Abstract:The universal soil Ioss equation has been payed great attention and Widely used in many countries since it put forward.It is difficult to be directly used in China because it is vast in territory and greatly regional variation in climate,soil.topography etc Based on deep analysis and quantitative evaluation to factors which have influence on soil erosion the chinese researchershope to estabilish erosion prediction model which is suted for their country or a certain region。Some main progresses and achievements in evaluation study to those factors are introduced in China since 1980s。

Abstract:Based on the information of 33 times rainfall,runoff and sediment yield at No 3runoff plot in Zizhou Tuanshangou watershed,the variation of rainfall and runoff-sediment yieldon slope surface under diffrent rain pattern are analyzed by using statistic method。

Abstract:Considering the factors of climate,hydrology,landforms,soil,vegetation and land u-tilization synthetically,handing the erosion of slope surface and ravine separately a new quanti-tative model is put out to calculate soil erosion in loess plateau by taking the minimum gully unit of DEM as the basic unit of soil erosion.Then taking the practice at Fugu county Shaanxiprovince for example the ecquisiton of model parameters is studied and tested with geographic information system(GIS)technology.

Abstract:Vegetation construction is an important way for ecological environment administration in wind-water erosion criss-cross belt The vital problems in vegetation construction such as re-making forest and grass land of less benefit the techniques of gathering runoff for afforestation are studied in Shenmu experimental area Some proposals are put forward for vegetation con-struction in this area.

Abstract:Vegetation in Ziwu mountain secondary forest area undergot destruction by human be-ing and natural restoration The researched result showed that before secondary forest restora-tion,soil in this area was similar to present yellow loess soil With secodary forest restoration。soil gradually developed soil formation process was humification and leaching and soil type e-volved form yellow loess soil to brown forest soil But after forest destruction Because of severely accelerated soil erosion soil profile was gradually eroded and damaged and soil changed to yel-low loess soil.

Abstract:The input of both organic and inorganic energy for the crops of wheat pea potatohemp and corn and their output of energy through grain straw and root wre calculated from which the relationshiop of input and output energy of each crop the current state and problems of farming systems were analysed At last the amount and structure of energy input for farming sys tem were studied with optimization analysis.

Abstract:Subregion I of loess gully region is the key diatrict of soil erosion in the middle reach-es of Yellow river,silt arrester is one of the inportant measures against soil and water loss,and the dyke land is the main farmland with high and stable yields,The rational arrangement and comprehesive application model of dyke system in its development are raised and its benefits are analyzed based on the investigation,experiment and observation

Abstract:An analysis has been made on dynamic relationship among the population economy and ecology in Guizhou province。Up to the end of 1988,soil erosion area covers 43.5%of theprovince it is 2.1 times more than that of 1952.The Wu river the South-pan and North-pan river watershed are the most serious areas with soil and water loss in Guizhou province Soil ero-sion on hillslope land is the first to be affected on erosion area and quqntity It has been indicated that the basic reason of soil and water loss is enlarged by population growing and grain inadequate in the province Soil and water loss lead the degradation of regional economics system and natu-ral disasters sush as drought and waterlogging to be more and more frequent and serious Now soil erosion bas become an important obstacle for further economic development and impover-ished an origin in rural district In accordance with sustainable develo;ment the countermeasures to prevent and control the soil erosion in Guizhou province are proposed