Abstract:Soil erosion process research produces the knowledge and science used in the development of current process based erosion prediction model. This presentation will highlight past efforts in deve loping erosion process concepts that lead to the development of current process-based erosion prediction model, i.e., WEPP. Recent erosion process studies have produced data sets that challenge some of the WEPP model concepts. We hope erosion process and model research in USA could enhance soil erosion research in China.

Abstract:The supplied water of the west route of Water Transferring Project from South to North of China is for industry, life and eco environment. Among these, water used for eco environment represents a great ratio. When the transferred water reaches 1.70×1010m³, the amount used for eco environment can be as high as 6.30×109msup>3 or 37.0% of the total. The benefits of the project on eco environment in water received area are analyzed. The analysis indicates that the project is the water resource guarantee for western China development. It can increase the runoff of the rivers in that region and improve the water environment, stop and control soil and water loss and land desertification, decrease natural disasters, improve the agricultural eco environment and local survival for the inhabitant, alleviate no water flow in the lower reaches of the Yellow river and solve related eco environment problems, restore the eco system and enhance environmental capacity and load bearing capabilities. From the sense of eco environment improvement, the west route of Water Transferring Project from South to North of China is a magnificent ecological construction project.

Abstract:From the view of natural resource utilization and protection, a study on the principle of potassium loss under different land use patterns in a red soil watershed was conducted in Zhejiang province of southern China. The results showed that K loss in a catchment with less vegetation cover and non soil conserving practices was highest, while lowest K loss occurred in catchment with vegetation conservation. K loss in an extensive farming catchment was higher than that of catchment in which comprehensive measurements for conservation were practiced. K loss was concentrated in the plum rainy season (May and June) and the typhoon rainy season (August), accounting for more than 90% of the total K loss. K was lost mainly in a particular form, accounting for more than 94% of the total K loss. The factors impacting on K loss were precipitation, rainfall erosion index, runoff and sediment.

Abstract:The effects of rational planting, the paddy upland system, rotational tillage and mulching corn straws on physical and chemical characteristics of soil with high content sands of plain area were studied. The results showed that the system of "twice upland aod one paddy, five times cereal cropping system in two years" could not only raise crop production, but also improve the physical and chemical properties of soil. The paddy upland system increased clay dispersion content and soil fertility. The rotation tillage, minimum tillage and non tillage practices were beneficial to improve soil fertility, increase soil properties and save man power. The mulching corn straws had very significant profit on raising soil fertility and crop yield. The experiment and its application were successful and may support a virtuous cycle of eco agriculture.

Abstract:Assessment of water soil environmental effect on water resources development is a basis for the assessment of water resources availability. The relations among the water soil environmental effects on water resources development are analyzed. And the necessity of constructing an indicator system and basic principles while constructing the system are discussed. A gross framework is designed for the system based on its principles, and some questions which arose while constructing the index system are also discussed.

Abstract:From the viewpoint of practicality,the data of routine confined compression-collapse tests and dyna mic subsidence tests of loess from three loess areas of Xi'an,Lanzhou and Taiyuan under different moisture conditions are analyzed and arranged.Based on these data, the relation between the dynamic deformation characteristic parameter and the static deformation characteristic parameter is presented, and the possibility of evaluating the dynamic characteristic by using the parameter of routine static characteristic are discussed.

Abstract:With Ansai county as the target area and Participatory Rural Appraisal (PRA) as the main method, a survey was carried out on farmers'perception and acceptance of farmers' expectation for the cropland conversion program. The results show that the policy is not publicized and flexible enough to deal with the actual situation; and subsidies and technical guidance are also not enough. The authors give some suggestions on these problems, of which farmland construction and technical investment are very important to the conversion of slope farmland to forest or grass land.

Abstract:A comprehensive index is used to analyze the regional disparity of soil erosion in Guangdong province. The result shows regional disparity of soil erosion is distinct in Guangdong province as a whole, and erosion in the northeast is greater than in the northwest. Natural erosion occurs mostly in granite mountainous hilly regions and the Pearl river delta hill along the seashore in Guangdong province. Human caused soil erosion is mainly in Pearl river delta region, where the economy is developing most actively. This includes Shenzhen, Zhuhai, Dongguan at the center and extends to eastern seashore, eastern mountains and western seashore gradually.

Abstract:The infiltration properties of slope farmland are studied by means of the water storage method and the simulated rainfall method respectively. The results show that the measured soil steady infiltration rates measured by the water storage method are greater than those measured by simulated rainfall. Using the water storage method may only reflect infiltration properties of soil itself, but the simulated rainfall method may simulate better natural rainfall. The steady infiltration rates measured by using two methods are a better linear relationship.

Abstract:Located in the transitional zone from agricultural areas to husbandry areas, Zhungeer county has typical characteristics of fragile ecological situations with serious soil and water loss. After introducing the regional natural characteristics related to land use, the land quantity and its change, spatial change and the level and benefit of change are analyzed. The results show that, in the period of 1987-2000, work of land harness has achieved notable effects, for example, the area of forest and grass land increased, and the unused land decreased obviously. However the land productivity is still lower. It is indicated that the driving forces of land use are policy, population change, crop output, industry development, financial support and law of land protection.

Abstract:Hydraulic seeding is an affordable, widely applicable and efficient mechanized technique to establish an extensively and actively growing vegetation cover for slope stabilization. A dug typical slope of the key water control project at Feilai gorge in Guangdong province was selected as the test plot to study the application of hydraulic seeding technique for slope stabilization. The result shows that the speed for the seeded lawn to cover the slope surface effectively depends mainly on the ecological characters of the main species, the environmental condition for the seed germination and growth, and some other factors. These factors are closely related to the seed categories, the plant growing help chemicals, soil states, climatic conditions etc.

Abstract:DEMs play an important role in the supervision and preservation of soil and water conditions, but at present, it is difficult to construct large scale DEMs. An idea and technical method to construct a DEM based on index contour is put forward for the first time. Using loess hilly and gully area as test sites, the authors assessed the accuracy and application feasibility of this type of DEM. The experiment shows that although there are some certain errors in these simplified DEMs, as well as in the terrain features derived (i.e slope, aspect, surface curvature, donga density, surface roughness and undulation), these DEMs can satisfy the application and analysis of terrain. It is a quick, concise and effective technical method.

Abstract:A lot of research has been carried out on soil and water conversion in the loess plateau. This resulted in the accumulation of a large quantity of spatial data. Improved management of these data well is becoming essential. Based on 1∶500 000 scale thematic data in the loess plateau, a method and process for building a database using the Librarian model of ARC/INFO is introduced. This database can be used to extract, query and display the spatial data. At the same time, the metadata of database is described.

Abstract:Runoff and sediment data from hydrological stations provide the database for studying regional soil and water loss. Yet up scaling of these point data is needed to represent the regional area. Based on published hydrological data, runoff and sediment were calculated for evaluating units by dividing the study area into hydrological polygons, combining hydrological data with the hydrological polygons map, setting up the accumulative relationship between subcatchments and validating the runoff and sediment data. A national spatial hydrology database is built to assist spatial analysis. A preliminary application of the database is demonstrated by an example using data from 1955.

Abstract:The Geographic Information System (GIS) has the strong abilities of spatial data analysis and visualization.It can reflect the spatial distribution of the non point source pollution.Integrating GIS with the non point source pollution model can greatly reduce the difficulty of non point source pollution modeling.The current situation of non point source pollution study in China and abroad is summarized.Combing the BASINS system and the PLOAD model developed by USEPA,the application of GIS in the study of non point source pollution in watersheds is analyzed from the three aspects of data input, parameter extraction and result visualization,and is simulated at the Yanjiang watershed in Zhejiang province as a case study.This analysis could provide some use for reference in this field.

Abstract:Through a systematic investigation into the ecological environment in alluvial plain area of Huxian county, it is suggested that the evolution of the ecological environment in this area is strikingly marked by human activities. Since the founding of the People's Republic of China, this area has undergone three stages: the rurality period before the year 1966, the degeneration period during the Cultural Revolution and the deterioration period under the circumstances of commodity economy. Though the change in nature is one cause of the environmental deterioration, human activities, especially the unreasonable development activities controlled by the government, are the dominating factor.

Abstract:An area of 956.1 km² is effected by soil loss in the Jiulong river basin, covering 14.13% of the total land area. Soil and water loss has resulted in severe problems such as soil degeneration, frequent drought and flood, river bed aggradation and damage to water conservancy facilities, which have been emphasized by the people and government of all levels in Jiulong river basin. The control targets of the Jiulong river are as follows: controlling soil loss from 200 km² of land during the period of "the 10 th five years", 300 km² during the period of 2006-2015, and 400 km² during the period of 2016-2030. For soil and water conservation in the Jiulong river basin, extending the comprehensive controlling patterns of small watersheds and harnessing orchard soil and water losses are very important.

Abstract:There are 33 wild fruits, 2 semi cultivation fruits, and 15 species cultivation fruits in the Yan'an Eco agriculture Demonstration Area,and 5 cultivation fruits can be introduced into this area.The rose family is the biggest family,with 15 wild fruits,1 semi cultivation fruit,and 10 cultivation fruits.Apple is the first magnitude cultivation fruit.Siberian apricot,David peach,wild jujube and shinyleaf yellowhorn are valuable wild and semi cultivation fruits.Cultivation fruit species and variety arrangements are unreasonable and the yield unit area is small.This is badly in need of adjustment and increase.