Abstract:The principal achievements by the committee of soil and water conservation of Shandong Province in the last three years were:1)one's understanding; 2)making the guide to work clear; 3) making new advances in the path of harnessing; 4)raising further comprehensive results; 5)making a new development in comprehensive type of harnessing, resulting in obvious economic and ecological results. However, these areas which have been harnessed is only 20-30% of the whole，a large square is being faced with more serious loss of soil and water and harm of wind or sand, and the speed to harness is too slow to suit the need of the ecological development and the prosperity with the poverty to be shaked off. In the coming years, the conservation of soil and water should be thought as a protracted，national，and basic strategy. Thus the program must be doing well, the contracted responsibility to exploit and harness the small J watershed must be further perfected, and making the good job of the conservation of soil and water on the strength of the whole society, and prevent the loss of soil and water according to law.To do the works above well，the key lies in the leadership and the stress is putting on the work.

Abstract:In the resent years, a better ecological，economic，social results and results of soil and water conservation have been achieved through the soil and water conservation works in Linyi area of Shandong Province,It is mainly'for a steadily better understanding and a heightened self-consciousness in malting a good job of soil and water conservation, putting the soil and water conservation of the whole area into a new stage by persevering in reform and making innovations courageously, solving problems concerned with soil and water conservation by heightening leadership and spreading propaganda better.

Abstract:Based on the results of experiment, model and productive control in the experimental plots of soil and water conservation of Ansai county，North Shannxi Province, for many years, and the characters of the semiarid region in the hilly loess region，the author makes an attempt to discuss systematically the ecological agriculture of soil and二water conservation type in the hilly loess region, including rational use of water resource in soil; programme of the construction of the forest-protection of water and soil conservation on the basis of the influence of artifical forest on dry condition in soil layer;development of dry farming as far as possible so as to raise food production; establishment of the artifical grassland and development of the animal husbandry; harnessing slopland and renouncing steep slopeland-farming and planting trees,etc. The paper suggests and discusses the problems about protection of agricultural environment and system of ecological,agricuture of soil and water conservation type.

Abstract:Water in the Yellow River is charged with much silt. The mean volume of silt flow reaches 1,6 billion tons a year，and a cubic metre contain about 35 kg, The Yellow River is famous for much silt in the world, so it is. called "silt river", The river course of lower reaches of the river burst frequently in history, resulting in a heavy disaster to the people. Since the foundation of the new China, the soil and water conservation work in the middle and upper reaches has been made extensively, the large, middle and small type of reservoir and a great number of silt arresters and terrace have been constructed; and the trees and grasses have been planted extensively, so that the volume of silt flow into the Yellow River can be controlled. Although we have won great successes in the works above, we must not become unrealistically optimistic. We have to know that harnessing the Yellow River is an arduous and long-term task. We must not lower our guard.

Abstract:The Panxi Region is located in southwest Sichuan, where there are 220>natural landslides of more than 500，000 cubic metre and 51 man-made landslides of more than 10，000 cubic metres and 687 movable debris flow ditches.The landslides of the middle and small-scale distributed in the edge of fault trough or basin are most easily transformed into huge debris flow.The.large-scale bedrock landslides distributed in valley of the strong uplifted are not easily transformed into debris flow，but the specific broken landslides transformed into large-scale debris flow will be possible. The most large-scale bedrock landslides distributed in the lump of fault differ in movability are easily transformed into middle and small-scale debris flow.The landslides differ in lithology have different influence for debris flow.The landslides of the loose pile layer and man-made are strong then the bedrock landslides of Xigeda Formation clay rock and sandy shale strata and coal strata.The landslides in limestone strata are possible to form thin debsris f low.

Abstract:Debris flow acts violently in Panxi where man`s economic action is frequent. It damages the.natural ecology environment, especialy the forest ecological system to exploit the resources during the long history and economy development in the region, for instance, to cut down forest serIously, to destroy forest and reclaim wasteland, to reclaim on steep slope,to explore stone for road construction, to mine and wantonly pour dregs and take biological energy resource excessively, etc,，induce the expansion of the mountain disaster and the debris flow suffering because of the de struction of the natural condition and the forest of hilly land in different extent,The debris flow hits the overall arrangment of the natural economy development and constructon seriously, affecting mine, communication and transportation, hydroelectric construction, urban andrural development,and the production in agriculture, husbandry and so on. Counter-measures to debris flow are to prevent and protect or to control in multiple way,Human should previously protect environment and prevent the occurence of the debris flow when carrying on economic activity.If the debris flow can not be controlled shortly,the arrangment of the economic constructin should keep away from the dangerous deris flow region,i .e,，take preventive measures before it occures. The harness means to,the debris flow should be the following ways, to do the most neccesary control work ahead (engineering measures prior to other)，to combine the biological and engineering measures for harness, and to attach importanceto social preventing and protecting measures.

Abstract:The existent main disasters on the Yangtze valley are flood,loss of water, erosion of soil and deposit of silt. Among them, the loss of water and erosion of soil lead up to a decrease of productivity of land, a reduction of yield, a shortening of channel and a loss of reservoir efficiency. To construct total protection forest system on the whole valley is the fundamental to control or eliminate these disasters. It includes: 1)the system of forest for conserv'ation of water supply on high mountainous gorge district in upper reaches; 2)the system of soil and water conservation forest in middle reaches; and 3)the system of protective belts of agricultural land and bund protective forest in plain of middle and lower reaches. After completion of these systems, the ratio of forest cover in the Yangtze valley may reach 20-30% and the virtuous cycle in the ecological system will be realized.

Abstract:Storm rainfall is a key and dynamic factor to erode soil in the Loess Plateau. Usually, serious soil erosion on the Loess Plateau is caused by a few storm rainfall.Hence, studying storm rainfall standard and further making,storm rainfall division in the Loess Plateau are of great significance for soil and water conservation planning in the Loess Plateau. Though several storm rainfall standards in the Loess Plateau were made before，it cannot utterly meet the needs of soil ail witer conservation works fully because they mainly paid attention to flood prevention and scarcely to soil erosion.In this paper,we develop the storm rainfall standard in the consideration of roil erosion,that is,soil erosion storm rainfall standard in the Loess Plateau Fby simulated rainfall. Here, storm rainfall is defined as the rainfall because rof which runoff appears on the slopes, and storm rainfall is subdivided into-common storm rainfall which cannot cause rills on the slopes and heavy storm rainfall which can cause rills. Experiments were made on the plot(5 x 1.5 = 7. 5m E ) which unif orm loess parent material, 20 degree of slope and no vegetation by lateral sprinkling rainmaker. Based on statistic analysis and energy conversion of experimeritai result, soil erosion storm rainfall standard for the natural rainfall in the Loess Plateau is made (tab, 4)

Abstract:In the Loess Plateau with broken topograhpy and steep earth's surface, the rain redistribution always takes place on hillslopes. Based on field studies, some conclusions have been drawn by us:1, The relationship between received precipitation on slope and steep degree is expressed by equation P,=Pcosasins [f(1)〕2, The critical value of the unredistribution of precipitation on hillslope is enumerated:7°-7mm, 15°-4.3mm, 27.5°-3.2mm,30°-2.8mm;3, Change law of soil-moisture storage from hilltop to the slope base= In the dry season, the most soil-moisture storage is situated in the central section of hillslopej after the rain season the soil-moisture storage is increasing little by little down the slope.

Abstract:In order to accomplish the task of soil and water conservation program of Shanxi province, we have made a thorough investigation of present situation of land use and control by the statistics to form a network of unit kilometer and stored more than 800,000 data which are put into IBM-PC/XT computer. We have developed the software of database of Shanxi land resources. The software uses Chinese character display and could print out the data and graph of the administrative division or river basin required.We start to manage soil and water conservation of Shanxi Province by computer.

Abstract:An investigation of land resources in Shanxi province was conducted by the method cf sampling investigation in planning the soil and water conservation of the Loess Plateau. The sampling point was first located from the topographic map of 1:500,000 in scale on the network of squares,then the information of land resources in the fields were taken at one Ni-lometer intervals, and it made up a controled network of present land utilization of Shanxi province.Based on the principle of forming image by assemling points, a present land utilization map，1:500,000 in scale for Shanxi province is, first compiled.It has provided a complete set of an overall and systematic basic map,for planning soil and water conservation.

Abstract:Soil erosion makes for damages on the farm where it occurs as well as off the farm. The off-farm economic losses caused by soil erosion are considered as macroscopic in nature and very harmful to national economic construction, and those occuring in China are discussed tentatively in the folowing five aspects; 1，Reduction of the use efficiency of stream flow;2，Aggravation of flood damage; 3,Damage to river navigation; 4，Sedimentation_ of reserviors; 5，Shrinkage in lakes' areas.

Abstract:The tendency of development of modern science shows mainly that science and technology are turned acceleratively into productive forces.The social stability and progress create proper conditions for developing production, .The development of science itself has become crossing and infiltrative each other, and comprehensive, but the work in the disastrous sciences have made progress slowly as a result of the failure to take forceful measures and correct policies, resulting in heavy disaster, heavy losses and treat to the people in their production and daily. The work of the disastrous science needs to be enhanced and developed. If the departments work with one heart and mind, and with supporting each other，the natural disaster can be conquered surely.