Abstract:Based on the distribution of hydrological stations, the study area was divided into 98sections controlled by hydrological stations and then, 234 soil erosion units were determined according to the different soil erosion areas. The variation of sediment yield, sediment reduction rate, and the area variation and spatial distribution were analyzed for different degrees of sediment yield in the different soil erosion areas in different control periods.The control standards for the different soil erosion areas on the Loess Plateau in the future 20years were put forwarded:Soil loss is controlled at 3.6×10⁸t and soil erosion modulus is less than 1300t/(km²·a). For the different soil erosion are-as, soil erosion modulus is 3000t/(km²·a) in loess Mao hilly and gully region,2000t/(km²·a) in loess Liang hilly and gully region, 2000t/(km²·a) in arid loess hilly and gully region, 1000t/(km²·a)in loess gentle slope hilly and gully region, 1000t/(km²·a) in wind and sand loess hilly and gully region, 1000t/(km²·a) in lo-ess piedmont hilly and gully region, 300t/(km²·a) in forest loess hilly and gully region, 1500t/(km²·a) in loess tableland hilly and gully region, 3000t/(km²·a) in loess residual plateau hilly and gully region, 500t/(km²·a) in loess terraces region, 500t/(km²·a) in wind and sand grassland region, and 100t/(km²·a) in plateau mountain and rock region.The key control areas in the future 20years are loess Mao hillyand gully region (2.20×10⁴km²), arid loess hilly and gully region(1.50×10⁴km²), loess tableland hilly and gully region(8600km²), and loess Liang hilly and gully region(4600km²).

Abstract:利用高分辨率遥感影像的判读, 结合现场调查、校核和前人资料分析, 研究了西藏自治区帕隆藏布江上游然乌-培龙段冰湖的分布变化规律。 结果发现:(1)该区有大小冰湖131个, 其中面积>0.01km²的有99个, 最大冰湖面积达到0.976km²。 (2)99个面积>0.01km²的冰湖中冰碛湖最多达68个, 占68.7%;分布于海拔4 500～5 000m的冰湖有53个,占53.3%。 (3)可对比的83个冰湖中, 冰碛湖总面积2005年为7.21km², 较1988年的7.03km²仅增加2.56%。 其中, 面积减小的有45个, 占54.2%,面积增加的38个, 占45.8%。 (4)近18a来, 该冰湖区总面积变化很小, 但部分冰湖面积增大异常, 受海洋性冰川影响, 在该区域内出现大范围冰湖溃决的可能性很小, 但暴发零星冰湖溃决的可能性很大。

Abstract:Aiming at the erosion disaster by the"7·27"rainstorm, the rainstorm central area located in Wangjiabian Town, Jiaxian County, Northern Shaanxi Province, was selected as a site to investigate the erosion situations of road, river bank, river channel, housing construction, sloping farmland, afforestation land and natural recovered grassland. Then, several typical slopes with different restoration measures were chosen to measure standing vegetation, topography, soil crust and soil erosion.The effects of different eco-logical restoration measures and recovery levels on soil erosion by the rainstorm were investigated primarily. The reasons for the erosion disaster by the severe rainstorm were analyzed. Results show that vegetation coverage, vegetation species diversity, slope and soil biological crust have the important effects on the rain-storm erosion.

Abstract:The catastrophic debris flow disaster occurred in Zhouqu County in August 8, 2010 caused greatcasualty and property damage. Survey, empirical analysis and inductive inference were made to investigatethe causes of the Zhouqu debris flow disaster by analyzing the geological conditions of the debris flow. Two main causes were the natural factors like mountain collapse by earthquake, strong rainstorm suddenly oc-curred in a particular place and antecedent severe drought, and the human factors like disordered exploita-tion, poor flood control engineering quality and unreasonable urban development planning.Thus, the deep causes were derived, i.e.,the lacks of the environmental evaluation, early warning system and mechanisms for disasters, and consciousness for preventing and reducing disasters.The measures for prevention are put forward, i.e.,early warning, accurate monitoring and rescuing emergency. The establishment of the com-prehensive system of early warning and prevention may fundamentally prevent the recurrence of similar geo-logic hazards.

Abstract:Based on the land use maps in 1995, 2000 and 2010, as well as the statistical data of cropland use in Zhengning County of Gansu Province, cropland distribution change and cropland protecting pressure were studied before and after the "grain for green" project by using ENVI, ArcGIS and SPSS.After the "grain for green" project, most of low-quality slope croplands were returned to forestland, and some of high-quality plain croplands were occupied by expanding construction land.The spatial pattern of croplands changed from scattered and irregular to concentrated and regular distribution.Factors for cropland protecting pressure in Zhengning County can be divided into artificial, policy and natural factor.The artificial factor is mainly de-termined by people's living standards and crop production conditions, the policy factor is affected by restora-tion subsidy,and the natural factor is reflected by damage area of cropland.In order to relieve cropland pro-tecting pressure in the area where the "grain for green" project was implemented, more emphasis should be placed on protecting the existing plain cropland from being occupied by construction land, stabilizing a con-siderable ecological compensation level for avoiding reclamation of the returned cropland, and limiting agro-chemical inputs in order to reduce the risk of agricultural non-point source pollution?

Abstract:Loess landslide induced by earthquake is a serious secondary disaster in Xiji County of Ningxia Hui Autonomous Region. It has special characters not only in scale but also in density, the major type of which is characterized by low angle, high speed and far distance.Xiji County is in a more active period of seismic ac-tivity at present and old landslides may easily revive in the case of continuous rain and heavy rain or earth-quake, with a serious threat to people's lives and property and severe influences to local economic construc-tion. Based on detailed field data from geological disasters surveys in the county, a classified statistic of seis-mic loess landslides are made by size, formation age, thickness of sliding mass and other aspects.Then the boundary characteristic, surface and inner characteristic, deformation characteristic and sliding characteristic of the landslides are analyzed.Furthermore, the spatiotemporal distribution of the landslides are summa-rized. The research may provide a theoretical basis for the forming mechanisms of the landslides.

Abstract:The upper Hanjiang River basin is the water source area of the middle route of the south to north water transfer project. Thus, water conservation and eco-environmental construction in the middle route of the south to north water transfer project is of great importance.Due to serious water environment pollution and soil erosion in the upper reaches of Hanjiang River, the ecosystem of the basin is degrading. Water sam-ples were measured and soil and water loss was analyzed based on the observed data.Results showed that(1)water quality of Ankang Reservoir declined, especially nitrate nitrogen(NO₃-N)increased from 0.32 to 0.99mg/L 20years after water storage, increasing by 209.3%.(2)Water quality of Danjiangkou Reservoir was relatively better, but the average annual total nitrogen was in theⅣ grade and other indexes of water quality were in theⅠorⅡgrade.(3)Soil and water loss increased.In 2009, the total erosion modulus in the whole basin was more than 5000t/(km²·a); in Ankang City(7counties/district), as high as 16352t/(km²·a); and in Shiyan City, 3528t/(km²·a). The total amount of soil erosion was in the order of Ankang(7counties/district)>Hanzhong(7counties/district)>Shangluo(3counties/district)>Shiyan, which shows an increasing tendency.Therefore, the following countermeasures are put forward:strengthening water en-vironment pollution control, enhancing soil and water conservation and legal system construction, improving eco-environmental protection management and strengthening environmental infrastructure demonstration for private engineering project.

Abstract:An evaluation index system for the eco-environment population carrying capacity of Wuan City is designed based on ecological footprint theory. Ecological footprint model is applied to analyze the eco-envi-ronment population carrying capacity in 2000-2010. The sustainable development stature and driving factors are analyzed with the help of SPSS.Results show that the contradiction between ecological footprint and eco-logical carrying capacity was more prominent in 2000-2007. After 2007, the contradiction was alleviated to-wards a sustainable development through the transformation of economic growth and the improved utilization of natural resources.The population carrying capacity was strongly influenced by the per capita fossil fuel footprint that is the main factor for the dynamic change of ecological carrying population in Wuan City.

Abstract:Through the field investigation in the upper reaches of Hanjiang River, 4modern flood level marks after 1983were found on housing walls in Jiahe and Yangwei Towns of Baihe County. The ages of the 4flood level marks were determined accurately through local interview and consulting data.Then their peak dischar-ges were quantitatively figured out by the hydrology principle of slope-area method.Compared with the data observed from Baihe hydrological gauge station, the errors were found to be 0.5%～5.3% for Jiahe Town and-0.2%～5.1% for Yangwei Town. The result showed that flood level mark in river channel can be used to check peak discharge for an abrupt flood disaster under the influence of global climate change. It can not only improve the accuracy of flood discharge estimation in the river section short of hydrological data, but al-so provide the scientific data for water resources development and flood hazards mitigation.

Abstract:The western pipeline of PetroChina has, at present, the longest transportation distance among the petroleum pipelines in China. Because the pipeline was paved mechanically, original landform, top soil and vegetation were destroyed, which reduced soil anti-erodibility and caused soil and water loss.The natural sit-uation was firstly summarized and then, soil and water loss and its impacts on ecological environment were analyzed for the pipeline in Gansu Province.The "three synchronous steps" principle must be insisted on.In addition, the measures should be taken according to the following policies, such as the combination of com-prehensive control with comprehensive exploitation, scientific allocation of control measures, and prevention of soil erosion newly occurred

Abstract:The Xitiao River is the main branch of Taihu basin.Due to the disturbance of human, the river health has been damaged and its functions have been reduced gradually. Based on the meaning of river health, 3first-grade diagnostic indexes were selected, namely river morphology, social economic function and ecologic function. 18 second-grade diagnostic indexes were then determined by considering the present health status and obtained data of the Xitiao River. A multi-objective and multi-layer fuzzy model was used to diag-nose the river health and determine the index standard character values and the index weights.Through cal-ulation and analysis, the Xitiao River health was almost in the middle and good condition. The main factors were the changing river morphology and worse water quality.It is suggested that the main restoration meas-ures are to create diversity habits, control non-point source pollution and built adapting management pro-grams of reservoirs

Abstract:In order to speed up the development of rural economy, protect agricultural eco-environment and keep the ecological environment and economic development balanced in Suihua City of Heilongjiang Province, using the methods of entropy, evaluation and the model of coordinate development, the coordination between agricultural eco-environment and rural economy are analyzed based on the statistics of Heilongjiang Province and Suihua City in 2000-2009. Results indicate that the integrated development index for agricultural eco-environment and rural economy shows an upward trend, which implies that rural economic development is faster than agricultural eco-environment construction. The curve of coordinated development shows an up-ward trend, being the coordinated development with high quality.Before 2007, rural economic development was slower than agricultural eco-environment construction, whereas,from 2007, agricultural eco-environ-ment construction lagged behind rural economic development, which indicates that agricultural eco-environ-ment limits rural economic development at present.Some measures should be taken to deal with the “three wastes” pollution, to develop recycle economy in rural area, to use fertilizers and pesticides rationally and to reduce the pollution and destruction of agricultural eco-environment, so as to make agricultural eco-environ-ment develop with rural economy sustainably and harmoniously

Abstract:The carbon emission caused by various factors during the crop production process can be roundly evaluated using carbon footprint of farmland, which is an important indicator that can provide a guidance for energy saving and emission reduction in agricultural industry. In order to find out the carbon footprint of crop production, the carbon footprint of Pingluo County in Ningxia Hui Autonomous Region is calculated based on the investigated data of farmland production in the county by using basic theories and research ap-proaches of carbon footprint.Results show that the carbon footprints of rice, corn and wheat are 1 487.56±164.59, 913.03±142.99 and 809.75±144.99kg Ce/(hm²·a) and the carbon costs, 0.17±0.05, 0.08±0.02and 0.12±0.03kg Ce/kg, respectively. The application rate of chemical fertilizer is a main influence factor for the carbon footprint.Additionally, irrigation water and seedling production are the key causes of high-carbon footprint during rice production. To improve the benefits of fixing carbon, reducing emissions and adding carbon sinks of farmland, rice planting area should be reduced and corn and wheat planting areas should be expanded.Meanwhile, the construction of fertilizer-saving, low-carbon and efficient agricultural cropping patterns is an effective way to realize energy saving and emission reduction of the farmlands in Pingluo County

Abstract:In order to understand the situation of intensive land use completely and evaluate the reasonable de-gree of intensive land use correctly, an evaluation indicator system for intensive land use is established from economic, spatial and ecological performances.By applying FAHP method to the calculation of index weights, the compound evaluation model established by fuzzy comprehensive evaluation and comprehensive index evaluation methods is used to assess the situation of intensive land use in the Xi'an economic and tech-nological development zone. Results show that the score for the reasonable degree of intensive land use in thezone is 78.67, indicating that intensive land use in the zone, as a whole, is rational, the reasonable degree of economic and spatial performances is ordinary, and ecological performance is very good.Finally, some sug-gestions are proposed according to the evaluation result. The study may provide reference for the quantitative evaluation of reasonable degree of intensive land use, regional land use and development orientation, as well as planning and decision-making.

Abstract:Vulnerability characteristics of the Huaihe River floods are analyzed based on the historical disaster data to represent the vulnerability of hazard bearing body.The impact factors for the flood vulnerability are investigated by means of the gray relational analysis method for the inversion of food vulnerability indices. Results show that(1)the vulnerability of flood disasters in the Huaihe River basin decreases from the stem river to both sides. There is also a south to north decreasing trend in the whole basin. (2)The GDP per capi-ta, annual precipitation and the density of population in the basin have a significant correlation with the vul-nerability of flood disasters. (3)Waterlogging control area and flood control area are weakly correlated with the flood vulnerability.The study may provide a scientific basis of policy making and adjustment for regional disaster mitigation.

Abstract:The evaluation of coordination degree between land use and socio-economy is of great significance to guide the development of land use and socio-economy in a region.The index system and model for an com-prehensive evaluation of land use and socio-economy in Gulang County were constructed by referring to the concepts of coordination degree and coordinated development degree.Accordingly, aquantitative assessment was made for the relative/absolute coordination degree and coordinated development degree between land use and socio-economy from 2000to 2008in the county. Results from the research indicated that the change in the grade for relative coordination degree was greater, which belonged to the models of rapid economic devel-opment in 2001, 2002and 2006, retreated land use in 2003, and rapid land use development from 2004to 2005and 2007to 2008.The grade for absolute coordination degree was high, which belonged to the models of intermediate coordination in 2000and high-quality coordination in the other years. The coordinated devel-opment degree showed an upward trend year by year and underwent a transformation from the model of the slight maladjustment with a socio-economy lag to the model of the good coordination with a land use lag.

Abstract:The nutritious balance method and theory by Truog were used to estimate the main source of agri-cultural non-point source pollution, i.e., the total excessive nitrogen, and outline the changing trend on the relation of rural resident′s consumption level to agricultural excessive nitrogen pollution in Jiangsu Province by compiling Jiangsu Province′s agricultural production data in 1990-2007. Based on the stationarity test analysis of time series data, the simulating model projected that the correlation of excessive nitrogen emission to per capita consumption was well fitted by a cub-regression curve.Results indicated that:(1)Nitrogen in Jiangsu Province′s agricultural production has been excessive since 1990. In 2007, the total excessive nitro-gen reached as high as 1.487 million tons, 8.38 times of that in 1990. Per capita living consumption of rural residents increased from 787yuan in 1990 to 4792 yuan in 2007, with an average annual increase rate of 11.6% over the 17 years. (2)The study supported the evidence that the environmental Kuznets curve(EKC) was a possibility rather than a necessity, which had various forms, different turning points, and different time spans to the turning point appearance in different countries and regions. (3)The simulated correlation curve did not fully meet the standards of the EKC, or rather it showed N curve characteristics. In the end, we proposed that the governments should actively provide farmers with the guidance on the rational applica-tion of fertilizer, improvement of fertilizer use efficiency, and controlling agricultural non-point source pollu-tion through the development of efficient ecological agriculture and recycling agriculture.

Abstract:Intensive use of cultivated land plays an important role in national food security and sustainable economic and social development.By taking He′nan Province as an example, an evaluation index system of cultivated land is designed, which consists of the four primary indexes of input intensity, utility intensity, output effect and persistent state.Intensive use of cultivated land in He′nan Province from 1996to 2008is analyzed and its obstacle factors are revealed using entropy coefficient and catastrophe progression methods. Results indicate that:(1)The intensive use degree of cultivated land showed an increasing trend from 1996 to 2008, and a narrow range fluctuation influenced by natural disasters in 2002-2004. (2)The input intensi-ty, utility intensity, output effect and persistent state all showed an increasing trend from 1996to 2008. (3)The main obstacle factors influencing the intensive use level of cultivated land from 1996to 2008were the farm electric power input per area, farm machinery power per area, profit per area and urbanization level. The governments should increase investment in agricultural infrastructure, promote farmers′enthusiasm for production and improve the anti-disaster capability of agriculture.

Abstract:Land use is a result from the interaction between nature and human. Land use change affects not only landscape pattern change, but also ecosystem service value. By taking Changshou District of Chongqing City as an example, landscape indexes were selected and calculated, and landscape pattern change of the dis-trict was analyzed using RS and GIS technologies. The theory of ecosystem service values was used to ana-lyze the change of ecosystem service values of Changshou District from 2002 to 2009. Results showed that the total patch number for the landscape increased somewhat in seven years, and the patch areas and numbers of forest land, brush, town and residential land increased, while the patch areas and numbers of paddy, dry land and unused land decreased.The landscape diversity and landscape fragmentation index of the district in-creased slightly.Besides, the valuation of the ecosystem service of Changshou District ascended from 191 million yuan to 197million yuan in the past seven years, with a net ascendant value of 61million yuan, in which wood land played a greater role in ecosystem service values.The result showed that the ecological en-vironment had been improved somewhat.

Abstract:Evaluation of the farmland shelterbelt ecosystem service is of vital importance due to its practical application in regional economical development and ecological environment protection.In this case, farmland service function value of He′nan Province from 2001to 2005was evaluated by applying methods including market price, opportunity cost, and shadow price.Results showed that the total ecological service function value of the farmland in 2001and 2005were 1.04×10¹⁰ and 1.46×10¹⁰ yuan, respectively. The ecological service function index values followed such a decreasing order:soil protection>crops yield increment>biodi-versity protection>CO₂fixation and O₂release>air purification. The increment of total ecological servic was 1.53×10⁹ yuan each year. The service of soil conservation increment value was the largest(9.94×10⁸ yuan), followed by soil protection(3.01×10⁸ yuan), crops yield increment(1.25×10⁸ yuan), biodiversity protection(7.00×10⁷ yuan), CO₂ fixation and O₂release(3.77×10⁷ yuan), and air purification(7.79×10⁵ yuan). Due to the fact that the ecological service function value of the shelterbelt is tremendous, it is sugges-ted that ecological service market compensation mechanisms and perfected ecological service function valuated should be established as early as possible, so as to extend the farmland from an ecological style to an ecologi-cal and economical style.

Abstract:Based on 3 year(2007-2009) continuous observations, characteristics of woodland hydrological effects from the three typical models of converting cropland to forest were studied in Lanningxi small water- shed of the Three Gorges Reservoir region.Results are as follows:(1) Compared with sloping farmland,t he total soil porosity and non-capillary porosity increased from 4.2% to 11.5% and 69.1% to 162.6% , respec- tively. The maximum soil water capacity and non-capillary water capacity increased by 42.5% and 221.4% , respectively, after converting cropland to forest. (2)Initial infiltration rate and stable infiltration rate in A layer for each of the three models were between 2.73and 4.74mm / min and 1.30and 2.96mm /m in, respec-tively, which had no great differences from those on sloping farmland; and in B layer, between 0.14～0.87 mm/ min and 0.06～0.47mm/min, respectively, which were 0.85～5.21and 3.33～6.83times of those on sloping farmland. (3)The surface runoff depths for the three models were between 13.21 and 22.38mm, which were reduced by 74.7%～57.3% as compared with those on cropland.The average annual soil erosion modulus for the three models were between 137.1and 331.1t/km², which were reduced by 92.4%～81.6% in contrast to CK.

Abstract:Analysis of the economic benefits of land consolidation is an important content of land consolida-tion. With an attempt to apply extension theory and method to land arrangement project, the models of clas-sical field matter element, controlled filed matter element and evaluation matter element are constructed for the economic benefits of land consolidation.The incidence function model is also established using the exten-sion method of distance. A comprehensive correlation degree model for evaluation index and standard grade is then established based on the simple correlation function calculation of index weights. Finally, weighted pro-cessing is adopted for the correlation values and a series of weighted correlation values are obtained. The weighted correlation values are normalized to get average correlation values. When the method is applied to the actual project, the grade for the calculated economic benefits is 2.204, being in a "good" level. The re-search proves the scientific and practical nature of the evaluation model for land arrangement project benefits based on the theory and method of extenics and provides a new approach to the quantitative evaluation of land consolidation economic benefits with a good result.

Abstract:Under the action of the Wenchuan earthquake, the integrity of some mountains was destroyed and some slits appeared on the mountains. Main shocks caused soils and rocks damaged and its self-strength de-clined. The quantity of rainfall-induced landslides after the Wenchuan earthquake was much more than that before the earthquake.Five types of the landslides caused by the earthquake were classified based on the in-vestigation of rainfall-induced landslides after the Wenchuan earthquake. Active characteristics of rainfall-in-duced landslides were mainly embodied in the small and tremendous landslides widely developed along rivers and roads.Landslides and rainfall in the area had a better relationship and the delayed-time for the occurrence of landslides was very short.Massive landslides were developed under the condition of intensive rainstorms. In view of the development trend of rainfall-induced landslides, the small and medium landslides are dominant in the early time.However, the number of the small landslides will decrease but large or huge landslides will increase with increasing time.

Abstract:Flow velocity is one of the most basic and important hydraulic parameters. Clarifying the variation of rill flow velocity is of importance to reveal the mechanisms of dynamic rill erosion processes. Rill flow ve-locity on loess hillslope is studied through a multi-plot experiment under simulated rainfall with the addition of a steady in-flow at the top of the multi-plot system. The main findings are as follows:(1)Rill flow veloci-ties for different rainfall intensities decrease with runoff duration, which can be well described by an expo-nential equation.The decrements are great 6 min after runoff generation and then decline. The tendencies arebasically consistent for the decrements at different intensities. (2)Rill flow velocities for different slopes also decrease with runoff duration, which can be described by an exponential equation.The tendencies for the decrements on different slopes are consistent. The decrements are basically consistent during the whole run-off process. (3)The mean flow velocity increases with increased rainfall intensity, which can be well de-scribed by a logarithmic equation, and increases with increased slope steepness, which can be well described by apower equation. A dual logarithmic equation can be used to describe the variation of the mean flow ve-locity with rainfall intensity and slope

Abstract:Changes of relative humidity and vegetation coverage in Weihe River basin were studied and the effects of vegetation restoration on air relative humidity were analyzed quantitatively by using GIS, remote sensing technology and statistical methods.It was observed that:(1)The relative humidity had a latitude zonal distribution character, increased from north to south. The overall average relative humidity of Weihe River basin declined gradually and presented an upward trend during the last 10 years. (2)The overall vegetation coverage was improved, while the local vegetation coverage presented a bad trend. Nearly a third of basin was stable .Counties(cities) with an obviously improving trend were mainly located along the main stream as well as in the upper reaches of Jinghe River and Malian River and the middle reaches of Beiluo River. Counties(cities) with a degrading trend were mainly located in the middle and lower reaches of Weihe River and the middle and the upper rea-ches of Jinghe River. (3)Before the implementation of vegetation restoration, the main influence factors were precipitation, sunshine and temperature. After the implementation of vegetation restoration, the rela-tive humidity increased or decreased with the vegetation cover condition improving or degrading. (4)The NDVI in Wuqi County was negatively correlated with the winter relative humidity and yearly averaged rela-tive humidity. There was a significant positive correlation between the NDVI and the relative humidity in spring and summer. During the period from 1982to 2006, vegetation condition in summer had the same trendas relative humidity.Vegetation condition was better or worse when relative humidity was high or low.

Abstract:The characteristics of Cu²⁺ adsorption-desorption by soils in the Yellow River Delta were studied using isothermal equilibrium adsorption method.Differences in the adsorption-desorption capacity of soils in farmland and unused land were compared and the reasons for the differences were analyzed. Results showed that the adsorption capacity for the two types of soils increased with Cu²⁺ equilibrium concentration. he adsorption characteristics could be simulated by Langmiur, Freundlich and Temkin models.Langmuir model was found to be the best one. The maximum adsorption capacity of soil was 3961mg/kg for farmlandand 3 521mg/kg for unused land, respectively. The Cu²⁺ adsorption capacity of soil in farmland was much higher than that in unused land. The Cu²⁺ desorption capacity was far lower than the Cu²⁺adsorption capaci-ty. There was an obvious lag period of the Cu²⁺ desorption by soil in unused land, as compared with that in farmland. The Cu²⁺ desorption ratio for soil in unused land was greater than that in farmland, and the de-sorption ratio was between 0.1% and 0.35%in farmland and between 0.15% and 1.8%in unused land, respectively. The results from the comprehensive analysis suggest that the differences in the adsorption-desorption for the two types of soils are related with soil organic matter content which leads to more adsorp-tion points on the soil colloid surface in farmland.

Abstract:Ten runoff plots with different planting patterns were established for experimental observation in the Longli soil and water conservation demonstration area of science and technology in karst region of Guizhou Province.Results show that under the same rainfall condition, shrub land(such as Rubus idaeus), natural grassland and abandoned land presented the best function of soil and water conservation. Runoff yields on the three kinds of land were 0.71, 0.74 and 0.71m³ and sediment yields, 20.3, 20.3 and 20.16g. The function of soil and water conservation was poor for arbor planting pattern, because the shrub layer, herb layer and forest floor were not formed. Runoff yields for the three plots with arbor planting pattern were 1.18, 0.98 and 0.95m³ and sediment yields, 119.56, 126.56 and 125.89g. Because of no-tillage, sur-face crust and other effects, the function of soil and water conservation in slope farmland was better than that in runoff plots with arbor planting pattern.

Abstract:In order to study nitrogen and phosphorus losses on red-soil sloping land, field experiments under three typical natural rain events were performed to investigate the N and P transferring processes and their characteristics in the SWC Ecological Science and Technology Demonstration Park of Jiangxi Province.Re-sults showed that under the condition of natural rainfall, the processes of runoff and sediment on natural slope were not stable and continuous and had one or more peak values, because rainfall intensity was not sta-ble and continuous.The processes of runoff and sediment on natural slope were basically the same for the same rainfall event. The cumulative sediment yield and cumulative runoff with time showed a slight growth and then a rapid growth, and tend to change smoothly. The concentration of phosphorus was lower than that of nitrogen, and changes in P concentration were more stable than those in N concentration.There were nu-trition enrichments in eroded sediment, and the N enrichment ratio was lower than the P enrichment ratio under the three rain events.

Abstract:By selecting the research region located in Houzhai River basin of Puding County in central karst region of Guizhou Province, water samples of perennial spring water in forest area, farming area, rural resi-dential area and town residential area were collected and analyzed to investigate the influence of urbanization on the N and P concentrations in shallow groundwater and the change of water quality. Results show that the concentrations of NO^-₃and NH⁺₄in shallow groundwater were within 1.18～43.6 and 0.017～0.290mg/L, respectively, of which the concentrations of NO^-₃and NH⁺₄in the shallow groundwater of forest area, farm-ing area and rural residential area were in the range of the classⅢ water quality, but the concentration of NH⁺₄in town residential area was beyond the classⅢ water quality. The concentration of total P was within 0.012～0.682mg/L, but in rural and town residential areas, the concentration of total P exceeded the limit of water quality. The contents of N and P in groundwater increase in the process of urbanization, which ex-erts a significant impact on groundwater quality in the karst hilly area.

Abstract:To further understand and assess the effect of oil exploitation on soil environment in the Longdong region of the Loess Plateau, China, soil microbial-community characteristic and its relation with soil environ-mental factors under different oil pollution degrees were investigated by using plate culture and multivariate analysis. Results show that:(1)as for the total number of soil microorganism, the site plots(S_1-3)surround-ing oil pollution sources(30m)demonstrated the top, and followed by the site plots(S_7-9), 200 maway from the pollution sources, as well as the site plots(S_4-6), 100 maway from the pollution sources, demonstrated the bottom. Besides, the group of actinomycetes with a smaller number played a more important role in the change of Shannon-Wiener index. (2)The environmental factors including soil organic matter, TPHs, saltrate and available P in the site plots(S_1-3)demonstrated the top but the bottom in the site plots(S_7-9); and however, soilp H, available N and available K in the site plots(S_7-9)demonstrated the top but the bottom inthe site plots(S_1-3). (3)Principal component analysis(PCA)indicated that soil TPHs exerted the greatest in-fluence among the 8 environmental factors, and its increase directly developed the content of soil salt, organic matter and available P, which further affected other environmental factors including soil moisture, pH vaule, bacteria, fungi, actinomycetes and even total microbial amount. The results above revealed that rational de-velopment of soil bacteria and actinomycetes resources and exogenous supply of nutrition concerning N and Kcould stimulate the growth of native oil degradation bacterium and then raise the petroleum hydrocarbon deg-radation efficiency during the process of bio-remediation on petroleum-contaminated soil in the Longdong re-gion of the Loess Plateau, China.

Abstract:Application of polyacrylamide(PAM) in soil can not only improve rainfall infiltration rate, but also reduce soil erosion. Usually, PAM is applied on soil surface. In order to study the effects of the mixtures of PAM with other soil conditioners on rainfall infiltration rate and soil erosion, six application treatments were evalua-ted by mixing PAM(22.5kg/hm²) with superabsorbent polymers(45kg/hm²), fly ash(1500kg/hm²) and hu-mic acid(900kg/hm²). Results showed that the application of PAM mixed with soil conditioners could sig-nificantly increase rainfall infiltration rate and reduce soil erosion.Rainfall infiltration rate was 1.8 to 2.7 times higher than the control, while soil erosion rate was reduced by about 50% to 70%. The mixture con-taining PAM, fly ash and humic acid had the most significant effect on the increase in infiltration rate. Mixing PAM with superabsorbent polymers led to the greatest reduction of soil erosion.Moreover, there was no significant differ-ence when PAM was applied alone and mixed with fly ash and humic acids.Overall, the application of PAM mixed with fly ash had the best effect on the increase of rainfall infiltration and reduction of runoff. Soil erosion re-sistance was the best when PAM was mixed with superabsorbent polymer.

Abstract:Dynamic closed chamber IRGA method is used to study the relationship between soil respiration and temperature of four deserted grassland communities, i.e., Artemisia desertorum, Leymus secalinus, Glycyrrhiza uralensis and Agropyron crisatum, in grazing and enclosed plots, and reveal their effects on soil respiration in enclosed plots.The main results are as follows:The diurnal patterns of soil respiration rate in grazing and enclosed plots manifest a single-peak asymmetric curve, and the maximum soil respiration rate occurs at 14:00-16:00. Soil respiration rates in enclosed plots are higher than those in grazing plots, but the significant differences are distinct in the communities of the grazing and the enclosed plots at certain time. The correlation between soil temperature and soil respiration rates at 10 and 15cm depths are higher than that at 5and 20cm depths.At 15cm depth, air temperature is well correlated with soil respiration rate. Be-sides the Artemisia desertorumcommunity, the Q₁₀ values of other plant communities in grazing plots are re-markably lower than those in enclosed plots. The Q₁₀ values are in the order of Artemisia desertorum>Ley-mus secalinus>Glycyrrhiza uralensis> Agropyron crisatum.The Q₁₀ value of Artemisia desertorumcom-munity is greatly above other communities.

Abstract:The earth's surface erosion by runoff is essentially a result from gravitational potential energy of running water.Started with energy accumulation of slope running water, basic concepts and computational principles of the potential factor for running water erosion reflecting erosive power of original slope were presented.Algorithm of the computation for the potential factor was designed based on the high precision DEM, computation of the potential factor was completed for a simulated multiphase watershed, and the re-sult corresponding to erodent power points was acquired based on the potential factor. The spatial distribu-tion characteristics of erosive power points were analyzed and then, some preliminary discussions on the evo-lution of topography were made.Results showed that the research on slope erosion degree and its evolution in use of the potential factor is of theoretical significance and practical value.

Abstract:The objective of this laboratory experiment was to determine if leaf litter from deciduous tree spe-cies could be used to improve the chemical properties of a degraded soil in a coniferous forest in the gully re-gion of the Loess Plateau. Results showed that:(1) The application of Populus simonii leaf litter to a Platycladus orientalis forest soil significantly increased soil alkali-hydrolyzable N, organic C, and humin. The application of Hippophae rhamnoides leaf litter to a Pinus tabulaeformis forest soil significantly increased available P and to a Platycladus orientalis forest soil significantly increased pH value, available P, available K, and fulvic acid. The application of Caragana microphylla leaf litter to a Pinus tabulaeformis forest soil significantly increased available K, organic C, humic acid, and humin. (2) Leaf litter from Hipp-ophae rhamnoides had the greatest overall effect on Pinus tabulaeformis forest soil, followed by leaf litter from Caragana microphylla, Quercus liaotungensis, Populus simonii, and then Robinia pseudoacia. For the Platycladus orientalis forest soil, the positive effects of leaf litter declined in the order of Populus simo-nii > Hippophae rhamnoides > Quercus liaotungensis > Caragana microphylla > Robinia pseudoacia.

Abstract:In order to understand the effects of different improving patterns for badly degraded Robinia pseuc-doacacia plantation in the Yellow River Delta area, soil enzyme activity, soil density, porosity, saline-alkali content and soil nutrients under the plantation improved for five years were determined. Four improving measures, including cotton field, pure forest of Fraxinuschinensis, agro-forestry of F. chinensis + cotton and mixed forest of F. chinensis + R. pseucdoacacia, were selected, with the badly degraded R. pseuc-doacaciaplantation serving as the control (CK). Results are as follows:(1) The improving patterns clearly affected soil phosphatase, urease and polyphenol oxidase, but not soil peroxidase. Soil phosphatase and ure-ase activity increased, but soil polyphenol oxidase decreased. The activities of polyphenol oxidase and urease showed such an order of mixed forest>pure forest>agro-forestry>cotton field. Phosphatase activities in mixed forest, agro-forestry, pure forest and cotton field were 3.5, 3.2, 1.7and 1.6times of that of CK, re-spectively. (2) Soil density and soil salt content decreased after adopting the four improving patterns, a nd these indexes were in the order of mixed forest

Abstract:The radius, number and distribution of soil macropores under eight types of vegetation in the semi-arid region of western Liaoning Province were investigated using water breakthrough curve and Poiseulle equation. Results showed that under the different vegetations, the radii of soil macropores ranged from 0.5 to 2.3mm; weighted mean radii varied from 0.61 to 1.85mm ; and the overall mean value was 0.95mm, nearly two times the coarse aeration porosity standard. The macropores with the radius larger than 1.4mm accounted for only 2.73% of total macropore number and between 1.5 and 1.4mm, 97.27%, which showed that large radius pores were more than small radius pores. Soil macroporosity under the different vegetations ranged from 0.95% to 5.24%, which means that soil macropores constituted a small portion of soil volume. However, the mean radius of soil macropores was significantly correlated with steady effluent rate and satu-rated hydraulic conductivity. The mean radius determined 71% variances of steady effluent rate and 50% of saturated hydraulic conductivity.

Abstract:Rainfall erosivity shows the potential soil erosion induced by rainfall and is very important in pre-dicting soil erosion quantitatively. With the daily rainfall data from 12 meteorological stations in Jialing River basin, rainfall erosivity in the basin was estimated and its spatiotemporal variability was analyzed by using the daily rainfall erosivity model. Results showed that the spatial characteristic of rainfall erosivity was con-sistent with the spatial distribution of rainfall, declining from southeast to northwest and varying from 800 to 9000MJ·mm/(hm²·h·a). The inter-annual variation was great and C_v was between 0.346 and 0.493. However, result from Mann-Kendall test showed there was no significant trend of variation except Pingwu station with a decreasing trend. Rainfall erosivity presented seasonal dynamics in the whole year. The sea-sonal distribution of rainfall erosivity was highly centralized and rainfall erosivity from June to September oc-cupied 80% of the whole year. Rainfall erosivity had the periods of 21 and 35 years and different rainy-drier periods in the last 50years. Through the study, there was no significant trend of variation in annual rainfall erosivity, but rainfall erosivity was relatively concentrated in the summer and autumn. Therefore, some measures should be taken to prevent soil erosion or other disasters in flood season.

Abstract:Saline concentration and corresponding indoor hyperspectral reflectance spectra for seashore saline soil samples were taken as research objects.Characteristics of reflectance spectra and the distribution pattern of soil salinity were analyzed in detail.Accordingly, correlations between soil salinity and its reflectance spectra and transformation of spectra were discussed deeply. Then, estimation models of soil saline concen-tration were established by using multivariate stepwise linear regression and curve estimation method. Re-sults showed that the reflectance spectra ranging from 400to 900nm presented a feature of decreasing firstly and then gradual increasing, while from 600to 625nm, the reflectance spectra had a large difference for dif-ferent soil samples.There existed significant correlation between soil salinity and first derivatives of reflec-tance spectra and its inverse. The largest correlation coefficient was up to 0.739. Soil salinity can be best es-timated by using S function and the R² was 0.555. The research may provide a new measure for further dis-cussing the rapid detection of soil salinity at a large scale.

Abstract:By selecting two cultivars of Kenjiandao 5(K5) and Kendao 12(K12) as materials and measuring soil water potential(SWP) by soil moisture tensiometer, the effects of water supply on rice quality in grain filling stage were studied using potted planting method within a rainproof chamber.The primary results indicated that in the intermittent irrigation treatment with the SWP of-8～-10kPa in grain filling stage, the head rice rate for K5 was increased and its chalkiness rate and chalkiness degree was decreased, while the head rice rate for K12 was decreased and its chalkiness rate and chalkiness degree were increased.The amylose content, fat content and protein content of grains at each grain position of two varieties were enhanced and the rice taste values for the two varieties were reduced. In the unremitting irrigation treatment with the SWPs of-18～-20kPa and -28～-30kPa before the filling stage, the head rice rate for K5 was increased; the head rice rate for K12 was increased and its chalkiness rate and chalkiness degree were decreased; the length/width and protein content at each grain position of the two varieties were increased; and the rice taste values for the two varieties were reduced.

Abstract:By selecting two cultivars of Kenjiandao 5(K5) and Kendao 12(K12) as materials and measuring soil water potential(SWP) by soil moisture tensiometer, the effects of water supply on rice growth, development and yield before heading stage were studied using the potted planting method within a rainproof chamber. The primary results indicated that in the intermittent irrigation treatment with the SWP of-8～-10kPa before heading stage, the economic yield for K5 was increased and for K12, decreased. The Leaf-age courses for the two varieties were brought forward slightly and the plant heights were increased, while the stem numbers were decreased. The yields for K5 and K12 were decreased by unremitting irrigation under SWP of -18～-20kPa and -28～-30kPa before heading stage. The leaf-age courses for K5were lagged at begin-ning and then developed fast, while for K12, lagged during the whole growing stage. The plant height, s tem number, dry matter content and leaf area index for K5and K10were all decreased significantly. The intermit-tent irrigation treatment with the SWP of -8～-10kPa before heading stage can be used as irrigation index to harvest high yield and high quality rice in cold region, but it is not suitable to keep unremitting irrigation treatment with the SWP of-18～-20kPa during the stage before heading.

Abstract:Based on the average daily temperature, average daily maximum and minimum temperature data from the weather stations of Ejina Banner in the oasis of Ejina Banner in the 1960-2010s, the methods like s climate trending rate and correlation analysis were used to analyze the varying characteristics of beginning and ending dates of annual growth period, day number of growth period, and beginning dates of leaf expansion and yellow leaf stage for the Populus euphratica, as well as its response to climate change. Results showed that in the recent 51 years, the beginning date of annual growth was becoming earlier, but the ending date was becoming later; the annual growth period was prolonged; and the beginning date of leaf unfolding was becoming earlier and the beginning date of yellow leaf stage, slightly later. Correlation analysis shows that the beginning date of annual growth was greatly influenced by the average temperature in March and the end-ing date, by the average temperature in October. There was a significantly positive correlation between the growth period and the average temperature from March to November. The average temperature in April had a significant influence on the beginning date of leaf unfolding, and the correlation between them was negative with a correlation coefficient as high as 0.6782(α=0.001). The average temperature in September had a maximum influence on the beginning date of yellow leaf stage. The higher average temperature in Septem-ber, the later the beginning date of yellow leaf stage was. Therefore, there was an obvious response of the Populus euphraticato climate change in the study area.

Abstract:Based on the meteorological data of 57years in Yulin, Suide, and Yan′an of North Shaanxi Prov-ince areas, the meteorological factors and disasters were studied. Results indicate that the annual precipitati-on was decreased in warm events happened years and the average temperature was increased in warm events years. Compared with normal years the precipitation was decreased at 61. 59, 7 6. 10, 73. 33mm and average temperature was increased at 0.23, 0.13, 0.11℃. The precipitation and average temperature was decreased in cold events happened years. Compared with normal years the precipitation was decreased at 15.68, 25.61, 41.89mm and average temperature was increased at 0.22, 0.15, 0.24℃. Drought disaster was prone hap-pened in ENSO events years. The probability of drought meteorological disasters was greater than the proba-bility of La Nina years.

Abstract:Change of hydrological processes and its influence mechanisms are complex. On one hand, climate change and human activities affect hydrology and water resources ; and on the other hand, hydrology and water resources show responses to the impact. The duality and uncertainty make the research on the issue more complex and developed very slowly. Domestic research in this field is still at an early stage. This paper summarizes the latest research progress of hydrology and water resources effects caused by climate change and human activities at home and abroad, points out the weak links of the research in this field, and looks forward to the main research direction in future. It is found that the existing researches were mainly focused on a single factor of climate change or human activities impacting hydrology and water resources. However, there were few researches combining these two factors and making aquantitative distinction. In future, quantitative research should be enhanced and the importance of each factor should be separately identified, which are of importance to strength the research in the field.

Abstract:Ecological slope protection in highway engineering can not only prevent soil erosion effectively, b ut also has obvious effects on the reconstruction of biotope and the recovery of eco-system. Four types of typical ecological slope protection in Ba′nan and Nan′an Districts of Chongqing City, i. e. , bare slope, rhombic-structure grassing slope protection, tree slope protection and grassing slope protection, were selected to study the changes in soil erosion rate, relative coefficient, average soil erosion modulus, vegetation coverage, soil ingredient, etc. on each side slope. Results show that:(1) Among the four types of ecological slope pro-tections, the protective effect of the rhombic-structure grassing slope protection was the best; the tree slope protection, better than the grassing slope protection; and the bare slope, the worst. (2) The change of soil ingredient was affected not only by soil loss, but also by vegetation. (3) The soil and water conservation effect of the grassing slope protection was better than that of the rhombic-structure slope protection. In the late period, grass coverage increased slowly and thus the recovery effect of the grassing slope protection was worse than that of the rhombic-structure slope protection. (4) For the necessary elements in vegetation growth, soil loss for the rhombic-structure slope protection was relatively balanced.

Abstract:This research was conducted to investigate land use patterns and soil types in Zhaozhuang, a village of Yan′an City in Northern Shaanxi Province. 298land parcels, 14land utilization patterns and 28analysis units were analyzed according to 33high, medium and low-income household surveys. Based on the Cobb-Douglas production function model, the plot scale and the watershed scale were combined to analyze the eco-economic suitability of suburban rural land and explore the integration of ecological and economic benefits. Results showed that most of the land ecosystem types in Zhaozhuang village are appropriate for agriculture, except part of the lat-erite type. However, only some are highly suitable for traditional farming, while the others′suitability is not so high. For traditional farming such as corn and cereal, more organic fertilizers and rational fertilization are needed for an improved economic efficiency. For featured farming such as small melons and greenhouse vege-tables, improving the technical level is more important. For beans and cabbage farming, labor is less impor-tant for their yields. For tuber crops and turnips, the effects of technical level can be ignored.

Abstract:Increased exotic plant invasion has a great effect on ecology, especially on highway side-slope. In order to find out the influence degree of exotic plant invasion on local ecosystem, statistics are made for vege-tation on highway side-slope in He′nan Province by field investigation methods. 58 plant species are investi-gated totally. 4 kinds of exotic plant invasion are identified, of which some invades the region heavily, such as Conyza canadensis. However, some artificial plants are facing extinction due to inadaptable field environ-ment, such as Cosmos bipinnata. For above problems, control suggestions are proposed, such as taking arti-ficial control, shortening the time of vegetation restoration on side-slope, selecting ornamental plants critical-ly, and enhancing the research on exotic plant invasion.

Abstract:Wavelet neural network has better approximation and fault-tolerance for combining the time-frequency localization of wavelet transform and self-study function of traditional neural network. We took some typical landslides in hydropower engineering region as an example and built three wavelet neural net-work models of multiple factors for landslide deformation prediction, on the basis of analyzing basic charac-teristics and the relationships between landslide deformation and main influencing factors of the landslide. By analyzing and comparing the results of the models, we found that the wavelet neural network model including the two factors (displacement rate and rainfall) has the highest prediction accuracy in the three models.

Abstract:By taking removed soil fertility betterment project in the Three Gorges Reservoir area for an exam-ple, and through analyzing the engineering characters of the project, performance evaluation index system is divided into the performance and effectiveness indicator systems by the principles of science and operability. Accordingly, analytic hierarchy process is used to determine index weights. Finally, the analysis of project performance evaluation is made by fuzzy comprehensive evaluation method. The analysis shows that the com-prehensive evaluation vector for the effectiveness indicator system of the removed soil fertility betterment project is 0.8751 and for the performance indicator system, 0.6170. By the principle of the maximum mem-bership degree, the project is a quality project, no matter the effectiveness or performance evaluation.

Abstract:Irrigation schedule for walnut tree under drip irrigation was studied through a field experiment with orthogonal design method. Results showed that the total water amount was between 711. 77 and 814. 38mm for different lower limit treatments of soil moisture. In the growing period, daily water consumption for the treatments was 3. 57～4. 18mm/din April, 3. 78～4. 87mm/d in May, 5. 9～7. 35mm/d in June and July, being highest, and 3. 6～4. 46mm/d in August. Comprehensive analysis of yield, protein, fat and kernel rate showed that the lower limits of soil moisture were 60%, 60% and 50% in flowering stage, fruit expan-ding stage and stone hardening stage, respectively. Suitable irrigation was 12 times one year and the quota of irrigation was 680m³/hm².

Abstract:An orthogonal experiment was conducted to study the effects of chemical dissolution and biodegradation on the remediation efficiency for artificially contaminated soil by heavy metals Cu, Zn and Pb, as well as phenanthrene, naphthalene and pyrene. Humic acid (HA) was selected as eluent to strengthen the performance of microbial degra-dation of organic pollutants, which can effectively improve the degradation efficiency of degrading strain. Ac-tivated sludge was selected as degradation agent to strengthen the HA elution of heavy metals. The goal of this study was to reduce the polluted effect of heavy metals and polycyclic aromatic hydrocarbons (PAHs) in soil and increase the remediation efficiency. Results showed that the optimal conditions for remediation were temperature 35℃, pH 6.5, inoculation amount of activated sludge 2.0% and humic acid 5mg/g. In this condition, the remediation efficiencies for phenanthrene, naphthalene and pyrene were 73.4%, 80.5% and 68.2%, and for Cu²⁺, Zn>²⁺ and Pb³⁺, 75.5%, 64.2% and 71.7%, respectively. The addition of HA and activated sludge could significantly enhance the remediation of contaminated soil. It showed well the syner-gistic effect between chemical dissolution and biodegradation to remediate contaminated soil.

Abstract:Seeding brick can create a good living environment and guide the development and growth of plant roots. Moreover, Seedlings can be transplanted without time limit. Seeding bricks were made of red clay, loess, and white and black soils blended with 0%, 5%, 8% and 10% wheat straw and evaporation experiment was then conducted for the bricks. In terms of the evaporation measured for the same soil, the seeding bricks were in the order of seeding brick with 0% wheat straw > seeding brick with 5% wheat straw > seeding brick with 8% wheat straw > seeding brick with 10% wheat straw. Results showed that the wheat straw content affected the evaporation of the seeding bricks significantly. The more wheat straw content, the smaller evaporation was. Therefore, adding wheat straw could reduce evaporation loss of the seeding bricks. In terms of the evaporation, the seeding bricks blended with wheat straw of the same percentage but different soils were in the order of red clay brick> black hemp soil brick> mountain white clay brick>loessal soil brick. However, the differences between them were little. Comprehensively, the evaporation loss of loessal soil seeding brick with 10% wheat straw was the least.

Abstract:By considering the nonlinearity, spatial and temporal heterogeneity and dynamic uncertainty of soil moisture process, Elman recurrent neural network model is applied to the prediction of soil moisture in Linyi and Pingyi stations. Results show that the model achieves a high accuracy of soil moisture simulation and the simulated values agree well with observed values in the whole process. The mean absolute errors of prediction precision for Linyi and Pingyi stations are 1. 08%and 1.07%, and the mean relative errors, 10.2% and 11.0%, respectively. Elman recurrent neural network model can be used to find some evolutional characters and regular patterns from complex soil moisture system by taking advantage of its nonlinearity, non-append-age and self-adaption capacity. Therefore, the model provides a simple and efficient method which provides high accuracy and reliable precision for soil moisture simulation. In order to further evaluate the superiority of this method, a longer series of data, more investigations in other regions and more comprehensive influence factors are needed to deepen theoretical study and analysis because of limited samples and the highly dynamic uncertainty of soil moisture process.

Abstract:As one of the indices for basic mechanical properties of stabilized soil, elasticity modulus affects structure′s static and dynamic analysis and calculation. So, experimental research on elasticity modulus is of practical significance. In view of few researches on elasticity modulus of stabilized soil and by taking the inde-pendently developed soil stabilizer as a research object, the three factors of soil stabilizer dosages, d ifferent moisture contents and different ages affecting the MBER stabilized-soil′s elasticity modulus are separately studied by laboratory experiment using soil samples collected in Yangling experimental area. A stress-strain relationship curve is obtained from experimental result and the stabilized-soil′s elasticity modulus is found to be between 300and 1 000MPa. The stabilized-soil′s elasticity modulus is increased with the increases in soil stabilizer dosage, moisture content and age and however, it begins to drop down as a threshold value of mois-ture content occurs. By reasonably controlling soil stabilizer dosage and moisture content, mechanical prop-erties of the stabilized soil can be improved for an improved stabilized soil.

Abstract:Hydropower development has an inevitable impact on local environment, while promoting socio-economic development and improving the quality of people′s lives. The loss and gain analysis of ecological en-vironment, expressed by currency in a unified dimension, may provide a basis for engineering decision be-cause of its general evaluation on environment. An evaluation index system is established and the benefits and costs from hydropower development are analyzed by taking the environment affected by two scenarios of cascade hydropower development in the Naqu River for an example. Results show that the direct ecological values from two scenarios of cascade hydropower in the Naqu River are 1.05×10⁸ and 1.46×10⁸ yuan per year and the indirect values, 5.13×10⁷ and 5.04×10⁷ yuan per year, while the ecological environment costs are 9. 40×10⁷ and 9.73×10⁷ yuan per year, respectively. The ratio of the direct environmental benefit to the environmental cost from the two scenarios is 1.1∶1 and 1.5∶1, respectively, which illustrates that the benefits exceed the costs and the scenario two is superior to the scenario one. The valuation methodology of ecoenvironmental value in the hydropower development is not yet mature and currently, there is no unified evaluation standard. So there are some differences in the completeness and accuracy of the evaluation contents, as compared with the practice. The evaluation system can only provide a reference basis for the construction of hydropower development and environmental protection.

Abstract:In order to determine the effects of super absorbent applied by different methods on soil moisture, soil temperature and maize growth, field experiments were conducted in the Hetao irrigation district, I nner Mongolia. Super absorbent was applied using the four methods of furrowing, mixing, broadcasting and holing in contrast to the case without super absorbent applied. Results showed that all application methods increased soil moisture, particularly there were significant effects at drought stage when maize is in tasseling-silking and grain filling. All application methods decreased soil temperature at seedling and trefoil stage and inhibited the growth of maize seedling. All application methods promoted maize growth from jointing to maturing, extended maize growing period, and increased maize yields and biomass, water use efficiency, w ater production rate and irrigation water production rate. Among the four application methods, the effect of furrowing was better and the effect of broadcasting was worse. Optimum application method of super absorbent should be the furrowing in Hetao irrigation district in maize production.

Abstract:To investigate groundwater dynamic in the Luohuiqu irrigation district of Shaanxi Province, different research methods for groundwater dynamic are comprehensively analyzed. The method of support vector machines (SVM) is proposed for predicting groundwater dynamic and building predicting model and two computer programs are compiled using MATLAB. Practical effectiveness of the theory of the SVM for groundwater dynamic prediction is discussed based on the irrigation data measured for many years. Results show that the SVM regression model can well express the complicated coupling relationship of groundwater dynamics. Therefore, the application of this method to the prediction in the irrigation district is feasible and practical.

Abstract:In Hexi irrigation area of Gansu Province managed for eight year corn seed production, field test method was used to study the relationships among soil improved special fertilizer, physical properties of seed production cornfield and corn economic traits and benefits. Results showed that the factors affecting corn production followed the order of CO(NH₂)₂>(NH₄)₂HPO₄> PVA and ZnSO₄·7H₂O. Best combination for the factors is 30kg/hm ² PVA, 736kg/hm² CO(NH₂)₂, 420kg/hm²(NH₄)₂HPO₄ and 52kg/hm²ZnSO₄7H₂O. Withthe increases of soil improved specific fertilizer, corn field total porosity, capillary porosity, non-capillary porosity and aggregates increased, but bulk density decreased. When soil improved special fertilizer application increased, corn botanical traits, economic traits and yield increased, but yield increment by unit(1kg) amount of soil improved special fertilizer decreased gradually withthe increase of soil improved special fertilizer, showing the law of diminishing return. Withthe increased amount of soil improved special fertilizer, marginal corn yield and profit in the reduced profit margins. The additional 337.50kg/hm² application rate over the 1350kg/hm² soil improved special fertilizer made revenue to be negative. The optimum economic fertilization capacity was 1350.01kg/hm² and theoretical corn yield was 6700.99kg/hm².

Abstract:Comprehensive evaluation of soil and water conservation in a development and construction project is the base of category management. Analytic hierarchy process is used to construct an evaluation model of soil and water conservation based on the status of soil erosion, effects of soil and water conservation and soil erosion harms. Moreover, different types of development projects are analyzed. Results showed that soil and water conservation benefits for point projects are better than linear projects, but the fluctuation of soil and water conservation benefits is smaller than linear projects. Soil and water conservation benefits for real estate project are the biggest; power plant project, the second; and mine project, the worst. The fluctuation of soil and water conservation benefits, from largest to smallest, is in the order of power plant project, mine project and real estate project.

Abstract:In order to quickly and effectively compute the soil erosion modulus of more than 30000 field inves-tigation units in soil and water conservation survey(the first national water conservancy survey), water ero-sion modulus calculator software is designed and developed based on Chinese soil loss equation(CSLE) by using. NET platform of microsoft and AcrEngine development kit. By taking the data of field investigation units selected in Ansai County of Shaanxi Province as an example, the software is applied to calculate the water erosion modulus of the units and the calculated result is compared with that by operating ArcMap with manual method. Results indicate that the calculated result using water erosion modulus calculator software is accurate and reliable, and it can improve the calculation efficiency greatly. The software can be used for water erosion modulus calculation in regional soil erosion survey.

Abstract:Based on ecological footprint analysis method, the impacts of highway construction on ecological environment were investigated in a case study of the Baoji-Hanzhong highway. Ecological footprint of pol-lutants was taken into account to calculate the change of the ecological footprint and ecological capacity for the counties along the highway before and after the highway construction. The impacts of the highway con-struction on local ecological environment were also evaluated and predicted. The ecological deficit of the counties along the highway increased by 0.0164hm² and the ecological tension index also increased slightly after the construction of the Baoji-Hanzhong highway, which implies that the local ecological environment and ecological safety have been affected by the highway construction.

Abstract:Highway side-slope is one of the most seriously damaged areas in highway construction. Based on an experimental study in the Xi′an-Ankang highway of Shaanxi Province, 19 side-slope protection forms are summarized and analyzed , i. e. , retaining wall, gridiron protection, paved stone slope, drainage consolidation, etc. . 22 scientific research sites were set on tipical slopes and secondary slopes in the Xi′an-Ankang section to observe the changes of shrub stem, diameter and height, lawn coverage, survival rate, emergence rate and growth potential, as well as to analyze the relationship between vegetation growth and environmen-tal conditions. It is clarified that a suitable protection form should be determined by the characteristics of specific engineering. The result from the analysis can offer scientific reference for selecting an ecological sideslope protection mode in highway construction.