water content in different soil layers because of the vertical vegetation structure. (2) Soil water content in S. superba varied within higher values, while it changed within lower values in C. lanceolata. Soil water content at different soil layers significantly correlated with the precipitation, and the three typical forests showed a same changing trend with annual rainfall. (3) Soil porosity in P. pubescens was higher than that in S. superba and C. lanceolata and its property of shallow root and fast growing exerted great effects on surface soil water content.[Conclusion] Precipitation is the most important factor that influence soil water content, and the variation of soil water content is the result of rainfall and vertical vegetation structure and transpiration.

Abstract:[Objective] To evaluate the effects of soil water change and alternate drying and wetting on soil CO₂ emissions in order to provide basis for soil carbon cycle in oasis farmland.[Methods] Soil samples were taken from oasis farmland in Xinjiang region, which was used for incubation experiment in laboratory. CO₂ concentration was analyzed by meteorological chromatograph.[Results] (1) Compared with 60% WFPS(water filling soil porosity), 40% WFPS had a significant inhibiting effect on soil CO₂ emissions(p<0.05), while 80% WFPS was no significant influence on soil CO₂ emissions(p<0.05). At the end of the experiment, compared with 60% WFPS, accumulation of soil CO₂ emissions of 40% WFPS was reduced by 26%(p<0.05), while accumulation of soil CO₂ emissions of 80% WFPS was increased by 0.04%(p>0.05). (2) After multiple wet dry cycling, soil CO₂ accumulative emissions under alternate drying and wetting condition was significant lower than that of constant moisture treatment(p<0.05). Under different drought intensity, the effect of severe drought on soil CO₂ emission rate was higher than that of the moderate drought. But after multiple wet dry cycling, the effect of severe drought on the accumulation of soil CO₂ emissions was lower than that of moderate drought(p<0.05). With the increased of drying and wetting alternation, the effects on soil CO₂ emission rate was reduced significantly, especially for maximum soil CO₂ emission rate.[Conclusion] Drying and wetting alternation can reduce soil CO₂ emissions, and the amount of reduction increases with the increasing of drought intensity in Xinjiang oasis soil.

Abstract:[Objective] In order to provide fundamental data for a better understanding of the current pollution status and management for the malodorous black rivers, especially to prevent and control the eutrophication of Taihu lake, the spatial distribution and morphological characteristics of sediment nutrient in a rural malodorous black river were analyzed and evaluated.[Methods] Thirteen surface sediment samples along the Northern Branch of Zhangxia Stream in Zhoutie Town of Yixing City, Jiangsu Province were collected from the upstream to the downstream. The spatial distribution of total nitrogen concentration(TN), total phosphorus(TP), ammonia nitrogen(NH₄⁺-N), nitrate nitrogen(NO₃^--N), organic nitrogen(Org-N) and total organic carbon(TOC) were investigated. The component distribution of carbon(C), nitrogen(N), phosphorus(P) in surface sediments were studied by coupling analysis for pollution assessment.[Results] Org-N was the main component of nitrogen in surface sediments with an average concentration of 2 193.69 mg/kg, accounted for 90.86% of TN. Concentrations of TN, Org-N, TP and TOC presented a fluctuant increasing trend from upstream to downstream, and the highest values were 2.98, 3.46, 6.29 and 1.59 folds of the minimum values, respectively. The concentration of NH₄⁺-N increased slowly at the initial stage and then decreased rapidly, while the concentration of NO₃^--N showed an opposite trend. Mean ratio of C/N for the entire stream was 12.07, and the organic matter were mainly sourced from exogenous input. In addition, concentrations of TOC and TN showed an extremely significant positive correlation (p<0.01, n=13). Mean ratio of C/P was 2.04, and concentrations of TOC and TP showed a significant positive correlation (p<0.05, n=13). Mean ratio of N/P was 2.04, and concentrations of TN and TP showed an extremely significant positive correlation (p<0.01, n=13). As a result, the pollution of nitrogen and phosphorus was homogenous.[Conclusion] Organic pollution is the main pollution for rural malodorous black river in the Taihu lake watershed, where the nitrogen pollution is mainly Org-N pollution.

Abstract:[Objective] Studying the influences of vegetation on rainfall infiltration and runoff erosion and sediment yield in order to provide a scientific basis for rationally allocating the vegetation in gravel soil slope in the Three Gorges area.[Methods] Runoff plots containing gravel soil were set with different types and coverage of vegetation. Artificial rainfall experiments were conducted.[Results] The amount of runoff showed as follows bare slope > shrub slope > herb slope > grass shrub mixed slope, in contrast, infiltration and runoff showed the opposite trend. The interflow in vegetation-covered slope was greater than that in the bare slope. Infiltration rate obeyed the law of logarithmic function, while the runoff yield strength varied as power function. The regulation mechanism of grassland to water and sediment was mostly direct sad blocking. The relationship between cumulative runoff and cumulative sediment yield showed as the power function.[Conclusions] Vegetation measures can effectively reduce soil and water loss in gravel soil slope, and different vegetation measures represent the different reducing benefits.

Abstract:[Objective] Analyzing the distribution characteristics of phosphorus forms in typical inflow rivers in buffer zones of Erhai lake in order to provide the basis for ecosystem restoration in Erhai lake.[Methods] The sediment samples were collected in Zhonghe river, Mocan river and Mangyong river in the buffer zone of Erhai lake. Four different phosphorus forms, including total phosphorus(TP), inorganic phosphorus(IP), Fe/Al-P and Ca-P in the sediments were measured.[Results] The contribution rate of different land-use types was different with the various phosphorous forms. The variation trend of the phosphorous forms in three rivers was different along the way. The structure of the buffer zone in Erhai lake was not reasonable, and need to be improved. The content of phosphorus forms in estuary sediment was as follows(in a descending order):Zhonghe river > Mocan river > Mangyong river. The phosphorus in Zhonghe and Mocan rivers was mainly Fe/Al-P, while it was mainly Ca-P in Mangyong river. There was a significant positive correlation between the change of TP in sediments and the Fe/Al-P, OP(organic phosphorous).[Conclusion] The change of OP in sediments influenced the content of Ca-P, Fe/Al-P. The content of Fe/Al-P had a great contribution to the content of IP. The correlation between Fe/Al-P and Ca-P was not significant.

Abstract:[Objective] Analyzing the relationships between plant growth and precipitation, soil water and groundwater in order to provide the scientific basis for vegetation restoration and protection in desertification control.[Methods] We collected precipitation, soil water, groundwater, vegetation biomass and coverage data baseed on long-term locating monitoring in the middle reaches of Hehe river basin. The characteristic parameter algorithm, correlation and stepwise multiple regression analysis was used to investigate the response characteristics of natural desert plant growth and inter-annual and annual variation of soil water content.[Results] (1) The change of soil moisture content, biomass and coverage was the greatest, the change of precipitation was secondary, while the change of groundwater depth was minimum. The biomass and coverage showed an obvious increasing fluctuation trend, while the precipitation, soil moisture content and groundwater depth showed a slight decreasing trend. (2) In the growing season from March to November, the annual variation of soil moisture content in each layer were basically the same, and so were the variations of average vegetation coverage and biomass. (3) The regression equations were established to model the relationship between soil moisture content at 0-20 cm depth and vegetation cover and biomass. R fitting test, F test, t test was used. The partial regression coefficient for vegetation coverage and biomass was 99.0% and 91.4%, respectively. The accuracy of predicted changes in vegetation coverage and biomass was 86.5% and 78.9%, respectively.[Conclusion] There is a close relationship between the growth of desert vegetation and changes of environment water in middle reaches of Heihe river. Consequently, desert vegetation can be recovered by water resources management, and water resources management can be assessed according to the vegetation growing condition.

Abstract:[Objective] To analyze the spatial and temporal characteristics of the soil moisture variation in vadose zone in order to provide basis for the study on the "four waters transformation" dynamic cycle.[Methods] Using the concept of the potential energy of soil water dynamics, the characteristics of the moisture in vadose zone and changes in water potential with time and depth was studied.[Results] The significant difference was observed in soil water potential distribution in each season. Soil water potential reached the highest in June and August, even got saturation in some blocks. On the contrary, it dropped to a minimum in period from December to next March. Soil moisture of 50 cm depth was affected greatly by seasons and water potential changed dramatically. Yet soil moisture below 50 cm depth was substantially independent of the season changes. And between 50-140 cm depth water potential was relatively stable; Beneath 140 cm, it was only influenced by gravity potential.[Conclusion] The factors such as rainfall, irrigation, evaporation, groundwater depth and others could cause the changes in the profile distribution of soil water potential, thus causing changes among a variety of soil water movement states.

Abstract:[Objective] To analyze the risk analysis of loess shallow landslide under different rainfall conditions in order to provide an effective way for the loess shallow landslide hazard analysis and evaluation.[Methods] The paper took Tianshui City of Gansu Province as a case study and wrote a program to analyze the shallow landslide hazard according to SHALSTAB model under ArcGIS platform. Then the distribution of shallow loess landslide was predicted with consideration of different rainfall conditions.[Results] With the increase of rainfall, the shallow landslides increased significantly, and the proportion increased from 0.166% to 3.624% when the rainfall increased from 5 mm/d to 320 mm/d, increased by 20 times.[Conclusion] When the precipitation is low, shallow landslides area main distributed in rainfall concentrated area. When the precipitation increases, shallow landslides extend upward along the loess valley. The comparison with the actual landslide disasters showed that the calculation results are accurate and reliable.

Abstract:[Objective] To analyze the soil condensation water in three plant communities in Hulunbeier grassland in order to provide basis for the effective utilization of water resource in restoration of grassland vegetation in desertified land.[Methods] Three plant communities, Artemisia capillaris, Cleistogenes squarrosa and Leymus chinensis were selected to measure the formation time and amount of soil condensation water as well as their dynamic changes by weighing method and the effects of vegetation type, and environmental factors were analyzed on the formation of soil condensation water.[Results] (1) The soil condensation water began to form 18:00 and began to evaporate after 6:00. Soil condensation water dynamic changes showed bimodal pattern, one of the first peak appeared at about 20:00 while the second peak appeared at about 4:00; (2) Soil condensation water amount in different plant communities showed significant differences(p<0.05). From July to September, the daily mean amount of condensation water in the three plots, A. capillaries, C. squarrosa and L. chinensis, was 0.28 mm, 0.22 mm and 0.32 mm, respectively in July, 0.50 mm, 0.35 mm and 0.69 mm in August, and 0.28 mm, 0.23 mm and 0.37 mm in September; (3) Soil condensation water in different depth of soil follows as an order as 0-5 cm > 20-25 cm > 5-10 cm > 10-15 cm > 15-20 cm, the amount of condensation water in 0-5 cm layer in L. chinensis plot was up to 0.147 mm, followed by the A. capillaries plot(0.125mm) and C. squarrosa plot(0.094mm).[Conclusion] There was two sources of soil condensation water. Different types of plant communities resulte in the different contributions of these two sources to the total amount of soil condensation water. L. chinensis can form more soil condensation water, which may play a more important role in restoration of grassland.

Abstract:[Objective] To research the erosion morphology characteristics of river section in order to provide a scientific basis for the evolution of landform hydrological of downstream, the analysis of the impact of human activities and the rationality of the runoff(sediment) of upstream.[Methods] Based on the data of Shanshui and Makou stations in Pearl River dalta, Indices of the river section erosion morphology were derived. By using simulated annealing algorithm to optimize the projection pursuit model, we analyzed the evolution characteristics of river erosion morphology.[Results] As the actual ratio in 2009 of the Sanshui station was much higher than that in other years, the river section erosion in 2009 was completely different from other years. Changes in erosion patterns of other years were stable in Sanshui station. For Makou station, in spite of more erosion morphology changes, according to 5 indicators which reflect the erosion morphology of river section, the variation types of the section shape can be divided into 2 types of erosion morphology.[Conclusion] In summary, the sectional area in Makou and Sanshui station increased since 1990s, and the water capacity showed an increasing trend.

Abstract:[Objective] We study the landscape ecological risk in Tampa Bay watershed of America at temporal and spatial scale in order to provide scientific reference for exploitation, utilization and protection of Chinese harbor basin.[Methods] The TM/OLI remote sensing data in Tampa Bay watershed in 1985, 1995, 2005 and 2015 and the land use data were collected as the main data source, the landscape ecological risk evolution model was constructed, and the temporal and spatial characteristics of landscape pattern and ecological risk in Tampa Bay watershed was analyzed.[Results] (1) The area of artificial landscape was significantly larger than the area of natural landscape. (2) In 1985, the low and relative low ecological risk area accounted for 24.16% and 20.30%, respectively, in the Tampa Bay watershed. After 1995, the low and relative low ecological risk area was decreased, while the moderate ecological risk area was increased significantly. High and relative high ecological risk area was keep increasing until 2015. (3) During the last 30 years, about 3 210.84 km² of low ecological risk area was converted to high risk area, which accounted for 48.65% of the total area in the whole basin. The high ecological risk area expanded along the harbor side, and sporadic distributed in the mainland side of the Northeast area.[Conclusion] Impacted by human activities, the changes of landscape pattern and ecological risk in the Tampa Bay basin watershed was great during the past 30 years. The increasing rate of ecological risk level within the later 10 years was significantly lower than that at the initial 20 years. More attention has been paid on the protection and management of the ecological environment with the development and utilization of resources in the harbor.

Abstract:[Objective] We investigated the variations of soil organic matter in paddy land of Hangzhou suburb over the last 30 years in order to provide basis for accurate soil fertility management and high intensive agricultural production.[Methods] Historic materials and current soil quality survey data were collected and compared to investigate the variations of soil organic matter.[Results] From 1982 to 2012, the mean content of soil organic matter decreased by 2.95%. The changes of soil organic matter varied with soil types. The mean content of soil organic matter in culture muddy-sandy field, silt paddy land, Fe-accumuli-stagnic anthrosols, muddy-sandy field and silt loamy paddy land showed an increasing trend, especially, in culture muddy-sand field, soil organic matter increased by 22.86%. In contrast, the mean content of organic matter in degleyed clayey paddy soil, blue silt loamy paddy soil and yellow loamy paddy soil showed a decreasing trend, and this decreasing trend in degleyed clayey paddy soil reached to 22.59%.[Conclusion] The content of organic matter in the paddy soils changed greatly during the past 30 years, and this change varied among different soil types. Fertilization structure, tillage practices and farming system were the main reasons that cause the variations of soil organic matter.

Abstract:[Objective] We analyze the impacts of land use change on the spatial distribution of soil organic carbon in order to assess the variation of carbon storage in regional ecosystem.[Methods] Land use data was derived from remote sensing image in the years of 1979 and 2013 in the Tianjin Binhai new area. Soil samples were collected in different land use types, and soil organic carbon was calculated. Combined with the second national soil survey data, variations of soil organic carbon were analyzed.[Results] Land use in the study area changed greatly during the study period, with a large area of cultivated land, tidal flat and unused land transformed into new construction land. Meanwhile, soil organic carbon storage changed from 1.23×10⁷ to 9.98×10⁶ t during the study period.[Conclusion] With the enhanced human land-use activities, the spatial distribution of soil organic carbon storage is degraded from high carbon into low carbon storage distribution pattern.

Abstract:[Objective] To analyze the land consolidation regionalization, an important content of land consolidation planning, in order to provide basis for determining the key regional land consolidation and land consolidation planning.[Methods] We took Lanzhou City, Gansu Province, an ecological fragile area in Northwest China, as the research area. With the consideration of regional natural geographic features, land use characteristics and major regional ecological problems, a preliminary dividing index systems including terrain, rainfall, soil type, vegetation type, water loss and soil erosion was constructed. The established index systems were further improved based on regional water resource supply, water resource distribution and administrative divisions. ArcGIS spatial overlay analysis function was used.[Results] A two level regionalization system that named by the "orientation+landscape+land use type" was established, and the second level is more detailed. Lanzhou City was divided into 7 zones and 15 sub-zones.[Conclusion] The reasonable indicator systems should be selected for land remediation in the process of comprehensive land consolidation in Northwest China, and the characteristics of land resources, water resources and ecological environment conditions should also be considered for the different zones in the perspective of ecological protection.

Abstract:[Objective] To study the changes in vegetation coverage around Ertan reservoir when it is filled with water, in order to provide the basis for assessing the impact of reservoir filling on vegetation growth surround the reservoir.[Methods] We used the dimidiate pixel model to predict the vegetation coverage of the study area in each November from 1999 to 2014 with the Landsat TM and environmental CCD images as the information sources. We then detected areas with obvious changes in vegetation cover through waveband operation and threshold segmentation.[Results] From 1999 to 2014, the vegetation cover in the study area increased year after year, and the high coverage area expanded greatly. However, the vegetation cover decreased in some areas due to human activities, soil erosion, farmland and landslide, which accounted for 19.5% of the total area; the region with obvious increase in vegetation cover accounted for about 39.8% of the total area, mainly concentrated areas near to the reservoir.[Conclusion] The Ertan reservoir had improved the growth of vegetation around, and the vegetation cover has increased year by year as a whole.

Abstract:[Objective] To investigate the spatial distribution of saline alkali land in Manasi irrigation area, in order to understand the type and the spatial and temporal changes of local saline alkali land, and find out appropriate improvement measures.[Methods] Based on the soil data in 1985, Landsat TM images in 1998 and CBERS(China-Brazil earth resource satellite) images in 2006 and 2014, the RS and GIS technology was used to extract the information of soil salinization during four periods. The land transfer matrix was used to analyze the spatial-temporal changes of salt-affected land in Manasi irrigation region during the past 30 years.[Results] (1) The area of soil salinization land in Manasi irrigation region had increased from 4.27×10⁴ to 7.90×10⁴ hm² during the past 30 years. (2) Soil salinization was mainly distributed in the inner area of Manasi irrigation region, represented as a block pattern.[Conclusion] Nature factors are the internal causes of the formation and change of the soil salinization, and anthropogenic influence is one of the driving factors that promoting the development of soil salinization, especially for the secondary salinization of oasis.

Abstract:[Objective] To study the spatial-temporal changes of vegetation cover in the past 14 years and its future trend in the upper reaches of the Heihe river in order to provide a support for the regional ecological protection.[Methods] Based on the MODSI-NDVI data from 2001 to 2014, we did the quantitative analysis by linear trend analysis and Hurst index.[Results] The vegetation cover in the study area had been improving slowly, showing a "volatility-improvement" trend on year scale, the mean NDVI decreased gradually from southeast to northwest and shows a meridional zonality. The area with increased vegetation cover accounted for 47.74%, whereas the area with deceased vegetation cover accounted for 21.81%. The improved areas are mainly distributed in the central and northwestern parts of study area with alpine steppe significantly improved. The degraded areas are mainly located in the southeast of study area with alpine meadow significantly degenerated. The vegetation cover in the upper reaches of the Heihe river will increase in the future.[Conclusion] The vegetation cover in the upper reaches of the Heihe river is high and the future trends of the vegetation cover is toward improving, but we need to take measures to protect areas still degenerating in Qilian, Minle and Shandan County.

Abstract:[Objective] The characteristics of plant communities in the natural slope and erosion gully of the subalpine meadow in Lingshan Mountain in Beijing City were investigated and analyzed to provide theoretical basis and technical support for vegetation restoration in erosion gullies.[Methods] The characteristics of plant communities at different sites were studied using the methods of standard ecological investigation methods and statistical analysis.[Results] (1) The Shannon-Wiener index and Margalef index were all as follows:erosion gullynatural slope; (2) The community similarity coefficient and β diversity index between the community of the natural slope and erosion gully were 0.884 and 0.178, respectively, which mean the plant community composition in erosion gullies and natural slopes had higher similarity; (3) The niche breadth and the important value of Poa sphondylodes Trin and Carex dispalata were larger both in the natural slope and erosion gully, which showed that these two species were main dominant species. In addition, most species had niche overlap in both natural slope and erosion gully, but the niche overlap values were relatively small.[Conclusion] Erosion gully is in the early succession and tend to restore the natural state. P. sphondylodes Trin and C. dispalata are the pioneer dominant species of community.

Abstract:[Objective] To analyze the cognition and behavior of different household in order to provide support for the government policy making and guide farmers to strengthen the supervision and protection of cultivated land.[Methods] This research took Zhoukou City in He'nan Province as an example, to investigate household's cognition and behavior of cultivated land protection by stratified random sampling and participatory rural appraisal(PRA) assessment method. The factors that influence farmer's cognition and behavior were studied by using binary Logistic regression models.[Results] (1) With the improvement of education, the cognition of household on the importance of farmland, time investment preferences, confidence in the prospects for the cultivated land protection, and the agricultural pollution prevention showed as:Ⅰ < Ⅱ < Ⅲ < Ⅳ. In contrast, the willingness to participate after compensation, regularly using organic fertilizer or soil testing fertilizer, and to prevent other people from destroying the arable land showed as:Ⅰ > Ⅱ > Ⅲ > Ⅳ. (2) Some of the factors that influence the behavior of farmers were similar in all types of household, while the others were different. The same factors included education degree, investment preference, willingness to accept compensate. The factors that influence the household with high average age and less labors included age, the number of farmers, and the way of compensation. The factors that influence household specialized in agriculture included family gross income, cultivate area and arable land fragmentation. The factors that influence natural assets household(work short in farming, and high non-farm income) included non-farm income, the economic benefits of grain production. The factors that influence assets type household(living in town and invested less in farming) included cultivated land economic location, the current food prices and policy compensation mode.[Conclusion] As the direct participants of cultivated land protection, household's cognition and behavior determines the effectiveness of farmland protection to a large extent.

Abstract:[Objective] With the continuous increase in grain output and agricultural policies adjustment during 1990-2012, the temporal-spatial evolution of grain production and its driving mechanism was studied in order to provide theoretical support for food security policy making in Huaihe River basin.[Methods] The space center and spatial pattern of grain production were analyzed dynamically based on the regional gravity model and spatial autocorrelation method.[Results] (1) The total grain output and per county grain output increased since 1990s. The counties with high grain production distributed in the middle part of Huaihe river basin, while the counties with average grain production distributed toward the middle and up part of the basin. (2) The space center of grain production in Huaihe river basin moved to west and south and the center of grain production moved to the Shuixi County of Anhui Province from the Central Jiangsu Province during the study period, and the spatial pattern tend to be stable. (3) The counties with high grain production tend to aggregate in the junction area between He'nan and Anhui Province and the counties in coastal area of Central Jiangsu Province. While the counties with low grain production tended to cluster in the edge area of western He'nan Province. The number of counties with the aggregation of high-low and low-high is small, but its spatial distribution changed greatly.[Conclusion] The dominant factors, such as water and soil resources change, new agricultural technology and policy inclination, grain comparative benefits, common drive the evolution of basin spatial pattern of food production.

Abstract:[Objective] To analyze spatial dynamic characteristics and interrelationship between cultivated land changes and grain production in order to provide a scientific basis for improving the level of intensive utilization of cultivated land and increasing grain production.[Methods] Using land use change data obtained by remote sensing and the agricultural statistical data from local governments in 1990-2013, with the theory, technology and methods of geography and economics, we analyzed the spatial-temporal dynamic patterns of regional arable land and grain production, and developed a farmland-grain elasticity coefficient to depict the interrelationship between farmland and grain production and reveal the impact mechanism of arable land dynamic change on grain production.[Results] (1) The arable land in 1990-2000 was significantly expanded, which increased in the central and northern part in the study area while it decreased in eastern part. The grain production increased gradually. The grain production was very sensitive to the arable land changes in Siziwang Banner, and less sensitive to the arable land changes in other areas. (2) The total arable land was significantly decreased in 2000-2013, mainly occurred in central and southern area. The trend of grain production in the study area was increased after the first decrease. The food production capacity was significantly improved in the eastern and western area in the Ulanqab City and the sensitivity to arable land was low.[Conclusion] Cultivated land changes in 1990-2013 have significant effect on grain production of the Ulanqab City. The sensitivity of the grain production to the cultivated land changes has significant regional differences as well as in different periods, which was lower in 2000-2013 than that in 1990-2000.

Abstract:[Objective] We took Jiangsu Province as a case study to investigate the key influence factors, the variation characteristics and the relationships between urbanization development and water resources development and utilization in order to coordinate the development of urbanization and utilization of water resource.[Methods] Evaluation index system of the comprehensive development level of urbanization and potential development and utilization of water resources in Jiangsu Province was constructed by entropy weight method. The response relationship model and correlation analysis was employed.[Results] During the study period, especially from 2008 to 2012, Jiangsu Province was in a period of rapid economic development. The economic and social development level was lagged behind the population and area increase, and the urbanization was not coordinated. With the advance of urbanization process, the level of water resources development and utilization increased steadily, however, the water resource amount decreased and the water resources pollution increased year by year. The shortage of water resources restricted the development of urbanization in 2004, 2009, 2010.[Conclusion] There is a certain response relationship between urbanization process and water resources usage. At present, Jiangsu Province is facing the task of improving the coordination of urbanization, it need to reform the traditional expansion of urbanization and to use the water resource rationally and efficiently.

Abstract:[Objective] To analyze the consolidation potential and capacity of rural residential land at a small scale in order to provide references for the rural residential land consolidation.[Methods] Taking 25 administrative villages in Weiyuan County, Gansu Province as the research objects, we estimated the consolidation potential and capability of rural resident. The land use data surveyed in 2010 was collected, the analytical hierarchy process and clustering analysis method was used, and ArcGIS software was employed.[Results] The consolidation potentiality area in Qingyuan Town was 330.063 hm². Under the concept of ecological civilization, 8 indicators covering ecological conditions, production conditions and living conditions were selected to construct the modified index system. The consolidation capability showed that the potential consolidation area was 186.561 hm², and the potential release level was 56.52%. Among the 25 villages, the consolidation potentiality in Shangmo village was the greatest, while the consolidation potentiality in Beiguan, Kezhai and Qinwang villages was the least.[Conclusion] According to the consolidation potentiality and correction coefficient, the consolidation capability of rural residential can be divided into 4 modes, including retained mode, merged mode, reduction mode and agglomeration mode.

Abstract:[Objective] To analyze changes in ecosystem water regulation services before and after the implementation of ecological projects in the Three-River headwaters region, Qinghai Province, and to evaluate the ecological effect of these projects objectively.[Methods] This paper calculated the water regulation amount of forest and grassland ecosystems with rainfall storage capacity method.[Results] The water regulation services of forest and grassland ecosystems increased in fluctuations from 1997 to 2012, with the averaged value of 1.54×10¹⁰ m³/a within the region and 430.67 m³/hm² per unit area. The regulated amount of water in the later period(2005-2012) increased by 15.60% than that in the earlier period(1997-2004). Spatially, water regulation service capacity gradually decreased from southeast to northwest. Water regulation amount per unit area of different basins in descending order was Lantsang River basin > Yellow River basin > Yangtze River basin. Water regulation amount after the implementation of ecological projects was higher than before under both real climate conditions and mean climate conditions. In the earlier period, the water regulation service was mainly affected by regional climate change. While in the later period, it was overlaid the effects of ecological projects. In these two conditions, the linear trend of water regulation amount from 2005 to 2012 was 1.94×10⁹ m³/10 a and 4.64×10⁸ m³/10 a, respectively.[Conclusion] Implementation of the ecological projects had certain positive effects on improvement of water regulation service, with a contribution rate of about 23.98%.

Abstract:[Objective] Assessment of the vulnerability of water resources in Beijing-Tianjin-Hebei(BTH) region was carried out in order to provide theoretical and data support for water resources management.[Methods] This study focuses on the vulnerability of water resources in BTH, a highly populated and developed region yet with serious water resource problems. An indicator system of water resources vulnerability was established by integrating resource pressure, development pressure, pollution pressure and management pressure(RDPM) using the concept theories of water footprint while analytic hierarchy process was used to determine the weights of different indicators. Then the water vulnerability was assessed from 2003 to 2013 for the BTH region.[Results] The BTH region was exposed to problems such as poor water resources endowments, high water exploitation, serious water pollution and unbalanced management. Beijing City had a relatively high level of water resources management, it still suffered from serious water pollution. Tianjin City has made a great progress in water resources management, but the water resources vulnerability did not show a declining signal and new management approaches need to be explored. Compared to Beijing and Tianjin City in terms of water resources management, there is a big lag in Hebei Province, whose water resources vulnerability seems to be more serious in these years. As a result, Hebei has been a "short slab" of water resources management in the BTH region.[Conclusion] It is imperative to relieve the pressure on water pollution, increase the management strategies in Hebei Province, allocate water resources reasonably and improve water management in all BTH regions.

Abstract:[Objective] Assessing water storage capacity of three types of wetland in Zoige wetland in order to provide the scientific basis for the assessment of the hydrological function value of wetland ecosystem.[Methods] We measured the physical properties and maximum retention capacity, and evaluated soil water storage capacity of three types of the Zoige alpine wetland.[Results] (1) Within a depth of 0-60 cm, the soil bulk density of three types of wetland increased with soil depth increase, but at the depth of 80-100 cm in marshes, 60-80 cm in swamp meadow and floodplain wetland the soil bulk density decreased; (2) Within the range of 0-100 cm, the soil capillary porosity of marsh meadow shows a decreasing trend with depth, but no apparent trend in the other two wetland types; (3) Within the range of 0-100 cm, the mean value of soil bulk density in three types of wetland showed an order as marshes(0.46 g/cm³) < swamp meadow(1.08 g/cm³) < floodplain wetland(1.25 g/cm³); The average of the maximum soil water storage capacity was as marshes(239.40 t/hm²) > swamp meadow(171.18 t/hm²) > floodplain wetlands(148.51 t/hm²).[Conclusion] The water storage capacity of the marsh is the best. So when implementing wetland conservation and restoration in Zoige region, the marsh outside the reserve should also be included in the planning.

Abstract:[Objective] We analyze the risk zoning of regional geo-harzards in order to provide a scientific basis for regional geo-hazards prevention and reduction in Zhouqu County, Gansu Province and similar areas.[Methods] We established regional risk assessment models for shallow geo-harzards under different rainfall characteristics, by using SINMAP model.[Results] The distribution pattern of disaster spot in low-lying areas was consistent with high humidity area. With the increasing of rainfall, the shallow soil moisture and area of wetness region increased gradually, and extended to the ridge and gentler slopes. With the rise of rainfall warning level, 1 hour rainfall amount increased from 10 mm to 56 mm. The area proportion and landslide proportion in the stable region decreased by 22% and 38%, respectively, the related proportion in the unstable region increased by 121% and 125%, respectively, and the related proportion in the potentially unstable region was the highest, and reached to 35% and 39%, respectively. Meanwhile, the basically stable and potential unstable region was gradually transferred into unstable and very unstable region. The potential of geological harzard occurrence in the study area was increasing gradually. The geo-hazards such as landslides and debris flow could be triggered when the warning level was raised to the level Ⅳ blue warning, while when the warning level was raised to the level Ⅲ yellow warning, the risk degree of geo-hazards was increased significantly.[Conclusion] Rainfall is a factor that induced geo-hazards in Zhouqu County. In case of heavy rainfall suitable conditions, the risk of geo-hazards remains severe.

Abstract:［目的］ 评价石羊河流域土地利用结构，为石羊河流域土地利用总体规划的修编、土地利用机构的优化以及土地资源的可持续利用提供依据。［方法］ 利用解译的石羊河流域5期（1980，1995，2000，2006，2012年）土地利用数据，基于TOPSIS方法，采用熵值法确定指标权重，结合灰色关联度分析，对石羊河流域土地利用结构的合理性进行综合评价。［结果］ （1） 5期石羊河流域土地利用结构合理度总体上较高，均在75%以上，在时间上总体呈波动上升趋势。其中，2006到2012年上升19.54%，增幅最大；（2） 不同土地利用类型变化对土地利用结构的合理性影响不同，其土地利用结构合理性关联度依次为：未利用土地（0.973 8）> 林地（0.961 1）> 草地（0.950 4）> 耕地（0.935 2）> 居民用地（0.757 6）> 水域（0.709 0）；以石羊河流域耕地为参考数列，对影响耕地的其他土地利用结构进行了灰色关联度分析，发现对耕地影响最大的是林地（0.938 5）和未利用地（0.935 0），其次是草地（0.902 1），再次是居民用地（0.797 7）和水域（0.722 9）。［结论］ 限制石羊河流域未利用土地的开发，保护林地，调整草地和耕地比例，控制居民地的过快增长和严格保护水域，对优化石羊河流域土地利用结构具有决定性的作用。

Abstract:[Objective] Investigating the potential pollution risks of livestock manure to soil and other environment in order to provide a scientific basis for prevention and control non-point source pollution caused by breeding industry.[Methods] Taking Shaanxi Province as an example, nitrogen and phosphorus cropland load of livestock manure were calculated and the spatial and temporal distribution features were analyzed.[Results] (1) Nitrogen and phosphorus cropland load of livestock manure in Shaanxi Province reached to the maximum in the period from 2006 to 2007, while decreased dramatically to the minimum in 2008, and then increased gradually. From 2008 to 2010, the average value of nitrogen and phosphorus cropland load increased by 73.0% and 59.4%, respectively. Although nitrogen and phosphorus cropland load of livestock manure in Yan'an and Weinan City was the lowest among all the cities, the growth rate was the fastest. (2) According to the spatial distribution of nitrogen and phosphorus cropland load between 2008 and 2010, nitrogen and phosphorus cropland load was the maximum in Hanzhong City, while it was the minimum in Yan'an and Weinan City. In 2010, the average value of nitrogen cropland load showed as:Hanzhong > Ankang > Yulin > Baoji > Xianyang > Shangluo > Tongchuan > Xi'an > Yan'an > Weinan, and the average value of phosphorus cropland load showed as:Hanzhong > Shangluo > Baoji > Yulin > Xianyang > Xi'an > Ankang > Tongchuan > Yan'an > Weinan.[Conclusion] Based on a comprehensive analysis in Shaanxi Province, it suggests that livestock manures should be disposed intensively in Hanzhong, Ankang, Shangluo, Baoji and Yulin City, so that the pollution risks of soil and water resource can be decreased.

Abstract:[Objective] To study the factors influencing nitrogen and phosphorus release in eutrophication lake sediment in order to provide the scientific significance for eutrophication lake management.[Methods] Taking the urban landscape lake, Cuihu lake, which eutrophication is more serious, in Kunming City, Yunnan Province, as the study area, by controlling the different pH value, temperature and nutrient concentration of overlying water to simulate factors that affect the release of nitrogen and phosphorus in sediment.[Results] (1) Under the same conditions, the release rate of nitrogen and phosphorus in sediment was affected by the pH value of the water, and the release rate of the neutral environment (pH=7.5) was higher than that of acidic and alkaline water. Under conditions of sediment release for 5 hours, 10 hours and pH=7.5, the release of phosphorus was 5.88 mg/kg and 8.28 mg/kg respectively, nitrogen emission was 22.8 mg/kg and 38.4 mg/kg. (2) The release of nitrogen and phosphorus increased with the increase of temperature. Under temperature 20℃, the nitrogen and phosphorus release reached 28.62 mg/kg and 3.75 mg/kg. (3) The release rate of nitrogen and phosphorus in sediment decreased with the increase of the concentration of overlying water, while it increased with the extension of storage time. When overlying water with ammonia concentration of 0.31 mg/L placed for 5 hours, the sediment nitrogen emissions reached a maximum of 21.63 mg/kg. When it was placed for 10 hours with ammonia concentration of 2.37 mg/L, the sediment nitrogen emissions reached a maximum of 39.22 mg/kg, when the phosphorus concentration of the overlying water was 0.14 mg/L, sediment total phosphorus release reached to the maximum; When it was placed for 5 hours and 10 hours respectively, the maximum release of phosphorus reached 4.25 mg/kg and 4.91 mg/kg.[Conclusion] The release of nutrients in sediment is very complex, and its release rate is influenced by the pH value, temperature, and nutrient concentration of water.

Abstract:[Objective] Based on the analysis on benefit and loss of soil and water conservation for provincial roads construction projects in Weifang City of Shandong Province to evaluate the influence degree of soil and water conservation of the local provincial roads construction projects.[Methods] Taking 4 different highways(S220, S221, S321 and S327) in Weifang area as an example, the soil and water loss impact indices(SWⅡ) for four provincial roads construction projects were quantitatively analyzed and evaluated.[Results] The SWⅡ of S220, S221, S321 and S327 was 0.194 2, 0.158 8, 0.175 8 and 0.167 1, respectively, which was lower than the average SWⅡ value of national highway construction project in China. The results indicated that the impacts of soil and water loss caused by highway construction project in Weifang City were lower than the national average level. The main reason for the low SWⅡ in Weifang was that the average occupation land area(4.82 hm²/km) and influence extent(0.91 hm²/km) was smaller and the earth excavation and filling volume(5.06×10⁴ m³/km) and waste residue(400 m³/km) was less, the influence time was shorter (21 months) and the amount of soil and water loss(437 t/km) was less.[Conclusion] For different highway projects, to reduce their impacts on soil and water loss, the construction area and earthwork volume should be reduced. Specifically, by increasing the soil erosion conservation area can mitigate the impact of project construction on soil and water loss and can protect the eco-environment.

Abstract:[Objective] To analyze the dynamic response of concrete filled steel tubular pile structure under the impact of the load of debris flow in order to provide scientific support for the design of the structure.[Methods] The numerical simulation of concrete filled steel tubular pile structure was carried out for three different load conditions using finite element analysis software ANSYS, and the stress, strain and displacement response of structure was analyzed to detect the most unfavorable load conditions.[Results] The impact of large rock at the top of the pile pipe of empty reservoir was the most unfavorable load condition. Among three kinds of load conditions, the impact force was the main factor causing structural damage. The concrete filled steel tubular pile had good anti-impact performance. Under the smaller plastic deformation, the structure bear a large impact force. The larger the component stiffness, the greater the peak impact force peak. The connecting part of the pile pipe and the beam pipe, the root of the pile pipes and restrained beam pipes were the weak parts of the dam, so the strengthening measures should be taken into the design.[Conclusion] Concrete filled steel tubular piles is a material saving blocking structure, and it has good stability and anti-impact performance.

Abstract:[Objective] To study the technologies on the extraction of information on the production and construction projects based on the high resolution remote sensing data in order to provide a quick way to timely capture the overall information on the distribution of production and construction projects, and to monitor soil and water conservation.[Methods] Taking some areas in Yulin City of Shaanxi Province as the study area, using GF-1 images acquired in 2013 and 2014, we used the object-oriented direct comparison method to extract the change information. Then combined with spectrum analysis and shape characteristics, pseudo changes were removed, and new bare land and impervious surface were acquired. In addition, with the help of expert knowledge, the distribution information of possible production and construction projects in the construction period was obtained.[Results] The accuracy of new bare land and impervious surface reached 83.53%, and the accuracy of possible production and construction projects in the construction period reached 95.56%.[Conclusion] This method can effectively extract the distribution information on production and construction projects in the construction period.

Abstract:[Object] To analyze the relationships among urban green space, catchment area and water point in order to relieve urban storm runoff.[Methods] Based on the latest concept of "sponge city" and ecological stormwater management, we took Zhengzhou City as a case study. The study area was divided into 93 catchment areas. By using water balance method, parameters of green space were calculated.[Results] We summarized the regression relationships between the existing green space and the catchment area, and obtained different green space/water catchment area ratios under different rainfall conditions(50, 100 and 200 mm). The result showed that the regulation and storage effect was the best when the green space ratio was 30%.[Conclusion] Urban green space can be optimized by increasing urban green space scale, reasonable layout and the concrete implementation ways.

Abstract:[Objective] To determine the optimal statistical unit, analyze the spatial distribution of topographical relief in Shaanxi Province in order to provide basic data for the classification of geomorphic types.[Methods] Based on the 90 m resolution SRTM(shuttle radar topography mission), DEM (digital elevation model data), the relief amplitude of Shaanxi Province was extracted with neighborhood statistics analysis. We selected 34 rectangular neighborhood windows (2×2, 3×3,4×4,…,35×35) and 20 circular neighborhood windows(the radius ranged from 2 to 21), and calculated the ratio of relief amplitude at different rectangular windows and circular windows. The optimal calculation unit was calculated by using the mean change-point analysis method. Classification map of relief amplitude in Shaanxi Province was obtained, and the features of relief amplitude were analyzed.[Results] The ratios of different topographic relief types varied greatly. The optimal statistical unit at rectangular neighborhood was 12×12, with an area of 898 704 m², while the optimal statistical unit at circular neighborhood was R=8, with an area of 1 254 191.4 m², indicating that the circular neighborhood was different from the rectangular neighborhood. Generally, the terrain in Shaanxi Province was relatively flat, and the relief amplitude was mainly at small and medium level.[Conclusion] The mean change-point analysis is an ideal method to determine the optimal statistical unit.

Abstract:[Objective] A rapid and quantitative study has been done on soil erosion in Guizhou Province in order to provide scientific basis for the management of soil erosion and land use decision.[Methods] With the support of GIS technology and data on the rainfall, soil type, land use, DEM and MODIS-NDVI, we used RUSLE model to estimate of soil erosion.[Results] The annual average soil erosion modulus of the study area was 880.81 t/km², which belongs to mild erosion. Most area belongs to the micro erosion with soil erosion modulus less than 500 t/(km²·a), which accounted for 59.60% of the total study area. Soil erosion area(above the mild erosion) reached 71 164.14 km², which accounted for 40.40% of the total area. The area above strong erosion level was 10 431.60 km², which accounted for 5.91% of the total area and mainly distributed in the northwest and northeast of the research area, and in the Northern Dalou Mountain, Wuling Mountain, Southeastern Miaoling Mountain and Western Wumeng Mountain with high altitude and middle east of Wujiang River, southwest of North Panjiang and other river basins.[Conclusion] Woodland, farmland, grassland and region between elevation of 600~1 600 m is the key area for soil and water conservation in the future.

Abstract:[Objective] To research regional soil erosion and reveal the spatial distribution of soil and water loss in order to provide theoretical support for regional soil and water conservation and eco-agriculture construction.[Methods] Soil erosion in Lushui County of Yunnan Province was studied by using GIS and RUSLE model. The factors in the RUSLE model included rainfall erosivity, soil erodibility and slope and length, vegetation cover and soil maintain measures factors. Spatial distribution map of soil erosion modulus in Lushui County was obtained by using GIS spatial analysis module. The soil erosion intensity was classified according to the grading standards of SL 190-2007, and the spatial distribution pattern of soil erosion intensity was analyzed.[Results] (1) According to the area, soil erosion intensity in Lushui County in 2014 was mainly micro degree of erosion, which accounted for 86.86% of the total area. While according to the average soil erosion modulus, soil erosion amount was 4.24×10⁶ t, the average erosion modulus was 1 373.1 t/(km²·a), and the soil erosion intensity was mainly slight erosion. (2) Soil erosion in the unused land and cultivated land was more severer. The erosion area in the slope between 25° and 50° was accounted for 75% of the total erosion area, in which the cultivated land accounted for 63%. Moderate and intensive erosion distributed mainly on the cultivated land, indicated that the slope farmland and unused land contributed the most to soil erosion.[Conclusion] The steep slope, cultivation and unreasonable use of unused land are the main causes for the severer soil erosion in the study area. It is not suitable for cultivation in the slope above 25°. To maintain soil and water, we should optimize the agricultural industrial structure.

Abstract:[Objective] To compensate for the defects in the evaluation index system and the used methods in the diagnosis on the cultivated land ecological security in order to analyze the ecological security level of cultivated land.[Methods] On the basis of defining the cultivated land ecological security, the evaluation index system for cultivated land ecological security was developed using the PSR(pressure-state-response) model, and then an empirical analysis was conducted in Sichuan Province by entropy method and grey prediction model.[Results] The ecological security of cultivated land in Sichuan Province was gradually improved from critically safe to safer level from 1999 to 2013, but the level of "safer" was not high in 2013. The pressure index and status index generally showed a downward trend, while the response indexes showed a upward trend. Crucial constraints on the improvement of cultivated land ecological security include fertilizer load per unit of cultivated land, cultivated land per capita, pesticides load per unit of cultivated land, land reclamation rate and soil erosion. The ecological security level of cultivated land in Sichuan Province would show a steady upward trend from 2014 to 2018.[Conclusion] These methods are suitable in the evaluation of cultivated land ecological security because the evaluation index system based on the PSR model can accurately reflect the relationship among various elements of the cultivated land ecological security, while the entropy method and grey prediction model can detect the problems in the cultivated land ecological security.

Abstract:[Objective] To analyze the influence factors of the Mengdigou reservoir bank stability in order to provide new train of thought to evaluate the stability of reservoir bank.[Methods] On the basis of the analysis of the engineering geological conditions and the interpretation of unfavorable geological phenomenon, this paper classified the bank into different segments. Then using the principle of the slope unit, we then taken these segments as independent research objects and analyzed the factors affecting the bank stability. And then we used three-dimension factor safety of slope units as an index of the stability evaluation and used analytic hierarchy process(AHP) to analyze the factors affecting slope stability. Finally we established hierarchy analysis and evaluation methods for the stability of reservoir bank based on the slope unit.[Results] The method was tested in the engineering practice, showing that the method is reliable and practical.[Conclusion] Tanking the slope unit as the research object, using the AHP can effectively analyze the stability of reservoir bank, which can support the decision of project.

Abstract:[Objective] To analyze the potential factors affecting sustainable development of the ecological water transfer and rehabilitation project(EWTRP) in Heihe river basin, so as to provide scientific basis for the regional ecological environment restoration.[Methods] 550 farmers were interviewed by filling out the questionnaires on their participation in the EWTRP, and then the questionnaire data was analyzed through logistic regression modeling method.[Results] Farmers in the middle reaches had accepted the EWTRP, but most farmers were reluctant to participate in the water-saving agriculture due to cost efficiency and land scale and irrigation technologic limitations. In addition, the EWTRP had also affected the farmers' livelihood.[Conclusion] Water resources shortage is still severe because of inadequate investment in water-saving agriculture. The project affects farmers' livelihoods which is increasing the riskes in maintaining ecological management achievements. Thus, for the success of the programs about environmental restoration, besides the ongoing ecological water transfer project, the eco-compensation mechanism of water resource needs to be established to support the development of water-saving agriculture. We must improve the farmers' livelihood diversification, and realize harmonious development of farmers' livelihood security and environmental protection.

Abstract:[Objective] To regulate the market behavior of soil and water conservation technical service in order to provide the technical support for the development of China's soil and water conservation plan and technical service credit evaluation.[Methods] This paper used the related industry credit evaluation system and theoretical analysis as a reference, took soil and water conservation plan compiling technical service as an example, to establish the credit evaluation system. The relevant documents and materials were collected, experts consulting and field investigation was conducted.[Results] In accordance with the principle of index screening processes, seven level Ⅰ index, 21 level Ⅱ index and 47 level Ⅲ index were determined, and formed a technical service credit evaluation index system for complete soil and water conservation scheme compiling. The weight of the level Ⅰ index was determined respectively based on weight factor judgment method and analytic hierarchy process(AHP).[Conclusion] Each index and weight of the established index system in this paper is based on the experts consulting and field investigation, which has a strong realistic foundation and is of great importance in the development of the technical service credit evaluation for soil and water conservation in China.

Abstract:[Objective] To verify and use TRMM(tropical rainfall measuring mission) 3B43 precipitation product in the Heihe river basin(HRB) in order to understand the spatial distribution of precipitation and provide reliable data for hydrological and ecological studies.[Methods] The TRMM 3B43 V7 precipitation data and 11 meteorological data in HRB was collected from 1998 to 2013. The indices including CC(correlation coefficient), RMSE(root-mean-square error), ME(mean error) and MAE(mean absolute error) were used to assess the accuracy of TRMM data within the basin, and the spatial distribution characteristics of each index was investigated.[Results] It showed that there was an extremely significant correlation between TRMM and the observed data, but the TRMM data might be a little bit overestimated, monthly average rainfall could be overestimated by 2.84 mm, and seasonal and annual value could be overestimated by 34.1 and 8.55 mm, respectively. The value of CC and RMSE decreased from upstream to downstream, the ME value in upstream was far lower than in the middle and lower reaches at all three scales. The value of MAE was the lowest in upstream, but it is highest in the middle reaches at the annual scale, and a similar trend was found at the seasonal scale. The MAE value decreased from upstream to downstream at the monthly scale.[Conclusion] According to the TRMM data, the distribution of the annual average rainfall decreased from the southwest to north and central part of the basin. The precipitation gradient distributed showed as upstream > midstream > downstream. The annual precipitation distributed unevenly, mainly concentrated in the period from May to September.

Abstract:[Objective] To analyze the necessity and main issues in stand improvement in the middle reached of Heihe river basin in order to solve the problems of poor information, backward technology, lack of funds and poor economic efficiency in reality.[Methods] Stand improvement model was investigated in Linze County of Gansu Province based on the internet plus concept.[Results] The information exchange platform realized the smooth flow of information, funds integrate, and cooperative communication. Stand monitoring platform and technology exchange service platform could utilize the new technology to achieve real-time monitoring and solve technical problems in stand reconstructing. Business strategy service platform could maximize the forest by products economic benefits. Scientific research platform could conduct technical integration demonstration.[Conclusion] The model of stand improvement based on internet plus is an effective way for the construction of forestry ecological engineering system.

Abstract:[Objective] To provide theoretical basis for artificial afforestation by analyzing the effects of artificial afforestation on soil fertility.[Methods] Soil nutrient data of Aohan Banner, Inner Mongolia Autonomous Region in 1983 and 2013 was collected, and the analytic hierarchy process and element matter model was used to assess the classification of soil fertility variation in 1983 and 2013.[Results] After 30-year afforestation, the content of organic matter and nitrogen in five different types of soil were increasing, while the content of phosphorus and potassium were decreasing. Soil nutrient level showed an increasing trend as well.[Conclusion] Afforestation can increase the content of soil organic matter, and the reasonable artificial forest structure is helpful to maintain soil fertility.

Abstract:[Objective] To solve the issues of large coal gangue waste land area and high cost in vegetation restoration in sandy area of Northern Shaanxi Province.[Methods] Three sand thickness(30, 50 and 70 cm) and a semi-covered Artemisia sand barrier(2 m×2 m) were set. Four different kinds of native shrub species including Sabina chinensis, Amygdalus pedunculata, Amorpha fruticosa and Caryopteris mongholica were selected for the experiments.[Results] The survival rate, saving rate, the amount of new growth and diameter had improved due to the increase of sand thickness. Multi-factor variance analysis showed that there were significant differences among different species. Significant differences were found between A. fruticosa Linn and other types, and between C. mongholica Bunge and S. vulgaris(p<0.05). There were no significant difference between C. mongholica Bunge, A. pedunculata Pall and S. vulgaris (p<0.01). There were significant differences among the 30, 50 and 70 cm sand thickness, and there were no significant differences between 50 cm and 70 cm sand.[Conclusion] With the consideration of all factors, a sand thickness of 50 cm is optimal in land reclamation and ecological restoration in the coal gangue waste land.

Abstract:[Objective] To explore the effect of a compound predicting model in forecasting the deformation time series of landslide in order to provide a new way for the landslide deformation prediction.[Method] Based on support vector machine and BP neural network, a compound predicting model of landslide displacement sequence and rate series was established. The basic information of landslide was analyzed, and extracted. The regression and multi-factor models were constructed by using two kinds of predicting methods, and two time series was predicted. The BP neural network was used to optimize the results.[Result] There was a great correlation between the water level of the landslide reservoir and the two deformation sequence. The stability of the landslide was likely to be weakened by periodic fatigue, and it could be predicted by the compound prediction model of landslide deformation.[Conclusion] The relative prediction error of this study is small, which greatly improves the prediction accuracy and stability of the landslide deformation, and proves the validity of the prediction model.

Abstract:[Objective] To determine the effect of different vegetation types and nutrients on the enzyme activity in order to provide a theoretical basis for the restoration of rocky desertification areas in the eastern part of Yunnan Province.[Methods] Soil enzyme activity was used to evaluate the effect of restoration, and the soil quality evaluation method based on fuzzy mathematics was adopted to derive the soil enzyme index under different restoration approaches to compare the effect of each approach. Based on correlation analysis of soil physical and chemical activity and enzyme activity, structural equation model was adopted to quantify soil physical and chemical environment and enzyme activity environment, and then to analyze the influence of different soil physical and chemical environment on different enzyme environment.[Results] The order for enzyme activity was shrub and grass mode > mixed coniferous and broadleaf forest > broadleaf forest mode > coniferous forest mode > bare land; According to the principle of structural equation model, the sub-nutrient environment composed of total phosphorus and organic matter had a positive impact on enzyme environment which was composed of the activity of urease, catalase and polyphenol oxidase activity.[Conclusion] The shrub and grass mode and mixed coniferous and broadleaf forest both have a good effect on the recovery of rocky desertification. The influence coefficient of nutrient environment on enzyme activity was 0.87.

Abstract:[Objective] To determine the utilization of phosphorus in slope ecological rehabilitation substrate in order to provide theoretical basis for optimizing substrate formulation.[Methods] Adsorption-desorption characteristics of phosphorus in five types of slope ecological rehabilitation substrates were studied via constant temperature shaking culture. Then, the adsorption-desorption capacity and loss risk of the five substrates were compared with factor analysis.[Results] The maximum adsorption capacity(Q_m), maximum buffering capacity(MBC) and phosphorus sorption index(PSI) have shown that the phosphorus fixation capacity of the five substrates was in an order of the natural secondary forest > the external-soil spray seeding > the thick layer substrate > the framed beams soil covering > the vegetation-compatible concrete. It showed that Q_m had positive correlation with clay content, while it had negative correlation with organic matter content and pH value. The desorption ability of the five types of substrates was the vegetation-compatible concrete > the framed beams soil covering > thick layer substrate > the external-soil spray seeding > the natural secondary forest. The average desorption rate had significantly positive correlation, and it also had positive correlation with organic matter content. The negative correlation was found between the average desorption rate and clay content. This study showed that Q_m, MBC, PSI, the average desorption rate and easy desorption phosphorus(RDP) could best reflect the phosphorus loss risk of five different substrates. It showed that from high to low, the order of the phosphorus loss risk was the vegetation-compatible concrete, the framed beams soil covering, the external-soil spray seeding, thick layer substrate and the natural secondary forest.[Conclusion] The natural secondary forest has the highest conservation capacity of phosphorus in the five ecological rehabilitation engineering ways, while the vegetation-compatible concrete has the lowest. In slope ecological rehabilitation engineering, the proportion of clay content should be increased and the dosage of cement should be decreased, or buffering material be added into substrate, so that the substrate can have a stronger phosphorus adsorption capacity, the larger phosphorus storage, the smaller phosphorus loss risk. Thus, the utilization ratio of phosphorus can be improved and the supplying ability can last longer.

Abstract:[Objective] To establish a flood warning model for the mountainous area of Beijing City based on vertical-mixed runoff model in order to provide theoretical basis for the calculation of critical rainfall.[Methods] Considering the weather conditions in Beijing City, vertical-mixed runoff model was used to simulate runoff generation, unit hydrograph and linear reservoir method were applied to simulate overland runoff concentration, Muskingum method to simulate flood routing, and submerged discharge was used to represent safety discharge. The parameters of a flood warning model in the area can be determined by field experiment and calibrated by historical data.[Results] Coefficient of determination, peak-flood discharge, peak time and aging level conformed to the requirement and regulation of mountain flood forecasting through the validation of historical precipitation and hydrological data. In addition, the predicted possibility of a flood is in accordance with reality.[Conclusion] The accuracy of this model is good and can be applied to the early warning of flood in Beijing mountainous area with confidence, thus reducing casualties and property losses. This model also lays a foundation for the calculation of critical rainfall of flood in the mountainous area of Beijing City.

Abstract:[Objective] To study the effect of the wood vinegar on sandy soil microbial biomass and enzyme activity in order to provide the theoretical basis for improving the sandy soil biological quality.[Methods] Compared with the effect of adding tap water on sandy soil, we added different dilution times(200, 150, 100, 50 and 20) of wood vinegar to the soil using pot planting method. Further, the contents of soil dissolved organic carbon, nitrogen and phenol, soil microbial biomass carbon and nitrogen, as well as soil enzyme activities were determined.[Results] Application of wood vinegar to sand soil could significantly decrease soil pH value, increase the contents of readily soil oxidizable carbon, soil dissolved organic carbon, nitrogen and phenol as well as inorganic nitrogen. When the dilution ratio of wood vinegar was greater than 50-fold, the contents of microbial biomass carbon and nitrogen and the activities of β-glucosidase and alkaline phosphatase and dehydrogenase increased with the decrease of dilution ratio of wood vinegar. Compared with the application of 20-fold dilution of wood winegar, the microbial biomass carbon and nitrogen and the activity of β-glucosidase and alkaline phosphatase and dehydrogenase were decreased with the application of 20-fold dilution of wood vinegar. However, the activity of α-glucosidase, leucine aminopeptidase, acid phosphatase and polyphenol oxidase significantly increased with the decrease of dilution ratio of wood vinegar within a certain range(greater than 20-fold dilution) of wood vinegar.[Conclusion] Different concentrations of wood vinegar will affect sandy soil microbial biomass and soil enzyme activity.

Abstract:[Objective] The effect of potato starchy residue on corn seedling growth and soil nutrient preserving characteristics were studied to provide a way to utilize the residue.[Method] The plant height, stem diameter and dry weight of corn seedling and soil bulk density, total porosity, capillary porosity, aeration porosity, moisture content, field moisture capacity, capillary water holding capacity, nitrogen fertilizer, leaching of phosphorus and potassium of sandy loam soils were determined in sandy loam soils potato starch residue of 0, 1.00, 5.00, 10.00, 20.00, 30.00 g/kg with indoor artificial natural environment and injector tube leaching method.[Results] Soil bulk density, soil porosity and soil moisture content of the treatment with 30 g/kg of starch residue had significant changes compared with CK. Soil volume weight decreased by 7.24%, soil total porosity increased 10.15%, soil moisture content increased 21.25%. The leaching of soil nitrate nitrogen, ammonium nitrogen, available phosphorus and available potassium content decreased 97.13%, 91.03%, 63.85% and 66.40% respectively. Corn dry weight of seedlings was increased by 13.47%, corn fresh weight of seedlings increased by 15.79%, corn plant height of seedlings decreased by 8.90%, corn stem diameter increased by 25.53%.[Conclusion] The suitable amount of potato starch residue applied in sandy loam soils was 30.00 g/kg, which could improve the soil physical and chemical properties and enhance the ability of preserving fertilizer and promote the dry matter accumulation of corn seedling.