Abstract:[Objective] The ecological restoration effect of inoculation of Amorpha fruticosa in mining area of degraded vegetation was studied, to provide theoretical basis and field experimental data for the application of arbuscular mycorrhizal fungi in the ecological reconstruction of arid and semi-arid coal mines in Western China.[Methods] Take Amorpha fruticosa as the host plant, the symbiotic status of arbuscular mycorrhizal fungi and Amorpha fruticosa was observed in field conditions and the improvement of plant rhizosphere soil in coal mining subsidence area was studied.[Results] Through 4 years continual monitoring, the results showed that the inoculation promoted the growth of Amorpha fruticosa, inoculation survival rate was higher than 30%; the mycorrhizal infection rate and hyphal density of inoculated Amorpha fruticosa were significantly higher than those of the control; the rhizosphere soil available phosphorus of the inoculated Amorpha fruticosa increased and the pH value decreased. According to these, the ecological restoration effect was achieved.[Conclusion] Under field conditions, mycorrhizal fungi can promote the formation of plant-mycorrhizal symbiosis and improve the nutrient environment of plant-mycorrhizal symbiosis.

Abstract:[Objective] It is a foundational mechanism to indicate different impacts of artificial vegetation collocation on the runoff deepth and soil erosion amount at the side slope of mine dump in semi-arid zone.[Methods] Based on three artificial plant collocations(tree with shrub and grass, shrub with grass, and grass) and contrast plot(no vegetation), we employed statistics method to analyze relationship between the side slope erosion(including side slope runoff and soil erosion amount) and rainfall in daily scale from May to Sep. in 2014 and 2105.[Results] (1) For controlling effect of the runoff, tree with shrub and grass, and shrub with grass performed better in three types and its runoff amounts had no significant difference, their values were 42.9% and 52.6% of the contrast ones, respectively. (2) For the erosive controlling effect, no significant differences between the three types and the contrast plot were found, the amounts of the three types were 2.3%~6.7% of the contrast. There were linear relation between daily rainfall and the side slope erosion.[Conclusion] Vegetation collocations had better effects in erosive control than in runoff prevention, and over 93% of erosion control and 28%~57% of runoff prevention were obtained in comparison the corresponding contrast.

Abstract:[Objective] To analyze and explore the causes and the spatial patterns of the freeze-thaw(FT) erosion in Qinghai-Tibet Plateau, and to provide important data support and decision-making references for soil and water conservation research and eco-environment protection in this region.[Methods] The driving force factors of FT erosion(the rainfall erosion and wind field strength during FT period) and the precipitation during FT period(indicating the soil water content) were introduced to establish an evaluation system of FT erosion and then the spatial distribution pattern of FT erosion were analyzed.[Results] The evaluation model of FT erosion had high applicability in Qinghai-Tibet Plateau with the overall evaluation accuracy of 92%. The FT erosion area were widely distributed, covering 63.68% of the total area; and the non-FT erosion zones were mainly distributed in the lower reaches of the Yarlung Zangbo River Basin, Qaidam Basin and the Hengduan mountains. The intensity of FT erosion increased with the increase of slope. The erosion intensities of 15°~24° and ≥ 24° slope zone were severe while that of ≤ 3° slope zone was relatively slight. The spatial distribution patterns of FT erosion intensity among different vegetation types were significantly different. The FT erosion intensities of broad leaved forest and crops were relatively severe while that of meadow was slighter.[Conclusion] The FT erosion of Qinghai-Tibet Plateau belonges to the level of moderate erosion and the spatial patterns are significantly affected by terrain, plant types and climate factors.

Abstract:[Objective] The effects of soil conditions on species distribution and diversity under Haloxylon ammodendron Forest were researched to provide references for biodiversity preservation.[Methods] Methods of canonical correspondence analysis and generalized additive model were used to analyze the effects of soil factors on species distribution and diversity under Haloxylon ammodendron forest in Mosuowan. The forest is located in the southwest of Gurbantunggut Desert, have three types as natural, natural-artificial and artificial Haloxylon ammodendron forests.[Results] (1) Soil water(SW), electrical conductivity(EC) and biological crust were the main factors of species distribution. Salsola ruthenica and Lappula semiglabra tend to distribute in high levels of soil water and electrical conductivity; whereas Timonium leptolobum prefer growing in soil with high pH value, for Corispermum hyssopifolium, conditions of low soil water and electrical conductivity, and of having biological crust, were seemed to be more preferable. Neotorularia korolkowii and Atriplex patens have good adaptability and can establish and distribute in all three forests. Natural regeneration of Haloxylon ammodendron was found increased with the decreases of SW and EC, increased with the increase of biological crust. (2) SW, EC, pH value and soil structure were the main influence factors of diversity. There were high significant positive correlations(p<0.01) between species diversity indices and contents of SW and silt, and there were significant negative correlation(p<0.01) between species and values of EC and pH. Under the condition of low soil water, about 2.19% and 6.28%, soil water was found to be the most factor that influence species diversity. When SW>8%, species diversity tend to be stable when SW increase. Species diversity decline obviously when pH value>9.0.[Conclusion] Undergrowth species distribution and diversity in Haloxylon ammodendron forest were influenced by a variety of soil factors, in which SW and EC played the most important role.

Abstract:[Objective] The aim of this study was to explore the spatial distribution characteristics and the regularity of available silicon in the soil of Dongting Lake, and to provide scientific basis and practical guidance for the development of precision agriculture in the Dongting Lake area and the maintenance of farmland.[Methods] The geo-statistics and GIS technology were both used.[Results] There was a significantly positive correlation between the content of available silicon in the Dongting Lake area and the yield of rice. Silicon is an important nutrient element for rice growth. The average available silicon content in the paddy field around Dongting Lake was 155.1 mg/kg. Though in most cases, it varied from 100 to 200 mg/kg, the margin difference was so great as to the highest content was 27 times of the lowest. Spatially, the content of the part was found higher than the values of periphery, and in the northwest part it had the lowest silicon. Soil available silicon has a strong spatial correlation, and its spatial variation is mainly affected by soil type, soil pH value, soil parent material and other factors.[Conclusion] Silicon plays an important role in rice growth and development. Because soil types in natural geographical environment is not the same, so soil available silicon content normally varies. The abundance of soil available silicon is affected mainly by soil parent material and has significant positive correlation with soil pH value.

Abstract:[Objective] The effects of polyacrylamide(PAM) on the migration and leaching loss of nitrogen, phosphorus and potassium in sandy soil were investigated to provide a more accurate scientific basis about how PAM acts in the migration and leaching loss of soil nutrient and for the improvement of water and fertilizer use efficiency.[Methods] A laboratory soil column experiment was conducted in the study. Four PAM application rates, 0.02%, 0.05%, 0.1% and 0.2% were tested against the control of containing no PAM.[Results] PAM effectively reduced the nitrogen leaching loss in soil. The leachate soluble N concentration was reduced by 28.8%~45.5% in comparison with the value of the control. The effectiveness of this action increased with the increasing rate of applied PAM. PAM clogged the natural flow path of soil solutions and therefore restrained nitrogen migration. PAM enhanced nitric absorption and immobility in the soil. The N concentration increased by 135.2%~285.7% when compared with the control value. PAM effectively reduced the potassium leaching loss in soil. The leachate soluble K concentration was reduced by 33.2%~51.8% in comparison with control value. PAM clogged the natural flow path of soil solutions, and therefore restrained potassium migration. PAM enhanced potassium absorption and its immobility in the soil. The K concentration increased by 42.5%~65.7% in comparison with the control value. The effectiveness of this action was increased with the increasing application rate of PAM. The 0.1% PAM treatment generated better results than those of others. In contrast, PAM did not reduce leachate soluble P concentration in comparison with the control. PAM affected both the phosphorus absorption and the immobility in the soil and the P concentration was decreased by 1.4%~14.3% in comparison with the control.[Conclusion] PAM effectively reduced the nitrogen and potassium leaching loss, and restrained nitrogen and potassium migration in soil. The effect of PAM on the reducing of phosphorus leaching loss was not observed.

Abstract:[Objective] The dynamics of soil moistures of different soil types and its relation to meteorological factors were studied in the Three-North Shelterbelt System Project of Western Heilongjiang Province, to provide reference for soil moisture prediction.[Methods] Using miniature meteorological station, soil moisture and relevant meteorological factors were monitored in situ. Their relationships were analyzed using multiple regression and correlation analysis methods.[Results] (1) Soil moisture showed a decrease trend in growing season for all the monitored soils, of which Phaeozem, Chernozem behaved more obvious. The variation coefficient of soil moisture for all the 3 soil types decreased with the increase of soil depth. (2) The correlation analysis showed that the soil moisture content was negatively correlated with light intensity and atmospheric temperature, but positively correlated with the air humidity. The correlation coefficients with rainfall and wind speed were comparatively smaller. (3) The multiple regression analysis showed that daily soil moisture consumptions of Phaeozem, Chernozem could be explained by illumination intensity(X₁), humidity(X₂), wind speed(X₃) and air temperature(X₄).[Conclusion] Soil moisture was regulated comprehensively by meteorological factors. The established multiple regression models could be used to forecast the changes of soil moisture in upland soil.

Abstract:[Objective] This experiment studied the effects of biochar addition on the content and horizontal transport of NO₃^--N in upland red soil in laboratory to provide scientific bases for water management and environmental protection in the fields.[Methods] Moisture diffusion rate meter was used to determine the horizontal transport velocity and concentration of NO₃^--N in soil at biochar addition rates of 0, 5, 10, 20, 30 and 40 t/hm².[Results] The horizontal transport velocity and concentration of NO₃^--N were significantly affected by biochar addition. A same trend, which performed an increase at first and then a decrease with the biochar application rate increased, was found in the horizontal transport velocity and concentration of NO₃^--N in soil and the diffusivity decreased with the increasing rate of biochar addition. When the application rate of biochar was 30 t/hm², the horizontal transport velocity and concentration of NO₃^--N in soil got the highest, which were 0.67 cm/min and 165.52 mg/kg, respectively. When the application rate of biochar was 40 t/hm², the horizontal transport velocity and concentration of NO₃^--N were lower than those of 30 t/hm². The transport concentration of NO₃^--N reached the maximum value at the surface of wet spearhead in all treatments, which existing on the interface between wet and dry soil. Biochar addition decreased the soil bulk density but increased the soil organic carbon content and total porosity so as to the horizontal transport of NO₃^--N in different treatments were changeable.[Conclusion] Biochar addition can improve the soil properties, and promote the horizontal transport of NO₃^--N in upland red soil. It is very important to pay attention to prevent the pollution of leaching loss of nitrogen and reduce the potential risk of surface water.

Abstract:[Objective] This paper were to demonstrate the defects potentially existed in present evaluation index system and diagnosis methods of the rural ecological civilization construction level from farmers' perspective.[Methods] The evaluation index system for rural ecological civilization construction level was constructed based on farmers' satisfaction, then an empirical factor analysis was conducted in Jiangsu Province.[Results] The farmers' satisfaction at the rural ecological civilization construction scored 3.683 6 in Jiangsu Province. Though the construction level was graded as "good" class, there still some room to be further improved. Crucial constraints on the improvement of rural ecological civilization construction level included the rural ecological environment, rural ecological economy.[Conclusion] The evaluation index system of the rural ecological civilization construction level based on the farmers' perspective and the factor analysis are reasonable and feasible.

Abstract:[Objective] Studying the control effect of Yuanmou fracture on debris flow in Dongshan area, to provide scientific basis for debris flow control in this area.[Methods] Based on the investigation of the valley along the Dongshan area, the control effect of Yuanmou fracture on Dongshan debris flow gully was studied.[Results] The relative position of debris flow gully to Yuanmou fracture has influences on the development of the debris flow, which can control the formation of Dongshan topography and geomorphology, can control the lithology and engineering characteristics of Dongshan formation and can control the formation of climate in Yuanmou County.[Conclusion] The Yuanmou fracture plays a controlling role in the formation of debris flow in Dongshan area, the frequent debris flow in Dongshan area can be attributed to it.

Abstract:[Objective] To provide scientific basis for the water pollution control of Hanjiang, the estimation based on the temporal and spatial distribution of non-point source pollution in Jinmen region of Hanjiang watershed was conducted.[Methods] The export coefficient model and the equivalent standard pollution index method were used to illustrate the temporal and spatial distribution and estimated the loads of the non-point source pollution in Jinmen region of Hanjiang watershed, including TN, TP, COD and NH₃-N.[Results] Rural domestic wastes, livestock breeding, rainfall, land use and urban runoff are the major sources of non-point pollution. Based on the pollution stress, spatial distribution of the pollution source load of different cities was found in the following order:Zhongxiang City > Shayang County > Dongbao District > Duodao District. The contribution of different pollutant sources had a rank of urban runoff < rainfall < land use < rural domestic wastes < livestock breeding.[Conclusion] The poor management of pollutants, particularly of the sewage (none or inappropriate treatment), might be the prominent reason of river eutrophication.

Abstract:[Objective] Exploring the topsoil grain size distribution and its sedimentary environment, to provide theoretical bases for ecological restoration and effective sand disasters control in the Dunhuang desert-oasis transitional zone.[Methods] Surface sediments were sampled by diagonal method in Dunhuang desert-oasis transitional zone, Grain size parameters were calculated by moment method. The spatial distribution and sedimentary environment of grain size were analyzed.[Results] (1) The contents of extremely coarse sand and extremely fine sand were both low in the research area. Desert and oasis were mainly composed of coarse sand and fine sand, and the transition zone was dominated by mid-sand. The grain size decreased from desert to oasis. (2) The sorting of the 3 sampling belt transects performed all better, among which, the desert was the best, followed by the transition zone, the oasis was the worst. (3) As for skewness, desert and transition zone were nearly symmetrical distribution, while oasis belonged to positive skewness. Kurtosis type was plat, which showed that responses of different sediment grain sizes to wind power were different.[Conclusion] The sand of oasis is dominated by aeolian environment, Mingsha mountain is mainly lacustrine or river environment, two different sedimentary sands appeared in the transitional zone.

Abstract:[Objective] Exploring the effects of monosodium glutamate wastewater on root characteristics and microbial diversity in rhizosphere soil of poplar, to provide theoretical basis and technical guidance for the breeding and forestation of poplar seedlings, and the popularization and application of monosodium glutamate wastewater as well.[Methods] A pot experiment including four treatments, i. e., CK(neither urea nor monosodium glutamate wastewater was applied), CF(100% of nitrogen was provided by urea), CM(100% of nitrogen was provided by monosodium glutamate wastewater) and CM+CF(50% and 50% of nitrogen were provided by monosodium glutamate wastewater and urea, respectively), was performed. The present study was conducted to determine the effects of different treatments on root construction level, root absorption area, microbial diversity index in rhizosphere soil, and the growths of ground diameter and height of poplar seedlings.[Results] The application of monosodium glutamate wastewater significantly promoted the root growth and construction of poplar seedlings, especially the promotions of the fine root weight and the ratio of fine root were obvious. In contrast to CF treatment, the CM+CF treatment significantly increased the total absorption area and active absorption area of roots, and the increments were 76.39% and 121.48%, respectively. At the same time, the maximum value of microbial diversity index was observed by the use of CM+CF, which had significant differences with other treatments. Additionally, this treatment also obviously improved the growths of ground diameter and height of poplar seedlings, indicative of 45.30%, 22.62% and 10.78% increases in ground diameter and 42.21%, 20.65% and 11.46% increases in height over the treatments of CK, CF and CM, respectively.[Conclusion] As a result, monosodium glutamate wastewater combined with inorganic fertilizer was beneficial to improve root characteristics and microbial diversity index in rhizosphere soil, and to promote growth of poplar seedlings.

Abstract:[Objective] The quantitative characteristics, the survival condition and the spatial distribution pattern of Ailanthus altissima regenerated saplings were investigated and analyzed to provide theoretical bases for natural regeneration of arbor, human-induced disturbance regeneration, and other regeneration promotion in urban green space habitat.[Methods] Time-specific life table, paired correlation function G(r) and H(r) were utilized to analyze the seedlings' living conditions, the distribution pattern and spatial association among seedlings with different age classes.[Results] There was a fluctuation in the structure of Ailanthus altissima regenerated saplings' population. The individuals at young and middle age-class were abundant, and the type of survival curve of the population was regarded as Deevey Ⅱ. Lifespan's curve of mortality rate and disappearance rate all had a stable stage in the early and late period, while in the middle period, the two items experienced decrease and increase successively. Individual mortality and disappearance rates reached the top peaks beyond the 5th age-class(8~10 cm).[Conclusion] Regenerated saplings were significantly aggregated in different degree and the aggregation intensity weakened with the increase of scale in both two pavement's types. The type of one side's pavement seemed randomly distributed when the scale is close to 3.7 m. There is almost no correlation relationship at small scale, however, when scale increased, positive correlation relationships between seedlings of different age classes was detected. The closer the age class of the regenerated saplings was, the stronger the positive correlation was.

Abstract:[Objective] The spatial distribution and influencing factors of soil organic matter in Shaanxi Province were analyzed to reveal the relationships between soil organic matter and the influencing factors as topography, vegetation types, climate and other soil properties, to provide scientific basis for the study of soil carbon sink(carbon source) function change in this area.[Methods] Eighty-five top-soil samples were collected from 12 regional sites with different vegetation types and topographic conditions. Methods K-means clustering analysis and redundancy analysis(RDA) were used by SPSS 16.0 and Canoco 4.5.[Results] The soil organic matter concentration belonged to 2~6 levels, spatially having a decrease trend from the south to the north, and from the west to the east of province wide. The maximum value was 1.89~14.84 times of the minimum one. The contents of soil organic matter at different sample sites from a same region was not at similar level. Except for longitude and frost-free period, the content of organic matter was significantly affected by several environmental factors. Among which, years of vegetation restoration and vegetation types were the greatest influencing factors, slope gradient and aspect also have their influences and have obvious interaction effect.[Conclusion] Significant increase in soil organic matter content was found when farmland was transformed to other lands but orchard. The increase was more obvious with the increase of farmland converted ages, whereby it made reverted farmland shifted from carbon source to carbon sink.

Abstract:[Objective] Five types of biochar were prepared by corn straw and sludge at different temperature, the effects of different biochar applications on basic soil physical and chemical properties were examined to provide scientific basis for the improvement of saline alkali soil and the ecological restoration of soil pollution.[Methods] Five types of biochars were prepared by corn straw and sewage sludge at the temperatures of 300,350,400,450,500℃, the structure and properties of biochars were characterized by scanning electron microscope(SEM), element assay and fourier transform infrared spectroscopy(FTIR). A laboratory incubation study was conducted to examine the effects of biochar on the basic physical and chemical properties in saline soil.[Results] The element C content increased and the elements O, H, N gradually reduced when temperature increased. With the increase of biochar, the content of organic carbon in the saline soil was significantly improved; while the mineral nitrogen, phosphorus, available phosphorus and available potassium changed very little; the content of CEC in the saline soil was significantly improved, the pH value was slightly lower, the content of soluble salts decreased significantly.[Conclusion] Corn straw and sludge-based biochar can improve the saline soil nutrient content and fertility index, and can reduce the soil salt. Corn straw and sludge-based biochar can be used for the improvement of saline soil.

Abstract:[Objective] This study analyzed the pollution characteristics and sources of polycyclic aromatic hydrocarbons(PAHs) in farmland soil from Xiaodian sewage irrigation area in Taiyuan City. The results should facilitate the development of farmland environment evaluation and soil pollution prevention strategy in the study area.[Methods] 15 surface soil samples were collected, and their concentrations and composition of 16 PAHs listed for prior control by US EPA were detected with a gas chromatography equipped with mass spectrometry (GC/MS). The sources and ecological risks of the soils were assessed.[Results] The results showed that 16 PAHs were generally detected, with the detection ratio of 100%. The total PAHs concentrations varied from 0.315 to 7.661 μg/g, with an average value of 3.568 μg/g. In terms of composition, the contents of PAHs of 2, 3 rings accounted for 64.2% of the total PAHs, the contents of PAHs of 4 rings accounted for 14.2%, and the percentage of 5, 6 ring-PAHs was 21.6%. Thus, the contents of PAHs with low and middle rings were much higher. Based on ratio method and in-site investigation, it was induced that the PAHs sources were not only related with water quality and history of sewage irrigation, but also with the sources from the combustions of wood, coal and fossil fuels.[Conclusion] Compared with the relative research of farmland soils at home and abroad, PAHs pollution in this area was in medium or higher level. According to the standards recommended by Maliszewska-Kordybach, the total concentrations of PAHs exceeded the limited value in all the sampling points. However, these values were below the "National Environmental quality standards for soils(GB15618-2008)" proposed by China.

Abstract:[Objective] General trend and terrain gradient distribution pattern and the influence factors of land use change in Dianchi watershed were analyzed to provide the optimal allocation of land use pattern and the reference for the sustainable development of land resources.[Methods] We used range and dynamic degree of land use to analyze the general trend of land use change. The terrain distribution index method with respect to the terrain factors(landform relief, slope, aspect, terrain niche) was analyzed. Influence factors of the terrain gradient effect were analyzed by qualitative analysis method.[Results] (1) The main land use types of the study region from 2000 to 2014 were cultivated land, forest land, grassland and construction land, among which, grassland had obviously decreased and construction land obviously increased. (2) The pattern of land use type in different terrain gradient has obvious level distribution and change trend. With the increase of topographic gradient, the proportional coverage by water area, cultivated land and construction land, grassland and unused land, woodland gradually increased. These land use types preponderated at lowest, low and mid-low, mid-low, mid-high and high terrain gradients, respectively. With the increase of topographic gradient, the distribution index of water area, cultivated land and construction land(except the lowest level gradient of cultivated land and construction) declined, the distribution index of grassland and unused land didn not change obviously, the distribution index of forest distribution increased. (3) Terrain gradient effect of land use pattern change is mutually influenced by basic terrain factors, promoted social and economic factors and control policy factors of macroeconomic regulation.[Conclusion] The terrain gradient distribution pattern of land use in Dianchi watershed changed distinctly and was affected by terrain, social economy and policy.

Abstract:[Objective] To investigate the difference of water holding capacity of litters in different stand types in Duolun County, and to provide basic data and relevant theory for forest soil water holding capacity in this area.[Methods] Duolun County in Xilinhaote City of Inner Mongolia was taken as the study area, in which 10 representative sites of woodland were selected. Weight of forest litter, water holding capacity and storage capacity were measured to analyze the differences of water holding capacity of litter among different forest types, the effect on moisture content as well.[Results] (1) Forest litter amount, water holding capacity and storage capacity were all higher than that of shrub. (2) The natural forest litter amount, water holding capacity and storage capacity were higher than the corresponding values of artificial forest.(3) The litter thickness significantly affected the water content of the surface soil, i.e., the thicker the litter layer, the higher the surface soil moisture content was.[Conclusion] Because of the influences of tree species composition, age, stand density and site conditions, the water holding capacity of different stand types varied greatly, but the change was basically the same. The influence of forest land on soil moisture was higher than that of grassland.

Abstract:[Objective] The effects of moisture in Hexi desert oasis area(taking Zhangye City in Gansu Province as the representative) on soil temperature was demonstrated and the association between soil temperature and fruit quality was explored to provide theoretical basis for facility delayed cultivation technology research.[Methods] Five growth stages(GS, PS, FS, ES, CS) were recognized for the cultivation of faculty-delayed grapes. In each growth period, a moderate moisture treatment(the lowest of soil moisture was about 55% of the soil field capacity).[Results] (1) Soil temperatures of different layers ranked as 5 cm > 10 cm > 15 cm > 20 cm > 25 cm. During the whole growth period of grape, the soil temperature in each soil layer increased first and then decreased. Water stress at certain growth stage not only improved soil temperature, but also played an important postponed role in soil temperature to the next growth stage. (2) GS treatment had the highest ear quality and greatest single grain weight; FS treatment had the highest soluble solids content; the total sugar content of CS treatment was the most; titratable acid content was lowest in CS.[Conclusion] Soil temperature of the grape was significantly affected by environment during the delayed cultivation. Soil heat was transferred from the surface layer to the deep layer during the daytime, and hence water stress can increase soil temperature. In order to increase the sweetness of the grapes, to reduce the acidity and to increase the maturity, soil temperature should be increased in the late growth stages. They are the fruit swelling stage and the coloring mature stage.

Abstract:[Objective] We chose the most significant rainfall indicators of landslides and debris flows in typical regions and built a critical threshold model for each sub-region in typical regions to provide a scientific basis for effective prediction of landslide and debris flows.[Methods] This study collected Sichuan's geological disaster cases occurred in 1999-2014, to define the typical regions of landslides and debris flows in Sichuan Province. We compared the threshold models that are made up of different rainfall indicators in each typical region to construct our rainfall threshold models.[Results] Average rainfall intensity and maximum rainfall intensity are used frequently as significant parameters in threshold models of landslides and debris flows in typical regions. Indirect rainfall is a precipitation indicator of landslides in typical region generally, direct rainfall is a precipitation indicator of debris flows just in typical region generally. Effective rainfall was adopted to the precipitation indicator both of landslides and debris flow threshold models in typical regions. Model with double factors were applied to most of typical regions of landslides and debris flows. Model with one factor was just applied to Wenchuan earthquake-stricken area, the critical threshold gradually raised from Wenchuan earthquake.[Conclusion] Different rainfall factor has different effect on disasters, each typical region has its own optimum rainfall threshold model. Model with double factors is more objective than those with just one factor, as they contain more rainfall factors.

Abstract:[Objective] The spatial-temporal variation of the eco-environmental quality in He'nan Province was analyzed to provide scientific bases for the monitoring, conservation and management of eco-environmental.[Methods] This paper evaluated eco-environment quality by eco-environmental quality index. The eco-environmental quality index was calculated by five indexes, which included the biological richness, vegetation coverage, water network denseness, land stress and pollution load. These indexes were calculated based on the grid-based collected multi-source and multi-temporal data, and technical criterion for eco-environmental status evaluation was also considered.[Results] (1) The main type of eco-environmental quality was "general" in He'nan Province, and it accounted for nearly 80% coverage of the whole areas, other types accounted for relatively less. The topography, land use types and regional development strategy had profound effects on the distribution of eco-environmental equality. (2) The eco-environment quality has showed a trend of reduction with small annual variation in recent years. Chronologically, it showed a unimodal distribution, showing no significant changes in the highest years, and the significant changes in the early and laters sides years. (3) The changes of eco-environmental quality were closely related to the regional development, which had showed a deterioration trend in recent 13 years. Influenced by the expansion of urban construction land, the degeneration regions had shifted from the midwestern to the southeast of He'nan Province.[Conclusion] The evaluation of eco-environmental quality based on gridding could reflect the spatial distribution characteristics and the influencing factors of regional ecological environment more distinctly. In order to improve the quality of ecological environment, regional development strategy must be coordinated with the ecological civilization construction.

Abstract:[Objective] The aim of this research was to examine the characteristics of land use change in central Binzhou City of Shandong Province so as to provide reference for the proper land planning and utilization.[Methods] Based on the Landsat images from 1996 to 2014, dynamic index, conversion matrix and spatial center of land use were used to quantitatively analyze the spatial-temporal change trend of land use in central area of Binzhou City.[Results] From 1996 to 2014, the average decrease rate of cropland was 3.63%/a, the increase rates of forestland, water body and construction land were 5.43%/a, 0.79%/a and 5.70%/a. The transferred-in area of forestland and water body was more than the transferred-out area. The transferred-in area of forestland reached the peak value in the period of 2005 to 2009, the transferred-in area of water body peaked in the period of 2001 to 2005. The spatial centers of cropland and construction land were respectively located on the southwest side and east side of the city square. The spatial center of cropland was moving away from city square toward the southwestern part. The spatial center of construction land was moving west toward the city square.[Conclusion] Cropland area decreased constantly, forestland and water body area decreased in the beginning and then increased, construction land area increased constantly in the central city. The major trend of land use change was the transfer from cropland to construction land. The implementations of hydraulic engineering and landscape engineering had great impacts on the transfers of forestland and water body. The spatial center movement of construction land was closely related to the development and construction of west urban area.

Abstract:[Objective] In order to reduce the negative impact of land consolidation on the ecological environment, and to strengthen the ecological conservation function of county land, this paper constructed an ecological network system.[Methods] The path cost module of ArcGIS software was used to generate the least path and to construct the network structure of the "node corridor matrix". Moreover, Fragstats 4.2 landscape pattern analysis and ArcGIS buffer analysis were used to analyze the ecological network index of landscape pattern and land use structure.[Results] (1) The results showed that constructing the key nodes with high ecosystem service value function can exhibit the green lung function of the garden completely. (2) Strengthening the construction of corridor and matrix can increase the landscape connectivity and can realize the optimization of the landscape function. (3) Based on the optimization of ecological connectivity, the number and quality of the existing ecological network patch can be improved significantly, and the diversity of biological species can be increased markedly.[Conclusion] The path cost module was used to integrate landscape patches into a relatively complete, stable and continuous ecological network that can make the ecological landscape spatial distribution in the area more reasonable, which can provide theoretical basis and technical support for ecological network construction of land remediation.

Abstract:[Objective] The research progress of moistube irrigation technology was reviewed to investigate the future research direction and provide available bases for the formulation of water-saving irrigation system and parameters. In addition, this review would play a key role in popularizing moistube irrigation technology.[Methods] The paper summarized the development history and application status of moistube irrigation technology, soil water movement under moistube irrigation, effects of moistube irrigation on crops growth, etc. and the drawbacks of moistube irrigation technology were analyzed.[Results] Moistube irrigation is an underground irrigation technology, having the advantages of uninterrupted adequate water supply for plant absorption and field irrigation were synchronicity. Moistube irrigation water was matched with plant water consumption. Meanwhile, moistube irrigation can come into being no-stress irrigation. In addition, moistube irrigation plays an important role in improving crop quality and yield. The moistube irrigation technology has become a leading international bionic type continuous irrigation system, and will have broad prospect of popularization in arid and semi-arid region.[Conclusion] This paper reviewed the development history and application status of moistube irrigation, the research progress of moistube irrigation technology mechanism, migration rules of soil water and the effects of moistube irrigation on crop growth, and put forward the key research fields needed to be further study, including the effects of moistube irrigation on soil nutrient migration; the effects of moistube irrigation on crop growth with different planting patterns; the effects of moistube irrigation on greenhouse gas emissions of farmland ecosystem.

Abstract:[Objective] The ecological compensation standard of Xiaohonghe River basin was studied in Zhumadian City to provide reference for establishing the account model of ecological compensation standard of river basin water quality.[Methods] Based on the operation and handing data of sewage treatment plants, COD, ammonia nitrogen and total phosphorus were selected as the representative pollution factors, then pollution treatment cost method and other statistical methods were used to carry out the research.[Results] The compensation values in Xiping County, Shangcai County, Pingyu County, Xincai County were 0.40, 0.46, 0.58, 0.88 yuan per ton, and the results were in good agreement with other related research.[Conclusion] The water quality-based ecological compensation standard accounting model assessed by pollution treatment cost model can well reflect the unit cost of each water pollution factor of river basin, which laid a solid foundation for the construction of ecological compensation mechanism.

Abstract:[Objective] It is one of the key basic issue in the prevention and control of water environment by exploring effective prediction methods about cyanobacteria bloom in lakes and reservoirs.[Methods] Combined with the class random characteristic showed in the chaotic evolution of cyanobacteria bloom, this paper proposed a dynamic clustering algorithm based on the optimization of validity functions to achieve the optimal cluster number of cyanobacteria bloom and small-scale neighborhood optimal prediction. First of all, monitoring data were classified objectively by the proposed dynamic clustering algorithm to reduce effectively the search space and to improve the prediction accuracy. Then the optimal number of neighbors for all kinds was obtained using the particle swarm optimization algorithm, which was used to determine the number of participating in the local regressive algorithm. Finally, a dynamic regressive prediction model was established.[Results] The model established using the concentration data of chlorophyll a at the Jinshu monitoring site of Taihu Lake in 2011 was used to model and predict short-term variation of it in 2012. The predicted value of the model was consistent with the actual trend and the relative error was 12.02%, and was smaller than the ones predicted by other models, such as linear regression algorithm based on traditional clustering, BP neural network, and phase space reconstruction algorithm, whose relative errors were 15.21%, 19.51% and 38.42%.[Conclusion] Numerical results showed that the prediction accuracy of this method was relatively high, hence the feasibility and effectiveness of the optimization prediction method proposed were proved.

Abstract:[Objective] Concerning the shortage in the extraction of plain river network based on DEM, we adopted a new method to extract plain river network and to provide basis for automatic drainage extraction method.[Methods] Using Acr Hydro Tools and SWAT, the river network of Yaojiang river basin in Ningbo City was extracted in DEMs with different contour. The extracted total area of the basin and total length of rivers were used as the main index of quantitative analysis. Relative error formula, matching error formula of river network and Visual Similarity Duplicate Image Finder software were used for comprehensive evaluation and error analysis.[Results] With the help of the real river network, the extracted results based on Neat DEM by Acr Hydro Tools and SWAT were very bad. However, the extracted river network, basin and total basin export based on Adjacent DEM were consistent with the actual, and the precision and similarity were also high.[Conclusion] Extracting basin and river network with Acr Hydro Tools and SWAT are all desirable, but the SWAT is more convenient. The quality of river network extraction is dependent on DEM contour and also dependent on whether the DEM is tangent with the total basin export or not.

Abstract:[Objective] Evaluation of spatial-temporal characteristics of the water resources carrying capacity of Yangtze River economic zone is of great significance to the rational utilization of water resources and the sustainable development of the region.[Methods] An evaluation index system of water resources carrying capacity that include 18 indices from four aspects, including social economic, the quantity of water resources, water consumption and wastewater discharge, was established. The spatial-temporal characteristics of water resources carrying capacity of the Yangtze River economic zone were evaluated using the principal component analysis method.[Results] The water resources carrying capacity of the Yangtze River economic zone increased during 2004-2013. The main factors to drive the increasing of water resources carrying capacity are natural conditions of water resources, population and economic growth, and water pollution control. The spatial differences of water resources carrying capacity of the Yangtze River economic zone are significant. The water resources carrying capacity of the eastern and the middle regions is in good situation, whereas the water resources carrying capacity of the western region is relatively poor except Sichuan Province.[Conclusion] These differences are mainly attributed to the natural conditions of water resources and the economic development level.

Abstract:[Objective] The groundwater pollution status of a depot in Huangling County of Shaanxi Province were simulated to provide scientific guidance for auxiliary prediction and prevention of groundwater pollution in oil depot area.[Methods] Based on the initial parameters obtained through field investigation, we established a groundwater flow model using Visual Modflow software. Then through model identification and verification, we obtained the final hydrogeological parameters. And we derived a groundwater solute transport model in reference to water flow equation and contaminant transport equation.[Results] We simulated two hypothetical scenarios:one is under normal working condition and another one is when oil leakage happened for the oil tank. The range and degree of pollution were predicted by numerical simulation. The impact of pollutants was predicted that it would become the greatest in the following 20th year of leakage.[Conclusion] The results obviously showed that the contaminant transport mainly via flow direction, the impact on water environment tends to gradually increase with time going on. And there was a negative correlation between the concentration of pollution and the distance from oil tank. Oil tank leakage will cause more severe pollution to the water environment than normal operation can do, under that case, pollution is far beyond the scope of the depot area.

Abstract:[Objective] The calculation method with regard to the carrying soil stability in a vegetation restoration project performed on the rock slope was discussed.[Methods] The acting forces both from resisting shear root and friction root were simulated, and then converted them into anti-shear strength and served as an added value to the stability of carrying soil. Further, a mathematical model associated with the soil stability on the rock slope was established, and was verified by the vegetation restoration project of the Jinan-Laiwu expressway.[Results] (1) The stability coefficient of carrying soil was a function of shear strength without root(F_s), bulk density(γ), thickness(d), and increment of root shear strength(τ_R). (2) The anti-shear strength of the root could be the sum of resisting shear root(τ_Rg) and friction root(τ_Rg). (3) The stability coefficient is persistently smaller than its measured counterpart, and the deviation rate is small. Also, the soil stability coefficient was positively correlated with the initial vegetation restoring period (i.e. 3~5 years).[Conclusion] The determination of carrying soil stability coefficient could be employed as the parametric design and evaluation for the vegetation restoration project on the rock slope.

Abstract:[Objective] Method of determining appropriate drain area threshold was demonstrated to reflect the actual river drainage network.[Methods] Based on the DEM data of Longchuan River basin, the automatic extraction module of watershed drainage network in ArcGIS software was used to extract relevant drainage information. After that, a function between river network density and catchment threshold was fitted, which was used to determine the appropriate drainage threshold by finding the turning point of its first derivative function and/or the inflection point of the second order derivative. This was simultaneously exemplified by the Longchuan River basin. In this case, the threshold was determined by finding where the ratio change of river network density equal to the change rate of the water drainage threshold.[Results] The river networks under different catchment drainage threshold were compared and found that no obvious differences existed with regard to the catchment threshold length of the main channel and the geographic location, but other features of river network were apparently different. In the case of the Longchuan River basin, its appropriate threshold was thought to be 0.12 km².[Conclusion] The river network extraction precision varied with the drain area threshold. The proposed method in the determination of the catchment threshold is less subjective, and is more objective, which can be used to provide some bases for the monitoring of regional soil erosion.

Abstract:[Objective] An comprehensive evaluation index system of urban land ecological security was established and the dynamic change of land ecological security and the main obstacle indicators were analyzed in 2004, 2009 and 2014. These were expected to provide bases for regional land use decision-making and ecological maintenance.[Methods] Dynamic evaluation and land ecological security were analyzed using grey relation projection model, dynamic degree and standard deviation. The obstacle indicators and its degree of land ecological security were measured by obstacle degree model.[Results] (1) The total degree of land ecological security during 2004-2014 increased slowly, but generally it was still in a lower level. The environmental subsystem had experienced two stages from slow promotion to gradual degradation; simultaneously, the economic one also had experienced two stages from rapid promotion to slow promotion; meanwhile, the social one always had been in a slow promotion stage. The internal coordination degree of land ecological security was improved gradually. (2) The categories, the obstacle degree, and the order of obstacle factors of land ecological security were all in dynamic change, the obstacle factors had evolved from economic factors to resources and environmental types. (3) In order to treat these problems exposed in land ecosystem security, it should be proceed with sustainable land use and healthy urbanization, hereby to achieve the coordinative development among economy, environment and the society of Nanchang City.[Conclusion] The evaluation results of land ecological security research were thought accordant with the objective reality. In view of the main problems exposed to the land ecosystem, relevant countermeasures are put forward wherein.

Abstract:[Objective] Suitability of plantation species in the central-southern region of Taihang mountains were studied to provide theoretical and technical supports to improve vegetation restoration in Taihang Mountainous ecological fragile area.[Methods] Suitability of 17 common plantation species were evaluated using analytic hierarchy process(AHP). Based on nine evaluating indicators, we used 9 point scaling expert questionnaire to screen indicators and to calculate weight with judgment matrix. According to the weight scores, species were divided into four levels:level I(most suitable), level Ⅱ(suitable), level Ⅲ(not very suitable), level Ⅳ(not suitable).[Results] (1) There were nine indicators that were recognized included in the evaluation index system of soil and water conservation plantation, and four indicators in the evaluation index system of timber plantation. (2) Weight values of soil and water conservation plantation ranged between 0.022 7~0.088 9. (3) Weight values of tree species on timber between 0.024 1~0.1441.[Conclusion] Tree species that possibly can be used for soil and water conservation were graded as followings:I-Platycladus orientalis, Sabina chinensis, Armeniaca sibirica, Amygdalus davidiana; Ⅱ-Pinus bungeana, Quercus liaotungensis, Populus davidiana, Pinus sylvestris, Pinus tabulaefor, Juniperus communis, Larix principis-rupprechtii; Ⅲ-Betula platyphylla, Robinia pseudoacacia, Elaeagnus mollis, Rhus Typhina; Ⅳ-Ailanthus altissima, Populus cathayana; For timber plantation, tree species had:I-Larix principis-rupprechtii, Pinus tabulaefor mis,Quercus liaotungensis;Ⅱ-Sabina chinensis, Platycladus orientalis, Populus cathayana, Populus davidiana, Betula platyphylla, Ailanthus altissima, Pinus bungeana; Ⅲ-Robinia pseudoacacia, Rhus TyphinaⅣ-Sabina chinensis, Juniperus communis, Armeniaca sibirica, Amygdalus davidiana, Elaeagnus mollis.

Abstract:[Objective] In order to find efficient regeneration method, and to provide scientific guidance for artificial cultivation and landscape producing, the study focused on the effects of the type, concentration level of different exogenous hormones and cutting diameter of Acer tetramerum on the cutting rootage.[Methods] The study was carried out by cuttage experiment and statistical analysis.[Results] (1) The rooting rates of cutting propagation in the treatments of IAA(indole-3-acetic acid), IBA(indole butyric acid), NAA(1-naphthyl acetic acid) and GA(gibberellin acid) were significantly higher than those of controlled group, among which, the treatment of IBA performed the best. (2) The rootage rates of cutting propagation reached its maximum value at the concentration levels of 50 mg/L of IAA, 200 mg/L of IBA, 50 mg/L of NAA and 50 mg/L of GA, respectively. (3) The maximal average rootage rates of thick cutting(D ≥ 7 mm)reached 54%. At this cutting thick, the highest rootage rate(77%) was recorded in the treatment of IBA at concentration level of 200 mg/L.[Conclusion] The optimal combination of cutting rooting for Acer tetramerum is as follows:in early September, with the diameter>7 mm, and using 200 mg/L IBA.

Abstract:[Objective] This manuscript aimed to simulate and forecast the land use structure under multiple development scenarios of Yangzhou City in Jiangsu Province, as well as to explore the paths to realize them, which were expected to provide considerable scientific references for land use planning and formulating.[Methods] The system dynamics(SD) model was used to simulate the land use system.[Results] The main land use types would vary under different scenarios. Under the protection of farmland scenario, the arable land area would increase; while under the ecological protection and economic development scenarios, the arable land would decline slowly. Either urban industrial and mining land, or land for traffic or water conservancy area would achieve stable growth in all three scenarios, but the growth in the economic development scenario would be quicker than that under the other two scenarios. The forest land area increase sharply under the scenario of ecological protection, but remain would not change or even decrease slightly in the other two scenarios. Under the scenario of farmland protection, urban expansion and the occupation of cultivated land should be under control. Besides that, unused land development and rural residential land consolidation should be strengthened to replenish cultivated land. In the ecological protection scenario, the ecological service value of waters, beaches should be protected. This might help to adjust industrial structure, and transform the traditional GDP to green GDP.[Conclusion] SD model can not only simulate the land use change under different scenarios, but also can reveal the complex nonlinear relationship between land use and socio-economic system, which is conducive to the sustainable use of land resources regulation.

Abstract:[Objective] Land use change and its response to human activities were analyzed comprehensively in Bailongjiang Watershed of Gansu Province during 1990-2014, to provide reference for land use optimization in the future.[Methods] Based on the land use data interpreted from the remote sensing images of 1990, 2002 and 2014, this paper calculated the rate of land use change, the direction of land use transformation and the degree of land use in Bailongjiang watershed of Gansu Province during 1990-2014.[Results] The integrated dynamic degree of land use of the whole watershed increased from 10.24% to 17.59%. The change of land use types was mainly in grassland, arable land and forestland of the watershed during 1990-2014. Comprehensive change index of land use degree of all districts ranged from 1.38~6.65 during 1990-2002 to -15.43~0.17 during 2002-2014.[Conclusion] It proved that land use by human activities had converted from simple development to ecology prone one. Land use shifted from the types of destructiveness, extensive-type and low efficiency to the ones of conservation, intensive-ways and high efficiency in Bailongjiang watershed of Gansu Province during 1990-2014.

Abstract:[Objective] Constructing a flood forecast model of Qingshitan Reservoir to provide a reference for actual forecasting business, and also to provide support for the study of hydrological and meteorological laws in the area, e.g., Guilin City, where information in the upper reaches is lacked.[Methods] HEC-HMS(hydrologic engineering center and hydrologic modeling system) is a hydrological model system with multiple production and distribution modules. It is suitable for the analysis and calculation of hydrological problems in different areas. It is widely used in flood forecasting, disaster prevention and mitigation. This model was used in hydrological modeling of the upper reaches of Qingshitan Reservoir in Guilin City, to simulate the flooding process of Qingshitan Reservoir in the event of heavy rainstorm in the watershed as a basis for flood forecasting.[Results] The average deterministic coefficient of HEC-HMS model was found to be 0.88 by the study. The peak flow rate and peak current error all reached Grade B prediction criteria.[Conclusion] The HEC-HMS model is suitable for the Qingshitan basin and can be used for the flood forecasting of the Qingshitan Reservoir.

Abstract:[Objective] We aimed to provide decision-making bases for flood disaster prevention, mitigation planning and risk management in urban community level based on the analysis of influencing factors and assessment of flood resilience in urban community.[Methods] The Hongqi district in Xinxiang City, He'nan Province was taken as the study area, and the questionnaire method was used. Sixty-four variables were selected to build a pre-selected index set based on the literature review and discussions with experts. The correlation analysis and principal component analysis were used to reduce the number of variables, and the flood resilience of urban community was assessed.[Results] (1) The key factors influencing urban community flood resilience could be summarized as physical factors, institutional factors, economic factors, population factors. (2) The capability of community flood resilience was not high, and nearly 80% of the communities were at a level below average. (3) Physical variable was the main factors influencing urban community flood resilience, followed by economic, demographic and institutional factors.[Conclusion] It is a feasible way to put forward the concrete and targeted strategies and measures for improving the flood resilience in urban community based on the analysis of influencing factors and assessment of flood resilience.

Abstract:[Objective] The paper studied the classification of the erode gullies in small typical watersheds on the loess plateau in Gansu Province aimed to lay foundation for the better development of soil and water conservation and ecological management in the Loess Plateau.[Methods] Based on the results of the first national water resources and water power investigation, using GIS technology and math model of physiognomy geometry ration, the gullies were graded quantitatively and erosion gullies are classified from geology, geomorphology, size, and shape. Therethrough, the characteristics of erosion gullies in the Loess Plateau were inferred from.[Results] The results showed that in small watershed scale on Loess Plateau in Gansu Province, most of the erosion gullies are those, in hilly and gully regions, that have semi-opened, moderate fragmented and semi-main groove typed characteristics; In Loess gully regions, that have semi-opened, moderate fragmented and branch gully typed characteristics.[Conclusion] In the hilly and gully region, the fifth gully is narrow and steep, the gully fragmentation is high and the amount of soil erosion is great. It is difficult to manage and use the gullies.

Abstract:[Objective] The changing regularity and cycle characteristics of annual runoff of Yingluoxia in Heihe River was researched to provide theoretical and scientific bases for water allocation and water resources management.[Methods] Based on the measured data of runoff from Yingluoxia hydrological station in Heihe River basin during 1944 to 2014, Morlet wavelet analysis, Mann-Kendall mutation and gray prediction were used to analyze the trend of runoff and its variation characteristics.[Results] Yingluoxia annual runoff had a slight upward trend, the tendency of annual runoff anomaly percentage rate was 2.78%/10 a. Yingluoxia runoff wavelet variance figure had four obvious peaks, in turn corresponding to 43-year, 56-year, 12-year and 9-year time scales. Among them, the maximum peak is at 43-year time scale, and this is the first major cycle of runoff change. According to the cyclic alternation of main runoff, the Yingluo Gorge basin will be in the period of abundant water in 2020, and the annual runoff is predicted to be 1.843 billion m³.[Conclusion] The annual variation of runoff is obvious and the runoff is increasing in Yingluoxia basin.

Abstract:[Objective] To explore the regularities of rainfall infiltration in shallow loess, and to provide reference for studying the mechanism of loess landslide caused by rainfall.[Methods] One monitoring site was set up in Dalu Dicth, Shaanxi Province by arranging the monitoring instrument both in cracks and no-cracks at different depths. The observed results were dealt with numerical simulation to analyze the regularities of rainfall infiltration.[Results] (1) Soil moisture was recharged by rainfall and was drained away through evaporation in the area. The main affect of rainfall on water content was the tempo-spatial responses to the rainfall. There had a hysteresis for temporal response, which was more obvious with the increase of the depth. The effect of evaporation on soil water content was influenced by the depth and the exposed area of soil. The greater the depth of soil was, the smaller the effect would be. (2) The soil water content was very sensitive to rainfall, e.g., when precipitation was less than 3 mm/d, the rainfall almost had no effects on the water content of soil, however, when precipitation was 3~40 mm/d, the rainfall was observed having positive effect on soil water content.[Conclusion] The infiltration process simulation under different conditions showed that the effect of crack was little, and also the infiltration depth of loess in study area was limited.

Abstract:[Objective] This paper examined the spatio-temporal variations in the value of ecosystem services and then predicted it to provide support for formulating compensation policy in ecological environment construction and future urban development.[Methods] Based on land use data and relevant statistical data in the Yangtze River delta from 2000 to 2014, with the method proposed by Costanza wherein the values of ecosystem services are calculated with regard to the value coefficients of ecosystem services per unit area in the Chinese terrestrial ecosystem and the sensitivity analysis, this paper examined the spatio-temporal variations in the value of ecosystem services and then predicted it by Markov model.[Results] The total value of ecosystem services decreased from 130 389 million yuan in 2000 to 129 425 million yuan, reduced by 0.74%. In addition, the ecosystem service value of water supply, recreation and culture function and waste treatment increased while other ecosystem functions declined. From the perspective of spatial analysis, the ecosystem service values of Changzhou, Nanjing, Ninbo, Taizhou, Taizhou, Yangzhou City increased, while values of other cities decreased. The land use structures of the Yangtze River delta in 2015 and 2017 were predicted using the Markov model. The trends of woodland and cultivated land will maintain a continual increase while the construction land will be in a continual decrease in the coming three years. The total ecosystem services value will have a decrement of 276.65 million yuan.[Conclusion] Therefore, the importance of ecological service value should be given more consideration in future land adjustment, especially for the protection of cultivated land and water and improvement of land utilization intensity. it is very important to control the occupancies of cultivated and forest land by construction, to continually increase the effort of afforestation and maintain the function of ecosystem.

Abstract:[Objective] This paper was aimed to deepen the cognition to the vector properties of land use change, to further extract the profundity information in the characteristics and the rule of land use change, and to enrich the land use change research methods, to provide relevant reference for the regulation of land resources.[Methods] On a perspective of land use transfer flow, two concepts termed land use transfer rate and the land use transfer chain were introduced. Data of MSS/TM/ETM remote sensing image were used to make a case study of land change process in Tongxin County in arid area of central Ningxia Hui Aotonomous Region.[Results] Cultivated land and grassland had increased in the study region, however, the area of unused land had reduced during 1978-2015. At countywide scale, land use transfer rate had decreased gradually in Tongxin County. With respect to the land use transfer of different lands, the transfer rate of cultivated land increased firstly and then decreased; land use transfer rate of grassland reduced firstly and then rose; and land use transfer rate of unused land experienced a variation of deduce-rise-deduce in Tongxin County. From 1978 to 1987, grasslands were mostly transformed to unused lands in Tongxin County. From 1987 to 1996, the land use transfer flow was diversified. Since 1996, grasslands were expanded in the processes of cultivated land transformation and the unused land was also amplified, for it was exploited attentively. From 1978 to 2015, the transformation of land use in Tongxin County was mainly referred to the loss and protection of arable land. Among the transformation types, one-way chain had two main types referring to 31(grass turn arable land) and 61(unused cultivated land); reciprocating chain called Ⅱ_a, mainly had the types of 161(cultivated land-unused-cultivated land) and 131(cultivated land-grassland-cultivated land).[Conclusion] There existed a great proportion of "reciprocating chain" of land use change in Tongxin County during 1978-2015. In the future, more attention should be paid to the connotation revealed by the called reciprocating chain of land use change, and relevant countermeasures should be taken in the development and management of land resources.

Abstract:[Objective] The trend, fluctuation and change cycle of runoff and sediment discharge at Datong hydrometric station were analyzed in order to reveal its characteristics of long time series, which were expected to further provide theoretical basis for the development and evolution of estuarine delta.[Methods] Using Mann-Kendall test, Pettitt change point, Mexican Hat wavelet transform methods, the characteristics of runoff and sediment discharge were analyzed at Datong station in the past 60 years.[Results] The results showed that there was no significant change trend in the mean annual runoff at Datong station, while the inter-annual fluctuation was large and annual distribution was uneven. Repeated periodic oscillations were presented in the runoff series, the major cycle periods of the time series were about 6 and 44 years, respectively. Furthermore, sediment discharge had been declined obviously over the past 60 years and its annual distribution was uneven. There existed significant hopping site in the mean annual sediment discharge. In 2002, the hopping site of step down was first grade, the second grade was in 1984 and the third grades were in 1968 and in 1991. Repeated periodic oscillations also existed in the sediment discharge series, the major cycle periods of the time series were about 12 and 30 years, respectively.[Conclusion] There were no obvious trend and abrupt change of annual runoff at Datong station, but periodicity existed to some extent. There was a significant downward trend of annual sediment transport with obvious periodicity and abrupt change.

Abstract:[Objective] Studying the relationships among issues of urbanization, economic growth and nitrogen emission in 31 provinces of China from 2001 to 2015, and to provide theoretical support for the sustainable development of urban environment.[Methods] Co-integration test, panel unit root test, and Granger statistical causality test were used jointly.[Results] (1) The urbanization of China, particularly of the western, central and eastern areas, contributed to the economy development. The urbanization and the successive economy development led to the increase of nitrogen emission. The urbanization in western area contributed more proportional than it did in central and eastern areas. In contrary, the economy development in eastern areas had lager contribution. (2) The panel causality results revealed that there were a long-run bidirectional causal relationship among urbanization, economy development and nitrogen emission. Two unidirectional links were found, one was from urbanization to economy development, another one was from urbanization and economy development to nitrogen emission. For different region, the causal relationship exhibited different direction traits. In eastern and central areas, the relationship between urbanization and economy development was long-run bidirectional. While the link from urbanization to N emission, and the link from economy development to N emission were both short-run and unidirectional.[Conclusion] The government should reduce the amount of nitrogen by controlling the speed of economic growth and urbanization, and by adjusting the industrial structure and increasing the utilization rate of energy.

Abstract:[Objective] Through the research on space optimization method and control strategy of coastal beach development, the paper aimed to provide some bases for exploring an efficient path of beach resources protection and development.[Methods] Taking Dafeng District of Yancheng City of Jiangsu Province as an example, the spatial optimization pattern of coastal beach resources development was revealed by means of integrated development suitability assessment and departmental planning coordination method. The space control concept was introduced in order to discuss the development path of spatial control of tidal flat resource in Dafeng District.[Results] The empirical analysis showed that the appropriate coastal areas of ecological protection, agricultural production and port-industry-city development were 401, 323 and 444 square kilometers, respectively, accounting for 34.3%, 27.7% and 38% of the total area.[Conclusion] It is proposed that basic protection of environmental quality, highly efficient and intensive use of the urban space are all the key criteria for the spatial regulation of the tidal flat area. Meanwhile, it is still necessary to trace and analyze deeply for the development scale and intensity control of the tidal flat area.

Abstract:[Objective] The common problem in the processing of remote sensing images, that is different classification algorithms may lead to different identification results of ground objects, was discussed, to provide reference information of urban change and decision making based on LULC analysis.[Methods] In this research GlobeLand 30 product and CA_Markov model were selected to monitor and analyze land use degree, entropy change of land use, spatial-temporal change of land use in Zhengzhou area from 2000 to 2020.[Results] (1) There was a great land use degree change from 2000 to 2010. During this period human-made cover type was increasing greatly; on the contrary, wetland, farmland, grassland were in a decreasing trend. Where human-made earth surface and wetland changed significantly. (2) The amount of land use was 8.04, entropy of land use and equilibrium degree were promoted, while dominance index decreased. (3) There were 68.88% and 49.99% increases for human-made earth surface and grass land respectively, and there were more than 30% increases for both of water surface and wetland.[Conclusion] There was a significant difference of landscape from 2000 to 2020. The complexity of land use was increasing, and the proportionality of land use raised.

Abstract:[Objective] The carbon effect of urban agricultural land was estimated in Nanjing City to provide development experience for other cities with urban agriculture.[Methods] The carbon emissions from agricultural land in Nanjing City were calculated from 1996 to 2014 based on six main carbon sources of chemical fertilizers, pesticides, agricultural film, agricultural diesel, irrigation and tillage. At the same time, the variations of three main carbon sinks, including forest land, grassland, garden, were explored to illustrate the carbon effects of agricultural land use changes. In the end, the trend of carbon emissions from agricultural land in Nanjing City was predicted based on the gray GM(1,1) model.[Results] From 1996 to 2014, the carbon emissions from agricultural land use in Nanjing City showed a three-stage variation of "rising-fluctuating-steady decline". Chronically, the carbon sinks of both forest land and grass land decreased from 2005 to 2014, but their decreasing rate was different. From the view of regional comparison, due to the city carrying function was different, regional carbon sinks differed greatly. In terms of the carbon effect of the change of agricultural land use, the carbon sequestration in Nanjing City from 2000 to 2008 increased at first and then decreased; and carbon emission caused by construction occupancy experienced a Z-shaped variation. Based on the gray GM(1,1) model, the isobar metric forecasting method was used. It was estimated that the agricultural carbon use in the city will be 1.11×10⁵ t by 2020.[Conclusion] The trend of carbon use in Nanjing City was closely related to the economic development and the process of urban agriculture development. The reductions of forest land and grass land area reduced the original carbon sink effect. And as a result from economic development and urban construction needs, the continued growth in construction land have great impact, which will result in a large number of carbon emissions in Nanjing City.

Abstract:[Objective] The temporal and spatial variation trend of rainfall erosivity in Jilin Province from 1961 to 2015 were analyzed to provide scientific bases for agricultural and ecological protection, as well as soil and water conservation.[Methods] Based on the daily rainfall data from 46 meteorological stations in Jilin Province from 1961 to 2015, rainfall erosivity was estimated and the temporal and spatial distribution was analyzed with correlation coefficient, climate tendency rate and the inverse distance interpolation methods, respectively.[Results] The spatial distribution of rainfall erosivity has a decreasing trend from the station of Jian to the northwest and northeast region. The spatial distribution of average annual rainfall erosivity is similar to that of average annual precipitation. The temporal distribution of yearly averaged rainfall erosivity is similar to that of multi-year average precipitation, which has a peak in July. 34.8% meteorological stations have incline rainfall erosivity. For most of the western region, there is a downward trend; while for more than half of the stations in eastern region is on the rise, among with Changbai station was significant. The changes of average rainfall erosivity of each decade in different regions are not consistent, and have fluctuation. The spatial distribution of rainfall erosivity contour in different decade differ slightly.[Conclusion] Rainfall erosivity in Jilin Province is consistent with the precipitation in temporal and spatial variation, and the trend of rainfall erosivity in different regions is different, and almost dose not pass the significance test.

Abstract:[Objective] Investigation and calculation of the regional self-development capacity(RSC) were the keys of alleviating poverty and promoting development persistently in Qinba Mountain areas.[Methods] Based on the ecological economic perspective, taking Qinba Mountain areas as a typical example, a complicated system of RSC with four dimensions, including industry capacity(IC), market capacity(MC), space capacity(SC) and soft power(SP) was built up. Then, the RSCs of all the counties in 2006, 2010 and 2014 were estimated and their spatio-temporal evolution were estimated by multi-index comprehensive calculation method.[Results] The RSC of Qinba areas is generally low and unbalanced. As a whole, the RSC of Qinba areas belongs to MC constraint-SC drive. From 2006 to 2014, the RSC in Qinba Mountain areas had the trend of aggrandizement, and "rising in central but declining in southeast" in spacial evolution. There are differences among the four dimensions of RSC in spatio-temporal evolution. The internal structure of RSC was unreasonable in Qinba Mountain areas.[Conclusion] The entire Qinba Mountain areas is weak in self-development ability. The regional restriction and the driving factors are also different. In the future, targeted measures for development can be made when considering the aspects of regional industrial structure, market position, ecological function and science innovation.

Abstract:[Objective] The application framework for ecosystem services evaluation in environmental impact assessment on tourism resort plan was established and then applied it in Suzhou Taihu Lake National Tourism Resort.[Methods] According to the features of tourism resort, the study was carried out by ecosystem service function value evaluation.[Results] On the conditions of scale adjustment of tourism development, and maintenance of water area and wetland, the resort can keep the original ecosystem service function. The ecological service function value increased 53 million yuan after the adjustment.[Conclusion] Construction land growth led to the decrease of water area and wetland, whereby reduce the value of ecosystem services.

Abstract:[Objective] The characteristics and influencing factors of civil social behavior in the construction of water-saving landscape in Xi'an City were explored to provide scientific bases for the better construction of water-saving landscape city and popularization of reclaimed water in garden.[Methods] Correlation analysis based on questionnaire survey data of 13 districts and counties in Xi'an City was conducted by means of SPSS and AMOS.[Results] Xi'an City public awareness of water conservation is higher, especially women, older people, highly educated people, those people that had experienced water shortages, and those considering water shortage existed in the city, they all have higher awareness of water conservation. That meant factors of gender, age and perception of city water shortage degree have significant influences. The acceptance of reclaimed water used is generally in accordance with the awareness of water storage.[Conclusion] The factors of gender, age and perception of urban water shortage positively influence water saving awareness. Factors of age and education level positively influence the acceptance of reclaimed water. Water conservation consciousness positively influences the acceptance of reclaimed water in garden.

Abstract:[Objective] To identify and quantify the drought during crop growing season in Midwest of Jilin Province and analyze drought hazard in order to provide scientific reference for drought mitigation.[Methods] Based on the meteorological data from May to August during 2005 to 2014 and the corresponding MODIS NDVI products that was combined every ten days and have 500 m resolution, SVDI(spatial vegetation drought index) was calculated to analyze SVDI spatial and temporal distribution characteristics. The index applicability was illustrated in terms of drought-induced agricultural production decrease and yield anomaly. Furthermore, the density distribution of ten-day SVDI from May to August was calculate to demonstrate drought hazard.[Results] (1) Compared with VCI, SVDI behave better for drought recognition. Combined with agricultural drought production and yield anomaly, SVDI showed higher correlation in the initial and final growth period of crop growing season. (2) During 2005-2014, the area hited by severe drought from May to August in Midwest of Jilin Province fluctuated obviously, and had a transiting trend to central and southwest parts. (3) In Midwest of Jilin Province, drought occurrence had higher probability in periods of early and late May, June, and late August, whereas, in early August and late June, the drought hazard are higher. Tongyu County has high drought hazard from May to August so that it should be taken as a key county to be protected.[Conclusion] The results showed that using SVDI to identify and quantify drought is feasible, also drought frequency during crop growing season in Midwest of Jilin Province shows obvious regional traits.

Abstract:[Objective] This paper discussed the causes and impacting factors in the evolution of the Luoma Lake to provid a basis for the rational development of the lake and the sustainable use of its water resources.[Methods] Based on the chronical data published in articles of the past five hundred years, and statistical and digital analysis was used.[Results] The dredges of Jia canal, middle canal and other water systems promoted the development and rehabilitation of Luoma Lake. There is a strong consistency in occurrence years between Luoma Lake siltation and Yellow River flooding. The reclamation of Luoma Lake was gradually intensified after Jiaqing era in the Qing Dynasty. The climate of the Luoma Lake area changed alternately in wet or dry weather and the wettest period occurred from 1720 to 1765 throughout the nearly 500 years.[Conclusion] The change of hydrological regime in the basin is the determinant factor of the lake evolution, besides that, the climate change and reclamation of beach also contribute to it. Importantly, the peculiar social value is potentially the virtual reason that is responsible for it.

Abstract:[Objective] The coupling link between the urbanization of Lanzhou City and ecosystem service value was analyzed quantitatively to provide scientific basis for appropriate land use in the process of urbanization in Lanzhou City.[Methods] The ecosystem service value and urbanization level in Lanzhou City were constructed and the entropy method was adopted to standardize the model. A coupled and coordinated model between urbanization and ecosystem service value was established based on the data collected from 2004 to 2014 in Lanzhou City. The relationship between urbanization and ecosystem service value, as well as the land use pattern of urbanization, were analyzed.[Results] (1) The urbanization level of Lanzhou City increased from 0.585 1 in 2004 to 0.659 6 in 2014, with an increment of 0.074 5 in 11 years, and annual rate of 0.006 8. And the overall trend of urbanization was increasing. (2) The value of Lanzhou ecosystem services increased from 8.342 billion yuan in 2004 to 9.502 billion yuan in 2014, with an increment of 1.178 billion yuan, and an average annual rate of 107 million yuan, it also showed an increasing trend.[Conclusion] The coupling relationship between urbanization and ecological service value of Lanzhou City in 2004-2014 was an inverted U shape. The overall coupling coordination degree was in moderate coordination state, and the coordination peak occurred in 2009-2012.

Abstract:[Objective] An extreme rainstorm was occurred in Yulin Region of Shaanxi Province in 26 July, 2017, resulting in very serious flood hazards and economic losses. The aims of this paper were to figure out the hazards of soil erosion in the rainstorm and provide basis for soil and water conservation and rainstorm hazards defenses.[Methods] Three small watersheds (Qingshuigou, Majiagou and Shejiagou) were selected as key investigation areas in Zizhou County (the devastated area in this rainstorm) in 2-6 August, 2017. Soil erosion of slope croplands, forest and grass lands after cropland abandoned, terraces, fields built by filling gullies, check dams and roads were investigated and analyzed.[Results] Rills developed evidently in slope croplands, and even small gullies developed in down slopes. While in forest and grass lands after cropland abandoned in 2000, sheet erosion was dominant and no obvious rills developed. In the new built terraces, the roads connecting two terraces, the field surfaces taking over the runoff from the roads, and the ridge in some sections were washed out seriously, and collapse occurred in the field walls. In fields built by filling gullies, crops and dam bodies were destroyed severely, the roads beside was eclipsed and the cutting walls were collapsed. Check dams were damaged more or less, but block runoff and sediment obviously. The main existing problems were wide spread steep slope farming, lacking storage and drainage systems in small watershed, deficiency in maintenance mechanism of soil and water conservation engineering, lower level of economic development, weak awareness of farmers in soil and water conservation.[Conclusion] Soil erosion under "7·26" extreme rainstorm was still severe, but it is slight in forest and grass lands after cropland abandoned. It suggested that soil and water conservation is still very important. Environmental protection measures should continue to be strengthened, and soil and water conservation, especially steep slope cropland abandonment should be increased in the fragile Loess Plateau of Northern Shaanxi Province. In the meanwhile, it is necessary to design and implement the storage, diversion and drainage network system in small watersheds.