Abstract:Based on the ten year data of the first period project for the four key control aid typicalinvestigation in yellow River basin,This paper analysed preserved rate of different control measuresin different type region,the relation between preserved rate and control cost.In addition,the ap-proaches of incresing preserved rate of measures are discussed in order to provide references for soiland water conservation in second period project.

Abstract:This paper summarizes the successive dynasties thoughts of harnessing the Yellow Riv-er,and analyses the two representative viewpoints of Yellow River management strategies in recentyears.It is considered that harnessing the Yellow River should see from the angle of the wholebasin,and the systematic viewpoint of harnessing the Yellow River is the basis of harnessing theYellow River,In it,comprehensive harnessing of the Loess Plateau is the key of harnessing the Yel-low River,and some countermeasures and proposals of harnessing the Loess Plateau are put for-ward.

Abstract:Soil erodibility of seven soils located in ziyang soil and water conservation fieldstation ofsichuan Academy of Agricultural sciences,ziyang,was studied under rainfall simulator.The resultshows:1.the soil erodibility of seven soils is yellow earthbrown purple soilred brown purplesoilgrey alluvial soilred purple soilyellow red purple soildarkbrown purple soil;2.thereis a significant linear relationship between runoff and rainfall duration,soil loss and rainfall duration, runoff and soil loss for seven soils,and Clear non linear relationship between soil moisture contentand runoff starting time for six soils.

Abstract:Through the field investigation and measurement,groundwater observation,irrigationtesting and the physical and chemical analysis of water and soil samples.this paper has prelimilarilydiscussed the sliding basic factors,distribution features,scale and harm of the landslides at the edgeof terrace,the formation mechanism of landslide is established as well.According to statistics,thereare 44 landslide in this region. From 1886 up to now,more than 20 Landslides have happened,thesliding ares of landslides varies from 0.2 to 2.5Km￣2,Since 1989,the direct economic loss caused byIandslide reached nearly 6 000 000 yuan by the average of 1 200 000 yuan per year.By the field ob-servation and indoor analysis,we think that the landslide in this region is generated by the ground-water from infiltration of irrigation water,the ground water expose in spring flow at the down partof slope。or bottom of pebble layer and the bottoln of old landslide。the mudstone at the bottom ofpebble layer is soften to mud by water,while it is comperessed and influenced,the sliding beIt willbe formed.The special stratum and high-steep slope landforms are all the essential factors for in-ducing of landslides.

Abstract:Leaf weight,stak weigh,leafand stakweight ratio and heigth of Astragalus Adsurgensall are morphologically important characteres of its above-ground part.It has been studied that therelationship bewteen those characteres and its forage yeild,as well as impacting of soil moisture andfertilizing amount on those characteres with the plot experiement.The resultes show as following:The grass yeild increases with leaf weight as the power function:The grass yeild is directly proportion to its stalk weight. The ratio of grass leaf and stalk weight decreases with its grass mass as negtive power func-tion.The changes of its heigth with time can be very good fitted to the Logistic equation. The effectof soil moisture and fertilizing amount on heigth,stalk weight and leaf weight are all excielentlypositive, which moisture effect is greater than that of fertilizing amount.

Abstract:Wild Astraganus adsurtgens is wild ecotype of cultural Astraganus adurgens.The resultof introdction shows:wild Astraganus adsurgens can get flowers and seeds on the areas which themean annual temperature are 5.0℃、7.0℃. and 12.9℃,The temperature is higher,The seed yieldand grass yield is higher.For getting more seeds,the seed propagation base should be set up in hightemperature area. Wild Astraganus adsurgens can symbiosis with grass on artifical grass land,thenthe higher grass yield can be get.

Abstract:Based on simple intrduction to the soil moisture sensor developed by us,the hardwareand software of the intelligent instrument based on single-chip microcomputer of soil moisture arediscribed and discussaed.

Abstract:The topography,whether,rainstorm characteristics, rock and earth properties,soiland water losses,etc of bedrock mountain land in rainstorm centre region were studied in the as-pects of disposing comprehensive controlling measure of soil and water conservation, designing gullyprotective engineering under rainstorm circumstance and controlling developing way. It makes peo-ple fully realize the ecological economic law in mountain area and found optimized ecological econom-ic medle taking perennial economic plant as the core. A balance system of forestry ecology will beobtained again and the target of beatiful enviroment and harmonious devclopment between natureand social economy will be realized.

Abstract:Bijie prefecture of Guizhou province is situated on the roof of yunnan-Guizhou plateau.In recent years,soil and water loss in this area is very severe,which results in desertification,de-creese of soil fertility and increase of the area of lower-yield farmland,the phenomenon of pollutingand occupying farmland against the law is widespread the above factors hinder the development ofthe agricultural productivity,Based on analysis of the resons of destruction of land resources.theauthor puts forward the protection policy of farmland resources and a serious of countermeasures,such as huilding terraces in the slop farmland,carrying out comprehunsive control taking small wa-tershed as a unit,regulating land utilization constructure and controlling the population increase.

Abstract:The soil and water loss in the source of the yangtze river is paied attention gradually inrecent years, It is not only widespread in whole watershed but also very serious in parts. Mud-rockflow is the common serious erosion form and has some special erosion characteristics,so it is neces-sary to adopt some special measures to control it.Through the investigation to the cause of mud-rock flow in the Menzonggou wathershed inyushu county of Qinghai province. it is considered thatthe main causes are not only geology、landform、soil、rainfall、vegetation and mankind factor but alsomelting erosion and rainfall forms. According to the danger and characteristics of the mud-rockflows in this watershed ,the comprehensive control system for controlling gullies in combination withcontrolling slopland is put out to decrece the disasters to least.

Abstract:In order to find the approaches of preventing soil and water loss and recovering forestryand grassland vegetation in upper reaches of the yangtze rirer,the paper,according to the reason ofsoil and water loss of small watershed,discussed correct thought of soil and water conservationworks,steps,methods and techniques of controlling soil and water loss,and the relationship be-tween comprehensive control and development of agriculture and animal husbandry in the area. Inaddition,this paper tries to find the way from poor to rich in the minority pastoral areas,The expe-rience and scientific basis were provided for comprehensive control soil and water loss areas of upperreaches of the yangtze river.