Abstract:This paper analyses the effects of human activities upon soil and water erosion on the Less Plateau whereby to come to the conclusion that human activities are the major cause to acceldrate soil and water erosion on the Loess Plateau。Also, it analyses the .main cause that there have been no obvious changes in the sediments in the Yellow River,

Abstract:The intercepted precipitation and its variation of the canopy of Pinus tabulaeformis and Populus davidiana of 25 years old have been studied.The conclusion shows that the intercepted precipitation of Pinus tabulae-formis and Popular davidiana are 95,2mm and 73.4mm,accounting for 19.6and 14.700 of yearty total ramfall respectively; Intercepted rainfall is78mm and 71.lmm, accounting for 17.40o and 15,500 of rainfall; Intercepted snow is 17.2mm and 2,3mm,accounting for 45.1%and 5.900 of snowfall.The intercepted amount of the canopy changes with different seasons,In summer, the intercepted amount is 51mm,15.8} of the annual rainfall.In spring and winter,Pinus tabulaeformis intercepted amount is low, and intercepted rate is high, Also, both of them in Populus davidians are low, The interceptive process of the canopy is divided into three stages as intercepting,falling raindrop and saturating,The function between the accumulated interceptation and precipitation presents I=ap^b.

Abstract:Conserving soil and water with grasses in the lead and in combinaton of trees with shrubs is an effective measure of grasses combined with trees practised in controlling soil and water erosion in the upper reaches of the Hanjiang River and the Beijiang River for five years in Cuangd-ong Province, Grass plants with more foliages grow with more branches and craw over the ground, which can effectively prevent splash erosion，disperse, slow down, check and reduce surface runoff, improve soil permeability and reduce soil erodibility, What's more, the principle of "gaining success by quickness" and "regaining success by superiority" must be well grasped, and attention should be paid to the cultivation techniques and fertilizer application.

Abstract:The Wujiang River valley is a golden area for Gueizhou province to develop its economy, and is also of a strategical significance in vitalizing economy in the province and building up Southwest China, In order to make ecosystem turn into a better cycle, work should start from the ，conversion of sloping farmland into planting trees and grasses, The major measures and counter-strategies of which are as follows:(1)to carry out some related technical policy;(2)to work out the planning of the conversion of sloping farmland into planting trees and forage cro- ps based on a clear understanding of the existing conditions;(3)in controlling and developing watershed, first of all, one core should be grasped so as to achieve two adjustments(4)external and internal economic compensation should be given to the farmers'so as to solve their fear of attack from behind;(5)starting from the actual conditions,the conversion of sloping farmland into forest into. grassland can be insisted either unshakably or safely, and the same can not be done everywhere;(6)to help the farmers to search for the new way to result in prosperity for the immediate results and do a good job in the transference of excessive labour forces;and(7)to carry out the construction of ecological agriculture and ecological forests.

Abstract:The land types, land productivity classification and land use evaluanon in Zhengjiagou catchment located in the north of loess plateau were discussed in this paper, Based on .the land properties, the suitability and limitations of land, the land use evaluation system is developed.The results show that there are serious soil erosion and desertification and extensive land degradation in this catchment because of irrational land use and improper managements, We believe that adjusting land-use construction, increasing soil fertility and planting trees and grasses are main measures to exploite efficiently the land resources, to raise land productivity and to improve ecological environment in this catchment.

Abstract:This paper has been devetoped aconception model, working progrem and analysisng method of studying the land source carrying with the system scientific way, On the basic of above, we have analysed the land source carrying capacity and affect on its factors with the synthesis method in SHANG HUANG experiment area, we put forward thebasic policy of ensuring the food— population coordination development and of averting from destroying the frgile ecological enviroment at present the social and economic condition.

Abstract:Sanchuanhe watershed is one of the eight key integrated control areas of soil and water conservation in China, As the developing of control work and agriculture forestry and animal husbandry, soil of farmland is required more and more highly, This paper evaluates soil fertility of every type farmland, using PCA method, based on the investigation and measurement of soil fertility of different farmland in the watershed.A new classification of farmland has been suggested, It proposes scientific base for the regulation of different type farmland and. the development of ag-riculture.

Abstract:This paper deals with the existing conditions of soil and water erosion, harms and controlling strategies in Jiangxi Province, Also, it points out that the leaders at different levels and the responsible departments should further perfect the management system and regulations of ore mining and do things strictly in accordance with the“Regulation of Soil and Water Conservation" and strengthen the monitoring means of soil and water conservation and prevent and control soil and water erosion in the mining areas.

Abstract:In order to reconstruct eco-environment and to recover vegetation，and based on the survey of physical and chemical properties of agriculture in rare-earth tails, the method without soil-mulching has been abopted to plant 13 kinds of trees and shrubs as well as grasses since 1987。The trial results showed that tree-Phellodendon amurense Ropr .grew much betters and shrub-Lespedezabicolor Turcz and grass species---pas-palum wettsteinii Haeke planted can green the experimental area in the curren year.

Abstract:Taking Zhainugou small watershed for e}:ample,this paper deals with the guiding thinking of the matching model of forests and grasses in the comprehensive control of small watershed。In an overall layout，the multiple constraints should be taken into account, The suitable trees and grass species and their matching models for various establishing conditions have been screened in accordance with the ecological adptability of various tree and grass species. Also, the paper discusses the matching of forests and grasses in the comprehensive control of small watersheds in the semiarid loessal hilly areas.

Abstract:This paper analysed the rainfall behaviours, precipitation, rainfall intensity, homogeneity of rainfall distribution, sizes and distribution of raindrop diameter and terminal velocity of raindrops, Based on the researeh achievements by the Chinese and foreign scholars and the authors'actual work,the paper suggested some typical methods for the determination and calculation of the aboved variables_