Abstract:[Objective] The objective of this study is to analyze the characteristics of friction wind velocity and aerodynamic roughness over different underlying surface types in order to reveal the wind erosion potential in different underlying surfaces. [Methods] Wind velocity profiles were measured and used to determine friction velocity(u^*) and aerodynamic roughness(z₀) in four different underlying land types in the wind erosion season of 2010—2012. The sensitivity of friction velocity and aerodynamic roughness to wind erosion was analyzed. [Results] The friction velocity and aerodynamic roughness were positively correlated with the canopy height and vegetation coverage. The friction velocity was 0.33, 0.44, 0.61 and 0.81 m/s for the shifting sand dunes, the semi-shifting sand dunes, the fixed sand dunes and the oasis, respectively. While the aerodynamic roughness was 0.39, 13.58, 39.51 and 310.8 mm for the shifting sand dunes, the semi-shifting sand dunes, the fixed sand dunes, and the oasis, respectively. [Conclusion] The shifting sand dunes have the greatest potential for wind erosion, while oases have the least potential for wind erosion.

Abstract:[Objective] The objective of this study is to analyze the effects of different straw mulching treatments on slope runoff and sediment yield in order to provide technical support for soil and water conservation measures in sloping land. [Methods] Simulated rainfall was conducted to assess the effects of straw mulching on slope runoff and sediment yield under different rainfall intensity. [Results] Straw mulch could delay the initial runoff-yielding time, especially under lower rainfall intensity. As the rainfall intensity increased, the differences among all treatments decreased. The initial runoff-yielding time in the lower slope was longer than that in the upper slope. The mean runoff modulus and erosion modulus in the lower slope accounts for 61.57%~69.1% and 14.54%~18.31% of that in the bare land, respectively. The soil loss ratio(SLR) value ranged from 0.022 to 0.611, and in lower slope it accounted for 25% of that in the upper slope. The soil loss ratio decreased with the increase of straw mulching coverage. [Conclusion] Choosing the optimal straw mulching position and coverage can effectively reduce surface runoff and sediment yield, and it is of great importance for soil and water conservation in the Three Gorges reservoir area.

Abstract:[Objective] Longitudinal ridge slope soil erosion process was studied by using non-rige slope as control in order to provide scientific basis for the prevention and control of soil erosion in the northeast mollisol region slope. [Methods] Simulated rainfall experiments were conducted. The experimental treatments included two tillage measures (longitudinal ridge and non-ridge tillage), three rainfall intensities (50, 75 and 100 mm/h) and one slope gradient (5°, which was the critical slope gradient for changing longitudinal ridge to contour cultivation). [Results] Compared with non-ridge tillage, the total runoff rate and total erosion amount of the longitudinal ridge tillage increased by 1.2~1.7 times and 1.3~2.1 times, respectively. The runoff and sediment process also changed. Compared with non-ridge treatment, the concentrated runoff velocity in furrows of the longitudinal ridge increased by 1.0~2.3 times and shear strength increased by 0.7~1.2 times. Consequently, hillslope erosion pattern shifted from sheet erosion dominant to rill erosion dominant, and rill erosion occupied 55.3%~65.6% of total erosion amount at longitudinal ridge treatments. [Conclusion] The increase of runoff velocity and occurrence of rill erosion were two main reasons for the intensification of hillslope erosion at the longitudinal ridge treatment.

Abstract:[Objective] The effect of straw mulching(SM) on topsoil structure and air permeability were investigated to reveal the influences of straw mulching on topsoil physical properties and function in black soil sloping farmland. [Methods] This study was based on a long-term (7 years) field observation experiment of conservation tillage on black soil. Topsoil(0—10 cm) bulk density, porosity, saturated water content, field capacity, soil water stable aggregate and air permeability was analyzed and compared between straw mulching and conventional tillage(CT) field experiments. [Results] (1) The topsoil bulk density, saturated water content and field capacity of SM were higher than that of CT, while the soil total porosity and non-capillary porosity of SM was lower than that of CT.(2) Compared to the CT, topsoil water stable aggregate content (>0.25mm), mean weight diameter and geometric weight diameter in the SM soil was increased the by 10.41%, 45.28% and 22.58%, respectively, while soil air permeability was decreased by 30%. [Conclusion] Continuous 7-year SM improved the topsoil aggregate structure and water retention, but decreased the air permeability in black soil sloping farmland.

Abstract:[Objective] The objective of this study is to analyze the mechanism of water conservation in Phyllostachy pubescens forest in the hilly areas of Southern Jiangsu Province, and reduce the influences of intensive bamboo management on soil and water loss . [Methods] ECH₂O soil moisture content detection system was used to measure the volumetric soil water content (VSWC) at four soil depths (10, 15, 40, 60 cm) in P. pubescens forest in Nanjing Tongshan forest farm. The observed VSWC data (from June 2012 to August 2013) was used to analyze the variability of VSWC under different precipitation intensity. The VSWC curve at different soil depths under different precipitation intensity was made, and lateral flow was proposed to analyze its response to different rainfall conditions (light, moderate and heavy rain). [Results] The VSWC at the depth of 10 and 15 cm changed consistently with the variation of rainfall. The peak value of soil moisture content in the soil depth of 40 and 60 cm was delayed by 0.5 to 1.5 h, The variation amplitude of VSWC decreased from the surface to 40 cm of soil depth under light rainfall condition. The variation amplitude of VSWC increased from the 15 to 60 cm of soil depth under moderate rain and heavy rain conditions, and this trend was more obvious under the heavy rainfall condition. The maximum lateral flow under light, moderate and heavy rainfall condition was 10.17, 60.26 and 95.92 mm, respectively. [Conclusion] As the increase of soil depth, the synchronicity between the VSWC and rainfall declined. Obvious differences in the amplitude of VSWC were existed among different soil layer with different rainfall intensity. Rainfall infiltration was unsaturated infiltration. Lateral flow existed in vertical plane under each rainfall, and they mainly concentrated at 40-60 cm soil depths, and influenced by soil structure and precipitation intensity.

Abstract:[Objective] The objective of this study is to investigate the influence of water delivery process on diversity of the plants in Qingtu Lake in order to provide basis for functional analysis in this region. [Methods] After a four year locating observation, biodiversity index was applied to analyze plant diversity in Qingtu Lake shores. The relationships between plant diversity variation and underground water level were also investigated. [Results] The number of plant species reduced within 200 m range from the water surface, and the maximum reduction occurred at the surface of water while the minimum reduction occurred at 100 m. Shannon-Weiner, Pielou index and Simpson index showed a similar trend, richness and Shannon-Weiner decreased, while Pielou index and Simpson index increased. Simpson index changed greatly, and the spatial variation was greater than the temporal variation. In contrast, the temporal variation of the Cody index was greater than the spatial variation. [Conclusion] Importing water to Qingtu Lake had prompted the spatial distribution of plant species. The water source is centre for the belt distribution of the plant species, and the change increase with the rise of the underground water level.

Abstract:[Objective] The objective of this study is to analyze the composition and characteristics of soil organic carbon in jujube orchard with different planting years in Xinjiang arid area in order to provide a theoretical basis for the sustainable development of the regional fruit industry in this region. [Methods] Taking four different jujube orchards in the southern of Xinjiang Mengaiti County as the object, the total organic carbon, soil active organic carbon, organic carbon density and carbon activity in the orchard with different planting years were analyzed. [Results] With the increase of planting years, the content of soil organic carbon increased initially and then decreased. The content of soil organic carbon was the maximum at the surface of the soil, and it decreased with increasing soil depths. In contrast, soil organic carbon density decreased initially and then increased with the increase of planting years. Soil organic carbon stocks mostly concentrated in surface soil, and with the increasing planting period, it increased initially, reached the maximum at 10 a, and then decreased. Similarly, soil carbon pool activity also showed a decreasing trend initially and then increased with the increase of planting years. [Conclusion] The content of soil organic carbon in the study area increased with the increase of the planting years, and the accumulation of soil carbon pool was different in various planting years. The activity of soil carbon pool at different layer increased initially and then decreased.

Abstract:[Objective] To clarify the water holding capacity of forest litters of 5 different forest types (Cupressus funebris, Pinus armandii+Cunninghamia lanceolata, Cyclobalanopsis glauca+ Pinus yunnanensis, Eucalyptus robusta, C. lanceolata) in Feibai reservoir area in Mengzi City of Yunan Province in order to provide theoretical basis for constructing the forest of water and soil conservation, and for constructing the forest of conservation of water supply in the study area. [Methods] We used the quadrat sampling method, oven drying method and soaking method to determine the litter preservation, water holding capacity, water absorption rate and water interception. [Results] The litter amount in different forests followed an order of C. lanceolata(9.48 t/hm²)> P. armandii+ C. lanceolata(7.09 t/hm²)> C. funebris(7.02 t/hm²)> C. glauca+ P. yunnanensis(6.13 t/hm²)> E. robusta(3.20 t/hm²);The maximum water holding volume of different forests litters ranged from 7.85 to 13.91 t/hm², the maximum water holding rate ranged from 165.85% to 242.45%, and the maximum interception amount and the effective interception amount ranged from 7.48 to 12.62 t/hm² and 6.53 to 11.03 t/hm² respectively. The relationships between water-holding rate and immersion time in 5 different forest types were significantly fitted by logarithmic equation. The relationships between water absorption speed rate and soaking time could be described by power function. [Conclusion] The comprehensive analysis of water holding capacity of 5 different species indicated that Eucalyptus has a higher water-holding capacity and is more beneficial to the water conservation.

Abstract:[Objective] The objective of this study is to evaluate the effects of "soil and water conservation project" and "grain for green project" in Wuding river basin during 2000—2013 in order to provide data support for ecological rehabilitation project in this region. [Methods] By using linear regression, correlation and partial correlation, this paper analyzed the variations of NDVI and NPP and its driving factors in Wuding river basin during 2000—2013. [Results] (1) From 2000 to 2013, the growth rate of vegetation cover was 3.39%/a in the study area, which was faster than that in Loess Plateau (0.99%/a) from 1999 to 2008. The vegetation cover showed periodical characteristics, with two sustainable growth periods. (2) The vegetation cover was significantly increased in most area, especially the area distributed in the loess hilly-gully region in the southeast of the study area. The degradation area only accounted for 3.95%, and distributed on the both sides of the valley. (3) From 2000 to 2013, the accumulative total carbon sequestration was 1.96×10⁷ t, which equated to 22.82% of carbon emissions from energy consumption in Shaanxi Province in 2010. The value of accumulative carbon sequestration was 2.36×10¹⁰ CNY, which equated to 2.33% of GDP in Shaanxi Province in 2010. [Conclusion] Human activity was the main driving force that influence the changes of vegetation cover and carbon sequestration, especially the implementation of "soil and water conservation project" and "grain for green project".

Abstract:[Objective] We aimed to study the spatial characteristics of arable layer soil nutrient elements in the arid desert-oasis region in order to provide the theoretical basis for the rational development and utilization of land resources in oasis. [Methods] Based on the methods of GIS and geo-statistics, the spatial variation of the soil nutrient in arable layer and its driving factors were analyzed in Jinghe County, Xinjiang Uygur Autonomous Region. [Results] (1) The coefficient of variation(C_v) of effective phosphorus was the greatest (C_v was 67.45%), while the spatial variability of rapidly-available potassium was the least(C_v was 40.76%). (2) Organic matter, alkali-hydro nitrogen and effective phosphorus showed a strong spatial autocorrelation, and the spatial variability was mainly caused by structural factors such as terrain, soil texture and soil type. Rapidly-available potassium showed a moderate spatial auto-correlation. The spatial variability of rapidly-available potassium was not only affected by the structural factors, but also by the random factors such as fertilization and the planting structure. (3) The soil nutrient elements in the central area of Jinghe County oasis showed a patchy distribution, while in the outer of oasis, the content of soil nutrient elements was relatively low, and it showed a sheet distribution. [Conclusion] Organic matter is lacing, while phosphate and potash fertilizer is abundant in the arable layer soil in Jinghe County.

Abstract:[Objective] The objective of this study is to analyze the impacts of contour reverse-slope on the spatial distribution of soil moisture in sloping farmland during rain season serious in order to provide theoretical basis for the improvement of the contour reverse-slope in water source area of Songhuaba reservoir in Kunming City. [Methods] We set up contour reverse-slope in the sloping farmland in Yizhe valley, and observed the soil moisture content at different soil depth in different positions of slope during different periods. [Results] Soil moisture content in contour reverse-slope maintained at stable level after 2 rainy days. At the upper reverse-slope, it reduced by 2.71%. In contrast, soil moisture changed greatly in different positions of slope. Soil moisture at upslope reduced by 9.04%, while at the middle slope, reduced by 10.41%. [Conclusion] Contour reverse-slope can retain soil surface runoff and moisture, and influence the distribution of soil moister in 20—40 cm depths of soil layer.

Abstract:[Objective] The objective of this study is to explorer soil respiration features and its responds to soil temperature and soil moisture under different vegetation in order to provide references for the accurate estimation of payment changes and balance of soil organic carbon. [Methods] Soil respiration rate(R_s) of four typical succession communities including grassland, thin shrub-grassland, shrub land and forest land were observed by using LI-8100 soil carbon flux measurement system to investigate the influences of soil temperature(T) and soil moisture(W) on soil respiration in typical karst regions of Guizhou Province. [Results] (1) The seasonal variations of soil respiration rate of four vegetation types showed a similar unimodal distribution, with the peak occurred in summer and depression occurred in winter. The range of soil respiration rate in four vegetation types was 0.73~1.21,1.20~1.48,1.54~2.41 and 1.86~2.95 μmol/(m²·s), respectively. The average soil respiration rate was 1.65, 2.76, 2.45 and 3.43 μmol/(m²·s) in the observation period. (2) Univariate model indicated that soil temperature and moisture could explain soil respiration variation by 72.37% and 43.9%, respectively. Double factor model suggested that soil temperature and moisture together could explain 81.5%~91.2% of the seasonal variations in R_s. (3) The temperature dependence of soil respiration (Q₁₀) has been widely used in estimating soil respiration rate. Soil temperature and moisture were both negatively correlated to Q₁₀ of four vegetation types. [Conclusion] Soil temperature and moisture together influenced soil respiration rate and Q₁₀ values, and when the soil moisture was too high or too low, the effect of temperature was weakened, and the effect of the soil moisture reinforce.

Abstract:[Objective] The object of this study is to investigate the variation trend of crop water requirement and its correlation with climatic factors, so as to provide references for decision making in crop irrigation and drainage. [Methods] The crop water requirement and irrigation requirement of winter wheat in Shihezi region were calculated based on evapotranspiration calculation approach recommended by United Nations FAO and crop coefficient from 1961 to 2012. The variation trend and its climatic causes were analyzed for the crop water requirement and irrigation of winter wheat. [Results] (1) The crop water requirement of winter wheat showed a significant decreasing trend, and the greatest increase occurred at the overwintering and turning green stage with a rate of 2.65 mm/10 a. Winter wheat required the most water at the jointing to heading stage (130.23 mm). (2) In contrast, irrigation water requirement of winter wheat at different growth stages showed a decreasing trend with a rate of -3.11 mm/10 a. The irrigation water requirement of winter wheat was the most at the jointing to heading stage (88.65 mm). (3) Climatic factors such as precipitation, temperature, relative humid, sunshine duration, water pressure, wind speed, showed a strong correlation with the crop water requirement and irrigation requirement of winter wheat. Extremely significant correlation was found between precipitation and the crop water requirement and irrigation requirement of winter wheat. [Conclusion] Although water requirement of winter wheat increased during the past 52 years, the irrigation requirement of winter wheat showed a decreasing trend, which caused by the increase of precipitation.

Abstract:[Objective] The objective of the paper is to investigate the plant community diversity in Periglacial Landform of Mount Laotudingzi in order to provide the scientific basis for plant protection in this area. [Methods] Based on the data collected from 48 sample plots, we used species richness index and α diversity index to analyze the species diversity of the plant communities in rock stream, rock block field and rock glacier slope of Mount Laotudingzi. We also analyzed the related envitonmental factors. [Results] (1) Plant communities can be divided into 16 forest formations and 6 bushy formations belonging to 6 vegetation types which were broadleaved deciduous forest, theropencedrymion, dark coniferous forest, elfin forest, bush wood and meadow thicket. Of them, the theropencedrymion, broadleaved deciduous forest and dark coniferous forest mainly distributed in landform of rock stream; The bush wood and meadow thicket, the theropencedrymion and elfin forest mainly distributed in landform of rock block fields. The theropencedrymion, broadleaved deciduous forest, bush wood, elfin forest mainly distributed in landform of rock glacier side. Among 22 formations, some were distributed very locally, some may occur in all three habitats.(2) The value of comprehensive biodiversity index of plant community was: rock stream> rock glacier slop > rock block field; The value of biodiversity index of tree layer and shrub layer was also: rock stream> rock glacier slop > rock block field; The value of biodiversity index of herb layer was: rock block field> rock glacier slop > rock stream; (3) Species diversity was significantly different between different vegetation types;(4) Among the topographic factors, the altitude had the greatest impact on species diversity index, and the diversity index of shrub layer was the least sensitive to the elevation change. [Conclusion] The study area has relative high diversity, altitude is the dominant factor affecting the diversity pattern.

Abstract:[Objective] The objective of this study is to analyze the impacts of land use change on the hydrological process in the Hongru river basin in order to provide the basis and reference for the rational planning and utilization of local water resources. [Methods] Various scenarios of land use change were designed to simulate the hydrological process in Hongru river watershed based on SWAT(soil and water assessment tool) model. DEM(digital elevation model), land use data, soil data, daily meteorological data were used as the input to establish the SWAT model. Observation data from 2006 to 2008 were used to calibrate and analyze the sensitivity and uncertainty of the established model. Four land use scenarios(S₁: conversion of degraded farmland into forest; S₂: increase farmland; S₃: increase urban land; S₄: increase urban land, forest, and grassland) were set up for hydrological modeling. [Results] The runoff was expected to decrease by 4.23 % in S₁, while it was expected to increase by 3.01% in S₂, 4.91% in S₃ and 1.50 % in S₄. [Conclusion] Returning cultivated land to forest and grassland can reduce the runoff, while reclamation or urbanization will increase the runoff.

Abstract:[Objective] We aimed to study the effects of slope on soil pH value, carbon, nitrogen, phosphorus content in sandy land in order to reveal the variation of soil nutrients under different micro-topographical conditions, and provide a theoretical reference for environmental construction in sandy land. [Methods] The plots were selected from sandy land in Inner Mongolia grassland ecosystem research station(IMGERS). The effects of micro-topographical position on pH value, carbon, nitrogen and phosphorus content of soil were investigated. [Results] The pH values in different micro-topographical position showed as: sunny slope > slope base > shady slope > top of slope; The organic carbon content average showed as: slope base > shady slope > sunny slope > top of slope; The content of phosphorus showed as: slope base > shady slope > top of slope > sunny slope. Nitrogen content at the slope base and shady slope was higher than that at the top and sunny slope. [Conclusion] The variable coefficient of pH value, nitrogen, phosphorus content at top and sunny slope was higher than that at the base and shady slope. The variable coefficient of soil nutrient varied significantly among different micro-topographical positions.

Abstract:[Objective] The source area of Fenhe river is one of the most important water source area in Shanxi Province, but soil erosion in this area is severe. The objective of this study is to investigate the spatio-temporal variations of soil erosion in order to provide basis for soil and water conservation in this region. [Methods] We used the SPOT images(September in 2004 and 2009) as data sources, explored the spatio-temporal variations of soil erosion in the source area of Fenhe river based on GIS and USLE. The spatial autocorrelation of soil erosion in 2009 was analyzed by using GeoDa software. [Results] (1) The modulus of soil erosion showed an increasing trend from 2004 to 2009 in the source area of Fenhe river. The eroded land above moderate erosion increased as well, especially, the strong erosion and the severe erosion; (2) Spatially, severe soil erosion distributed in the southeast of the area, while slight soil erosion distributed in the northwest of the area; (3) Rainfall and vegetation cover were the most important factors that influence soil erosion in the area; (4) Except for the slight and severe erosion, the area transformed from the low to high level soil erosion was much larger than the area transformed from the high to low level soil erosion; (5) Spatial autocorrelation analysis revealed that soil erosion in the study area was spatially positive autocorrelated and spatial concentrated. [Conclusion] Soil erosion intensified continuously in the source area of Fenhe river, and soil erosion regulation should be strengthened.

Abstract:[Objective] The objective of this study is to analyze the spatial and temporal changes of vegetation NPP(net primary productivity) and carbon fixation and oxygen release in the three-river headwater region during the past 14 years in order to provide scientific basis for the ecological sustainable development in this area. [Methods] NDVI, meteorological data, the land-use data and the remote sensing data were collected. The spatial and temporal variations in NPP and amounts of carbon fixation and oxygen release were analyzed based on CASA model, carbon emissions model and Sen+Mann-Kendall model. [Results] (1) The mean value of NPP was ranged from 0 to 750 g/(m²·a), which accounted for 81.72% of the entire study area. The spatial distribution of average NPP presented a decreasing trend from southeast to northwest. And NPP in the lower altitude, rivers and dense woodland areas was higher than that in the alpine regions, which indicated that NPP was affected by altitude, rivers and land types. (2) The NPP showed an increasing trend in recent 14 years, with a growth rate of 7.26 g/(m²·a)(p>0.05). As to the inter-annual variation of NPP, about 23.64% of the study area showed a decreasing trend (2.3% of them p<0.05) while 76.36% showed an increasing trend (30.58% of them p<0.05). (3) As to the variation of carbon fixation and oxygen release, the cultivated land was larger than the forest land and other land use types. Variation of carbon fixation and oxygen release in forage land was small. [Conclusion] The alpine grassland ecosystem in the three-river headwater region was good, as it was less influenced by human beings. However, ecosystem in the low altitude, river and human activities intensive areas was complex and the locally degraded, and ecological environment in those regions need to be protected.

Abstract:[Objective] We aimed to analyze the relationships between soil properties and saturated hydraulic conductivity and altitude in order to provide the reference for soil properties and spatial heterogeneity of soil water proerties in the study area. [Methods] The ring knife was used to collect soil samples in six different sampling plot in Jiufeng low altitude area of Beijing City. Soil properties were analyzed and water penetration was surveyed. [Results] No significant correlation have been found between soil bulk density, total porosity and 0.25 water stable aggregates and altitude. The soil water content and gravel content showed a significant correlation with altitude. Soil water content increased while gravel content decreased with the increase of altitude. There was a significant correlation between high pore density and saturated hydraulic conductivity and altitude. In the 0—20 cm soil layer, macropore density and water conductivity increased with the increase of altitude. In 30—60 cm soil layers, macropore density and water conductivity decreased with the increase of altitude. [Conclusion] The effects of altitude on soil structure and water transport capacity is odvious, it should not be ignored in the future studies.

Abstract:[Objective] The aim of this study is to explore the variation characteristics of the micro-topography during the splash erosion under the rainfall intensity of 60 mm/h in order to provide the scientific basis for layout of the soil and water conservation farming pattern in loess slope land. [Methods] Four common tillage treatments (artificial backhoe, artificial digging, contour tillage and rake wear leveling) were prepared in the loess region. Artificial rainfall, laser scanning and GIS technology were adopted to generate high precision M-ΔDEM which can reflect the real variation of tillage slopes. [Results] Different tillage slopes showed low spatial variability, and its spatial pattern was mainly affected by tillage measures rather than rainfall. The rainfall in splash erosion had a general flattening effect on the micro-topography, and different tillage slopes showed an erosion balance within the scale of 1~1.3 m. Micro-topography has strong retarding effect on the splash erosion. The artificial digging and contouring tillage had a better soil and water conservation effect. [Conclusion] Micro-topographic stream with its fractal dimension can well reflect the complex characteristic of micro-topographic, and tillage treatments control the spatial and temporal variation of micro-topographic during splash erosion process.

Abstract:[Objective] Dynamic monitoring and evaluation of soil and water loss in China is the fundamental work for soil and water conservation. The goal of studying the method, technology and organization of dynamic monitoring is to improve the scientific validity of dynamic monitoring and evaluation. [Methods] Based on the analysis of current dynamic monitoring, this paper proposed the countermeasures to promote dynamic monitoring of soil and water loss scientifically. [Results] To improve the dynamic monitoring of soil erosion in China, we should focus more on the establishment of dynamic monitoring system at spatial scale, reasonable working system, scientific and convenient dynamic monitoring and evaluation system and unified technology system of dynamic monitoring. [Conclusion] To satisfy the requirements of the national water and soil conservation and ecological civilization construction and macro decision-making, further improvements in dynamic monitoring and evaluation of soil erosion is needed in China. It also can provide basis for government decision-making, economic and social development.

Abstract:[Objective] We aimed to use the existed laboratory test data in order to establish the coefficient of collapsibility prediction model based on the mechanism of loess collapsibility and data mining method. [Methods] The loess soil located at middle of the Loess Plateau was taken as the case study. Based on the results from in-situ immersion test and laboratory test conducted in this region, the test data were divided in to 7 classes according to their physical significance. Scatter diagrams with coefficient of collapsibility were then plotted. From these scatter diagrams, the relationships between loess collapsibility and each single physical-mechanical parameter were investigated. The correlations between all parameters and the coefficient of collapsibility were analyzed by partial correlation analysis. [Results] Plastic limit, liquid limit and plastic index were eliminated from the model due to the low correlation. The correlation coefficient from the highest to the lowest was: saturation, dry density, void ratio, soil depth, compression modulus and grain size from 5 to 15μm. We then used the data in RBF neural network in Matlab software to establish the prediction model of the collapsibility coefficient, which was based on the mechanism of collapsibility loess, parameter selection more comprehensive, modeling method more scientific. [Conclusion] The established model can predict the coefficient of collapsibility with low error value, which meets the requirement of the engineering application. The result of this research is of great importance to understand the collapsibility mechanism of loess soil.

Abstract:[Objective] To analyze the depth and distribution of karst soil in order to provide theoretical basis for using ground penetrating radar(GPR) in the research on soil distribution in karst peak-cluster depression area. [Methods] Through laboratory simulation experiment, this study established the relationship between GPR velocity of electromagnetic wave and soil water content in three types of soil texture(sandy clay loam, clay loam, silty clay) in karst region. Through the field measurement of soil texture and water content, the GPR image was calibrated and interpreted based on the right formula. Then the soil depth was estimated and verified by excavation. [Results] We found the theoretical models of cubic polynomial relationship between electromagnetic wave velocity(ν) and soil water content(θ) for the three soil textures. It showed that soil depth in the field was consistent with the results estimated with theoretical model, and the error range was 0—10 cm. The 2-dimension images reflecting soil depths in the different location under the survey line and the 3-dimension images reflecting soil depths distribution in the quadrant were generated using GPR software. Soil mainly distributed within the depth of 50 cm. [Conclusion] GPR technology was feasible to detect the depths and distribution of discontinuous soil in karst region.

Abstract:[Objective] The objective of this article is to reveal the spatial heterogeneity of the driving forces of per capita cultivated land area change in middle reaches of the Yangtze River based on geographically weighted regression(GWR) model in order to provide basis for the management of cultivated land resources in this area. [Methods] By investigating the current situation of cultivated land area per capita in this area, the Moran's I index of cultivated land area per capita was analyzed. A comparison was made between ordinary least squares(OLS) and GWR by using the relevant data. Based on GWR, a regression analysis on the influencing factors of cultivated land area per capita was analyzed in each city. [Results] (1) The influence of urbanization ratio on cultivated land area per capita varied from positive to negative correlations, with an enhancing influence degree and obvious spatial differences. (2) The growth rate of population and the per capita cultivated land area showed negative correlations in most areas, while they showed positive correlations in local areas, with a decreasing influence degree and large spatial difference. (3) In most areas, the proportion of the gross output of the first industry and cultivated land area per capita were positively correlated, while they were negative correlated in local areas, with a decreasing influence degree and large spatial difference. (4) The influence of grain yield per unit area on cultivated land area per capita changed from negative to positive correlations, with an enhancing influence degree. [Conclusion] The research shows that GWR is better than OLS in reflecting the spatial heterogeneity of the driving factors, and the results of GWR clearly reveal that different factors bring different degree of effect on cultivated land area per capita in different areas.

Abstract:[Objective] To assess the benefits of comprehensive management and provide support for government policy making. [Methods] The concept of DPSIR model was introduced into the eco-environment benefit evaluation index system. AHP-entropy and TOPSIS method was used to evaluate the eco-environment benefit of the comprehensive management in ten tributaries in Inner Mongolia section of the Yellow River. [Results] Value of the integrated management in ten tributaries from highest to lowest was: Hantaichuang > Xiliugou > Hashilachuang > Husitaihe > Maobula > Muhaerhe > Dongliugou > Boergasetaigou > Heilaigou > Haoqinghe. The comprehensive effect index was high in the middle, but low in both sides. Hantaichuan was class Ⅱ, while the other tributaries was class Ⅳ, and the comprehensive management in this region was poor. [Conclusion] The internal structure of the DPSIR-TOPSIS model was clear, and it well explained the intrinsic link between watershed comprehensive management engineering and environment-economy-society system. This study provides a new method for assessing the eco-environment benefit of comprehensive management.

Abstract:[Objective] The objective of the research is to study the key factors that influence the water resource carrying capacity in Guiyang City of Guizhou Province in order to provide basis for the sustainable development of water resources and soci-economy in the city. [Methods] Taking Guiyang City as a case study, the water resources system was divided into three subsystems including water resource, ecological environment and soci-economic subsystems. Evaluation indices were selected and multilevel fuzzy comprehensive evaluation model was established. [Results] The result showed that water resources carrying capacity improved continuously from 2003 to 2013, which contributed to the socio-economic development in Guiyang City. The evaluation index of water resource subsystem fluctuated, and decreased slightly during the study years. The evaluation index of ecological environment subsystem increased significantly, while the evaluation index of socio-economic subsystem decreased dramatically. [Conclusion] The contribution of water resources subsystems to water resources carrying capacity has decreased. The improvement of ecological environment is the main driver of the increasing water resources carrying capacity, while the socio-economic subsystem is the main obstruction of water resources carrying capacity.

Abstract:[Objective] The paper is to study the compensation for farmland preservation in Jiangsu Province based on the breakeven funds in order to provide support for cultivated land protection. [Methods] We attempted to introduce the non-market value into zoning farmland compensation. Based on compensation standard, farmland demand was adjusted. We also measured the compensation funds when farmland deficits or surplus funds are breakeven in different regions . [Results] (1) The standard of regional compensation for farmland preservation in Jiangsu Province was 5.685 yuan/(m²·a) in 2010, including economic, social and ecological value. The cities could be classified into five cultivated land deficits zones and eight surplus zones, and the land deficits zones should pay 3.78×10¹⁰ yuan to the land surplus zones when funds were breakeven. (2) In general, most of the developed regions were cultivated land deficits zones, while most of the developing regions were cultivated land surplus zones. [Conclusion] It is necessary to establish the regional compensation mechanism for farmland preservation, enhance the incentive mechanism and plan rationally in China.

Abstract:[Objective] The objective of this study is to analyze the variations of soil pH value and surface charge under salt stress, and its influences on the structure of soil water-stable aggregates in order to provide basis for the soil amelioration in horticulture and vegetable garden. [Methods] The laboratory incubation experiment was applied to investigate the effects of salt accumulation on pH value, electrochemical properties and water-stable aggregates of yellow cinnamon soil in the surrounding area of Hefei City. Four salinity treatments(0.3%, 0.6%, 0.9%, 1.2%) and a control treatment(CK) were set up and incubated for 60 d at 25 ℃ in incubator. The samples were then collected from the incubator at 10 d, 30 d and 60 d separately, for the following analysis. [Results] Soil pH value decreased with the increase of salt concentration. Compared to CK, soil pH value of the sample incubated after 60 d decreased by 0.53 at 1.2% salinity level. The amount of soil negative charge decreased with the increase of salt concentration, while there was no significant change in positive charge. The simulated salt with Ca²⁺, Mg²⁺ improved the cementation of micro-aggregates, and resulted in an increase of the amount of macro-aggregates. [Conclusion] Salt can decrease soil pH value and soil negative charge, and improve soil cementation, and also increase the amount of micro-aggregates.

Abstract:[Objective] The influences of soil bulk density on point source infiltration in gravel-sand mulched field were studied in order to provide basis for the development of drip irrigation technique in sandy area. [Methods] Bare land(no vegetation and sand mulch) was selected as the contrast group(CK). Based on laboratory simulation experiment, this article studied the influences of different soil bulk density(1.23 g/cm³, 1.38 g/cm³, 1.53 g/cm³) on point source infiltration pattern in gravel-sand with different planting years(new gravel-sand mulched field, middle gravel-sand mulched field, old gravel-sand mulched field). [Results] The point source vertical cumulative infiltration showed a negative correlation with soil bulk density and planting years. Soil bulk density showed no significant effect on the infiltration depth in the initial period of infiltration. While infiltration depth were significantly influenced by the density as the infiltration reached the soil, and bulk density decreased with the increase of infiltration depths. Horizontal infiltration distance of CK increased with the increase of soil bulk density, while the change of horizon infiltration of gravel-sand mulched field was not obvious. The moist body aspect ratio was represented with λ, the λ of CK and sand mulch soil decreased with the increase of soil bulk density. When sand mulch soil bulk density was constant, λ decreased with the increase of planting years. The λ of CK increased with the increase of infiltration time in the initial days of infiltration and then became stable. The λ of sand mulch soil increased significantly with the increase of infiltration time in the initial minutes of infiltration, while it decreased when infiltration reached the soil, and the increase of λ was not obvious in the late minutes. [Conclusion] Gravel-sand mulch promote the vertical cumulative infiltration of soil moisture, and point source vertical cumulative infiltration show a negative correlation with soil bulk density and planting years.

Abstract:[Objective] The objective of this study is to analyze the influences of N addition on population characteristics and reproduction strategies of Bothriochloa ischaemum population in order to assess the impact of N deposition on the ecological environment. [Methods] This study was conducted to investigate the responses of population characteristics and reproduction strategies of B. ischaemum population to N addition based on four N addition treatments, including control CK(0 g/(m²·a)), low nitrogen (2.5 g/(m²·a)), middle nitrogen (5.0 g/(m²·a)) and high nitrogen (10.0 g/(m²·a)) for two years. [Results] (1) The N addition significantly increased the height and biomass of B. ischaemum population, population biomass reached the maximum with middle nitrogen treatment. (2) N addition had changed the nutrient allocation strategies of B. ischaemum. Root-shoot ratio decreased with the increments of N addition. (3) N addition promoted sexual reproduction and vegetative propagation of B. ischaemum population, enabled its high ability of breeding and competition. [Conclusion] Moderate N sedimentation or N addition (<5 g/(m²·a)) can promote the growth and development of B. ischaemum population, and improve its ecological function in soil and water conservation.

Abstract:[Objective] In order to prevent the seepage problems in reservoir and cofferdams in lots of overhead structures, the paper try to use a new controllable clay composite paste in strata with following water. [Methods] An experiment was designed to study the effect of a new type of compound paste with a new admixture, which has low fluidity, controllable condensing time, good water resistance and water release, on the anti-leakage and sealing process in the soil strata with flowing water. [Results] The content of curing agent and quick condensing agent in the paste has a significant effect on its resistance to water flow, the initial condensing time and the flow rate. Adjusting the content of curing agent and quick condensing agent could effectively change the physical and mechanical properties of the composite paste, thus meet the engineering requirements. [Conclusion] This kind of controllable clay can be used to deal with the leakage problems in the dynamic water stratum with strong permeable sandy pebbles and effectively improve the seepage-proofing ability of the reservoir.

Abstract:[Objective] The objective of this paper is to study the effect of mulching with straws of four cadmium tolerant species on heavy metal accumulation of accumulator in order to select cadmium tolerant species which can promote the growth cadmium accumulation of Capsella bursa-pastoris. [Methods] A pot experiment was conducted to study the effects of mulching with straws of four cadmium tolerant species (Ranunculus sieboldii, Mazus japonicus, Clinopodium confine and Plantago asiatica) on growth and cadmium accumulation of Capsella bursa-pastoris in Cd-contaminated soil. [Results] The soil mulching with R. sieboldii, M. japonicus, C. confine and P. asiatica straws reduced the shoot biomass, total biomass and leaf SPAD value of C. bursa-pastoris compared with control. Compared with control, the soil mulching with R. sieboldii, M. japonicus, C. confine and P. asiatica straws reduced the whole biomass of C. bursa-pastoris by 37.61%, 52.14%, 43.76% and 21.71% respectively. Only C. confine straw increased the cadmium content in root of C. bursa-pastoris, and R. sieboldii and M. japonicus straws increased the cadmium content in shoot of C. bursa-pastoris by 18.61% and 12.87% respectively. The cadmium exactions in root, shoot and whole plant of C. bursa-pastoris decreased when mulched with four cadmium tolerant plant straws. [Conclusion] The soil mulching with four cadmium tolerant plant (Ranunculus sieboldii, Mazus japonicus, Clinopodium confine and Plantago asiatica) straws cannot enhance the ability of Capsella bursa-pastoris to remedy cadmium contaminated soil under pot experiment conditions.

Abstract:[Objective] The object of this study is to reveal the effects of whole film casing mode bunch on soil microbial number and microbial biomass in dryland in order to provide basis for its popularization and application. [Methods] The field experiment was carried out to study the effects of different mulching methods on soil microbial number and microbial biomass at different growing periods of winter wheat. [Results] The whole film casing mode bunch increased soil microbial number and microbial biomass significantly in different growing periods of winter wheat. Compared with traditional planting methods, the whole film casing mode bunch(M₁) increased the amount of soil bacteria, actinomyces, fungi, ammonifier nitrobacteria and soil microbial biomass C and N by 32.07%, 31.27%, 44.56%, 32.54%, 79.20%, 29.90% and 29.41%, respectively. While the whole film without overburden bunch(M₂) increased the amount of soil bacteria, actinomyces, fungi, ammonifier, nitrobacteria and soil microbial biomass C and N by 10.23%, 10.57%, 26.51%, 37.85%, 107.22%, 20.68% and 18.02%, respectively. The amount of soil microbes and microbial biomass started to rise at the regreening stage, reached the peak at jointing or heading stage, and then decreased slightly at the later stage of growth in all treatments. [Conclusion] The amount of soil microbes and microbial biomass decreased with the increase of soil depths in the whole film casing mode bunch. Therefore, the whole film casing mode bunch could improve soil microbial number and microbial biomass.

Abstract:[Objective] To design the soil-electric-acoustic sand table model in order to provide a more intuitive dynamic demonstration model for soil and water conservation education. [Methods] Based on the characteristics of a small watershed, the type of soil erosion, and soil and water conservation measures were demonstrated with the light, electricity and sound system. The soil erosion intensity, the soil and water conservation measures and the monitoring of soil and water conservation were demonstrated with the aid of the miniature artificial rainfall system. [Results] The soil-electronic sand table model was actually a simplified small watershed, which was divided into 12 large demonstration areas. The model focused on the expression of topography, terrain and geographical characteristics of natural elements. It could demonstrated the watershed boundary and its relations with adjacent watersheds, the basic elements of watershed system, biological and engineering measures for soil and water conservation, hydrological network system composition and concentration process. [Conclusion] The soil-electronic-acoustic model could provide an emulative, interesting, experience, autonomic and interactive model for soil and water conservation teaching, and could enhance the students' learning interest and initiative, and improve the teaching effect.

Abstract:[Objective] The objective of this study is to improve the RUSLE (revised universal soil loss equation) model for its using in the southern red soil area in order to provide scientific basis for soil erosion control in Changting County of Fujian Province. [Methods] Based on RUSLE model and combined with GIS and RS technologies, we assessed the soil and water loss in Changting County. The rainfall erosion factors were calculated by a new developed method. The remaining factors that were used in RUSLE model were derived by improving or using the existing methods. [Results] A map of soil erosion intensity grades distribution in 2013 was obtained by an empirical research. The results show that soil erosion in Changting County has been improved in 2013, but still serious. The dominated types of erosion were slight and moderate loss. The area most affected by soil erosion was Hetian, Cewu, Zhuotian and Sanzhou Township. [Conclusion] To reduce the human activities and increase the vegetation coverage are the main effective measures for erosion control in the future.

Abstract:[Objective] The objective of this study is to analyze the precipitation and soil conditions of the plants in the west section of the second west-east natural gas transmission pipeline project, in order to select the suitable grass species for the pipeline soil and water conservation. [Methods] Based on in-situ monitoring, we investigated the influences of soil property change due to disturbance, natural rainfall, soil and other natural conditions on the restoration of artificial vegetation. [Results] Medicago sativa, Agropyron cristatum, Achnatherum splendens and Melilotus suaveolens were selected as the optimal plant species for pipeline soil and water conservation. The growth and development of these four species was monitored in different construction regions. [Conclusion] To select the suitable plant species for soil and water conservation is of great importance for the soil loss control and pipeline security.

Abstract:[Objective] This study aims to verify variation of vegetation net primary productivity(NPP) in Shaanxi Province in recent years in order to evaluate vegetation growing conditions. [Methods] Based on the Carnegie Ames Stanford approach(CASA) model, this study estimated the monthly NPP from 2003 to 2012 in Shaanxi Province. The annual and inter-annual variation of NPP were analyzed at both spatial and temporal scale. [Results] (1) The NPP in Shaanxi Province showed an increasing trend and increased (p<0.01) at a rate of 3.940 6 g/(m²·a). The total annual NPP increased from 84.44 Tg (1 Tg=1 012 g) in 2003 to 91.98 Tg in 2012(in terms of carbon content). (2) The NPP varied greatly in different seasons. The highest NPP occurred in summer, which accounted for 52.43% of the total NPP, and NPP in July, August accounted for 18.52%, 18.41% respectively. NPP in March or August increased significantly or extremely significantly, while no significant change of NPP was found in the other months. (3) Annual variation of NPP for different vegetation types was comparatively stable, and showed an increasing tendency except the permanent wetlands. The fastest increase of NPP was crop land (p<0.01), with an average annual increment rate of 5.89 g/(m²·a). (4) The NPP in Southern Shaanxi was higher than the northern, 78.53% of the area showed a growing trend in NPP, and 24.47% of the area increased significant or extremely significant. Only 2.27% of the area showed a significantly or extremely significantly decreasing trend in NPP, those areas were mainly distributed in the central Shaanxi Province and surrounding area of Xi'an City. [Conclusion] The vegetation growing conditions in Shaanxi Province was generally improved, but the local region were deteriorating.

Abstract:[Objective] The objective of this study is to explore the ways for reducing the leaching loss of speciel fertilizer for rubber tree in order to provide reference for increasing the efficiency of speciel fertilizer for rubber tree utilization. [Methods] An intermittent soil column leaching experiment was conducted by adding water-retaining agent to speciel fertilizer for rubber tree, and the rainfall in the third fertilizer application-period(September) in each year was simulated. Three water-retaining agents including carboxyl methyl cellulose(CMC), polyacrylamide(PAM) and sodium polyacrylate(PAA) were selected. The effects of water-retaining agents on releasing characteristics and leaching losses of nitrogen and potassium from speciel fertilizers for rubber trees were explored to choose the proper application ratio of water-retaining agent and speciel fertilizer for rubber tree. [Results] All the 3 water-retaining agents showed inhibiting effects on leaching losses of nitrogen and potassium from speciel fertilizer for rubber tree. PAM had the best inhibiting effect at a dosage of 6%, and the relative for nitrogen and potassium losses in the first leaching was 44.73% and 57.16%, respectively. Compared to the control treatment, accumulated leaching losses of nitrogen and potassium was decreased by 20.20% and 14.87%, respectively. [Conclusion] Leaching losses of nitrogen and potassium from speciel fertilizer for rubber tree can be reduced by adding water-retaining agent to specific rubber fertilizer.

Abstract:[Objective] By studying the ecological effects of shelter forest construction of Taihu Lake levee, we aimed to provide technical support for future shelter belts construction and environmental improvement in this region. [Methods] The shelter forested lands and farmlands at Yixing City were chosen as the test plots. Field survey was conducted and soil samples were collected. Soil conditions, plant diversity and surface runoff was investigated to analyze the heterogeneity of soil properties and biodiversity. [Results] The results showed that, with the construction of the ecological shelter forests, soil permeability was improved, surface runoff was reduced and plant species diversity was enhanced. [Conclusion] The construction of ecological shelter forests can improve the regional environment, enhance soil status, and increase biodiversity in Taihu basin, and is the effective ecological measure for the environment comprehensive treatment in Taihu Lakebasin.

Abstract:[Objective] The objective of this study is to analyze the anti-erosion effect of vegetation and provide the theoretical basis for sand control measures in Kara Bailey project area of Xinjiang Wei Autonomous Region. [Methods] Plants in the study area were investigated, and the data of vegetation cover, crown width, height and characteristics of sand accumulated by pants were collected. The SPSS software was employed for statistical analysis, and regression curves were used to establish the model to quantitatively analyze the relationship between plant morphological characteristics and sand accumulation. [Results] The study area was dominated by Kalidium foliatum, and there were some other plants such as Alhagi sparsifolia, Anabasis elatior. (2) The effect of gravel cover on vegetation density and coverage was more significant than that on plant height and crown width, and vegetation density and coverage decreased with the increase of the gravel coverage. (3) With the increase of plant height and width, the sand accumulation increased exponentially. (4) The influence of sand accumulation on plant morphology showed as: plant height> longitudinal crown > lateral crown. [Conclusion] Vegetation in the study area has an anti-erosion effect, and this effect is influenced by vegetation morphology and surface gravel cover.

Abstract:[Objective] The objective of this study is to analyze the recheck and division of key prevention and controlled area for soil and water loss in Jiangxi Province in order to provide the basis for soil and water conservation planning in Jiangxi Province. [Methods] Based on the original division of the "three district" in Jiangxi Province, we used the soil erosion data from the first national water resource survey to recheck and divide the soil erosion control zone. A county(administrative area) was taken as a unit in division. The requirements for soil and water loss in key prevention and controlled area, and the existing planning results were considered. Quantitative analysis, and the"2+1" and "double standards" patterns was employed. [Results] There were 10 key prevention and controlled area with soil and water loss, which accounted for 39.9% of the total area in Jiangxi Province. The strategies for soil erosion prevention and control were proposed. [Conclusion] The results of this study can provide basis for soil and water conservation and governmental macro policy decision in Jiangxi Province in the future.

Abstract:[Objective] The importance of soil and water conservation function was evaluated in order to provide references for reasonable function division and measures of soil and water conservation in Jiangsu Province. [Methods] According to the characteristics of natural environment, social economy, land use and soil erosion in Jiangsu Province, the importance of soil and water conservation function and its spatial distribution were comprehensively evaluated. Four soil and water conservation functions including soil conservation, farmland protection, water quality maintenance and living environment maintenance was selected. [Results] The importance of soil and water conservation function in Jiangsu Province was at a higher level. The function area of utmost and moderate importance accounted for 42.10% and 46.44% of the total area, respectively. The main soil and water conservation functions were soil conservation and farmland protection in the northern of Jiangsu Province, farmland protection and water quality maintenance in the central, and water quality maintenance and living environment maintenance were in the southern of Jiangsu Province. [Conclusion] The evaluation results revealed the importance of soil and water conservation function and its spatial distribution.

Abstract:[Objective] The objective of this study is to investigate the spatial-temporal pattern of water resources ecological footprint and evaluate the sustainable utilization of water resources in Zhejiang Province in order to provide theoretical basis for the regional development and policy making. [Methods] Based on the theory of ecological footprint, this paper calculated the ecological footprint and the ecological carrying capacity of the water resources in Zhejiang Province. [Results] From 2003 to 2013, the ecological footprint of the water resources showed an upward trend with a slight fluctuation, while the ecological carrying capacity of the water resources fluctuated greatly. The water resources per capital was surplus in the research area, and showed an increasing trend. The utilization of the water resources was secure, as the utilization efficiency of the water resources was increasing year by year. Ecological footprint of the water resources in all cities were divided into three levels: high, medium and low in Zhejiang Province. The ecological carrying capacity of the water resources and the water resources per capital showed a decreasing pattern from southwest to northeast in research areas. The water resources ecological security in southern regional was higher than that in the northern regions, while the utilization efficiency of the water resources in eastern region was higher than that in the western and northern regions. [Conclusion] Although the sustainable utilization of water resources in Zhejiang Province is increasing, great differences existe among different cities. Government should take relevant measures such as reasonable adjustment of industrial structure, construction of water conservancy facilities, intensification of water resources recycling and strengthen of water resources security, to improve the efficiency of water resources using based on development stages and goals.

Abstract:[Objective] Nine runoff plots with various vegetation covers in the Wangdonggou watershed in Shaanxi Province were selected to analyze the effects of vegetation cover on the soil physical and chemical properties in order to provide support for ecological construction in Loess Plateau. [Methods] Soil bulk density was measured by using the cutting ring. Soil saturation moisture, the capillary moisture and the saturated hydraulic conductivity was measured by the constant head method. Soil organic were analyzed by the potassium dichromate external heating method. [Results] It showed that saturation moisture, capillary moisture, soil organic matter in grass and shrub land were significantly higher than that in the pure and mixed woodlands, while there was no significant change in soil bulk density and saturated hydraulic conductivity. [Conclusion] Grass combined with shrub are beneficial to maintain soil nutrition, keep water, and conserve soil. Platycladus orientali woodland are worse in improving physic-chemical properties and soil and water conservation.

Abstract:[Objective] This article analyzed the soil and water conservation measures of Hesheng watershed of Ning'an City in Heilongjiang Province in order to provide technical support for soil and water loss control in hilly area of northeast China. [Methods] Based on the field survey and investigation, land use map and google images, we analyzed the spatial distribution of land use in Hesheng watershed by using ArcGIS 9.3 spatial analysis function. The benefits of soil and water erosion control were evaluated. [Results] The soil erosion control measures in the watershed mainly included terrace plants, soil conservation, erosion ditch protective forest, check dam, ecological restoration, five-hole culvert waterway bridge and culvert. [Conclusion] The economic internal rate of return rate of soil erosion comprehensive treatment project in Hesheng watershed was greater than the social discount rate. Economic net present value was greater than 0, and the benefit-cost ratio was greater than 1. The project meets the requirements of the national standards, and can provide references for soil and water loss control in other regions.

Abstract:[Objection] The objective of this study is to explore the ecological water demand calculation method in the southwest wet regions in order to provide scientific data for water resources allocation in karst areas. [Methods] We took Yanjin river basin in Guizhou Province as a case study. The Penman method, Kristensen-Jensen model, Mike SHE distributed hydrological model(DHI), and environmental function setting method was employed to calculate the optimal water demand from farmland, forest and grass ecosystems, water ecosystems in Yanjin river. [Results] The total amount of ecological water demand in Yanjin river was 1.39×10⁷ m³ to 2.04×10⁷ m³. Agricultural water demand in the basin was the most in April, July and August. The forest grass system didn't show the phenomenon of water lacking. The differences in water amount between dry season and abundant water period in the river were great, and the amount of available water was 3.84×10⁷ m³ to 9.17×10⁷ m³. To ensure the balance of ecological water, the main time of water intake was from May to August. [Conclusion] Farm crop water demand need to be concerned when water was taken from the river. The crop types and planting area also need to be considered when agriculture water was reserved. Moreover, we need to follow the rules of rainfall and ecological water use, to ensure the production of ecological water all the year round.

Abstract:[Objective] The objective of this study is to investigate the characteristics of land use landscape and its eco-environmental effects in northeast agriculture and forestry interlaced zone in order to provide scientific basis for resource utilization and ecological environment protection. [Methods] Based on the method of landscape ecology and 3S technology, remote sensing images in 1991, 2001, 2007 and 2013 were used, and landscape index calculation and model analysis were employed to study the evolution of land use landscape pattern and ecological service value. The driving forces of land use landscape evolution were also investigated. [Results] During the period from 1991 to 2013, landscape indexes varied as a "V" or "Λ" shape. The landscape indexes and diversity indexes decreased, while patch average area, sprawl and contagion indexes increased. The landscape fragmentation decreased, and the stability and diversity of landscape were damaged. The total value of ecosystem services decreased initially, and then increased continuously and reached to 5 242 995.5 thousand yuan in 2013. Forest was the greatest landscape type, which contributed above 40% for the total value of ecosystem services. [Conclusion] Land-use landscape and the value of ecosystem services changed greatly in the study area during the past 22 year, and population increase, economic development and government policy were the main driving factors.

Abstract:[Objective] The objective of this study is to analyze the land use change and the influences of policy factors on land use change in mining area in order to provide scientific support for the sustainable use of regional land resources. [Methods] This paper took Xuejiawa, Ningwu County as the study area, by using the RS and GIS technology, and used the remote sensing images of 1990, 2005 and 2013 as data sources to quantitatively analyze the land use dynamic changes and the land use degree of the study area in two different periods of 1990—2005 and 2005—2013, and to analyze the major policy driving forces in land use of the study area. [Results] The mining land increased greatly from 1990 to 2013. The results demonstrated that the comprehensive dynamic degree of the land use from 2005 to 2013 was higher than that from 1990 to 2005. As for the single dynamic degree of land use in the two periods, the mining land showed the highest variability among all land use types, with the variability in the previous period was far greater than the later period. [Conclusion] From 1990 to 2013, land use change was in recession generally. The mining industry policies are the driving forces of land use change in the study area, ecological environment protection policies and arable land protection policies also profoundly affect land use change in Xuejiawa Township.

Abstract:[Objective] The objective of the study is to investigate and analyze the seed plant flora resources in order to provide the support for improvement of the economic income of local residents and the structure of rural industry. [Method] Based on collected data, a comprehensive analysis of the characteristics of the area, the life style and the resources of the seed plants was carried out by cousulting the list of seed plant. [Results] In south margin of Tengger desert, there are 31 species of seed plants, belonging to 16 families, 31 genera and families. The Chenopodiaceae, Compositae, Gramineae and Herbaceous plants accounted for 67.7% of the total species. The ecological species, fodder species and medicinal species accounted for 83.87%, 51.61%% and 58.06% of the total species respectively. [Conclusion] The Chenopodiaceae, Compositae and Gramineae are families with large number of species, and occupied an important position in the flora resources in this region and played a key role in the preservation of flora of the reserve. The herb species are the important life forms, and with the fodder and medicinal species accounted for a larger proportion.

Abstract:[Objective] In order to prevent water quality deterioration due to the financial constraint and to provide scientific support for government decision, it is necessary to define the primary cost compensation standard for water transfer. [Methods] The principal component analysis and the cost substitution method was used. Because of the cost dispersion of substitute industry in underdeveloped areas, this paper used expected profit instead of opportunity cost. [Results] The primary water protection cost in Ankang City of Shaanxi Province was 1.85×10⁹ yuan in middle route of South-to-North water transfer project, but the economic compensation from the central government account for only 50%. [Conclusion] The central government should provide more compensation in order to prevent the deterioration of water quality.

Abstract:[Objective] The objective of this study is to evaluate the impacts of the comprehensive land use planning on the ecological environment in order to prevent and alleviate the adverse environmental impacts during the project implementation processes. [Methods] The Bohai new area in Cangzhou City of Hebei Provine was selected as the study area. Based on the land use planning data and the existed land use data from 2009 to 2013, the ecosystem service value assessment method was used, and the sensitivity index and grey prediction models were employed. The changes in land use and ecosystem service value were analyzed from 2009 to 2013 in the study area. The value of ecosystem service in the year of 2015 and 2020 was predicted, and compared with the planning data. [Results] (1) From 2009 to 2013, the area of the construction land has greatly exceeded the total area of the planned construction land, and the ecosystem service value decreased by 1.11×10⁷ yuan. This indicated that economic benefits were overemphasized, whereas the ecological benefits were neglected during the project implementation processes. (2) The prediction results showed that the ecosystem service values were expected to be reduced by 7.08×10⁷ in 2020 and the ecosystem service function in the study area were expected to be weakened. [Conclusion] The local government should pay more attention on the eco-environment degeneration issues during the project implementation processes, and take positive and effective measures to improve the relationship between economic development and eco-environment protection.

Abstract:[Objective] The objective of this study is to analyze the carbon sequestration benefits of Zanthoxylum bungeanum forest in order to provide support for the benefits assessment of karst rocky desertification control projects. [Mehtods] Z. bungeanum in Huajiang karst rocky desertification treatment demonstration site was chosen as the research object. The biomass, soil depth and soil holding capacity of Z. bungeanum forests with different forest ages were investigated in different rocky desertification areas(intensive, moderate and light desertification intensity). The carbon sequestration benefits of Z. bungeanum forests were then estimated. [Results] It was found that the carbon sequestration decreased with the increase of the desertification intensity. The carbon density of Z. bungeanum forest in light rocky desertification areas was 3.24 t/hm², while it respectively was 3.12 and 2.81 t/hm² in moderate and intensive rocky desertification areas. With the increase of the soil depth and soil hold capacity, the carbon sequestration of Z. bungeanum forest increased. [Conciusion] The average carbon density of Z. bungeanum forest was 3.06 t/hm², and the optimal carbon sink economic benefits was 19.2 thousand yuan of per hectare to 25.6 thousands yuan of per hectare.

Abstract:[Objective] The objectives of this paper are to discuss the evolutionary process of agricultural eco-economic system from 1986 to 2013 at Wangdonggou watershed in gully region of Loess Plateau, analyze coupling status between agriculture system and eco-economic system in different development stages in order to provide support for economic and social sustainable development of the region. [Methods] Based on the long-term monitoring data and agricultural household survey at Wangdonggou watershed in gully region of Loess Plateau, we established agricultural eco-economic system comprehensive evaluation indices, and analyzed coupling situation in the process of agricultural eco-economic system using a coupling model. [Results] (1) The composite evaluation index of agricultural ecosystem and agricultural economic system increased from 1986 to 2013 at Wangdonggou watershed; (2) The agricultural eco-economic system had underwent recovery phase, harmonious development phase and reconversion phase, and the current coupling status was harmonious development phase. [Conclusion] In the evolutionary process of agricultural eco-economic system, it could develop efficiently and stably through optimizing agricultural resources and finding new growing point.

Abstract:[Objective] To explore the technology and method of the analysis and evaluation of debris flow disaster in the west Kunlun area of Xinjiang Region. [Methods] Taking Maeryang area of Xinjiang Region as the research area, and studied the characteristics of the geological environment in the region with the collected previous data and other information sources. Through interpretation of ETM⁺ images on the study area, the debris flow sites were identified. The terrain and topographic characteristics were also analyzed with DEM data. [Results] The appropriate indicators were selected for debris flow hazard assessment, and an index system was developed for risk assessment. The general risk area, medium risk area, high-risk area and extremely dangerous area were 31.69 km², 40.70 km², 38.31 km² and 25.83 km², with an area ratio of 23.21%, 29.81%, 28.06% and 19.92%, respectively. [Conclusion] Extremely and high danger zone in the study area account for 47.98% of the total area, mainly distribute in the northwest and central regions, and which is highly dangerous geologic disaster occurrence areas.

Abstract:[Objective] The study analyzed soil conservation service among different slopes, soil types, and land use types in order to provide support to soil conservation and land-use planning. [Methods] In this study, DEM, soil map and land use map was used, revised universal soil loss equation (RUSLE) and GIS method was employed to investigate the spatial distribution characteristics of soil conservation service and its influence factors in Qushui river small watershed. [Results] (1) The total soil conservation capacity was 1.10×10⁷ t/a, while mean soil conservation capacity was 384.74 t/(hm²·a) with the high importance of ecosystem sevices. (2) In addition, spatial distribution of soil conservation service exhibited a successive increase from river terrace to slope area. (3) Intensive erosion area, sloping area (8°~25°), arable land, calcic purplish soil and red-brown purplish soil region were the hot spot for soil conservation. [Conclusion] Significant differences in soil conservation service exist among different slopes, soil types, and land use types. Soil conservation service can be improved by improving soil condition, increasing vegetation cover, and adopting soil erosion control measures.

Abstract:[Objective] The objective of this study is to analyze the carbon storage and spatial distribution of regional forest resources in order to provide a scientific basis for management and planning for the local forest carbon sinks. [Methods] Based on the forest resource inventory data in Hebei Province, the carbon storage and density in Qinhuangdao City were calculated. The biomass expansion factor continuous function method established by Fang Jingyun was used to calculate carbon stock in tree species. The average biomass was used to calculate carbon stock in shrubs and economic forest. [Results] In 2005, the carbon storage of forest vegetation was 4.30×10⁶ t, the average carbon density was 11.72 t/hm². The spatial distribution of forest vegetation carbon storage exhibited a declining trend from north to south, whereas carbon density gradually increased in the same direction. The carbon storage of forest stand accounted for 56.04% of total forest vegetation carbon storage, and average carbon density of forest stand was 12.09 t/hm², respectively. Natural forest stands was higher than artificial forest in carbon storage, and the carbon sequestration of forest stand was mainly distributed in young and middle-aged forest, which accounted for 56.31% and 24.70% of carbon storage, respectively. [Conclusion] Forest vegetation have a great potential for carbon sequestration in Qinhuangdao City.

Abstract:[Objective] This article explored the possibility of the application of spatial autocorrelation method in the soil and water conservation zonation in order to provide guidance for the future work. [Methods] Taking the black soil region of the Northeast China as the study area, this paper used the method of spatial autocorrelation to analyze the distribution characteristics of the climate, landform, soil, plant and other factors in the study area and then derived dry and wet climate regionalization, geomorphic regionalization and soil regionalization separately. Finally, the soil and water conservation zonation of the black soil in the northeast of China was got by using the geometrical packing method. [Results] The study area was divided in to 10 synthetic units by overlay analysis. Adjusted according to the distribution characteristics of the plant, rainfall and geographical factors, the study area was then summarized into 8 classes, 2 zones finally. [Conclusion] The results showed that the zonation result is comparatively accurate, and this method is not only practical but also improve work efficiency.

Abstract:[Objective] The research was conducted to analyze the mineralization characteristics of soil organic carbon in Abies nephrolepis forest at different elevations in Altai mountains in order to provide the theoretic basis for the decompose and conversion processe study of soil organic carbon under A.nephrolepis forest. [Method] The soil samples were collected in A.nephrolepis mixed forests at elevation of 1 300~1 500 m, 1 500~1 700 m and 1 700~1 900 m in Altai mountains in Burqin County in Xinjiang Uygur Autonomous Region, and soil organic carbon content was analyzed and compared. The mineralization characteristics of soil organic carbon were further explored using double exponential equation. [Results] (1) Soil organic carbon and active carbon content decreased with increasing soil depth in all three elevation gradient, and the surface accumulation was obvious. (2) The trend of mineralization of soil organic carbon at three elevation gradient was similar. The cumulant of CO₂-C was bigger at early stage of mineralization. In the middle and late stage, the curve flatten out gradually, the increasing rate of cumulant of CO₂-C decreased. (3) The mineralization characteristics of soil organic carbon in A.nephrolepis forest in each layer can be well simulated using double exponential equation. (4) After 100 days of mineralization, the soil activated carbon at each elevation gradient was not still fully decomposed. (5) Mineralized carbon and soil total organic carbon and active carbon content were significantly correlated. [Conclusion] The mineralization process of soil organic carbon obviously varied with elevation, soil active carbon concentration affected mineralization process directly.

Abstract:[Objective] The objective of this study is to clarify the growth rule (i.e. maximum growth potential) and regenerating process of Caragana korshinskii and in order to provide basis for the rational utilization of C. korshinskii. [Methods] We evaluated the 24-years in-situ observation records of growth process of C. korshinskii in the semi-arid regions of Ningxia Hui Autonomous region using quantitative statistical analysis. [Results] (1) The growth of C. korshinskii was mainly impacted by water, especially the soil moisture. The shrubbery at the lower slope always grew better than the ones at the middle and upper slope. Soil water contents at soil layer of 0 m to 8 m in the middle or upper slope significantly influenced the growth of C. korshinskii. During the middle period of C. korshinskii growth, branching numbers, ground diameter and the aboveground biomass varied significantly among different parts of slopes. However, the senescence of plants was severe at the later stage since the physiological and ecological functions of C. korshinskii degraded year by year. (2) Except its biological characters, environmental factors and growth indexes also impacted the growth of C. korshinskii. The biomass at the lower slope was influenced by the numbers of branching. The biomass at the middle slope was impacted by the branching number, ground diameter and the plant height, while ground diameter, plant height and crown width controlled the shrub biomass at the upper slope. (3) All growth indexes were significantly positively related with the cumulative temperature and evaporation. The former was important factor at all parts of slopes. [Conclusion] Hydrothermal conditions are the main limitation factors for the growth of C. korshinskii.

Abstract:[Objective] The objective of this study is to analyze the temporal and spatial distributions of debris flow of China railways in order to provide basis for debris disaster prevention of China railway. [Methods] Based on the debris flow disaster data of China railway during 1951—1996, the frequency, spatio-temporal distribution and their dynamic characteristics were analyzed. [Results] During the period of 1951—1996, there were 17.5 times debris flow disaster events each year in China railway, and among them, 3.8 times were serious debris flow disaster events. The most serious debris flow disaster events occurred in the year of 1964, 1979 and 1981. The debris flow disasters mainly took place from June to August(account for 90%), and August was the peak season(account for 40.2%). As to the regional distribution of debris flow disasters of China railway, the disasters mainly occurred in Southwest, Northwest and North China. The most disaster events occurred in Longhai line, and followed by the Dongchuan, Chengkun and Baocheng lines. [Conclusion] Debris flow disaster is the result of various internal and external factors. Except for factors such as heavy rain, bad terrain and geological conditions, human activities are the main causes for debris flow disaster.