Abstract:[Objective] The characteristics of precipitation and its sediment effect in Wujiang river basin was investigated, in order to provide theoretical reference for soil and water conservation, ecological restoration, disaster prevention and mitigation, and the rational use of water resources.[Methods] The accumulative anomaly curve methods and double-mass curve were used to analyze rainfall characteristics in interannual, chronological and flood seasons, and to analyze the contribution rate of rainfall erosivity and human activities sediment effect.[Results] ① From 1956 to 2014, the annual precipitation and annual erosive precipitation showed a decreasing trend, and the annual precipitation experienced five wet-dry-alternate periods. ② Rainfall occurred mostly in 1970s and 1990s, and about 32.57% of the precipitation caused soil erosion in the basin during the past 59 years. Erosive precipitation occurred mostly in 1960-1979. ③ The precipitation in flood season was mainly erosive precipitation, and the erosive precipitation mainly occurred in June. ④ According to the double mass curve equation, the contribution of precipitation erosivity to river sediment discharge in the last 6 years of 1980s, 1990s and the first 14 years of the 21st century was 15.55%, 2.84% and 12.46%, respectively.[Conclusion] The rainfall erosion and sediment yield in Wujiang river basin occurred more in flood season. After 1983, the variation of sediment discharge was mainly influenced by human activities.

Abstract:[Objective] To estimate regional soil erosion modulus and the dynamic change accurately for soil and water conservation planning.[Methods] Using USLE (universal soil loss equation) model, the soil erosion modulus in Jiangxi Province in 2001 and 2015 were estimated with remote sensing data, meteorological data and DEM. Then the temporal and spatial changes of soil erosion intensity in Jiangxi Province from 2001 to 2015 were analyzed.[Results] From 2001 to 2015, soil erosion in Jiangxi Province showed a declining tendency. The soil erosion modulus in 2001 was 7 042.4 t/(km²·a) and the soil erosion modulus in 2015 was 6375.3 t/(km²·a), decreased by 9.5%. The soil erosion intensity has decreased in most of the cities in Jiangxi Province. The soil modulus decreased significantly in Fuzhou, Yichun, Ganzhou and Pingxiang Cities. But soil erosion modulus increased in a few cities such as Jiujiang, Nanchang and Xinyuin. The transformation matrix of soil erosion intensity indicated that soil erosion intensity remained unchanged in 52.7% of the total area of Jiangxi Province from 2001 to 2015. About 25.8% of the total area experienced soil erosion intensity transformation from high level to low level during 2001-2015.[Conclusion] The soil erosion situation in Jiangxi Province has improved in general, but the soil erosion in some cities has expanded further, and the situation of soil and water loss remains serious.

Abstract:[Objective] The aim of this study is to investigate the soil erosion degree in the Three Gorges Reservoir area in order to provide the basis for regional soil erosion control.[Methods] The revised universal soil loss equation (RUSLE) model was used in conjunction with MODIS-NDVI data, DEM elevation data and land use classification data to evaluate the spatial distribution of soil erosion quantitatively in Three Gorges Reservoir area from 2000 to 2010.[Results] ① Soil erosion in Three Gorges Reservoir area was severe except for the western regions during the period from 2000 to 2010. Soil erosion in Yangtze River was dominated by severe and extreme intensity erosion. ② Soil erosion in Three Gorges Reservoir area was improved from 2000 to 2010, and the area of intensive soil erosion was decreased from 1.71×10⁶ hm² in 2000 to 6.82×10⁵ hm² in 2010. Average soil erosion modulus decreased from 36.75 t/(hm²·a) in 2000 to 22.79 t/(hm²·a) in 2010. ③ After years of erosion control, the area of intensive, severe and the extremely intensive soil erosion decreased, while the area of mild and moderate soil erosion increased.[Conclusion] Mild and moderate intensity soil erosion control need to be enhanced in the study area.

Abstract:[Objective] To investigate the hydrodynamics characteristic of soil water in different sites in the mining area in order to provide a scientific basis for ecological restoration in the mining area.[Methods] The soil water characteristic curves, unsaturated hydraulic conductivity, bulk density, porosity, particle size and compactness were measured to investigate characteristics of soil quality, water-holding capacity, readily available water content and water conductivity in different site types.[Results] The capacity of soil water-holding and water-supplying exhibited as:damaged area < restoration for 3 years area < restoration for 5 years area < restoration for 10 years area < restoration for 15 years area < undamaged area, and soil water-holding capacity and water-supplying capacity at 20-40 cm was lower than that at 0-20 cm, which indicated that remediation effect was not obvious. The improvement of soil structure showed as:damage area < remediation area < undamaged area, and the improvement of subsurface soil quality in remediation area was not obvious. The exponential function fitting between suction and unsaturated hydraulic conductivity was good (r²>0.95). Under the same suction, the unsaturated hydraulic conductivity was smaller as:soil bulk density was greater. There was a negative correlation between unsaturated hydraulic conductivity and bulk density, while a positive correlation between unsaturated hydraulic conductivity and total porosity, and this correlation decreases with the increase of suction. Readily available water content of 0-20 cm exhibited as damage area < restoration for 3 years area < restoration for 5 years area < restoration for 10 years area < undamaged < restoration for 15 years area, and readily available water content of 20-40 cm soil layer was smaller than that of 0-20 cm.[Conclusion] The readily available water content was negatively correlated with bulk density and compactness, and positively correlated with total porosity and clay content. The soil quality and water storage capacity had been improved through restoration progress.

Abstract:[Objective] To investigate the distributions of soil enzyme activities in different aggregates fractions for the different revegetation types in the Loess Plateau in order to provide basic data for vegetation restoration project.[Results] The field investigation and the laboratory experiments were used to explore the effects of vegetation restoration on soil enzyme activities.[Results] The soil enzyme activities in the natural grassland and Caragana korshinskii lands with the 15 and 25 year ages were higher than that in crop land. The activities of soil enzyme activities increased with the increase of the aggregate sizes in small and moderate sized aggregates(1~2 mm, 2~3 mm and 3~5 mm), but decreased in the big sized aggregates. Soil enzyme activities were mainly distributed in the moderate aggregates (1~2 mm, 2~3 mm and 3~5 mm). The small(<0.25 mm, 0.25~1 mm) and large(>5 mm) soil aggregates showed less soil enzyme activities. In the 0-20 cm soil layer, soil enzyme activities increased with the age of C. korshinskii, while it was stable in the 20-40 cm soil layer.[Conclusion] The activity of soil enzyme is gradually strengthened with the increase of plantation years, and the slope farmland is not conducive to the improvement of soil enzyme activity. Natural grassland and the C. korshinskii lands improved the accumulations of soil enzyme activity and should be protected in the future.

Abstract:[Objective] To analyze the effects of vegetation degradation on litter decomposition in Gahai wetland in the Eastern Qinghai-Tibet Plateau, we aim to provide the basis for research on biogeochemical cycles of biogenic elements in wetland.[Methods] Using the litter bag technique, we examined the decomposition rates and their influencing factors in typical peatlands and swamp meadows in the Gahai wetland.[Results] There were significant differences in litter decompositions among different vegetation degradation stages. Vegetation degradation inhibited litter decomposition in general, but the responses varied with different wetland types. In the growing season (from May to September), the litter decomposition rates of undegraded healthy vegetation were significantly higher than that of degraded vegetation (P<0.05). The order of average decomposition rates in swamp meadows was, undegraded (0.028 9 g/d) > medium degraded (0.028 7 g/d) > slightly degraded (0.028 0 g/d). There were clear inter-annual variations of litter decompositions for each vegetation degradation stages. For all three years, in the growing season, the litter decomposition rates were faster in 2014 while relatively slower in 2015 and 2016. Temperature and precipitation conditions enhanced litter decomposition, but the effect was not significant.[Conclusion] The decomposition rates were simultaneously influenced by the quality of the litter, meteorological characteristics and soil environmental factors. In comparison, the effect of the quality of the litter was greater.

Abstract:[Objective] To study the hydrochemical characteristics of the surface water and groundwater as well as their effects on the Populus euphratica growth in desertification area, in order to provide theoretical support and scientific basis for the conservation and rejuvenation of P. euphratica.[Methods] Field investigation was conducted and the samples were collected at Xinjiang Tarim P. euphratica national nature reserve. The hydrochemical characteristics of middle reaches of Tarim River and their effects on growth of P. euphratica were studied.[Results] ① In the studied area, hydrochemical types of the surface water were mainly SCa_Ⅲ or ClNa_Ⅲ (Based on the O. A. Arliekin's classification). The pH value of the surface water was below 8.0. The pH value of the surface water was 7.42~7.82 where P. euphratica grew well. ② Total hardness and total alkalinity, TDS of overflowing river were ranged as 325.3~769.5, 142.6~290.3 and 782.2~1 037.5 mg/L, respectively. P. euphratica was able to grow normally in the environment of brackish water (TDS>1000mg/L). The water in this nature reserve was contaminated by the drainage of farmland, and the ammonia nitrogen content was 0~0.45 mg/L.[Conclusion] The distribution of the P. euphratica with different diameters characterized an inverted pyramid structure, thus its rejuvenation was confronted with difficulty.

Abstract:[Objective] This study aims to quantitatively analyze the state of soil erosion in Guangxi Zhuang Autonomous Region, especially on the relationship between soil erosion and land uses and provides a basis for scientific control of soil erosion.[Methods] Based on RUSLE model, the modification factor M of karst rocky desertification was introduced to construct the soil erosion model suitable for Guangxi Zhuang Autonomous Region.[Results] ① In 2015, the soil erosion modulus of the region was 135.51 t/(km²·a). The soil erosion thickness was 0.08 (mm/a). The soil erosion area was 2.52×10⁴ km², and the soil loss was 3.21×10⁷ t, of which the soil erosion area of karst area was 1.86×10⁴ km², accounting for 73.81% of the soil erosion area and 31.01% of total soil loss. ② The percentage of soil loss from different land uses in total soil loss was:cultivated land(37.58%) > woodland(30.94%) > grassland(16.10%) > garden land(6.39%) > industrial and mining land(4.09%) > bare land(2.16%).[Conclusion] The land use changes induced by human interferences have greatly affected the spatial pattern of soil erosion in the whole area.

Abstract:[Objective] The effects of constant phosphorus fertilization on corn seed production were studied to provide the basis for reasonable phosphorus fertilizer application.[Methods] Field experiments and laboratory analysis were conducted in irrigated desert soil and alluvial soil.[Results] Except for Ca₂-P, total phosphorus, available phosphorus, total inorganic phosphorus, total organic phosphorus, and the other fractions of inorganic and organic phosphorus increased significantly under 8 years continuous cropping of corn seed with 525 kg/(hm²·a) of chemical phosphorus fertilizer. The inorganic phosphorus amounted to 65.2%~70.2% of total phosphorus, while organic phosphorus accounted for 6.5%~11.4%. Ca₁₀-P > Ca₈-P > Al-P > Fe-P > O-P. MLO-P > HRO-P > MRO-P > LO-P. Ca₁₀-P reached to the highest at 5th year, and Al-P and O-P increased constantly in irrigated desert soil. Ca₁₀-P increased constantly while Al-P and O-P reached to the highest at 5th year in alluvial soil. The phosphorus increased by 3.94%~37.38%. Inorganic phosphorus declined from soil surface downward to a depth of 60 cm. The proportion of different fraction varied in different soil layers. Ca₁₀-P, O-P, Al-P and MRO-P was gathered in soil layer of 40-60 cm while Ca₂-P and HRO-P gathered in soil layer of 0-20 cm. The highest apparent efficiency of phosphorus fertilizer was 4.89% and phosphorus active coefficient was lower than 2% after 8 years continuous cropping. And the residual of exogenous phosphorus was 174.3 kg/(hm²·a) which means the lower conversion ratio of total phosphorus.[Conclusion] The movement of phosphorus was slow in two soils and accumulated with lower soluble fractions in surface soil layer with continuous cropping. The proportion of attachment and retention and the transportation of phosphorus by soil decreased constantly and possibly gathered toward bottom layer, which will cause high ecological risks on healthy development of ecological environment. Phosphorus fertilizer should be decreased or stop to use, also some suitable methods should be used for phosphorus utilization on alluvial soil.

Abstract:[Objective] The aim of this study is to solve the issues of low water and fertilizer capacity, low organic matter content, low yield and unstable grain production of brown desert soil, in order to provided technical support for the sustainable development of maize industry in Hexi inland irrigation area.[Methods] The brown soil of Suzhou area in Jiuquan City, Gansu Province was selected and the field experiment method was conducted to screen the multi-functional soil improver formula and investigate the improvement effect on brown desert soil.[Results] The optimum ratio of multi-functional soil conditioner was:organic ecological fertilizer:water retaining agent:special fertilizer for corn production:polyvinyl alcohol was 0.978 3:0.000 9:0.019 6:0.001 2. The optimum application rate of multi-functional soil improver was 68.75 t/hm², and the theoretical yield of maize was 6.64 t/hm². The total porosity, capillary porosity, non-capillary porosity, agglomerates, saturated water holding capacity, capillary water holding capacity, non-capillary soils were significantly increased by 22.75%, 22.76%, 22.74%, 9.50%, 22.75%, 22.76% and 22.74%, respectively. The contents of organic matter, CEC, available N, available P and available potassium increased by 35.01%, 21.64%, 0.63%, 2.26% and 2.09%, respectively. Fungi, bacteria and actinomycetes increased by 93.97%, 35.35% and 20.78%, respectively. Invertase, urease, phosphatase and polyphenol oxidase increased by 61.82%, 44.64%, 40.00% and 64.29%, respectively. And maize yield and fertilization profits increased by 39.23% and 31.82%, respectively.[Conclusion] The application of multi-functional soil conditioner could improve the physical, chemical and biological properties of brown desert soil and improve the yield of maize.

Abstract:[Objective] The effects of different vegetation types on soil enzyme activities, nutrients and microbial diversities were studied aimed to provide support for the vegetation construction in Loess Plateau.[Methods] According to the characteristics of the study area, four vegetation types (meadow, Caragana microphylla, Populus tremula and Artemisia) were selected. The differences and correlations of soil enzyme activities, soil nutrients and microbial diversities in different soil layers within the same and among vegetation types were evaluated with the SPSS. The corrections of soil microbial and environmental factors were analyzed with Canoco.[Results] ① Under different vegetation types, the soil enzyme activities and soil nutrients decreased with the increasing soil depth. The enzyme activities were the highest in Artemisia. The pH value of the meadow increased with the soil depth, and the content of organic carbon in surface soil was the highest. The content of nitrate nitrogen was the highest in P. tremula, and the content of ammonium nitrogen was the highest in C. microphylla. ② There was a significant or extremely significant correlation between soil nutrients, and there was an extremely significant correlation between soil enzyme activities. There was an extremely significant correlation between soil enzyme activities and soil organic carbon. There was also a significant correlation between soil enzyme activities and soil nitrate nitrogen. ③ High soil microbe diversities were found in the surface soil (0-10 cm) at the phylum level. The fungicidal communityⅠhad a positive correlation with soil pH value, nitrate nitrogen and ammonium nitrogen, but negatively correlated with soil enzyme activities; fungicidal community Ⅱ had a positive correlation with soil enzyme activities, but negatively correlated with nitrate nitrogen, ammonium nitrogen, organic carbon and pH value. There was a negative correlation between fungicidal communityⅠand fungicidal community Ⅱ and Ⅲ. There was a positive correlation between bacteria and enzyme activities and a negative correlation between bacteria and soil nutrients.[Conclusion] Vegetation types affect soil enzyme activities, nutrients and microbial diversities. In the process of vegetation construction, the Artemisia should be planted to improve the soil ecological environment.

Abstract:[Objective] By studying the vegetation coverage changes with elevation, slope degree and aspect in upstream watershed of Minjiang River, we aim to provide support for eco-environment improvement and soil erosion control in favorable terrain in the area.[Methods] With the support of GIS and RS, we extracted vegetation coverage and topographic factors from Landsat-8 OLI remote sensing images and DEM data, and then overlaid them. The statistical samples were constructed to analyze the correlation between vegetation coverage and topographic factors.[Results] Firstly, the vegetation coverage in study area was overall in good condition and the area of the medium and above vegetation coverage accounted for 75.0% while low vegetation coverage area is only 15.2%. Secondly, vegetation coverage decreased with the increase of elevations and slopes after the initial increasing, the maximum value ocurred at the elevation of 2 500~3 000 m and the slope of 25°~45°. The vegetation coverage in sunny slopes was slightly higher than that in shady slopes. Lastly, the topographical factors may produced different effects in areas with different vegetation coverage. In areas with low vegetation coverage, the slope degree exerted significant influence while the influence of elevations was significant in areas with extremely high vegetation coverage. There was no significant correlation between other vegetation coverage and topographical factors, which revealed a complex relationship between vegetation and terrains in upstream watershed of Minjiang River.[Conclusion] The vegetation coverage is closely related to the topographic factors in upstream watershed of Minjiang River, and the change of topographic factors has an important impact on the ecological environment.

Abstract:[Objective] The paper aims to explore the effect of inoculating plant growth-promoting rhizobacteria (PGPR) on the rhizosphere soil of Fraxinus chinensis under different salt stress conditions, and to clarify the improving effect of PGPR on salinity tolerance of F. chinensis and provide theoretical support for the extension of PGPR in salt stress environment.[Methods] We used a pot experiment covering different salt stresses[light salt stress(LS), moderate salt stress(MS), and severe salt stress(SS)] and corresponding inoculating PGPR to evaluate the effects of different treatments on the biological characteristics of rhizosphere soil and growth of F. chinensis.[Results] The microorganism population, the contents of microbial biomass carbon and microbial biomass nitrogen, the activities of urease enzyme, polyphonic oxidase enzyme, catalase enzyme and invertase enzyme under salt stress conditions were significantly decreased, and the decreased magnitude become larger and larger along with the increasing salt stress, whereas the corresponding indexes showed an increasing trend after inoculating PGPR. The populations of bacteria, actinomycetes and total microbial by LS+P treatment achieved the maximum value, increased by 14.64%, 24.01% and 17.04% compared with CK, respectively, and the activities of urease enzyme, polyphonic oxidase enzyme and invertase enzyme had no significant differences between LS+P and CK treatments, while they significantly increased compared with the other treatments. Meanwhile, the root volume, total absorption area and active absorption area also demonstrated a trend of decreasing as the degree of salt stress increased, but the corresponding indexes increased after inoculating PGPR. The active absorption area in LS+P treatment markedly increased by 15.97% in comparison with CK. Additionally, compared to CK, the ground diameter and plant height significantly decreased in the treatments of different degrees of salt stress, while an opposite trend was presented after inoculating PGPR. And the ground diameter and plant height in LS+P treatment had no significant differences compared with CK, whereas they significantly increased compared with the other treatments.[Conclusion] The inoculating PGPR under light salt stress could significantly improve the biological characteristics of rhizosphere soil and growth of F. chinensis, and the effect was significantly higher than inoculating PGPR under moderate and severe salt stress.

Abstract:[Objective] The characteristics of soil respiration rates were studied in different land use types of the hilly region in the Loess Plateau in order to investigate the features of the carbon cycle of different land use types.[Methods] Soil carbon flux of five land use types such as Onobrychis viciifolia, Medicago sativa, abandoned land, M. sativa with terraces and Astragalus adsurgens in standard runoff plots were monitored by LI-8 100 system, the surface temperature, soil temperature at 5 cm and soil moisture were monitored.[Results] ① The diurnal variation of soil respiration rates showed peak curves with higher in the day time and lower in the night time, which showed the same trend with temperature. The annual soil respiration rates were as follows:A. adsurgens (terraced)[2.27 μmol/(m²·s)] > O. viciaefolia[1.79 μmol/(m²·s)] > M. sativa[1.77 μmol/(m²·s)] > M. sativa (terraced)[1.62 μmol/(m²·s)] > abandoned land[0.77 μmol/(m²·s)]. ② Soil respiration rates showed obvious seasonal variation, and the highest appeared in summer, followed by spring and summer, the lowest was in winter. There were significant differences of soil respiration rates between summer and other seasons(p<0.05). ③ The correlation between soil respiration rates, surface and soil temperature were significant in different land use types (p<0.05). The correlation between soil respiration rate and soil temperature was higher than that of surface temperature in all the land use types except abandoned land, soil temperature values (5 cm) Q₁₀ of each site varied from 1.94 to 3.00. ④ No significant linear relationship was found between soil respiration rates and soil moisture (p>0.05), whereas significant correlation was exhibited between soil respiration rate and the interactions of soil temperature with soil moisture (p<0.01).[Conclusion] Soil respiration rates of terrace are better than slope land, and the soil quality was significantly improved by vegetation restoration.

Abstract:[Objective] To explore the spatial distribution of the soda saline-alkaline land in Western Jilin Province and provide a theoretical basis for the prevention and treatment of saline soil in this region.[Methods] We extracted information on environmental factors from remote sensing images by ArcGIS and analyzed the relationship between the distribution of the soda saline-alkaline land and environmental factors through regression analysis and correlational analysis methods.[Results] ① Beyond the buffering distance of 30 000 m of the hydrographic net, the area of soda saline-alkaline land decreased with the increasing distance from hydrographic net. ② The area of soda saline-alkaline land was significantly affected by multi-year average annual wind speed (R=0.716, p<0.05), multi-year average annual precipitation(R=-0.597,p<0.05) and maximum value of the multi-year annual precipitation(R=-0.652,p<0.05) respectively. ③ The altitude and slope gradient were key factors influencing the distribution of soda saline-alkaline land of the western Jilin Province. The area of the soda saline-alkaline land decreased with the increasing altitude and slope gradient.[Conclusion] The main environmental factors affecting the distribution of soda saline-alkaline land in Western Jilin Province were the distance from the hydrographic net, climatic factors and terrain factors.

Abstract:[Objective] Estimating the dynamic changes of groundwater resource changes and identifying possible safety measures, we aim to provide decision basis of managing available water resources and maintaining the ecological security of oasis.[Methods] Firstly, the total water demand of Cele Oasis was analyzed, and then the deficiency of water in oasis was calculated according to monitoring data on river and groundwater dynamics. Finally, the dynamic changes in groundwater level were analyzed using long-term monitoring data of groundwater.[Results] Results revealed that when considering the ecological water use, the average annual water gap in the Cele Oasis was 5.20×10⁶~1.15×10⁷ m³. On average, the annual decline in groundwater depth was varying from 0.27 m to 0.60 m due to continuous use of groundwater in Cele Oasis. During high flow years, the groundwater recharge was relatively abundant that did not make any obvious change in average depth of groundwater level except in its spatial distribution. During 2008-2014, the groundwater average depth showed more substantial fluctuations, but it basically maintained at the level of 21 m depth.[Conclusion] The change in groundwater depth in Cele Oasis is within safe range. But, in order to ensure healthy and sustainable development of the oasis, and to maintain the stability of groundwater depth, the current financial resources should be invested in water resources supervision and management. Besides, the construction of agricultural water-saving facilities should be viewed as a long-term development strategy.

Abstract:[Objective] To explore the effect of water-physical properties of feldspathic sandstone modified by a kind of hydraulic polyurethane (W-OH), and to provide the theoretical guidances for high slope protection of feldspathic sandstone.[Methods] By tasting indices such as the water stability and erosion resistance of the feldspathic sandstone modified by the W-OH, the modified mechanism was analyzed.[Results] It was indicated that the water stability and erosion resistance of the aggregates in modified feldspathic sandstone were obviously improved with the decrease of the particle size of the aggregates, the K was increase. The addition of W-OH significantly reduced the sediment yield and sediment yield on the slope.[Conclusion] Soil and water loss from the slopes decreased greatly and the slope stability was enhanced by cementing sands which a solidified layer on the surface of the feldspathic sandstone was formed.

Abstract:[Objective] The paper aims to discuss the influence of canopy rainfall penetration, canopy interception and trunk runoff on rainfall redistribution in the mountainous hilly forest of Northern Hebei Province, and provide a basis for forest construction and forest structure adjustment in this area.[Methods] The correlation analysis and regression analysis of forest rainfall data were conducted on SPSS.[Results] The penetrating rain accounted for the largest proportion, accounting for 70.22% of the total. The canopy interception accounted for 28.20% while the trunk runoff accounted for 1.58% (R²=0.997 9), there was no rain through the forest when the rainfall was relatively small. And when the rainfall outside the forest reached 0.78 mm, penetration occurs. Canopy interception played a very important role in the redistribution of rainfall. There was a significant power function relationship between canopy interception and rainfall outside the forest (p<0.01). There was a positive correlation between trunk runoff and rainfall outside the forest (R²=0.9703). When the rainfall reached 4.88 mm, the trunk runoff occurred in the broad-leaved forest, but the trunk runoff had a time lag, which was closely related to the forest itself and the intensity of rainfall. When the leaf area index is small, and the angle between branches is about 45%, the bark surface was smooth, trunk runoff was relatively easy to occur.[Conclusion] The forest canopy had an important influence on the redistribution of rainfall. The hydrological effects of the canopy of broad-leaved forest in northern Hebei Province were related to the forest health development.

Abstract:[Objective] This study aims to propose and test a new land use classification system for remote sensing monitoring of soil erosion in Yellow River basin.[Methods] Based on the soil and water loss in different areas across the Yellow River basin, and with the national standard of land use classification and the standard of soil erosion classification by Ministry of Water Resources as a reference, we proposed a new land use classification system for remote sensing monitoring of soil and water loss in the Yellow River basin according to the scientificity, feasibility and integrity principles.[Results] We finally developed a classification system for land use including slope farmland, terraced fields, forest land and grassland, construction development land, check dam, sandy land and other land types. This classification system was validated in five counties and the results showed that the classification system was reasonable.[Conclusion] The land use classification system in this study not only had the same precision of soil and water loss evaluation results with the traditional classification system but also improved the efficiency of remote sensing monitoring of soil and water loss in the Yellow River basin.

Abstract:[Objective] To summarize remote sensing monitoring techniques used in dynamic monitoring project of soil and water loss in Yellow River basin in order to explore a new and efficient approach for soil and water loss monitoring.[Methods] Based on resource 3 high-resolution satellite images, the object-oriented image classification approach was used to make semi-automatic classification of land utilization in Jungar Banner in 2014. The vegetation regression models were constructed to study the inversion of vegetation coverage in the project area.[Results] Based on semi-automatic classification of land utilization and the regression model of vegetation coverage, the experiment showed that the accuracy of field verification reached more than 90%, which satisfied the demand of high resolution and accuracy data acquisition for soil erosion monitoring.[Conclusion] The object-oriented image classification of land utilization and regression model of vegetation coverage can not only effectively avoid the error caused by artificial visual interpretation and save cost, but also improve the accuracy and efficiency for data acquisition.

Abstract:[Objective] Based on the Chinese soil loss equation (CSLE), this study aims to explore the method to quantitatively calculate soil erosion and improve the accuracy of soil erosion monitoring and reflect the effect of soil and water conservation effectively and objectively.[Methods] By using the CSLE model, the remote sensing interpretation and the statistical analysis, we quantitatively assessed the soil erosion in the overlapping area of the Zhungeer Banner and Huangfuchuan river basin.[Results] The total erosion in the study area was 13.778 3 million tons in 2015, and the annual erosion modulus was 4 920.23 t/(km²·a). The erosion was mainly moderate erosion, mild erosion and strong erosion are followed.[Conclusion] The soil erosion was quantitatively analyzed with CSLE model, and several factors such as rainfall, soil, vegetation, topography and measures were considered, which could be used for quantitative study of soil erosion.

Abstract:[Objective] In the Loess Plateau, six typical small watersheds were selected to monitor the shape features, development stage and morphological change of erosion gullies in these watersheds, and analyze stability of erosion gullies. We aim to build a preliminary assessment index system for erosion gully stability.[Methods] In these small watersheds, every time before and after the rain, sub-meter measurements were carried out in typical cross-section of main gully channel and branch channel, and gully head.[Results] The number of each class of erosion gullies in the six typical watersheds and the data of cross-section and gully head of branch channels were obtained. The assessment index system of erosion gully stability was preliminarily built.[Conclusion] The factors influencing the change of channel morphology are summarized as follows:precipitation, water conservation measures, vegetation cover, catchment area, slope, matter of earth's surface and so on.

Abstract:[Objective] Land use structure is an important factor affecting soil erosion. By analyzing the dynamics of land use in Jungar Banner, we aim to understand the trend of land use change and provide basic data for soil erosion analysis in this area.[Methods] The transfer matrix of land use was used to study the land use change in Jungar Banner.[Results] The land use change in Jungar Banner was not significant between 2014 and 2016. Woodland, grassland, water area and land for water conservancy facilities decreased by 16.02, 12.66 and 2.48 km², respectively. The land for residential, industrial, mining and transportation use, other land (sandy land and bare rock) and cropland increased by 18.63, 10.53 and 1.72 km², respectively. The soil erosion area was increased by 70.8 km² in this region.[Conclusion] The reduced woodlands and grasslands in Jungar Banner are mainly converted into residential-industrial-mining-transportation land use and other land use types. Combined with soil erosion data, the increase of soil erosion in this area is mainly related to the decrease of woodland and grassland area, and changes in woodland and grassland coverage.

Abstract:[Objective] The paper aims to analyze land use changes in recent years in the Daliuta Town of Shenmu County, Shaanxi Province, and provide a reliable basis for reasonable development and utilization of land resources in this region.[Methods] Based on high resolution images in 2010 and 2015, we extracted the land use information in this region through image interpretation, generated the land use transfer matrix, and analyzed the land use changes between two periods.[Results] From 2010 to 2015, the area of cultivated land, residential and mining land, water body, water conservancy facility land and grassland have been increased. The area of forestland, sand and bare land have been reduced.[Conclusion] The land use level of the area is high, and the land structure tends to be reasonable.

Abstract:[Objective] To improve the efficiency and accuracy of soil and water loss sampling survey, in order to reduce the difficulty and cost.[Methods] First, photos with a certain amount of overlap covering the survey area were taken by the unmanned aerial vehicle (UAV). The ortho images and DEMs were then obtained by using the tilt photogrammetry technology, geometric processing, multi view matching, triangular mesh (TIN) construction and automatic processing. Instead of the traditional way of working and technical process, the boundary and attribute information of different plots in the investigation area was obtained by artificial interpretation.[Results] The application of micro roter UAV improved the accuracy of the land boundary effectively, reduced the difficulty and cost of the field survey, and greatly saved the time of investigation.[Conclusion] The application of micro rotor UAV technique has improved the reliability of soil and water loss assessment results, and is of great importance for promoting the application of sample survey methods in the evaluation of soil erosion in all levels of government, as well as the development of soil erosion quantification technology.

Abstract:[Objective] This paper discusses the application of three quadrant methods in the construction of high standard basic farmland in order to provide basis for the construction layout and development models of high standard basic farmland in County.[Methods] Taking Susong County of Anhui Province as an example, this paper classified the construction areas of high standard basic farmland by using three quadrant methods, and evaluated the construction of high standard basic farmland from two aspects:farmland quality suitability and feasibility of social economic condition. Among them, the qualities of cultivated land were judged from site conditions, physical and chemical properties and utilization condition and so on. While social and economic conditions were from the agricultural land productivity, land use status and the wishes of the public and so on.[Results] The cultivated land area of the high suitability and high feasibility region was 3 046.67 hm², accounting for 14.89% of the total area of construction land. High suitability and low feasibility region area was 10 974.53 hm², accounting for 53.62% of the total area of construction land. Low suitability and high feasibility region area was 6 445.73 hm², accounting for 31.49% of the total area of construction land. Based on the analysis of the constraining factors and the distributions of high standard basic farmland in the three areas, the spatial layout and construction models of high standard basic farmland were put forward.[Conclusion] Using the three quadrant method, the counties were grouped into three regions according to the cultivated land quality and socio-economic conditions. The high standard basic farmland construction layout and development models in Susong were dynamically connected with the three regions.

Abstract:[Objective] The paper aims to evaluate the influence of changes in parameters of SWIM (soil and water integrated model) on the simulation accuracy of runoffs in Wangjiaba region, and provides scientific support for flood forecasting and disaster reduction, and provides a reference for the application of SWIM in other areas.[Methods] Based on the measured data at Wangjiaba region during the calibration period (1959-1978) and the validation period (1979-2008), the optimal parameter combination was obtained, and the sensitivity of SWIM to the seven calibratable parameters in Wangjiaba region was quantitatively analyzed.[Results] The Nash-Sutcliffe efficiency (NSE) coefficients of runoffs in the calibration and validation periods were 0.79 and 0.81, respectively, with relative errors of 22% and 7.8%, respectively. With the increase of the thc parameter (correction factor for potential evapotranspiration on sky emissivity), the relative error increased significantly, and its sensitivity to the thc value was higher than that of the NSE coefficient. roc₄ (river routing coefficient) was more effective than roc₂ (river routing coefficient), while roc₂ had a larger effect on runoff in flooding season than in non-flooding season. With the increase of the sccor parameter (correlation factor for saturated conductivity), the simulation accuracy increased during the flooding season and decreased during the non-flooding season.[Conclusion] The calibrated SWIM model shows good applicability in Wangjiaba region. The results of SWIM simulation in Wangjiaba region are sensitive to variations in the parameters thc, cnum₁ (CN condition 1 when the curve number method code is 1), cnum₃ (CN condition 3 when the curve number method code is 1), roc₂, roc₄ and sccor, but not to variations in the parameters bff (base flow factor), gwq₍₎ (contribution of initial groundwater flow to runoff) and abf₍₎ (groundwater alpha factor).

Abstract:[Objective] To simulate and verify a flash flood process on June 17, 2016 in Nileke County of Xinjiang Uygur Autonomous Region by a FloodArea model, in order to determine the critical rainfall for flash flood.[Methods] A typical flash flood ditch was taken as the research object. Based on FloodArea model and using meteorological data, digital elevation model data and basic geographic information data in the flash flood ditch of Kemeng Township Nileke County, the correlations between the area rainfall with different cumulative aging and the simulated flood process line was analyzed, and the best set of correlations was used to construct the formula.[Results] It was found that the highest correlation occurred between the submerged depth of the basin and the corresponding 9 hour surface rainfall. The critical rainfall threshold at 4 levels of the 9 h cumulative rainfall was 12.80(forth level), 25.78(third level), 45.24(second level) and 64.71(first level) mm, respectively.[Conclusion] The floodArea model can well simulate the flood process in the study region, and the rainfall at different risk levels of the flash flood can be reflected.

Abstract:[Objective] To determine the area of soil covering, in order to guide the planning and designing in hilly area land reclamation project.[Methods] Using GIS technology, seven indicators including soil construction, traffic condition, site conditions, soil physical and chemical properties were chosen to evaluate the priority of soil-covering demand of a typical land reclamation project in Tongchuan City, Shaanxi Province.[Results] ① The grade Ⅰ priority of soil covering demand of farmland accounted for 46.2% of the total area of the field. The comprehensive benefits of covering soil were high and should be covered by soil preferentially. ② The grade Ⅱ priority of soil covering demand of farmland accounted for 23.7% of the total field, where the covering soil should be made practically according to soil source. ③ The region of grade Ⅲ and grade Ⅳ totally accounted for 30.1% of the field, which had less benefit or necessity of covering soil.[Conclusion] The evaluation results reflected the fact in land reclamation project area and classified the demand of covering soil, which could provide the theoretical foundation for the design and engineering practice.

Abstract:[Objective] To clarify and standardize the units of the revised universal soil loss equation (RUSLE), we aim to make RUSLE more useful in China.[Methods] By comparing the studies of RUSLE at home and abroad, we determined the most widely applied and accurate units of RUSLE factors and clarified the conversion coefficient between different units.[Results] The application of RUSLE in China, most of the statistical model established by regional units were converted to international units system by multiplying the conversion factor, and finally obtained the amount of soil erosion in international units. The others were the results of various factors represented by US units system through each factor of the corresponding statistical model calculation, the amount of soil erosion in the international system of units was obtained by multiplied by 224.2. The Joule unit system was widely used in the erosion estimation in China, and there were two area units, namely km² and hm². The unit of soil loss amount A was commonly used by international units as t/ha (t/hm²) or t/km², the rainfall erosivity factor R was (MJ·mm)/(hm²·h·a) or (MJ·mm)/(km²·h·a), the soil erodibility factor K was (t·hm²·h)/(hm²·MJ·mm) or (t·km²·h)/(km²·MJ·mm). The results of calculation methods established in different regions were converted into international units through the corresponding conversion coefficients. The consistency of the unit system of R and K factors was a critical step in the RUSLE application.[Conclusion] The conversion of R and K factors into international units through the corresponding unit conversion coefficient and the unit consistency of the two factors is the important basis for soil erosion assessment.

Abstract:[Objective] The objective of this article is to determine the best statistical unit to extract and classify the relief amplitude of Southwestern China, and then the characteristics of the amplitude structure and the classification of geomorphologic structure can be determined.[Methods] Based on ASTER GDEMv2 data and through Python module programming, the average relief amplitude in the Southwestern China and the typical experimental areas was extracted at n×n windows (n=2,3,4,…,181,182,183), and the best window area was calculated by the mean change point method.[Results] ① 2.43 km² was the optimal statistical unit for extracting amplitude relief in the study area. ② Fluctuation of terrain was moderate and low in the study area, with the relief amplitude between 200 m to 500 m having the highest proportion (38.68%), and that between 500 m to 1 000 m accounting for 23.58%. ③ As for the spatial distribution, the relief amplitude of the middle region was generally higher than that of other regions, followed by the southeast, lower in the northwest and northeast.[Conclusion] The method, computing relief amplitude with optimum statistical unit of 2.43 km², conformed to the regional terrain characteristics and balanced the various landform types.

Abstract:[Objective] To understand the patterns and processes of land use change, and to make full use of the time series land use data to investigate the characteristics of land use patterns.[Methods] Changsha City was selected as an example and the geographic information system (GIS) and IDRISI platform were used to calculate the transfer frequency of land use change and involved land use categories.[Results] ① With the increase of the times and categories of land use transfer, the corresponding changes in the number of pixels were reduced, and the change involved 2 categories and transfer once was more prominent. ② Urban expansion obviously occupied crop land and woodland in the periphery of urban region, the area was 202.86 km² and 169.96 km², respectively. While the construction land was converted into cropland to compensate for occupied crop and woodland in rural region, the area was 48.27 km² and 12.04 km². ③ The change pattern of other towns was similar with the central area of Changsha City but their radiating capacity was relatively weak.[Conclusion] Changsha's urban expansion is accelerating. Land reclamation can supply a small amount of cultivated land and forest land, but the urban expansion in the cost of outer cultivated land and forest land is still the main change mode. In addition, the local land use patterns and scales follow a certain urban hierarchy.

Abstract:[Objective] We aim to study topographic wetness index (TWI) based on terraces digital elevation model (DEM), in order to provide basis for the study of soil water content and runoff capacity.[Methods] Using 5 m resolution DEM, 1 m resolution DEM data generated with terrace information (T-DEM) based on the real field method and 1 m resolution DEM data generated from the laser point cloud data (H-DEM), we analyzed and compared the differences among three TWIs in the terrace fields of the Loess Plateau.[Results] First, the result of 5 m resolution DEM data could show the macroscopic distribution, but it was too coarse to show the terrain feature of terrace. Second, although the 1 m resolution T-DEM data could accurately show the terrain humidity of terraced field and obviously reflect the characteristics of terrace surface and ridge feature, it showed larger deviation compared to H-DEM in the single terrace surface and the ridge.[Conclusion] T-DEM can show the distribution characteristics of the TWI in terraced fields more accurately, but it has larger deviation in terrace surface and ridge in comparison to real terrace. T-DEM's generating method need to be improved in future study.

Abstract:[Objective] To analyze and evaluate the status of land remediation performance and potential grading, we aim to determine the basis and standard of land remediation input priority.[Methods] Using the data envelopment analysis model (DEA), the performance of 36 land remediation projects implemented in Huachi County of Gansu Province was evaluated. By comparing the ecological potential, quantity potential and the quality potential of different townships (towns), the input priority of the land remediation was determined.[Results] ① The technical, scale and comprehensive efficiency of land remediation in Huachi County was relatively high, which was 0.984, 0.984 and 0.969, respectively, and there were no obvious spatial differences among different townships (towns). ② There were large differences among the quantitative potential, the quality potential and the ecological potential of land remediation. ③ The county could be divided into 2 priority input areas, 5 secondary priority input areas, 3 general input areas and 5 tightening input areas.[Conclusion] It is an ideal method to combine the spatial difference and potential of the performance of land remediation to determine the input priority.

Abstract:[Objective] The paper aims to explore the carrying capacity of the green shrub roof and the purification effect on initial roof runoff in order to provide theoretical support for green roof designing and runoff resources utilization.[Methods] A green shrub roof structure was designed according to the carrying capacity of roof and the characteristics of roof runoff. Using vermiculite and perlite as water absorbent, and mixed with red loam and humus at a certain proportion. we made a substrate for roof greening. The roof shrubs were sprayed with simulated rainfall using collected roof runoff, and the dry and wet load and the effect of rainwater removal had been researched.[Results] The saturated water absorption of 1 m³ artificial soil was 0.65 m³, and wet bulk density of the substrate was 1 190 kg/m³. The carrying capacity of green shrub roof under dry and wet conditions was 261 kg/m² and 529 kg/m², respectively. The pollutants SS, COD, TN and TP in initial roof runoff were reduced by 60.1%~71.3%, 50.0%~61.8%, 49.2%~53.2% and 55.6%~67.7%, respectively.[Conclusion] The green shrub roof can meet the carrying capacity requirements of general building. Meanwhile, it has good purification effects on initial roof runoff.

Abstract:[Objective] To explore the effects of human activities on the hydrological processes in order to provide a certain basis for decision-making regarding ecological protection and sustainable development in Ganjiang River headwaters region.[Methods] SWAT (soil and water assessment tool) model was used to simulate the runoff and sediment in Taojiang basin during 1981-2013 based on the land use data of 1980, 2000 and 2015. And the effect of land use change on soil erosion was analyzed. The effects of sediment retention on Julongtan water conservancy project were analyzed quantitatively.[Results] ① Monthly runoff and sediment obtained from SWAT model were agreed with the observed data in Taojang basin, with Ens was 0.92 and 0.8, respectively. ② Land use variations during 1980-2013 showed little effects on the runoff and sediment output in Taojiang basin. ③ Soil erosion in Taojiang basin was mainly light ersion. Soil erosion modulus in meadow was the maximum, and the sediment yield in woodland was the maximum. ④ The Julongtan water conservancy project effectively intercepted sediment Taojiang basin. It was estimated that about 7.78×10⁶ t sediment was retained druing 2007-2013, accounted for 77.5% of the total amount of sediment transported into the Taojiang basin.[Conclusion] Land use change is not the main reason that causes runoff and sediment change in Taojiang basin. In contrast, the construction of Julongtan water conservancy project shows a significant effect on the variation of sediment in Taojiang basin.

Abstract:[Objective] To provide technical support for the Dajiuhu wetland protection and management, the service value of the Dajiuhu wetland ecosystem in Shennongjia forest region was evaluated.[Methods] The principle methods of the resource economics and ecological economics were applied to assess the value of eight service functions of the Dajiuhu wetland ecosystem by collecting the present available data.[Results] The total estimated value of the ecosystem services from the Dajiuhu wetland was 0.653 billion RMB, accounted for 30% of the gross domestic product (GDP) in the Shennongjia forest region in 2015. The value of floods storage, soil conservation, and entertainment as the leading services value, accounted for about 88.94% of the total value. The cultural service value occupied only 0.47% but it should not be ignored.[Conclusion] The service value of the Dajiuhu wetland ecosystem is very important to support the wetland protection in this region, but to a certain degree, there existed inseparable relationship with the decrease and function degradation of wetlands and the wetland ecosystem services function.

Abstract:[Objective] The characteristics, driving forces and existing problems in urban land expansion of Akesu City, Xijang Wei Autonomous Region are discussed, which provides a basis for the development and construction of this Oasis City.[Methods] With the Landsat TM/ETM⁺ satellite remote sensing images in 1990, 2000, 2010 and 2015 as data sources and using ENVI supervised classification, we extracted data on urban land, arable land, forest land, water body, unused land and other land used for four periods in Akesu City. We then analyzed the changes in urban land in Aksu by the index of expansion strength, velocity, center of gravity coordinate transfer, compact degree and elastic coefficient.[Results] In 1990, the area of urban land was 18.34 km², and the total area of urban land in 2015 was 91.61 km². The expanded area in 25 years was 73.24 km², and the net increase was four times of that in 1990. The expaned urban land was mainly from unused land and arable land, with an area of 43.84 km² and 28.04 km² respectively; The barycentric coordinates of urban land moved to EN, SW and SW, similar to traffic route change. From 1990 to 2000, the barycentric coordinates moved with a distance of 243.7 m. Yet they moved 832.2 m from 2000 to 2010, and 1 568.2 m from 2010 to 2015. The urban land expanded with a planar and ribbon shape, and the density of the perimeter of the urban land has been declining from 0.201 in 1990 to 0.066 in 2015, and the urban space was increasingly complex.[Conclusion] The urban land of Aksu City expanded continuously and rapidly from 1990 to 2015. The urban land expansion rate during the study period was higher than the rate of population growth, with an expanding gap between them. The elastic coefficient was 2.3 in 1990 to 2000 and 10.13 in 2010 to 2015, so the urban expansion and population growth were not reasonable. The non-agricultural population, economic development, policy, and traffic factors in Aksu City are the main driving forces of land use change.

Abstract:[Objective] To accomplish the goal of building a rich, harmonoius and beautiful Shaanxi Province, this paper aims to explore the integrated development paths of agriculture, rural areas and farmers(abbreviated to ARF) in Shaanxi Province and to understand the impacts of the evolution of ecological-social-environmental system on the integrated development of ARF.[Methods] Through the field investigation and literature research, this paper analyzed the relationship between ecological-social-environmental system evolution and the integration development of ARF.[Results] The integrated development of ARF changed along the consumption structure→industrial structure→occupational structure→income structure→stratum structure→social structure. Combining with the surveys and statistics, the authors believed that the pressure influencing the integrated development of ARF lies in the fragmented development that leads to the formation of a mutually restriction loop. Meanwhile the ecological conservation and the development of ARF were lagging behind the overall process of economic and social development. Potential development originates from ARF themselves and the evolution of ecological-social-environmental system. The five driving forces that promote the compatible and coordinated development of ARF with the evolution of ecological-social-environment system were as follows:national role, market power, organizational role, professional farmer and ecological environment.[Conclusion] To promote the integrated development of ARF in Shaanxi Province, more efforts should focus on improving the ecological-social-environmental system from three aspects:top-level design, connotation development and synergy perspective.

Abstract:[Objective] The objective of the study is to analyze the impact of different cropping systems on crop yield, soil bulk density and soil water content in Lanzhou City and to find the optimum cropping system in this area.[Methods] The potato(P), maize(M) and faba bean(B) was selected as test crops under 9 annual rotation patterns (P-P-P, M-M-M, B-B-B, P-B-P, M-P-M, M-B-P, B-B-P, M-M-B). The soil bulk density, soil moisture, crop yield and economic benefits under different rotation patterns were analyzed.[Results] P-M-P, P-B-P, M-P-M, M-B-P and B-B-P could significantly reduce soil bulk density in 0-40 cm soil layers, but had no significant effect on soil bulk density of 40-60 cm soil layers. The influence of rotation systems on soil water content was similar to that of water consumption, the order of the effects of crop types on soil water content, water consumption were maize > potato > faba bean, and WUE were potato > maize > faba bean, respectively. Under M-M-M treatment, the soil water content was the lowest, and water consumption was the highest, WUE of B-B-P treatment was the highest. The yield of rotation cropping was higher than that of continuous cropping. In 2016, compared with continuous cropping P-P-P treatment, the crop yield under P-M-P, P-B-P, M-B-P and B-B-P treatments increased by 40.37%~79.28%. Compared with continuous cropping B-B-B treatment, the crop yield under M-M-B treatment increased by 23.56%; Compared with continuous cropping M-M-M treatment, M-P-M treatment increased by 10.51%. Compared with continuous cropping, rotation cropping would more increase in crop yield and economic benefits.[Conclusion] With respect to soil bulk density, WUE, crop yield and economic benefits, P-B-P and P-M-P were superior to the other seven rotation patterns, which could improve soil environment, and increase yield and economic benefits, and should be encouraged in Lanzhou City. The economic benefits under M-B-P was lower than P-B-P and P-M-P treatment, M-B-P had higher WUE, which could improve WUE.

Abstract:[Objective] To analyze the characteristics of erosive rainfall and its relationship with sediment production in order provide a basis for soil and water conservation and ecological improvement.[Methods] Based on rainfall data of Jianshan river watershed and monitoring data of runoff plot from 2014 to 2016, we selected rainfall duration, rainfall, average rainfall intensity, the maximum rainfall intensity within 30 minutes and 60 minutes to analyze rainfall events, the amount and frequency of erosive rainfall under different level of rainfall and rainfall intensity, and then we analyzed the relationships between sediment yield and various erosive rainfall indexes.[Results] ① Threes years data showed that monthly change of rainfall generally conformed to Gaussian distribution and the rainfall in research area was mainly concentrated in May, June, Junly, August, September and October. The flooding season was in September. After October, the rainfall gradually decreased. In terms of the seasonal distribution, the rainfall was mainly concentrated in summer and autumn, and wet and dry season was clear. This pattern relates to continental monsoon climate. ② The mean sediment yield of corn field and tobacco field runoff plot was significantly higher than that in secondary forest, artificial forest and shrub-grass land runoff plot. ③ Within a certain range of rainfall intensity (0~5 mm/h), the sediment yield and rainfall of secondary forest runoff plots showed a significantly positive correlation with rainfall and I₆₀, and sediment yield of tobacco field runoff plots had a significantly correlation with rainfall.[Conclusion] ① The characteristics of rainfall is coincident with continental monsoon climate, with rainfall concentrated in summer and autumn and Gaussion distribution; ② The land use with different coverage produced big differences in interceping sediment and runoff. Tillage methods and crop species also have different effects on soil loss.

Abstract:[Objective] The paper aims to explore the combining effect of different surface soil treatments and vegetation restoration methods in wind field of Bashang areas in order to clarify the functions and effect of surface soil in vegetation restoration.[Methods] The effects of different treatments on vegetation restoration were analyzed. These treatments included cleaning and backfilling surface soil test, covering with new soil, surface soil treatment combined with vegetation restoration methods.[Results] The vegetation could be restored using cleaning and backfilling treatment and seed banks of surface soil. 16 and 17 species were found to germinate in the construction living area and spoil area respectively. Irrigating in time was necessary for seed germination after backfilling. There were significant differences in community coverage, average vegetation height, numbers of species as well as diversity index between vegetation restoration combinations, of which the backfilling surface soil + natural restoration was the best, while the land leveling+natural recovery effect was the worst. The invest in the combination of different vegetation restoration patterns was variable, of which new soil+artificial restoration input was the highest and the land leveling+natural recovery was lowest.[Conclution] Each wind farm should select suitable restoration methods according to construction and economic conditions as well as the vegetation restoration effects. Backfilling surface soil+natural restoration should be a top priority, and land leveling+natural restoration should be avoided.

Abstract:[Objective] The hazard assessment of debris flow was studied in order to provide an effective method for determining the weights of hazard assessment indexes in debris flow prone area.[Methods] In view of the weakness of single assigning weight method, analytic hierarchy process (AHP) and entropy method were adopted respectively to determine the subjective and objective weights of the debris flow hazard assessment indexes for the China-Pakistan highway, then the comprehensive weights were estimated based on combined weight method. Taking the debris flow along the China-Pakistan highway as a case study, this paper selected ten assessment indexes including magnitude, frequency, length of main groove, basin incision density, basin area, relative difference of elevation, longitudinal slope of main groove, maximum rainfall during 24 hours, thickness of loose deposit, length of mud and sand supply. The method mentioned above was used to assess the hazard of debris flow in this area after the acquisition of field data of debris flow. Besides, the results coincided with the set pair analysis method and field investigation results.[Results] Only five debris flow gullies, accounting for 25% of the total, were moderate dangerous, which meant that most debris flow gullies in this area were high dangerous.[Conclusion] The evaluation results were consistent with the field investigation, which confirmed the reliability of the method.

Abstract:[Objective] The aim of this study is to analyze the potential productivity of temperature, precipitation and climate according to the 40 years meteorological data at 13 weather stations in Jiangsu Province between 1971 and 2010, in order to provide theoretical basis for agricultural industry.[Methods] Based on meteorological data from 13 weather stations, the Miami and Thornthwaite Memorial models were used to calculate the potential productivity of temperature, precipitation and climate. The factors affecting the utilization rate of climate resources and the climatic potential productivity in Jiangsu Province were analyzed by using climate resource utilization formula, correlation analysis and regression analysis.[Results] ① In the past 40 years, the annual average temperature in Jiangsu Province showed an upward trend, and the annual precipitation did not show a regular change. The potential productivity of temperature and precipitation showed a similar trend as the annual mean temperature and annual precipitation. ② The climatic potential productivity showed a slight increase trend, and the climatic resource utilization rate showed a fluctuated rising trend.[Conclusion] Temperature is the main factor that influences climatic potential productivity in Jiangsu Province.

Abstract:[Objective] To analyze the water use efficiency of the main cities in order to promote the water ecological civilization urban construction and the development of Northern Slope Economic Zone in Tianshan Mountain.[Methods] Based on the data from 7 main cities in the north slope of Tianshan Mountains in 2004-2015, this paper analyzed the water use efficiency and the spatial and temporal differences of the cities by using the super efficiency DEA model and Malmquist index.[Results] ① Super efficiency DEA analysis showed that the utilization efficiency of water resources in the Northern Slope Economic Zone showed a rising trend, but fluctuated during 2004-2015, meanwhile, the water use efficiency during 2004-2008 is lower than that during 2009-2015. The water resources utilization efficiency in Urumqi, Karamay, Shihezi, Changji and Fukang City was relatively high, while the water resources utilization efficiency in Wusu and Kuitun City was relatively low. ② Malmquist index analysis result showed that the water resources TFP index in 7 main cities fluctuated greatly, and the growth was not stable, showed a "W" type fluctuation. Technical change was the main factor restricting the water resources utilization efficiency in the Tianshan Mountains. ③ SAR model indicated that the water use efficiency showed a spatial dependence. At the temporal and spatial scales, at the 0.05 level, significant correlations were found among the total amount of water, living water, water use efficiency and population and ecological water use. But the correlation between the distances between the cities and the related industrial water and agricultural water use and water use efficiency was not significant.[Conclusion] The government should make great efforts to improve the production technology, popularize water-saving technology, optimize the industrial structure, adjust the proportion of water resources and labor input and improve the contribution rate of technological progress, so as to improve the water resources utilization ratio of main cities in north slope of Tianshan Mountains.

Abstract:[Objective] To evaluate the current eutrophication state and provide basic data and theoretical support for the pollution control in Heihe River basin.[Methods] The total nitrogen (TN), total phosphorus (TP), permanganate index (COD_Mn), chlorophyll a (Chl.a), transparency (SD) were selected as indexes for water quality evaluation, and the comprehensive trophic state index and BP neural network were used to evaluate the eutrophication of Heihe River basin.[Results] The eutrophication status of Heihe River basin was mainly in medium level of nutrition. The nutrition status index of Yeniugou and Zhangye wetland were close to mild eutrophication. The eutrophication status of East Juyanhai Lake was severe and the total nitrogen index was high. The water environment of East Juyanhai Lake should be protected in time.[Conclusion] Compared to the comprehensive trophic state index method, the evaluation results of BP neural network are closer to the actual situation, and more objective and reliable.

Abstract:[Objective] To measure the sustainable level of land use in Qinzhou City, Guangxi Zhuang Autonomous Region in order to provide a theoretical basis for the rational utilization of urban land and scientific management.[Methods] By using PSR model, 15 evaluation indexes were selected for measuring the sustainable level of land use in Qinzhou City.[Results] The land use sustainable level increased from 2008 to 2010, and showed a fluctuation trend from 2011 to 2015. The results could truly reflect the dynamic change of land use sustainable level in Qinzhou during the past 8 years.[Conclusion] The rapid development of social economy and urbanization, and the rapid population growth are the three major factors that affect the land use in Qinzhou City. Policy adjustment and control measures are needed to manage the land effectively, and to ensure the sustainable use of land and steady development of social economy in Qinzhou City.

Abstract:[Objective] Effect of the soil and water conservation in Baiquan County of Heilongjiang Province has been evaluated for the soil and water conservation project. The results could provide some suggestions for further planning of the soil and water conservation and the development of ecological environment.[Methods] This paper analyzed the soil loss variation using the soil loss model for the soil conservation projects based on the field survey from 2008 to 2015. The land use data was extracted from the remote sensing images. The soil conservation was assessed based on the aforementioned methods.[Results] The land use was dominated by cultivated land and the area of soil erosion accounted for 27.37% of total land area. From 2011 to 2015, the land use transferred from cultivated land to settlements, industrial and mining land and forest land. The total area of soil erosion decreased by 193.8 km², and the ecological environment improved. The new area covered with soil and water conservation measures was 103.49 km². The total conserved soil was 507 338.86 t with the implementation of terracing measures, strip ridging and ridging, of which total conserved soil from 2008 to 2010 accounted for 3.80%. From 2011 to 2015, the soil conservation increased year by year, and the conserved soil in 2015 accounted for 34.04% of total conserved soil. The soil conservation of terraced fields was the largest, accounting for 40.21% of the total soil conservation, followed by strip ridging and ridging, accounting for 37.23% and 22.56%, respectively.[Conclusions] Soil and water conservation projects produced remarkable effect on soil conservation. The distribution of conservation measures should be optimized and investing more resources in terracing and strip riding for improving the conservation effect.

Abstract:[Objective] To provide support for selecting priority areas and making plans for soil and water conservation and developing the targeted soil erosion measures, this study analyzed the spatial distribution of the soil erosion in the Jianghuai hilly region, and explained the relationship between soil erosion and environmental factors such as land use type, slope, vegetation and soil type.[Methods] Based on the Landsat 8 image with 15 m resolution in 2015 and the "3S" technology platform, this study used the comprehensive evaluation method and the field investigation verification method to analyze the soil erosion distribution and its relationship with the environmental factors.[Results] ① The soil erosion area in Jianghuai hilly region was 1 409.60 km², accounting for 10.20% of the total area. And the erosion intensity was characterized with light erosion and moderate erosion in some areas. ② Under different land use types, the soil erosion occured mainly in the sloping farmland with larger topographic relief and relatively poor condition, as well as in woodland and grassland with relatively steep slopes and low vegetation coverage. The soil erosion was mainly occurred in the slope of 5°~15° in the boundary belt between mountains and plains. In terms of coverage, the soil erosion mainly occurred in areas with vegetation coverage of 45%~75%. Under different soil types, soil erosion easily occurred in dark soil, paddy soil and yellow brown soil because of low viscosity of soil layer, low organic matter content and low erosion resistance.[Conclusion] There is a close relationship between the soil erosion and the environmental factors such as land use type, slope, vegetation, soil type in the Jianghuai hilly region in the Huaihe River basin. And the area with sloping farmland, steep slope, low vegetation coverage, poor soil anti-erodibility is prone to soil erosion.

Abstract:[Objective] The objective of this study is to reveal the temporal-spatial variation of urban landscape during rapid urbanization in order to provide scientific basis for local land use planning.[Methods] Based on 5 phase remote sensing image data, using GIS technology and Fragstats software, the dynamic changes of land use and landscape pattern in Shanghai City was analyzed.[Results] From 1995 to 2015, the area of cultivated land, grassland and waters decreased, the area of woodland decreased firstly and then increased, and the area of urban and rural, industrial and residential land showed an increasing trend. The variation of cultivated land was the most while the variation of grassland was the least. Single land use type changed dramatically from 2000 to 2005. Comprehensive land use type increased initially decreased lately and then increased. The conversion of land use types mainly occurred between cultivated land and urban, industrial and residential land. The conversion between farmland and wood land was mainly characterized by the decrease of cultivated land and the increase of urban, industrial and residential land. The number of patches and landscape fragmentation increased continuously was the main feature in Shanghai City. Landscape diversity transformed from high in the middle into the high in midwest and northern part of the city.[Conclusion] The potential of the land use should furtherbe enhanced in future development of city, improve intensive land use, and protect the ecological service land.

Abstract:[Objective] To analyze the spatial and temporal pattern of PM 2.5 concentration and explore its correlation with land-use pattern in order to provide a basis for decision making in ecological protection and air pollution control.[Methods] Based on PM 2.5 concentration data as well as the land-use information in 2013, we divided the whole Nanjing City into 9 regions by means of Thiessen polygon method. We then systematically analyzed the temporal-spatial differentiation of PM 2.5 and its correlation with the variation of land-use pattern in a time-scale of year and season.[Results] In time scale, the concentration of PM 2.5 was the highest (129.93 μg/m³) in winter, and the lowest in summer (only 44.65 μg/m³). In spatial scale, according to the data of annual average PM 2.5 concentrations in each monitoring station, several sites such as Maigaoqiao and Ruijinlu had high PM 2.5 concentrations, reaching 78.90 and 78.56 μg/m³, while PM 2.5 concentrations in the Xianlin and Zhonghuamen Development Zone was the lowest with only 72.08 and 72.64 μg/m³. On the other hand, land-use patterns affected average PM 2.5 concentration, i. e., arable land, grassland, water and barren land, rural residential land were negatively correlated with PM 2.5, and water body has highest correlation with PM 2.5. In general, the landscape in terms of area, density, fragmentation and accumulation degree was the main factors affecting the PM 2.5 concentration.[Conclusion] PM 2.5 concentration showed an obvious spatial and temporal distribution pattern. The variation of land-use had important effects on PM 2.5 concentration.

Abstract:[Objective] To estimate the net primary productivity (NPP) of grassland in China during the period from 1993 to 2015, and analyze the relationship between NPP and hydrothermal factors, in order to understand the productivity of grassland and the impacts of climate change on ecosystems.[Methods] Based on long-term remote sensing data, meteorological data and vegetation type data, we used CASA model (Carnegie-Ames-Stanford approach) to estimate the NPP of grassland in China. The variation of NPP and the responses of NPP to hydrothermal factors were calculated by using one-way linear regression, second-order partial correlation analysis and GIS spatial analysis.[Results] ① The total annual NPP of grassland was 7.60×10¹⁴ g (measured in term of carbon), and the annual average NPP per unit area was 296.76 g/(m²·a). The NPP of grassland decreased gradually from south to north, and from east to west in China. ② The total NPP of grassland in China decreased undulately with the linear rate of -1.415×10¹² g/a (p>0.05) from 1993 to 2015. The total NPP of grassland decreased significantly at a rate of -2.312×10¹² g/a (p<0.05) from 1993 to 2010, while increased at a rate of 7.00×10¹¹ g/a (p>0.05) from 2011 to 2015. In total, the area of grassland with decreasing NPP was larger than that with increasing NPP, and the NPP in 40.40% grassland changed significantly. ③ Annually, the second-order partial correlation between NPP and total solar radiation and precipitation was statistically significant, while that between NPP and annual mean temperature was insignificant. In terms of area, the significant partial correlation area between NPP and solar radiation was the biggest, followed by that between NPP and precipitation, and the significant partial correlation area between NPP and annual mean temperature was the smallest.[Conclusion] Grassland NPP in China declined widely while increased locally from 1993 to 2015. This variation was mainly affected by total solar radiation and precipitation.

Abstract:[Objective] To investigate the variation of land ecological-living-industrial function pattern in order to provide scientific basis for the overall plan for land utilization.[Methods] With the interpreted maps from TM imagery in 1996, 2006 and 2015 of Helingeer County, Inner Mongolia, the quantity, spatial changes and the agglomeration characteristics of ecological-living-industrial land was analyzed by using the spatial analysis model and spatial change rate model.[Results] ① The amount of the ecological land decreased greatly at the initial stage, and then slowed down. The increase of industrial-living land was obvious, the annual rate of change was 5.9% and the dynamic degree was 12.06%. The spatial variation of industrial-ecological land varied dramatically. Industrial-living land showed a great increasing trend, and the variation of ecological land weakened gradually. ② The spatial variation of living-industrial land distributed in loess hilly region and mountainous region at earlier stage, and in the plain region at the later stage.[Conclusions] After 20 years of planning control, the industrial-ecological land and industrial-living land was mainly distributed in the north plain area, while the ecological land and ecological-industrial land was mainly distributed in the central and southern part in loess hilly and mountainous region. Moreover, the contradiction between industrial-living land expanding and the industrial-ecological land reducing has been contained at a certain extent.

Abstract:[Objective] The study aims to investigate the spatial distribution of mountain torrent disasters in order to provide support for the prevention and management of mountain torrent disaster in overall Jiangxi Province and river basins.[Methods] Based on formation mechanism of mountain torrent disasters, nine explanatory variables were selected from triggering factors, disaster inducing environment and disaster-bearing body. Five response variables from the survey data of mountain torrent disaster were used as the indices to evaluate the hazard degree. The spatial patterns of mountain torrent disaster were estimated based on the geographically weighted regression (GWR) method. The similarities and differences of mountain torrent disaster in three different regions of Jiangxi Province were analyzed using GIS technology.[Results] There were similarities and differences among the models of different mountain torrent disaster indicators in the same area, the same mountain torrent disaster indicators in different regions and the spatial distribution of mountain torrent disaster indicators.[Conclusion] Not only the geographical differences but also the differences between different disaster degree indicators should be taken into account in building each model. GWR can effectively explain the local spatial variability and the differences of important explanatory variables.

Abstract:[Objective] The characteristics of land use pattern in a ecological resettlement area of Hui Autonomous Region in 2005, 2010 and 2015 are discussed, and the changes of landscape pattern stability are analyzed according to the landscape pattern index so as to provide references for the subsequent industry development of ecological migration.[Methods] By constructing evaluation model for the stability of land use pattern using the data of Hongsibu District in 2005, 2010 and 2015, we analyzed the stability of landscape pattern in terms of landscape composition, patch features and landscape heterogeneity, and detected the dominant driving factors of stability by geo-detector.[Results] In past 10 years, the landscape pattern of land use in Hongsibu District changed greatly. The conversion between main land types was frequent with one-way characteristics. The overall stability of the landscape pattern declined. Grassland and cultivated land were the main landscape types in Hongsibu District and were the main components in regulating land use pattern stability. The results of GeoDetector indicated that the area, area ratio, number of patches, patch density, average value and standard deviation all had high influence on the landscape stability in three periods, while the changes of other indicators were obvious with a great fluctuation, but it had less influence on landscape stability on the whole.[Conclusion] From 2005 to 2015, the stability of land use landscape pattern in Hongsibu District changed obviously. The landscape pattern stability of land use in different periods changed differently.