Abstract:On the basis of scouring experiments indoors, the mechanism of the drop pit'genesis and development during the process of slope erosion is analyzed, and the relationship among headcut, bank landslip and downcut has been expounded. The variation regularity of the runoff and the sediment yield in each discharge was studied, and the relationship among the sediment, the runoff and the proportion of the rill area was obtained. Analyzing each erosion stress on the slope during the scouring, we get the runoff shearing sediment equation. The study shows that the sediment yield from runoff shearing take on a good positive correlation with the average runoff shear stress, and the critical shear stress of the runoff, by which the soil grain can just be dispersed, is 0.258 N/m².

Abstract:According to erosion vertical zone distribution in the loess hilly and gully region,the methods for demarcating distribution slope location of soil erosion patterns at small watershed are put forward.Based on erosion environmental characters in the loess hilly and gully region,the framework of the distributed water erosion prediction model at small watershed supported by GIS is designed.The fundamental erosion processes in this model included splash detachment,sheet flow detachment and deposition,rill flow detachment and deposition,ephemeral gully flow detachment and deposition,gully flow detachment and deposition,and channel flow detachment and deposition.Meanwhile,the calculation processes of this model are discussed in detail.In term of the principle of dynamic balance of mass,the calculation of sediment yield in the whole watershed is accomplished.

Abstract:By placing different rare earth oxide in different soil depth and different section across a slope in the field plots,the temporal and spatial process of soil erosion is studied under simulated rainfall situation.The results indicated that there is a dynam ic process from sheet erosion,ripple erosion near the plot bottom,headward erosion,and relative stableness of slope(ended on the erosion basis).Relevant erosion typeswere dominant within corresponding erosion stages.The emergence of rill head is the key factor boosting up the erosion of different section on slope.Under gentle intensity consecutive rainfall,headword erosion is dominant on the plots,and its erosion process is much more stable than erosion process of the first rainfall .

Abstract:By the analysis of water quality monitoring data of Dongting Lake watershed in 1989,1997 and 1999,it indicated that phosphorus pollution was particularly heavy,but the highest concentration of the heavy metals except Cu in each yearwas all lower than statewater quality standard grade Ⅱ;water pollution levels increase year after year at a high rate, except contam ination TN;point sources make a greater contribution to the pollution of Dongting Lake watershed and concentrations of the contam inates are higher in low water season than in high water season and tap water season. Due to the shortage of research on toxicity harmfulness coefficients of TN and TP, their values are obtained through an extrapolation approach using toxicity coefficients of heavymetals determ ined abroad. The coefficients are applied furthermore to risk analysis of pollution in Dongting L akewatershed. The research results show that TP contributesmost to the pollution risk in Dongting L ake watershed, while TN and Zn contribute relatively less.A dditionally, the risk coefficient value at Junshan monitoring site is relatively high, which poses potential ecological risk for its circum ference ecosystem.The risk values at other monitoring sites are lower and the potential ecological harm is minimal .

Abstract:Eco-problem is the main obstacle which restricts the sustainable development of the regional economy in poor areas.Based on the game theory, different behavior of each economic body is analysized in the process of eco-protection and reconstruction in Xihaigu region of Ningxia Hui Autonomous Region. It is pointed out that the inefficiency of the eco-protection and reconstruction is induced by short-term behavior and interest conflict among economic interest bodies. Furthermore,in order to realize really the win-win type of eco-construction and economic development,harmony mechanism should be established in accordance with every economic interest bodied.

Abstract:One major problem in re-establishing ecological system is soil and water loss.Through the project of comprehensive treatment of the Futian River of Shenzhen City, the quantity of soil and water loss caused during the engineering construction period is estimated, and the results of reliability and measurements of soil and water conservation are brought forward accordingly. As a primary point of discussion, the reliability analysis of water loss and soil erosion is probed as one aspect in environment evaluation.

Abstract:In the case of the survey and analysis on Xipo village of Chunhua County, Feimahe village and Nangou village of Baota District in Yan'an City, Shaanxi Province, the nineteen indexes on ecology, economy and society are chosen to evaluates comprehensively development levels of three villages with AHP method. The nineteen are organic matter, labor productivity, average net income per person, labor force utility, education level, birth rate. As a result, the general marks of the three villages respectively are that Xipo village is 0.8745, Feimahe village is 0. 4143, Nan Gou village is 0. 1101, which are in accordance with their reality. Based on the above results, we viewed the development method of this region should be agrofruit ecological agriculture.

Abstract:Soil and water conservation measures(SWCM)of the Loess Plateau could control soil erosion by intensifying the infiltration and weakening the runoff.Therefore,the infiltration quantity is one of the important indexes that scale the effect of the soil and water conservation.The infiltration quantity was often calculated by the annual rainfall which products runoff.However,the little quantity rain or low intensity rain in the year has nothing to do with the conservation in the Loess Plateau.It could lead to the estimation error about the change of infiltration with SWCM.The infiltration variating with the catchment SWCM level incensement is studied based on the data of rainfall and runoff of the Xichuan catchment during 1997 to 2001.A gray dynamic model is put forward to the infiltration quantity tendency in the Xichuan catchment was predicted by a gray dynamic model,GM(1,1).The result indicates that the annual rainfall which can product runoff shows the effect of SWCM on infiltration more clearly than the total annual rainfall.The gray dynamic model can be used to predicat the tendency of infiltration.

Abstract:Taking returning the plantation to forest or grassland in China as background, and according to the necessity of establishing slope plantation information system about national ecological retreating plantation county of Shannxi Province, its basic principles, technologic methods and main processes are established. It could efficiently searches digital and graphical information of land about ecological retreating counties in Shaanxi Province, and provide the significant reference of making relevant policy for the relating administrative department.

Abstract:The fractal dimension measure of watershed topography is the unsubstantial part of topography fractal study,and it is very important for the prediction model of soil and water loss in small watershed.Based on the principle of measuring the fractal box dimension and the character of watershed topography,the approach for measuring the fractal dimension of watershed topography is put forward by the technique of GIS,whose data is from contour line. We operated demonstration research by taking Chabagou watershed as an example.The results show that this approach is fast,exact,credible and can get the fractal box dimension of watershed topography of different scope.

Abstract:The modified Green-Ampt infiltration equation which is suitable to describe infiltration during an unsteady rain is widely used to simulate infiltration and runoff on the slope land.The average potential across the wetting front S_f is one of the most important parameters in it, whose validity is dependent on S f .The theoretical relationships among the parameters of the Philip equation and Green-Ampt equation are analyzed,and parameter S f in Green-Ampt equation can be calculated by the parameters values of the Philip equation. The infiltration experiments with surface ponding and unsteady rain were carried at the Changwu A gri-ecological Station in 1996, and the different values of S_fcalculated by Green-Ampt equation and parameters of the Philip equation were obtained based on the infiltration data w ith surface ponding. The validity of different S_f'_s values was compared by the runoff data of unsteady rain on a plane via the modified Green-Ampt equation by Chu (1978).The results showed that S f calculated by the parameters of Philip equation was valid for simulating the infiltration and runoff on a plane on the Heilu soil of theLoess Plateau.

Abstract:Based on the principle of ecological rehabilitation, the practical methods and characteristics of soil and water conservation, the items and indictors of onitoring items of ecological rehabilitation engineering of soil and water conservation are put forward. The indictors should include the state of every sort of rehabilitation engineering and its benefits, which could reflect the main elements of ecology, types of engineering and soil and water loss.

Abstract:The linearization construction and exploitation projects mainly include the projects like the highway, railroad,dike,ditch,natural gas and oil pipeline etc.,which distribute across the different districts online.In a case of reinforcement dike project of Yangtze River in Jiangxi Province,the scope,content,procedure,method,and result of soil and water conservation monitoring for linearization construction and exploitation projects are discussed.

Abstract:The project to convert farmland to grassplot for 9.00×10³hm² of the upriver irrigation area of the Tarim Valley is a segment of synthesis management of the Tarim Valley.The project involved 1.42×10³hm² reservoir irrigated area,3.60×10³hm² river irrigated area and 4.00×10²hm² water pump irrigated area. After coverting farmland to grassplot, the gross irrigation water need is less and the water previously used for cropland irrigation becomes available for environmental application. While selfsow nvegetation replaces some cropland, at the same time,the remaining farmland can be utilized for greater benefit. The gross saving of irrigatiion water can approach 3.10×10⁷m³,which can flow to the lower reaches of the Tarim River. Converting farmland to grassplot can have marked benefits for surrounding areas, and is propitious to the improvement of the environment in Tarim Valley.

Abstract:Karst landforms are very developed in southwest China,and it belongs to the typical region with eco-environmental fragility.The basic features of its eco-environmental system are analyzed based on diversity of ecosystem,capacity of population and environment,biomass(above and ground),sensitivity,capacity resisting natural disasters. So there are the principles of regulating ecosystem. Finally,corresponding harness and regulation measures for karst ecosystem in southwest China are suggested.

Abstract:Based on the investigation of the soil and water loss in Shizuishan City,comprehensive counter-measures of soil and water loss are presented. In the controlof the loss of soil and water in the city,the engineering measuresw ill be adopted and the biologicalmeasuresw ill be good complementarities.The prior control area should be in where exist the most potential hazard and where exist the circum stance of soil and water loss.The monitor and forecast alarm system of soil and water loss should be built step by step.

Abstract:On the basis of the characteristics of cold altiplano,and site type division of returning cropland to forest of the shallow loess hill areas in Datong County,Qinghai Province,the development thinking of returing cropland to forest and green ecology industry combination,returing cropland to forest and land rational use combination,and returing cropland to forest and raising farmer economy benefits combination were presented. According to the above,forest type,tree( grass) species and comprehensive control patterns were optimizedly collocated,and the patterns of returing cropland to forest and afforestation techniques in shallow loess hill areas of cold altiplano were found.This results could provide techniques foundation for this area and other similar areas.

Abstract:The Yellow River flows through Jinan City,Shandong Province,and takes an important role in Jinan's ecocity construction.The ecological security of the city is ensured by the river's strong dike.Local air quality benefits from the eco-corridor along the river.The Yellow River water resource is a base in the city's water supply.The coastal wetland has a significance function in providing ecological services.

Abstract:A ccording to the policy of vegetation restoration and different land use type adjustment in loess hilly region,vegetation restoration affecting the soil erosion,nutrient discharge and nutrient cycling and balance of watershed are reviewed on field plot and watershed.It is pointed out that vegetation restoration can reduce soil erosion and nutrient discharge,strengthen the ability of watershed nutrient cycling and balance,make the watershed nutrient cycling and balance develop to a health way on the watershed.Several issues should be deeply researched in the this area.

Abstract:Some problems and shortcoming in talent education are analyzed both in soil and water conservation science field and its practice,which lags behind the currient economical and urbanizational development in China.Based on this situation,the reforming thinking and its optimizational design in talent education on soil and water conservation science and ecological construction are put forth.As the personnel training scheme of optimum design is implemented,the personnel in soil and water conservation field would be trained out with the qualified knowledge and techniqueof ecological construction, and can meet the market demand of the present economy,society and new era. So, the optimum design of the scheme has certain directive guiding and realistic significance.