Abstract:[Objective] The relationship between water content, dry density, shear strength and erosion modulus of laterite in Yunnan Privince, was studied under rainfall condition, in order to provide a theoretical basis for further studies on the erosion mechanism of laterite. [Methods] The methods included artificial simulated rainfall and soil trough model experiments, soil test and relative theoretical analysis. [Results] (1) The relation of the cohesion of laterite with water content showed a quadratic curve relation. Near the optimum water content, the maximum cohesion occurred. The internal friction angle was approximate to the linear relationship with the water content change, and the internal friction angle decreased with increasing water content. Under the conditions of initial dry density 1.0, 1.1, 1.2, 1.3, 1.4 g/cm³, the correlation coefficient(R²) between cohesion and water content ranged from a minimum of 0.754 to a maximum of 0.934, and the R² between internal friction angle and water content ranges from the minimum of 0.944 to the maximum of 0.996. (2) The relation between cohesion and internal friction angle were close to linear relationship with the change of dry density. When the water content was constant, the curve of the relationship between cohesion and internal friction angle with the change of dry density had a certain variation, and the cohesion and internal friction angle increase with the increasing of dry density. (3) The shear strength decreased with increasing water content, and the amplitude was especially obvious when the water content was higher than the optimum water content. The shear strength increased with increasing dry density. (4) By the end of the rain, for laterite with different dry densities, the relationship between the slope erosion modulus and the shear strength showed a quadratic curve relation, and the correlation coefficient (R²) can be up to 0.988. [Conclusion] There is good correlation between the shear strength and the slope erosion modulus, and estimating the amount of the slope erosion with the shear strength of laterite after rain is possible.

Abstract:[Objective] The objective of this study is to explain relationship between soil biology and abiological characteristics on crude-oil contaminated soil and provide basic data and background information for its comprehensive remediation in eastern Gansu Province. [Methods] The changes of soil physical and chemical properties as well as enzyme activities in crude oil-contaminated soil in Qingyang City of Gansu Province were investigated using the conventional methods, and the genetic diversity of microbial community was analyzed based on PCR-DGGE. [Results] The contents of soil available N, available P, pH value and activity of soil urease decreased with the increase of soil TPHs concentration respectively(p<0.01), while the activities of soil polyphenoloxidase, dehydrogenase and catalase had a significant positive correlation with soil TPHs concentration respectively(p<0.01). As for the genetic diversity of soil microbial communities, Shannon-Wiener index in the studied sites with lower TPHs concentration was significantly higher than that of the sites with higher TPHs concentration(p<0.05). Moreover, nonmetric multidimensional scaling(NMDS) showed that petroleum-contaminated soil in Gansu Province were strongly affected by soil available N and available P, and following-affected by soil TPHs concentration, pH value, urease activity, Shannon-Wiener index of soil microbial communities and activity of soil catalase.[Conclusion] Impact of crude oil pollution on soil environmental factors in Eastern Gansu Province of Loess Plateau was mainly reflected by the nutrients effective circulation of nitrogen and phosphorus as well as soil microbial-communities diversity and soil urease activity, but there were no significant impact on available K, richness and evenness of soil microbial communities.

Abstract:[Objective] The paper aims to further reduce pollutant concentration and improve the reclamation rate of wastewater in iron and steel enterprises. [Methods] We adopted two sets of horizontal subsurface flow constructed wetlands for the treatment of discharged coking wastewater in iron and steel enterprises, and investigated the impacts of wetland vegetation with and without organic mulches on the treatment of discharged coking wastewater by constructed wetland in winter through the monitoring and analyzing the turbidity, chemical oxygen demand(COD), total nitrogen(TN), and total phosphorus(TP) concentrations in influent and effluent. [Results] In low-temperature season, the hydraulic retention time was 5 days, the average removal rates of turbidity, COD, TN, and TP was 68.55%,14.94%,14.20% and 71.26% in constructed wetland without organic mulches while the average removal rates of those in constructed wetland with organic mulches was 72.54%, 21.62%, 20.50% and 71.88%, respectively. The removal rates of COD and TN increased by 44.68% and 44.45%, respectively. [Conclusion] Organic mulches could be used as insulating material to help increase the purification rate of constructed wetland under the low-temperature condition.

Abstract:[Objective] The objective of the study is to investigate the effect of the seabuckthorn plant flexible dam (SPFD) on the longitudinal distribution of flow velocity and water depth, and to analyze the variation of the roughness coefficient and related influencing factors, thus providing the theoretical support for the application and extension of the SPFD, one of the ecological engineering for soil and water conservation, in the mountainous region. [Methods] We carried out the field flow experiment and used the theoretical analysis to investigate the effect of the SPFD on water flow and the variation of gully roughness coefficient. We also assessed the effect of the SPFD on the longitudinal distribution of flow velocity and water depth, and analyzed the roughness coefficient variation along the pathway direction under the different slopes of the test bed. [Results] The amplitude of flow velocity variation was related to the dam length, the plantation density of the seabuckthorn and the test bed slopes. The flow velocity variation amplitude increased with the increasing slope of the test bed with the longer SPFD. The heap water depth and the roughness coefficient at the upstream zone increased with increasing slope within the test bed with the higher seabuckthorn plant density. [Conclusion] The seabuckthorn plant flexible dam has obvious blocking effect on flow velocity in the front of the dam, and the dam length and the plant density are the main factors affecting the bloocking effect of the SPFD.

Abstract:[Objective] The objective of this study is to analyze the effects of rainfall intensity and land use on loss of organic matter in southwest coteau in Danjiangkou reservoir catchment and to provide help for preventing and controlling non-point source pollution and soil erosion of the region. [Methods] Artificial rainfall experiments, two-factor variance analysis method was adopted to investigate nutrient loss in different land use types in Danjiangkou reservoir catchment and the topsoil samples were collected from five common land use types to analyze the organic matter under six levels of rainfall intensity. [Results] (1) The rainfall intensity had significant effects on the loss of organic matter in runoff while land use types had little impact on it, the higher the rainfall intensity is, the more the organic matter loss. (2) Both rainfall intensity and land types had obvious influence on the organic matter content in sediment, increasing with the increase of rainfall intensity. The organic matter content in the sediment from farmland (terraces and hilly land) was higher than that from forest and grass land, which indicated the better effects of soil and water conservation of forest and grass land. (3) The regression analysis between the organic matter content in runoff and sediment with rainfall intensity showed that polynomial fitting gives best performance(except sediment fitting of shrubby grassland). [Conclusion] The most nutrients were rich in terraces soil, which could keep the nutrients and soil as a kind of soil conservation measures. Less nutrients were lost in woodland and grassland because of their better soil structure, which could reduce nutrient loss and soil erosion.

Abstract:[Objective] The objective of the study is to investigate heavy metal pollution and possible sources of heavy metals in surface dust in coach stations of Xi'an City, in order to provide support for improving the environment in coach stations of Xi'an City. [Methods] Dust samples were collected from 20 representative coach stations in Xi'an City and the concentrations of Cu, Mn, Ni, Pb, V, and Zn were measured by X-Ray fluorescence spectroscopy. Pollution level and environmental risk of heavy metals in the dust were assessed using the geo-accumulation pollution index and the potentially ecological risk index, respectively. Correlation coefficient analysis, principal component analysis and cluster analysis were used to identify the possible sources of these heavy metals. [Results] The mean content of Cu, Pb and Zn in the dust was 36.3, 107.7 and 113.5 mg/kg, respectively, which were significantly higher than their background values in soil in Shaanxi. The geo-accumulation index results indicated that the pollution level of Pb was medium, while other heavy metal pollution belonged to low-level. The potentially ecological risk index showed that the surface dust from coach stations was moderately polluted, and have medium ecological risk. [Conclusion] Source identification results suggest that Cu, Mn and Ni in the surface dust mainly came from nature and traffic, Pb and Zn mainly came from automobile exhaust emissions and worn-out parts, and V mainly came from the nature.

Abstract:[Objective] The study aims to analyze the effect of bio-organic fertilizer on the supply of soil nutrient, the nutrient absorption by Bok choy, and vegetable biomass under the conditions of decreasing application of chemical fertilizer, and to provide theoretical basis for the practice of fertilizer-decreasing application. [Methods] We used the pot-test, with Bok choy as target species, to investigate the effect of bio-organic fertilizer and different amount chemical fertilizer mixtures on alkali-hydrolyzing nitrogen, rapidly available phosphorus, potassium on soil, and vegetable biomass and absorption of nitrogen, phosphorus, potassium by Bok choy. [Results] The bio-organic fertilizer could increase the supply of soil nitrogen, phosphorus and potassium in the limited period time if applying the mixture of both fertilizer. Furthermore, under the condition of the decreasing 15%～25% of conventionally chemical fertilizer application, the mixture fertilization technique did not affect the fertilizer supply of the soil, thus decreasing the non-point contamination of agriculture and stress of environment pollution. Bok choy growing test verified that under the decrease of 15%～25% of conventionally chemical fertilizer application, the mixture fertilization method did not reduce the biomass, and absorption of nitrogen, phosphorus, potassium of Bok choy, thus enhancing the utilization ratio of fertilizer. [Conclusion] Bio-organic fertilizer not only activate the soil available nitrogen, phosphorus, potassium, but also stabilize the supply.

Abstract:[Objective] In order to reveal the structural change of feldspathic sandstone caused by thaw collapse, the mechanism of the freezing and thawing erosion of feldspathic sandstone was discussed. [Methods] Freezing-thawing tests were conducted using high-low temperature heat chamber H/GDWJS-100L with different moisture content, different freezing temperature and different dry densities. [Results] The amount of frost heave changed slightly when the moisture content of feldspathic sandstone was below 11%, while it increased significantly when the moisture content was over 11%. In the process of thawing, the initial thawing settlement moisture content was about 13%. When the moisture content was higher than 13%, thaw settlement occurred, otherwise, frost heave occurred. The maximum displacement of the feldspathic sandstone was closely related to dry density, the variation of maximal displacement was the least when dry density was 1.80 g/cm³. With the same moisture content and dry density, the maximum displacement of the feldspathic sandstone during melting increased with the decrease of temperature. [Conclusion] In the process of freezing-thawing, the displacement of feldspathic sandstone can cause the rearrangement of particles and the change of the pore characteristic, resulting in the structure change of feldspathic sandstone.

Abstract:[Objective] The objective of this study is to investigate the water-holding capacity of litter and soil and to provide support for planning and planting soil and water conservation forests in Taihang Mountains. [Methods] Drying method, indoor soaking and cutting ring method were used to determine the water holding capacity by litter and soil in different kinds of forest stands. [Results] The total storage by litter ranged from 9.96 t/hm² to 19.19 t/hm². The maximum water-holding volume of different forests was about 23.76 t/hm² to 66.72 t/hm², the order was Quercus variabilis and Platycladus orientalis mixed forest >Q. variabilis forest >Robinia pseudoacacia forest> controlled forestland. The maximum effective retaining water of litter occured in Q. variabilis and P. orientalis mixed forest while the minimum in controlled forestland. The water-holding capacity of litters and immersion time had visible logarithmic relationship(R>0.97), whereas the litter absorption rate and immersion time followed an exponential relationship(R>0.98). Soil bulk desity was about 1.14 g/cm³ to 1.55 g/cm³, the total porosity ranged from 38.62% to 43.76%. The order of effective water-holding capacity of soil in these forests was R. pseudoacacia forest>Q. variabilis and P. orientalis mixed forest>Q. variabilis forest>controlled forestland( maximum in R. pseudoacacia 106.85 t/hm², while minimum in controlled forest land 89.37 t/hm²). [Conclusion] The water holding capacity of forest lands was much better than controlled forestland.

Abstract:[Objective] The aim of the study is to investigate the accumulation and water-holding capacity of litters and soil hydrological characteristics in three different artificial forests in northern mountains of Lanzhou City and to provide theoretical support for the capacity of soil and water conservation of artificial forests in arid regions.[Methods] We carried out field investigation, and used indoor immersion method and cutting ring method to determine the litter volumes and water holding capacity as well as soil permeability and water holding capacity. [Results] The litter of Populus alba var. pyramidalis(36.74 t/hm²)> Platycladus orientalis(34.15 t/hm²)> Robinia pseudoacacia(16.01 t/hm²). The P. alba var. pyramidalis had the highest of maximum water-holding capacity(7.36 t/hm²) while R. pseudoacaciahas the smallest(4.91 t/hm²). The bulk density was P. alba var pyramidalis(1.466 g/cm³)> R. pseudoacacia(1.403 g/cm³)> Platycladus orientalis(1.27 g/cm³). The total soil porosity, non-capillary porosity and capillary porosity were P. orientalis > R. pseudoacacia > P. alba var. pyramidalis. The biggest soil water holding capacity was P. orientalis(0.731 g/cm³)> R. pseudoacacia(0.642 g/cm³)> P. alba var. pyramidalis(0.633 g/cm³). The soil infiltration rate of P. orientalis was significantly higher than other forest lands(p<0.05). [Conclusion] Among the three kinds of forest lands, P. orientalis forest land can promote the regional soil and water conservation capacity.

Abstract:[Objective] The study aims to analyze the characteristics of soil nutrients and stoichiometry in different communities in hilly-gullied region of Loess Plateau, and to provide theoretical basis for vegetation restoration. [Methods] Soil organic carbon, total phosphorous and total nitrogen were measured, and C:N, C:P and N:P were calculated. Significance test was done in data analysis. [Results] The contents of soil organic carbon and total nitrogen were at the 6th level, total phosphorous was at the 4th level. Soil nutrient contents of the study area were at a lower level. Soil nutrient contents of 0—10 cm were higher than that of 10—20 cm. The total phosphorous contents in different communities were not significant. The contents of organic carbon and total nitrogen in Caragana korshinskii dominated community were the highest, and the contents in Artemisia gmelinii dominated community were the lowest. The C:N in Caragana intermedia dominated community had no significant difference with other communities, except A. gmelinii dominated community. The C:P of A. gmelinii dominated community and Robinia pseudoacacia dominated community were lower than other communities. [Conclusion] The biomass and coverage of different communities were different, and it led to the differences of soil nutrients. The supply and absorption abilities of C, N and P were different across communities, and it led to the differences of stoichiometric characteristics.

Abstract:[Objective] The objective of this study is to research the variation of soil humus carbon content of Carya cathayensis(Chinese hickory) forest after intensive management, in order to provide theoretical basis for soil management in the forest. [Methods] Based on the long-term investigation, we collected the soil samples from forests that were intensively-managed for 5, 10, 15, and 20 years, respectively. We then analyzed the soil humus of the intensively-managed forests(IMF), and compared with the evergreen and deciduous broadleaf forest(EDBF). [Results] The variation of soil humus carbon content mainly occurred in the surface soil. Soil humus including humic acid carbon(HAC), fulvic acid carbon(FAC), and humin acid carbon(HMC) decreased as an EDBE were converted to an IMF. Compared to the EDBF, there was a decrease in HAC(42.8%), FAC(23.9%), and HMC(21.2%) in the Chinese hickory forests after a 5-year of intensive management. After a 20-year intensive management, HAC, FAC, HMC were decreased by 45.3%, 39.0% and 32.3%, respectively. As to the sub-surface, after 20 years, HMC increased by 94.2%. [Conclusion] Intensive management reduced the content of the soil humic acid and fulvic acid carbon at surface and sub-surface soil.

Abstract:[Objective] The objective of the study is to investigate the effect of the liquid film mulching in ridge and furrow planting conditions in order to provide theoretical support for the selection of the high-yield planting pattern in dry land. [Methods] Liquid film and plastic film mulching were applied in field plot conditions compared with no-film mulching planting in different tillage conditions. [Results] Compared to no-film mulching, the covered planting in ridge and furrow planting conditions increased markedly soil moisture in 0 to 40 cm profile, and increased soil temperature in 5 cm, 10 cm profile in the early stage of maize growth, and covered planting promoted the early stage growth of maize, increased the maize yield remarkably and improved the water use efficiency(WUE)(p<0.05). With the extension of covering time, the effects of harvesting water and keeping warm in plastic film mulching and liquid film mulching conditions weakened gradually. In the condition of less precipitation in pre-experiment, the collection of rain of furrow cultivation was not obvious, but warming effect was obvious. [Conclusion] The effects of the liquid film mulching planting were poorer than the plastic film mulching planting, and were superior to the no-film mulching planting in terms of harvesting water, keeping warm and increasing production. Considered the problem of “white pollution” of plastic film mulching planting, the liquid film mulching in furrow and ridge planting conditions is an ideal dry land covering cultivation technique.

Abstract:[Objective] The objective of this study is to explore the effect of vermicompost co-applied with inorganic fertilizer on biological characteristics in rhizosphere soil of maize and to provide theoretical basis for the development of the soil fertilizer system and reasonable fertilization of corn. [Methods] A field experiment was conducted to determine the effect of four treatments, CK(neither urea nor vermicompost was applied), CF(100% of nitrogen was provided by urea), VC(100% of nitrogen was provided by vermicompost), and VC+CF (50% and 50% of nitrogen was provided by vermicompost and urea, respectively) on root exudates, microorganism population, enzyme activities and humus composition in the rhizosphere soil of maize. [Results] The VC+CF treatment significantly increased root exudates, and microorganism population, microbial biomass carbon, as well as the enzyme activities of urease, invertase, catalase and neutral phosphatase compared with CF treatment. The bacterial population increased by 124.32%, 62.99% and 15.45%, and the urease enzyme activity increased by 44.27%, 23.53% and 12.50% compared with the treatments of CK, CF and VC, respectively. In addition, the VC+CF treatment also obviously increased the contents of humic acid and fulvic acid, and the ratio of humic acid to fulvic acid. However, effect on biological properties in rhizosphere soil of maize in VC treatment was less than that in VC+CF treatment. [Conclusion] In summary, vermicompost co-applied with inorganic fertilizer had better effect on micro-ecological environment in rhizosphere soil of maize.

Abstract:[Objective] The objective of the study is to analyze the land use change in Pangu River basin in Daxinganling region and explore the responses of runoff to different land use scenarios and provide the basis for the rational land use planning. [Methods] Using the land use data of 1987, 2000, 2011 and the hydro meteorology data from 1988 to 2012, combining the soil and water assessment tool model, we analyzed response of runoff to land use changes. [Results] The land use changes during period from 1987 to 2011 included a transformation from barren land to forest and grassland, an increase in forest land and a decrease in barren land. The percentage of runoff in flooding season decreases with increasing forest area. The increase in forest area reduced the long-time average annual runoff, the runoff in flooding season and the maximum monthly peak discharge. [Conclusion] The SWAT model could well simulate monthly flow process of the Pangu River basin and the runoff decreased with increasing forest area.

Abstract:[Objective] The aim of the study is to analyze the influence of mud on the moving ways, width and longitudinal distance and velocity of viscous debris flow on slope, and help to provide the references for disaster prevention. [Methods] The experimental model was built for viscous debris flow, and a series of model experiments were carried out through the device. The viscous debris flow composed of Chengdu clay mud and coarse particles. [Results] The adhesion force between the coarse particles increased, and the movement patterns changed from the inviscid debris flow to the viscous debris flow, and to the massive sliding with increasing mud density. The width and distance on slope decreased with increasing mud density. The migration process could be differentiated according to mud density. The velocity increases rapidly and the gradient is large when mud density was lower than 1.413 g/cm³. The migration process can be divided into two stages when mud density was higher than 1.413 g/cm³, the velocity increased slowly and the gradient changes little in the first stage but the velocity increased quickly, and the gradient changed quickly in the second stage. [Conclusion] The mud affects the movement pattern and the moving process of viscous debris flow.

Abstract:[Objective] The objective of the study is to research a new biological phosphorus fertilizer in order to improve crop yield in alkaline soil in the Yellow River Delta. [Methods] The cultivating method used in this study was inorganic phosphorus liquid culture medium. Fungi Aspergillus tubingensis(CT₁) was screened from the rhizosphere soil in the garden of Yellow River delta. We researched the phosphate-solubilizing ability of fungi. [Results] The phosphate-solubilizing ability of fungi CT₁ was reduced with the increasing of fermented liquid salt concentration. When the concentration of NaCl was between 0.03% and 6%, the concentration of available phosphorus was maintained between 523.5 and 338.5 mg/L. There was an obvious correlation between the available phosphorus concentration and fermented liquid pH vale. CT₁ could grow normally under four different kinds of carbon sources, and the glucose was the best culture medium. CT₁ could grow normally under four different kinds of nitrogen source, and (NH₄)₂ SO₄ was the best medium. Compared with uninoculated wheat, fungi CT₁ inoculated wheat, after 15 days of wheat cultivation, the length of the stem increased by 16.24%, the fresh weight of the stem increased by 12.35%, and the root length increased by 21.6%. [Conclusion] Phosphate solubilizing bacteria CT₁ could promote crop yield of saline-alkali soil, and can be used as a new phosphate-solubilizing fertilizer.

Abstract:[Objective] We aimed to study the characteristics of soil erosion and non-point pollutants-nitrogen and phosphorus in Danjiangkou reservoir area, and to provide theoretical basis for the establishment of agricultural non point source pollution model. [Methods] Through rainfall simulation experiments, we analyzed factors affecting soil and water loss and soil nutrients, including total nitrogen(TN), NH₄-N, NO₃-N, total phosphorus(TP), available phosphorus(AP), from purple soil, such as slope gradient and fertilizer measures. [Results] (1) The average infiltration rate and the initial runoff time decreased, however the total amount of runoff and sediment increased with the creasing slope. (2) The concentration of TN, NO₃-N, TP and AP in sediments decreased with the increasing slope when they were under the same treatment. The concentration of NH₄-N in runoff decreased under the condition of no nitrogen, and increased under nitrogen treatment. (3) The loss of TN was stable after the first reducing trend, the loss of NH₄-N under various fertilizer treatments showed a wave-like change, the loss of NO₃-N gradually decreased and flatten out at last under nitrogen treatment, but had almost no change under the condition of no nitrogen along with the rainfall time under the condition of the same grade. [Conclusion] The NO₃-N was mainly lost with runoff, which was 8 to 11 times of the loss with sediment. NH₄-N loss was mainly caused by the sediment erosion, which was 1 to 17 of times the loss caused by runoff erosion. The total loss of nitrogen was summary of the loss in runoff and sediment. The main way of the loss of AP and TP were lost by sediment, which were 1 000 to 6 200 times and 1 to 3 times of that by runoff erosion, respectively.

Abstract:[Objective] The purpose of this study is to explore the response of soil erosion to land use changes, and to provide reference for the prevention and control of soil erosion in the reservoir area, as well as to provide scientific support for the development of measures to ensure water quality security in Danjiangkou reservoir area. [Methods] Using land use data interpreted from remote sensing images, we analyzed the land use changes in the Danjiangkou reservoir area between 2002 and 2013. Additionally, using the revised universal soil loss equation(RUSLE), we simulated soil erosion to evaluate how it may response to land use change. [Results] During 2002—2013, the main land use changes resulted from conversions among forest, farmland and shrub-grassland, as well as expansion of construction area. Specifically, forest area expanded by 13.72%, the area of farmland only increased by 5.76%. Shrub-grass land area has decreased by 37.61%. The construction area increased twice. In 2002, 2008 and 2013, slight soil erosion dominated the most areas in the Danjiangkou reservoir area. In spite of the increased soil erosion intensity in construction area, the overall soil erosion intensity was reduced. [Conclusion] Implementation of grain-for-green policy, closing hillsides to facilitate afforestation, and urbanization contributed to land use and soil erosion change in the Danjiangkou reservoir area. The soil erosion in the reservoir area has a tendency to decrease in general, but in the area of urbanization, soil erosion has deteriorated sharply.

Abstract:[Objective] The objective of the paper is to study the variation of soil aggregate distribution, nutrient content and their correlation under different soil erosion intensities in red soil region, and provide the theoretical basis for improving the soil fertility and reasonable development and utilization of red soil. [Methods] The tested soil was sampled from different layers below the surface to simulate the natural soil erosion of different intensities, and soil aggregate distribution, nutrient content and their correlation was investigated. [Results] The aggregate size showed similar pattern in red soil with different erosion intensities, and was dominated by the aggregate size ≥2 mm. Compared to CK, ≥2 mm water stable aggregate content decreased by 1/3. With the increase of erosion intensity, the contents of nutrients, including organic matter(OM), total nitrogen(TN), total phosphorus(TP), anailable nitrogen(AN), and available phosphorus(AP), aggregate mechanical stability and water stability decreased. The content of OM, TN and TP in severely eroded soil decreased by 30%, AP by 50% and AN by 80%, respectively. Correlation analysis showed that the content of soil organic matter, TN, TP and AN significantly and positively correlated with ≥2 mm aggregate, >0.25 mm aggregate(WSA), the mean weight diameter(MWD) and geometric mean diameter(GMD)(p<0.05), whereas correlated negatively with aggregate fractal dimension(D) and percentage of aggregate disruption(PAD). [Conclusion] The soil erosion intensity affects soil aggregate distribution and nutrient content, and the application of organic fertilizer in red soil plays an important role in improving soil structure and fertility.

Abstract:[Objective] The land-use change during 2005—2014 was monitored in order to provide the scientific data for the policy making and ecological environment protection in Tianjun County of Qinghai Province. [Methods] Based on the IRS-P6 satellite image of 2005 and 2014, the technical methods and operation process of remote sensing monitoring for the land-use change in the key region of Tianjun county was studied. [Results] In 2009, the dominated land-use type was grass, which was slightly less than that in 2005. The area of mud flat and unused land was slightly increased. The area of the construction land was still smallest because the area proportion was only as low as 0.29%, although its annual growth rate was increasing rapidly. Regarding to the annual changes, the water area decreased by almost 66.2% in the past ten years and the annual decreasing rate was 6.62%. The area of construction land increased fast and reached 59.98% in the past 10 years and the annual increasing rate was 6.00%. [Conclusion] Local economy has developed fast during 2005—2014, and the urbanization level has been improved greatly. However, regarding to the total area proportion of construction land, the change of land-use in the monitoring area is little and the annual change rate is only 0.13%.

Abstract:[Objective] The determination method for total annual runoff volume is investigated in order to provide a new idea for the determination of control index of sponge city construction. [Methods] Combining with the relevant standards and research achievements in the construction of sponge city in China, the rationality about the method to determine the total annual runoff volume control at present are analyzed. Hefei City was taken as an case to discuss relevant problems using typical hydrological year method, long-term runoff serials method, runoff coefficient method and daily water balance method. The effect of variation of runoff control rate on control targets and the actual rainfall control of rainwater storage facilities in different scales were explored. [Results] This paper proposes a typical hydrological year method, and finds that the runoff control rate cannot be unlimitedly reduced with the rise of total annual runoff volume control target. The effective volume of rainwater utilization can be used to check the suitable range of total annual runoff control. [Conclusion] The typical hydrological year method, combining well with the design return period of rainwater system and its application in studing actual rain volume control, provides a new idea for the determination of runoff volume control in sponge city construction.

Abstract:[Objective] The study aims to predict and analyze the project impacts on the river flood discharging capacity, and provide methods for assessing flood controlling impacts of urban ecological park projects.[Methods] Based on MIKE 21, we constructed a 2-dimension water flow model for urban ecological park section in Weihe River in Baoji City, selected 1954 flooding process to verify the rationality of the model, and simulated three typical flow characteristics of flow field and changes in water level and discuss the urban ecological park impacts on river flood discharging capacity. [Results] Under the three typical flow flooding events, the water level along the river was below embankment and not a threat to urban flood discharging safety, and the flooding safety can be guaranteed. But as a result of flooding passage narrowing and increasing velocity, the erosion of the embankment was intensified, and reinforcement measures was urgently needed. [Conclusion] The river shape will affect the flow regime. The higher water flow speed will affect the stability of embankment structure thus influencing the river flood discharging capacity.

Abstract:[Objective] The objective of this study is to evaluate the benefit of land reclamation projects and to provide references for similar land remediation projects. [Methods] We used DEA-Gini criterion to quantitatively describe and evaluate the benefits of 14 land reclamation projects in Qingyang City, Gansu Province. [Results] Among 14 land reclamation projects, the comprehensive benefits of land remediation projects in the Choujiazhuang, Shancha Town of Zhenyuan Township of Heshui County and the Xipo Township of Zhengning County were 0.308, 0.378 and 0.342 respectively and at lower levels while the comprehensive benefits were 0.972 and 0.708 respectively in Nanyi Township and Pingzi Town of Ningxian County and reached a higher level. The remaining nine land reclamation projects was in the middle level. [Conclusion] Using DEA-Gini criterion evaluation results showed that there are still space for the improvement of economic, social and ecological benefits in 14 land reclamation projects

Abstract:[Objective] To explore the applicability of the combined forecasting model based on the third theory of quantification in combined landslide deformation and to provide a new idea for forecasting the combined landslide deformation. [Methods] We used GM(1, 1), support vector machine, BP neural network and MC prediction as a single prediction model of landslide deformation, and applied the third theory of quantification to analyze the importance of relative error interval and single prediction, and then determine the interval weights and the prediction error between groups, thus determining the combination weights of comprehensive prediction. [Results] The average value of relative error of combined prediction was 1.1% and the variance was 0.16. [Conclusion] Compare to single forecast model, the forecast accuracy and stability of combined prediction had been greatly improved.

Abstract:[Objective] The aim of this study is to investigate the spatial characteristics of settlements in Jinzhai County of Anhui Province and provide a scientific support for the overall planning of rural settlement construction and urbanization and optimizing the layout of the settlements in mountainous region. [Methods] Combining settlements' housing base surface shapes visually interpreted from remote sensing images and terrain properties derived from DEMs, and with the help of GIS spatial techniques, we analyzed the spatial relationships of river system, roads and terrain characteristics with housings in Jinzhai County. [Results] 59.8% of the housings were located in the range of 500 m from the river system, and 60.5% of the housings were in the range of 100 m to the road. Settlements tend to aggregate in the area with altitude below 400 m, slope below 20° and relief amplitude below 200 m. 45.8% of the housings are distributed in southeast, east and south facing aspects, among three aspects the south facing aspect have the highest ratio of housings. [Conclusion] There is strong relationship between river/road and settlements within limited distance. The river, road, terrain morphology and lighting conditions play very important roles in spatial patterns of settlements. The settlements showed obvious aggregation in areas with low elevation, low slope, low relief amplitude and good lighting conditions.

Abstract:[Objective] The objective of the paper is to investigate the changes in land use structure and driving forces of land use change, and develop predicting method. It will provide a reference for land use decision, especially for inhibiting construction land expansion and optimizing urban & rural land use structure with social and economic development. [Methods] We used principal component analysic(PCA), Logistic and Markov methods to detect the driving forces of land use change, and developed predicting methods based on mechanism and relations of state transition probability matrix of land use structure and driving factors. [Results] At Taixing City of Jiangsu Province, which is located in the “Yangtze River Delta” economic region, we measured the multiple driving-forces of changes in land use structure including urban development, economic policy, market and management. The land expansion by the urban industrial and mining increased by 25.85%, and the cultivated land was reduced by 22.21%. We also predicted the land use structure in 2010—2020, and the prediction accuracy was increased by 0.52% in study area. [Conclusion] The prediction model based on multiple driving-factors can explain relations between land-use change and its driving forces, improve prediction accuracy, and provide a new method for analyzing regional land use change.

Abstract:[Objective] The objective of the study is to monitor the spatio-temporal evolution of saline soil in Songnen Plain and provide a theoretical basis for the prevention and treatment of saline soil in this region. [Methods] We established a regression model based on MODIS images and the field measured samples to retrieve soil salt content on Songnen Plain quantitatively. Study period can be divided into three sub-periods: period one(2000—2004), period two(2004—2008) and period three(2008—2013). [Results] The area of saline-alkali land increased and salinization was becoming worse in period one and two, and the rate of increase reached 5 109.75 km²/a and 2 240.62 km²/a respectively. After the turning point in 2008, the area of saline-alkali land(mainly the light saline-alkali land) decreased in period three, but the salinization degree was still growing. [Conclusion] Songnen Plain salinization is not optimistic, we should take emergent measures to prevent the further salinization and to ensure the healthy development of eco-environment of Songnen Plain.

Abstract:[Objective] Taking Yanhe River basin as a study area, typical loess soil line equation was established by automatic algorithm to provide basic parameters for the calculation of the soil adjusted vegetation index. [Methods] Based on Landsat 8 OLI images, soil line was extracted by automatic algorithm, then the correlation coefficients between normalized difference vegetation index(NDVI), perpendicular vegetation index(PVI), transformed soil-adjusted vegetation index(TSAVI), adjusted transformed soil-adjusted vegetation index(ATSAVI) and test coverage were calculated; and the applicability of soil line equation in vegetation index extraction was also discussed in the Loess Plateau. [Results] (1) Compared with conventional method, the difference was small, and the automatic algorithm had high accuracy and stability; (2) The sequence of the correlation between vegetation index and test coverage was: PVI> NDVI> TSAVI> ATSAVI, which showed that PVI was the optimal vegetation index, NDVI was the next, TSAVI and ATSAVI were the worst to the extraction of vegetation coverage in Yanhe river basin; (3) Compared with NDVI, PVI index could reduce the influence of soil noise, and its sensitivity to different vegetation types was higher. PVI was more suitable for the Loess Plateau with low vegetation coverage. [Conclusion] It is suitable to extract the soil line by automatic extraction algorithm in Yanhe river basin, and the parameters can be used to calculate the soil-adjusted vegetation index.

Abstract:[Objective] This paper studies the geomorphic types from the perspective of information entropy and adds new index for landscape evaluation in Loess Plateau. The terrain can be fitted and evaluated by calculating the information entropy on the elevation data, which can provide a new theoretical basis for studying geomorphology. [Methods] Through analyzing terrain profile of the study area, we extracted the terrain profile line, then used elevation data to calculate the section line information entropy and elevation for different physiognomy types. We rendered terrain profile section line map and terrain information entropy diagram, and used them to test and evaluate the effect of geomorphic information entropy in expressing terrain information, and to calculate the index of dispersion degree, and to find the correlation between them through linear fitting. [Results] With a comparison of two charts, the two figures showed similar trends. The statistical indicators that there was a strong correlation between the elevation curve and the information entropy curve. The validation by erosion modulus showed that the information entropy was reliable in representing the topographic changes or erosion.[Conclusion] Terrain information entropy can be used to simulate the terrain, and the simulation results are farorable, it can be used to evaluate the landscape types.

Abstract:[Objective] The paper aims to compare the accurracy of BP neutral network and GM(1,n) in predicting construction land changes, which is beneficial to understand the urban development and provide refernces for general land planning. [Methods] With Siping City as the research object, we selected impact factors with the perspective of “city-rural integration” and used factor analysis to estimate the influence of construction land expansion and choose indicators. We then simulated and compared the predictions of construction land in 2012, 2013 and 2014 in Siping City using the BP neural network and grey model. [Results] The relative error with BP neural network was 0.8%, 1.1% and 2%, and the gray GM(1.1) model was 0.04%, 0% and 3.2% respectively. The BP neural network are better than GM(1.1) model. [Conclusion] BP neural network can provide a higher accuracy.

Abstract:[Objective] The objective of this paper is to explore the spatial and temporal characteristics of evapotranspriation(ET) in the Beiluo River basin, and provide theoretical basis for the study of ecological benchmark and ecological water requirement and the effect of returning farmland to forest. [Methods] Based on MOD16 remote sensing image data, meteorological and hydrological date during 2000—2014, and the land use date in 2011, we used river basin water balance method, method of mean value, the standard deviation method and the linear trend method to analysis the spatial and temporal variation characteristics of evaporation. [Results] The mean annual evapotranspiration of Beiluo River basin increased slowly with values ranged from 395.4 to 517.4 mm, and average evapotranspiration during the past 15 years was 446.74 mm. The monthly variation of evapotranspiration within the year show a unimodal pattern, it was mainly concentrated in the period from May to September, and its peak value occurred in August. The average relative error was 12.04% between spatial interpolation results based on measured rainfall and estimates based on MOD16-ET, the correlation coefficient was 0.81. The profile line of ET changed greatly from upstream to downstream of the Beiluo River basin, which presented the irregular “wave curves”. The spatial variation of annual ET was obvious in the basin. The ET showed an increasing trend in the midstream and upstream, while it showed a decreasing trend in the downstream. [Conclusion] In the recent 15 years, the evapotranspiration in Beiluo River basin showed an increasing trend, and human activity was the main driving force, especially the implementation of grain for green project and soil and water conservation project.

Abstract:[Objective] In this paper, we aimed to determine the critical rainfall of flash flood in Tibet, in order to provide the basic data for hydrological and meteorological warning in Tibet and serve the flash flood prevention. [Methods] We simulated the process of a flood in Southeastern Tibet by hydrodynamic model Floodarea, and calculated the submergence depth by using meteorological data of hourly precipitation, and we then obtained the critical rainfall of flash flood. To test the simulation result, we conducted a field survey to obtain the basic parameter of a flash flood disaster in August 2015 in Bayi Nyingchi region. [Results] The Floodarea model could be well used in the simulation of rainfall induced mountain flood process. The critical rainfall of flood submerged in different water depth could be calculated by adjusting the rainfall scenarios. According to the relationships between rainfall amount and submergence depth, the critical 6 hours accumulated rainfall amounts in four mountain flood ditches with different submergence depths(0.1, 0.5, 1.2, 1.8 m) were 33, 55.7, 75.4 and 91.9 mm, respectively. [Conclusion] Floodarea model software can be applied in the complex terrain mountainous areas that lack of hydrological observation data, in Tibetan Plateau. It can accurately simulate the flash flood disaster process and determine the critical rainfall. This study can provide reference for flood prevention and early warning in complex terrain mountainous areas.

Abstract:[Objective] The objective of this paper is to simulate the characteristics of precipitation in the future, in order to provide a theoretical basis for agricultural production and flood control and disaster mitigation in the region along the Yangtze River in Anhui Province. [Methods] Based on scenario of RCP4.5 greenhouse gas emissions, regional precipitation along the Yangtze River in Anhui Province during 1960—2065 was simulated using the MRI-CGCM3 model error correction data. [Results] The error correction model data can well simulate the variation characteristics of precipitation along the Yangtze River in Anhui Province. There were big differences in precipitation in different periods of the future, and more precipitation in spring and summer, less precipitation in autumn and winter. The increase of daily precipitation in the four seasons and the average annual precipitation of 2036—2065 was higher than that in 2006—2035, and the biggest difference in autumn. In terms of the data fluctuations, the precipitation fluctuations in different periods were larger in summer, smaller in the spring. The smaller fluctuations occur in autumn and winter of 2006—2035, and higher fluctuations in autumn and winter in 2036—2065. As for regional precipitation variation characteristics, the daily precipitation increases gradually from north to south with the seasonal characteristics of more precipitation in autumn and winter than that in spring and summer in Anhui Province along the Yangtze River in 2006—2065. Compared to 2006—2035, the geographical features of the regional precipitation change in 2036—2065 were more obvious and the seasonal variation rate increased. The geographical change strip trends and direction of precipitation anomaly varies by seasons. [Conclusion] The regional future precipitation increases but with higher variability along the Yangtze River in Anhui Province.

Abstract:[Objective] The objective of this paper is to explore the characteristics and forecasting methods of ice regime of upper reach of Wanjiazhai dam and Lamawan reach in Togtoh County after Wanjiazhai reservoir, and provide a basis for ice prevention and scheduling. [Methods] The processes of freezing-up and thawing of the river reach were analyzed based on the field observations from 1998 to 2015, including the dates and durations of both freezing-up and thawing and their relationships to the affecting factors like air temperature, flow rate, ice thickness, and number of days of frozen. The significant correlation coefficients were selected and BP neural network model was applied to predict the durations of the freezing-up, durations of thawing, and dates of thawing of the upstream reach respectively. [Results] The accuracy of the predicting results were up to 93% compared with the observed date. [Conclusion] Neural network model is suitable for forecasting freezing-up duration, breaking-up duration and breaking-date in upper reach of Wanjiazhai dam, and is more suitable for solving the problem of ice regime influenced by complex factors.

Abstract:[Objective] The objective of the study is to scientifically calculate the realized value of water and soil loss control goal of production and construction projects during the scheme compiling phase and to guide the layout of control measures. [Methods] Based on the analysis of consolidation and improvement rate of disturbed land, soil and water loss control ratio, soil erosion control rate, slag stopping rate, vegetation recovery rate and coverage and their achievable values, we analyzed existing problems in calculating control goal values and proposed some opinions and suggestions for solving these problems. [Results] (1) To calculate the six control goal values, parameters about the project area should be available. These parameters include the disturbed area of construction site, building and hardening area, waters and mining pit area, engineering and vegetation measures area, afforestation area, waste slag quantity and the actual block slag quantity; (2) To test the consistency with the above parameters and the measured quantities or related data; (3) If the calculated value cannot achieve the goal value, check out the goal value set or measures setting, and make necessary adjustment and correction according to the relevant regulations. [Conclusion] While calculating the six control goal values according to the requirements of specification, regional benefit calculation parameters should be availabel, and its consistency with regional measures of work amount or related data should be confirmed.

Abstract:[Objective] The paper aims to simulate the cultivated land evolution in Songshan District of Chifeng City, Inner Mongolia and provide scientific basis for the reasonable land use planning and management, ecological restoration and economic policy making. [Methods] The 1990, 2000 and 2010 TM remote sensing data was used to analyze the characteristic of cultivated land evolution in the study area. Using multi-criteria evaluation(MCE) method in GIS CA-Markov model, we simulated the spatial pattern of cultivated land in 2020. [Results] The cultivated land evolution showed significant spatial differences. (1) Due to the rapid urbanization in suburb, a large area of cultivated land has been converted into constructed land; (2) In rocky mountains of the west of Songshan District, more and more cultivated land have been abandoned due to serious soil erosion and poor soil resulted from higher elevation and steep slope, at the same time, the implementation of the policy of returning cultivated land to forest also led to the shrinking of cultivated land.(3) Altitude was relatively low and the terrain was flat in loess hilly region of eastern Songshan District, which was suitable for arable land. The increasing of cultivated land was mainly from the unused land and grassland.(4) In 2020, the simulated land use pattern of the study area showed that the fragmentation of cultivated land will be moderated, large-scale development will start. At the same time, the stability of cultivated land spatial pattern was increasing. [Conclusion] The precision of the model simulation results is high and provides support for cultivated land use planning and policy-making. At the same time, the results lay a foundation for the optimal allocation of land resources.

Abstract:[Objective] This study intended to compare the literature incremental trend of international studies on soil and water conservation, discipline distributions, cooperation network of institutions and authors, and research hot spots between China and foreign countries. It aims to provide a scientific and practical implication for scholars in the related fields, research institutions and government departments to enhance the citation frequency, strengthen international cooperation and pay attention to the research of agricultural science and so on. [Methods] Based on literature from 1986 to 2015 from the Web of science databases, CiteSpace visualization analysis software was used to analyze and process the citation data in the way of mapping knowledge domains. [Results] The literature on soil and water conservation increased steadily. United States, China, and Australia were ranked as the top three countries in the document output. European countries were the most high-yielding. The literatures span more disciplines, new disciplines emerged significantly. The cooperation between China and foreign institutions was closer; The tree diagram showed that an important cooperation ecological chain was established by China and America as an important output node. The most productive researchers were Belgian Poesen and Govers etc. who played an important role in bridging the academic cooperation between China and foreign countries. [Conclusion] The international research focus was similar. The soil and water conservation, soil erosion, runoff and model were the highest frequency hot keywords.

Abstract:[Objective] The objective of the study is to evaluate the instability probability of shallow landslide induced by rainfall, and to provide theoretical basis for related research. [Methods] We combine Mein-Larson model with infinite slope stability models of saturated soil by introducing and developing the Mein-Larson infiltration model, and establish deterministic models for rain-induced landslides under short duration rainfall with high intensity and long duration rainfall with low intensity. Then we establish a probability analysis method of the slope instability by combining the deterministic models with Monte Carlo method. [Results] One kind of evaluation method for the failure probability of shallow landslide induced by rainfall was proposed.[Conclusion] The probability method not only can describe the uncertainties in the process of occurrence and development of rain-induced landslides, but also can calculate the instability probability of rain-induced slope instability under the different rainfall time. The assessment results are in high agreement with the actual slope.

Abstract:[Objective] The objective of the study is to provide theoretical support for ecological restoration and sustainable management in the future by comprehensive assessment of eco-environmental vulnerability in Bailongjiang watershed in Southern Gansu Province. [Methods] Based on ecological sensitivity-resilience-pressure model and characteristics of eco-environmental systems in Bailongjiang watershed in Southern Gansu, we used analytic hierarchy process(AHP) method to assess eco-environmental vulnerability with GIS/RS technology. According to the eco-environmental vulnerability index, the study area was classified into five levels: slight vulnerability(<0.38), light vulnerability(0.38~0.44), moderate vulnerability(0.44~0.50), high vulnerability(0.50~0.57) and extreme vulnerability(>0.57). [Results] The moderately and highly vulnerable area accounted for 28.93% and 22.76% of the total area. Moreover, the highly and extremely vulnerable area was primarily distributed in the middle reaches of Bailongjiang watershed, which was characterized with low vegetation coverage, rapid urbanization and industry and agricultural development and frequent human activities. [Conclusion] The watershed is facing huge eco-environmental pressures. It is urgent to study the driving mechanism and evolution rules in order to provide support for ecological restoration and reconstruction in near future.

Abstract:[Objective] The objective of the study is to analyze the types, structure and functions of various extant fieldridges on farmlands and their application in practice, in order to provide support for planning and designing high standard basic farmlands in the Three Gorges Reservoir area. [Methods] The analysis was done through field investigation and literature reviews. [Results] (1) According to used materials, fieldridges could be classifyied into four types including stone fieldridge, soil fieldridge, soil-stone fieldridge and cement brick fieldridge. The fieldridge pattern could also be categorized into four types including combination of fieldridge and ditches, fieldridge with lynchet, fieldridge without lynchet and irregular fieldridge. In terms of functions, fieldridges include the fieldridge for walking, the fieldridge as a boundary of land ownership, and for the soil conservation. (2) The structure of extant fieldridges varies on sloping farmlands in the Three Gorges Reservoir area. Usually, the main functions and purposes of the fieldridges depend on their structures. For example, the upper-soil-bottom-stone fieldridges were used to establish hedgerow in most places where the high quality cultivated land was deficient, and the bottom soil-upper stone fieldridges were mainly used as a path for farming. (3) The proportion of soil fieldridges and stone fieldridges was about 65% and 15%, while the total of soil-stone fieldridges and cement brick fieldridges was about 8%. In addition, about 10% of sloping farmlands has no fieldridges in the Three Gorges Reservoir area. [Conclusion] The fieldridges with various types and structures are formed on sloping farmlands in the Three Gorges Reservoir area in the context of the specific geomorphologic features and complicated human-land relation, and different structures result in functional diversity of fieldridges. Currently, soil fieldridge has higher ratio and usage in the Three Gorges Reservoir area. The soil-stone fieldridge with merits of both soil bund and stone fieldridge, is a new widely used fieldridge in the Three Gorges Reservoir area. In the future, more focus should be put on the structure optimization, and popularizing this new fieldridge in sloping farmland consolidation and high standards basic farmland construction.

Abstract:[Objective] On the basis of the survey on ecological land use status in Savan water economic zone of Laos, the characteristics of ecological land in this research area is explored through the landscape index analysis and ecological sensitivity evaluation to provide the basis for land use planning, to ensure the rational land use and guarantee the healthy development of the ecological environment. [Methods] Appropriate indicators were selected in terms of landscape pattern and ecological sensitivity. Variation coefficient method was used to determine weights of evaluation indices, so as to analyze comprehensively the sensitivity and spatial distribution of ecological land in Savan water economic zone. [Results] The extremely sensitive area, highly sensitive area, medium sensitive area, low sensitive area and not sensitive area accounted for 1.42%, 19.36%, 32.85%, 46.01% and 32.85% respectively. Forest landscape fragmentation was the lowest, with minimal disturbance by human activities. Water and farmland landscape fragmentation were highest and have complex shapes. In addition, the two landscape types were significantly affected by human activities. Construction land area was small and its landscape fragmentation was in medium level due to the restriction of its development condition in the study area. [Conclusion] According to this research, the study area is divided into priority construction zones, secondary construction zones, transition zones, and conservation zones.

Abstract:[Objective] The objective of the study is to evaluate the effectiveness of debris flow disaster control project in development zone at cascade hydropower stations at severe landslides-affected Upper Yangtze River and provide references on effectiveness post-evaluation of debris flow control for other hydropower stations. [Methods] The Aizi and Dazhai gully debris flow regulation engineering in Jinshajiang River were chose as a case. The peak flow process of Aizi and Dazhai gully debris flow were calculated through the tracking investigation of three consecutive years from 2013 to 2015. The effectiveness of debris flow control engineering of Aizi and Dazhai gully in 2014 and 2015 were evaluated. The risk of debris flow was estimated. [Results] Post-evaluation model on effectiveness of debris flow control in the cascade hydropower stations of Upper Yangtze River development zone was put forward based on the results of the assessment system. The governance model of debris flow and mitigation strategies were proposed based on the water and electricity engineering debris flow risk control according to the characteristics of debris flow hazards in the development of cascade hydropower stations in the Upper Yangtze River. [Conclusion] Existing debris flow prevention and control measures of Aizi and Dazhai gully can meet flow requirements of five hundred-year debris flow under the conditions of impletion, and debris flow risk is less in the area.

Abstract:[Objective] The study aims to evaluate the investment efficiency in reclaimed water projects in different regions of China with consideration of social and environmental benefits of the investment, and intend to propose differentiated improvement strategies for different regions. [Methods] This study selected 22 provinces, 4 municipalities and 5 autonomous regions(excluding Hongkong, Macao Special Administrative Region and Taiwan Province) as the research objects and used DEA model and Malmquist index model to calculate the investment efficiency. [Results] The investment efficiency in reclaimed water in China was 0.858, and the efficiency was uneven among different provinces. The investment efficiency of reclaimed water in China is normal and it still has room to be improved. Investment efficiency of reclaimed water considering economic, social and environmental benefits is higher than that considering only economic efficiency. [Conclusion] Regional development is unbalanced, the investment efficiency is different among provinces due to different reasons. Therefore, provinces should be divided into different categories and different technology, management, policy and comprehensive improvement strategy should be proposed and carried out.

Abstract:[Objective] The overall features of contemporary agriculture with regard to society, economy and culture were depicted to illustrate the intrinsic social reason that might potentially slow down the agricultural progress. [Methods] Field investigation and interview, especially on the topics of ecological resources and sociocultural connotation were conducted in Shaanxi Province of Northwest China. The province was exemplified to analyze the intrinsic link between contemporary agriculture progress and society development, and to predict the agricultural evolution tendency. From social structure perspective, the effects of population emigration and stratum differentiation on the agricultural evolution were discussed. [Results] In terms of development concept, social foundation and equilibrium, a list of problems existed in agricultural development were thought rooted in social structure as the phenomena of breakout, imparity and gap. The agricultural development in the undeveloped areas in Northwest China were both affected by the rigorous environment and low level economy. Besides, it was also mutually affected by social structure factors as organization form, policy and administrative intervention. In other words, the agricultural progress itself was routinely shaped by external factors. [Conclusion] Choosing the operation mode for modern agriculture is essentially choosing the social formation for rural areas, which is closely related with the regional development trend.

Abstract:[Objective] The dynamic changes of water resource carrying capacity in agro-pastoral ecotone is analyzed, which will provide a theoretical reference for the sustainable development of the similar areas. [Methods] The study selects the Horqin District, Tongliao City in Inner Mongolia as a case study area, which is characterized with typical characteristics of agro-pastoral ecotone. Through the method of system dynamics simulation, we established the system dynamic model for the coordinated development of “society-economy-ecology” based on the limited water resources in Horqin District. Meanwhile, according to the characteristics of agro-pastoral ecotone and social economic development in Horqin District, five theoretical models of regional “society-economy-ecology” coordinated development were put forward, including natural growth model, primary industry-modernization model, secondary industry-dominated model, tertiary industry-led model and recycling economic development model. [Results] On the basis of system dynamic simulation, we used genetic projection pursuit method to optimize the simulation results, and found that the recycling economic development model was the model with optimal water resources carrying capacity.[Conclusion] (1) The proper arrangement of agricultural and pastoral proportion is a key to saving limited water resources in agro-pastoral ecotone; (2) The development of traditional industries in agro-pastoral ecotone would cause water resources scarcity; (3) Recycling economy is an effective way to improve the carrying capacity of water resources in agro-pastoral ecotone; (4) The increasing investiment on researches on the carrying capacity of water resources in agro-pastoral ecotone will help to provide the support for regional sustainable development.

Abstract:[Objective] The objective of the study is to explore the differences in soil physical and chemical properties in different seasons and slope positions in earthquake-stricken slopes after replanting forest species, and to assess the vegetation restoration and to provide the theoretical support for managing the slope. [Methods] According to the conventional methods, this study investigated the changes of soil physical and chemical properties, soil enzymic activity and herb growth, in Leigu Town, Beichuan County, Sichuan Province. The relationships between variations of soil physical and chemical properties and enzyme activities and the effect of vegetation restoration were analyzed. [Results] Soil nutrient levels and vegetation recovery showed no significant differences in different seasons and slope positions, however, they showed significant difference in undamaged natural slope. [Conclusion] In the current treatments and curing conditions, improved physical and chemical properties of soil can affect vegetation restoration. Much more attention needs to be paid to concepts of villagers and human disturbance. Soil and water holding capacity need to be monitored timely, pioneer herbs need to be replanted, and organic fertilizer can be used in the crop growing areas to improve soil fertility.

Abstract:[Objective] The objective of the study is to explain the changes of carbon footprint and carbon capacity and evaluate the carbon security and provide the theoretical basis for the development of low carbon economy in Xinjiang Uygur Autonomous Region. [Methods] Based on the theory of carbon footprint, we calculated the carbon footprint, carbon capacity and net carbon footprint from 2000 to 2014 in Xinjiang Region, and selected carbon ecological pressure index to develop a model for regional ecological security evaluation. [Results] The carbon footprint of Xinjiang Region increased from 1.08×10⁸ t to 5.04×10⁸ t during the period from 2000 to 2014, and the use of fossil fuel contributed 96% of total carbon foot-print. The carbon capacity increased too, and the carbon quantity of grass was the largest, followed by forest, cultivated land, garden land and urban green space. The net carbon footprint and carbon ecological pressure index increased. Since 2009, it had been in a state of “terribly insecurity”, and the carbon security was decreasing. [Conclusion] The increased consumption of fossil energy is the main cause of the growth of its carbon footprint and the decline of its carbon security. Although the efficiency of energy continued to improve in Xinjiang Region, it is still facing serious eco-environment problems in the future.

Abstract:[Objective] The objective of the study is to investigate the characteristics of water environment and influencing factors at road area of highway in the Qinghai Tibet Plateau, and to provide theoretical basis and scientific support for the construction of the Qinghai Tibet highway and water environmental protection measures. [Methods] Based on the test results of water environment along Gongyu highway(from Gonghe to Yushu County in Qinghai Province) and Qinghai Tibet highway(from Geermu to Lhasa City) in June to July of 2015, we analyzed water environment characteristics and influencing factors in highway road area in Qinghai Tibet Plateau. [Results] Statistic test showed that the significant differences existed in runoff water pollution in highway road area of the Qinghai Tibet Plateau, and high variability was found in the water quality indexes, with coefficient of variation(C_v) ranging from 11% to 396%, indicating that pollutant in runoff varies by location. We also compared water environment characteristics in typical highway areas, and found that water environment quality was better in new highway area than old highway area. The highway operation had a significant impact on water environment. Person test showed that runoff water, suspended solids(SS) and other water quality parameters was correlated with each other to a certain degree, indicating that SS was not only the main pollutants of runoff in the Qinghai Tibet Plateau region, but also is the carrier of other pollutants, including the heavy metals and chemical oxygen demand(COD). [Conclusion] Road runoff is the main source of the water pollution in road area, collection and treatment of road runoff and the use of new pavement will effectively reduce the impact of highway on water environment in the highway area.

Abstract:[Objective] The study aims to find out factors that influence the plant community structure and distribution pattern in the riparian zone along Ziya river, and provide references for related research. [Methods] In June, 2013, we investigated plant community structure and six environmental factors in 94 plots including altitude, levee type and land use type outside the levee in the Ziya river system. [Results] Totally, we found 249 species, which covers 51 families and 166 genera, of which, 199 species covering 43 families and 135 genera were found in the mountain regions in the mountainous region and 36 species covering 22 families and 35 genera were found in the plain. Phragmites australis, Artemisia mongolica, Vitex negundo, Artemisia annua were the dominant species in the mountain rivers and P. australis, Amaranthus retroflexus in the plain rivers. The species richness in mountain was significantly higher than that in the plain areas. [Conclusion] The altitude and the land use type outside levee significantly associated with the plant community structure. Hydrothermal conditions and human activities are the main factors affecting the vegetation composition and spatial distribution.

Abstract:[Objective] The aim of the study is to investigate the relationships between engineering activities and urban geological disasters, and provide help for the urban planning and construction. [Methods] Based on the on-site geological environment survey(geological exploration, geological surveying and mapping), we studied the geological disasters caused by engineering activities at Xiaoting District in Yichang City, Hubei Province and probed into the internal and external factors causing these disasters. [Results] Artificial excavation was the main cause of potential landslides on unstable slopes. Artificial refilling is the main cause of landslides with a potential to develop into debris flow. Geological disaster related to the expansive clay soil are also closely related to engineering activities. The excavation in road construction leads expansive clay soil to be unstable and to swell under the impact of rainfall, thus causing the road and steep slope deformation and failure.[Conclusion] The engineering activities are the main external factors causing the geological disasters. The flat, laminated and loose structure of the rock and soil mass, and the distribution of expansive clay soil are the internal factors of geological disasters.

Abstract:[Objective] The objective of this study is to reveal the development of erosion gully in a typical small watershed in the northern slope of Tianshan Mountains, in order to provide a scientific basis for early warning and control of gully erosion. [Methods] This paper selected 10 erosion gullies in the northern slope of Tianshan Mountains, field survey and GIS technology was used to investigate the characteristics and morphological formation of erosion gully. [Results] (1) There was a significantly positive correlation between the cross section area and the average width and the depth of the gully. Gully area was positively related to the length of gully. Significant positive correlations existed between gully volume and cross-sectional area, and between gully volume and gully area. No significant correlations were found among gully length, average width of gully and the mean depth. Similarly, no obvious correlation existed between catchment area and characteristic value. (2) Erosion gullies in the study area were all open-type and weak erosion type. (3) Gully density was positively correlated with the slope, as greater the gully density tended to occur at the steeper slope. However, there was no correlation existed between gully density and gully length. Gully density was the largest in the southern slope, while in the west and southwest slope, the gully density was relatively small. [Conclusion] The slope and aspect are important geomorphological factors influencing gully development at small watershed scale.

Abstract:[Objective] To increase the water resource use efficiency in a sustainable way and Provide theoretical basis for specific management in Jiangsu Province, we studied the temporal changes in relative efficiency of water resource use in Jiangsu Province from 2005 to 2014. [Methods] We collected data on water resources from 2005 to 2014 in Jiangsu Province, and calculated the technical redundancy rate, scale redundancy rate and relative efficiency of water resource use by traditional data envelopment analysis(DEA) model and its modified version; and detected significant influencing factors of the relative efficiency of water resources use using canonical correlation analysic(CCA) model. [Results] The relationship between scale redundancy rate and per capita GDP accorded with enriroment Kuznets curre(EKC), and technical redundancy rate was negatively correlated with per capita gross domestic product. The factors influencing technical redundancy rate and scale redundancy rate were not exactly the same.[Conclusion] The relative efficiency of water resource use increased steadily with the time, the main factors affecting the technical redundancy rate were water consumption per unit output value of ten thousand Yuan and proportion of the tertiary industry; but the main factors influencing scale redundancy rate were exploitation and utilization ratio of water resources and water consumption per unit output value of ten thousand Yuan.

Abstract:[Objective] The objective of this study is to analyze and summarize works on regionalization of soil and water conservation during 2014—2015 and provide support for regional comprehensive management of soil erosion. [Methods] RS and GIS technologies have been used to analyze and process data, and clarify the status and characteristics of soil erosion in Xi'an City with field investigations and data collection. Indexes were selected and analyzed according to certain principle. [Results] The whole Xi'an City was divided into six subareas of soil and water conservation, and different strategies were proposed for each subarea. The regionalization of soil and water conservation will provide important support for construction, social and economic development. [Conclusion] Soil and water conservation should be carried out on the premise of prevention first and protection priority. According to the regionalization of soil and water conservation, it is necessary to implement integrated management of soil erosion and environment in each patch by regarding center of the urban area as core and considering rivers and roads as corridor.

Abstract:[Objective] The objective of this study is to investigate the development characteristics and mechanism of the regional geological hazards in Shuitianba area in the Xiling Gorge, and to provide the basis for preventing and controlling geological disasters in the region. [Methods] The type, size, slope structure, lithology, elevation distribution and slope gradient of geological disasters were investigated in detail, and statistical analysis was done. [Results] The major geological disasters include landslides, collapses(dangerous rock) and unstable slopes, and vary from small to medium-sizes. Spatially, regional distribution was not uniform, geological disasters more developed in elevation between 300~800 m with slope range from 20° to 40 ° and belt-like geological disasters developed along the main structure and fracture. The vast majority of geological disasters were formed in three stages: Penglaizhen formation(J₃p), Suining formation(J₃s) and Shaximiao formation(J₂s) in the lithology of Jurassic, and mostly distributed in bedding slope. The geological disasters mostly occur in flooding season from June to September. [Conclusion] The internal factors affecting the formation of the geological disasters include topography, lithology, slope structure type and geological structure while external factors include rainfall, reservoir water fluctuation and engineering activities by human beings.

Abstract:[Objective] The objective of this study is to investigate the adaptability of Picea mongolica and its impact factor, and provide support for tree species selection in ecological construction in Hexi area. [Methods] According to the observation and research on the growth of P. mongolica in Hexi area and the related data of the provenance and introducing area of P. mongolica, we analyzed the adaptability of P. mongolica in Hexi area in terms of climate, seed seedling, seedling transplanting survival rate and growth rate. [Results] The temperature condition of Hexi area was suitable for the growth of P. mongolica, but soil water deficit caused by the lack of precipitation had to be solved by artificial irrigation. The growth rate of 7-year old P. mongolica was faster than that from the source area(Baiyinaobao), and the adaptability was strong, therefore, it showed a great potential in construction of farmland shelterbelt. [Conclusion] Picea mongolica has a great development potential in Hexi area.

Abstract:[Objective] The paper aims to understand the dynamic change of ecological environment vulnerability in Liangshan region from 2000 to 2010, and to provide references for regional ecological environment management and protection.[Methods] Using the technologies of RS and GIS and taking ecological sensitivity-resilience-pressure(SRP) model, we selected 16 evaluation indicators to conduct quantitative analysis on the spatio-temporal change of ecological environment vulnerability in Liangshan region during in 2000—2010.[Results] The ecological environment vulnerability of Liangshan region exhibited an overall trend of higher in south and lower in north; In terms of the single dynamic degree, the potential vulnerability was highest while moderate vulnerability was lowest, and the region's overall change speed was close to moderate level based on the comprehensive dynamic analysis, but the comprehensive index of ecological vulnerability indicated that the whole ecological environment vulnerability of the region exhibited a slow deteriorating trend.[Conclusion] The spatial distribution of ecological environment vulnerability in Liangshan region is obvious, and the ecological environment control efforts need to be strengthen.

Abstract:[Objective] The objective of this study is to analyze the vegetation dynamics and the impacts of climate change on vegetation cover in Maduo County of Qinghai Province, in order to provide decision basis for the ecological environment protection and planning of land resources. [Methods] MODIS13Q1/NDVI time series data, mean air temperature and precipitation data from 9 associated weather stations in growing-season during 2000 to 2014 were collected. Methods including maximum value synthesis, trend line analysis, correlation analysis, partial correlation analysis and multiple correlation analysis were applied. [Results] At temporal scale, NDVI had increased gradually at a rate of 0.012/10 a, which showed a good development trend for the vegetation cover in this region. At spatial scale, 65.84% area of vegetation coverage remained unchanged basically, while the increased and decreased area covered by 27.47% and 6.69% of this area, respectively. NDVI changes in the study area were mainly driven by non-climatic factors, which accounted for 83.61% of the area of the study area. In contrast, only 16.39% of the area was affected by climatic factors, of which, 3.96% was driven by a combined climatic factor of both air temperature and precipitation, 2.74% was driven by temperature and 9.72% was driven by precipitation. [Conclusion] Human activities are the key factors that affect the vegetation changes in Maduo County during the period from 2000 to 2014.

Abstract:[Objective] The study aims to evaluate the urban human settlements environment in Shannxi Province and provide a theoretical support for improving urban living environment quality and sustainable development of cities. [Methods] Taking 10 cities of Shaanxi Province as cases, we developed an evaluation system for living environment quality, and used the coupling coordination degree model to analyze the coupling coordination degree in the four subsystems, studied the temporal and spatial variations in human settlement environment in 10 cities from 2003 to 2013 in Shaanxi Province.[Results] (1) In general, the living environment quality was increasing but falling in some local areas from 2003 to 2013. (2) The quality of urban human settlements environment was spatially uneven. It was higher in Guanzhong plain while it was lower in Southern Shaanxi Province. (3) In terms of coupling coordination degree, the coupling coordination degree and coupling degree in the four subsystems of the living environment had increased but the coupling coordination degree was lagging behind the coupling degree. [Conclusion] The development of urban human settlements environment is uneven in Shaanxi Province, the provincial capital city and its neighboring urban area developed well, while urban human settlements environment developed slowly in Southern Shaanxi Province. More attention should be paid to the balanced development across different cities.