Abstract:The soil loss and deterioration of ecological environment over theworld have been recognized identically, the concerned are formulated andeffective measures accepted, the governments have paid much attentionto soil loss and deterioration of environment, taking protection of ecological environment as a national policy after the Second Conference on Environment Protection and promulgating a set of policies and measures.Meanwhile, it makes people anxious to damage when to be harnessed, todamage from many sides and harness by one side, even not to harnessseriously.The deterioration is still on,with unfavourable changing of environment on the earth it is thought as a severe problem and could not betreated lightly.Now the urgent task, facing the natural science, technicalscience,manage science, especially the sciences of environment, economy,ecology and soil conservation, is taking action urgently to raise plan,to work out effetive measures and to coodinate the relationship betweenmankind and nature to prevent deteriorating of the ecological environment.

Abstract:The conventional tillage system, such as harrowing, weeding by digging and tillage rotation, etc., often causes severe soil loss. It is of greaturgency to perform no till as the strategy of soil conservation. The system in no till can not only conserve soil and water efficiently, but alsoraise soil fertility and increase production and other benefit, saving manpower and reducing the input.The present obstruction is thought mainlyin conservative ideas, following old convention and unavailable tillagemehods. It is suggested to encourage and reward the farmers performingno till, to manufacture weed killers in low price, high efficiency and nopollution, to set model experiment to promote the work in larger areaand to spread in full scale, to obolish conventional tillage system gradually using administrative and economic means.

Abstract:The soil loss area of China is 1，500，OOOkm²，being one sixth of the land area of the nation, the annual soil loss amount is 55，000 million ton or more, farmland correspoding to 1，600，OOOha, large and 17 cm thick is des troyed, If it goes as this for long, the great loss would be irretrievable once the developed soil loss has brought harmness and dangerous conse quences, From now on the soil conservation problem should be an impor tant topic for discussion in the work of each grade government; effective measures should be adopted such as increasing the funds of harness, formulating the policies and safeguarding the activity of farmers, As soil and water conservation is also a major task of the water conservancy department, the old idea thinking only the water conservancy engineering as the orthodox task must be changed, Great number of reservoirs have fully deposited and have lost effectiveness, which is the inevitable punish ment to the water conservancy department,always neglecting soil and wa ter conservation, and saying yes but meaning no, Mistake and setback has given bitter lessons, For this the special technical cadres, especially the leaders in authorities of various grades for soil and water conserva tion, ought to be cultivatied in great attention, in order to well operate the harness of soil loss,

Abstract:A large landslip, occured on June 21, 1988 in Chaoyang commune ofShangrao County, Jiangxi Province, smashed Xiayuan village completelyand killed 78 persons with a lot of property lost. It is advanced to reinforce the popularization and propagating in sciences to induce notice of thewhole society; to survey and plan comprehensively, to observe and prodictin stress, it is thought that the prevention is the major task and dangerousor urgent points be controlled in advance. The occuring of hill collapse,landslip and debris flow is with time, region, condition, inducementand indicators, so long as the rules are mastered, the disaster can beprevented, that man can conquer nature could be realized.

Abstract:The cause that induces disorder is due to the indefinite division of work, of responsibility,the poor personal quality and not skilled specia lity,the continuous change of the system and concepts for statistics,The false is from the work style,doing as is told from higher authorities but from fact,working behind closed doors,estimating unreasonably and copy ing values from other special departments,The way to correct is mainly to arrange special person for special work，to employ worker according to his or her ability,to work in practice,to cultivate in speciality and to readjust the persons being not suitable for the work，it is also suggested to set stable and complete statistical system and regulation，to let the workers go down to the primary level deeply,to strengthen the relationship with related units and found the regulations to check and test.

Abstract:This paper describes the concept and method of estimating soil erosionrates of cultivated land from fallout Caesium137 measurements.The resultsof five soil profiles on cultivated land of weir and mound and terrace showthat the total content of ~(137)Cs in soil profile reflect erosion severity ofcultiated land well.The soil erosion rates,indicated by Kachnoskis and Quinescurves and calculated by the formula developed by authors,are basicallyconsistent with the analyzed values based upon measured data of runoffplots.

Abstract:Soil efficient thickness should be analysed in the appraising of erosion risk of soil, In this paper, combined with the charting of soil thickness of QinBa hill in southern Shaanxi, the method and step to chart soil thickness is studied with trend surface analysis and regression analysisy etcc..From the results of charting it can be seen that the mathematical method has nature of high logic, high accuracy of map spot,and that the maps made with this method could reflect the actual distribution and va riation of the soil thickness.

Abstract:The site factors of hillsides closed to afforest in southern Shaawi Province are divided into seven types using fuzzy cluster by progressive modification from centre, including the types of thick soil, gentle slope, rich rainfall with high elevation, rich rainfall with low elevation，poor rainfall with high elev0ation, poor rainfall with low elevation and stern slo pe in order, Among the seven types, the most advantages is tim first type, then the second to the sixth, th.e poorest is the seventh, the type of si;eep slope, The results demonstrate that this kind of quantitative cluster analysis method is characterized with fast result and objective, seientiific, simple and com0enient nature when used to divide the type of site factors of hillsides closed to afforest.

Abstract:It is known that the soil loss area of Jiangsu Province is about 4,395.5km~2 from the interpretation by remote sensing and the measurement byphotoelectric scanner, in which the area of slight to light erosion is3,674.4km~2, in moderate and strong erosion is 578.6km~2 and 142.5km~2 respectively, being amounted to 83.6%, 13.2% and 3.2% of the total respectively.From the point of risk extent, the area in no risk is 71.5%, in somerisk 14%and much risk 14.5% of the total. The control measures are toimprove the engineering systems of water conservancy and soil and waterconservation at first, to plant trees, brushes and grasses widely and topopularize the system of no till.

Abstract:Landslips in Sanchuanhe watershed in Shanxi Province aro classifiedand named by three indices of "slipbed". "stability", and "slip volunme". Inthe investigation,the color synthesized landsat images in scale of 1:100,000maps in scale of 1: 50,000 and 1: 100,000, and the maps of geology, geomorphology, water system, plantation and soil erosion etc., are taken asthe major resource of information. Then, by visual judgment the landslipsare determined in existence, type, stability and scale. The result showsthat the area of landslip are highly correlated with their lengthes and widthes. If the concerned data from the classification map of landslips distrition transformed in net of landslip is input to computer, controlled withmanage system of DBASE Ⅲ data base, the number, area and volume ofthe slips could be calculated,and ten special maps such as that of distribution intensity could be obtained,which would provide the information needed for the regional renovation and development.

Abstract:The impact of human activity on hydrology and sediment is great. On the upper reaches of the Yangtze River great amount of sediment is transported into the mainstream, which increases turbidity of the river and lengthens the turbidness time because of the sharp increa sing of population, the frequent destruction and the deterioration of the ratio of abundance to dryness, but the variation has not been found in checking，so it is thought that the sediment load at Yichang station in 1980's is completely the same as that in 1950's, i,e.，520 million ton, and affir med that the sediment load on upper reaches of the Yangtze River has not been changing for thirty years or more and it would not change essenti ally in the future, In this paper a preliminary study is made to the effect of human activity on the increment of sediment load in the section of Three Gorges, The results obtained is that the annual average sediment load at Y ichang station is 659 million tons and would be 685 millon tons in fnture fifty years.

Abstract:Soil loss on upper reaches of Banqiao reservior was highly serious.After the dam had been constructed the soil loss there was not harnessed, the management of the dam has been disappointing. When reportabout dangerous situation of the dam was reported to the departmentsin charge of water conservancy the bureaucrats disdain to pay attention.In the August, 1975, facing a flood people in charge were beingfrightened out of their wits,having no way to counter with,the dam wascollapsed unfortunstly, which created an unprecedented disaster by human being,several hundred thousands persons were killed. More than tenyears have passed since the occuring of the disaster, the scense of baremountain and hill seen just as it was before, but soil loss is getting greater, meanwhile, huge amount of cost is poured to build dam on the old site. The history is hard, if it went along the old routine, the Banqiaoreservoir will collapse certainly. A reservoir in Sichuan Province hadbeen collapsed for five times after building for five times, 13 sets ofdams of Yunnan Province were broken down in a time in 1985,a recentburst of a great dam in Shanxi Province destroyed 18 villages, submerged 300 or more villages. The number of 90 dams collapsing every year,announced in former years, might have been topped now. It is said thatwaterconservancy projects can change into water disaster projects. if thesoil and water conservation is neglected.

Abstract:In recent years about 200 large or middlescale cities of China are short of water,numerous of countries lack water for irrigation, water use for man and animals isdifficult. Water has become a critical factor to life, production, construction anddevelopment in many regions. Three special research results, including "water supply prediction of the energy base in loess plateau", "the hydrogeological problemsand countermeasures of the water supply for provincial capitals in loess plateau" and"exploitation and usage direction of ground water in the running water basinfound during the Cretaceous period in the plateau,"haved formed several tens ofgreat or middletype water resources, formulated the way for exploitation andusage, raised highly concentrated and practical measures and suggestion.