Abstract:In order to expedite the environment constmction on the loess plateau, it need to adhere to taking soil and water conser-vation as the core, to select and collocate the environment construction measures acc-ording to the special distribution laws of natural geographical environment, and the oneness of economic and eealcgic benefit in the process of environment construction. In addition, it is the essential assurance of environment constmction that to have the supports of proper and sustained policy and technology.

Abstract:The soil and water cx>nservation in loess plateau region is a systems engineering which contains two subtechnical sustenance system and social security system. But for a long time past, since lacking thorough analysis on the social security system many discordant problems have appeared between the two parts which restrict the developm-ent of soil and water conservation. Ther, fore, it is particularly important to stre-ngthen and improve the social security system. From this meaning, the conception, the reasonable system structure and virtu-ousmworking of the socialsecmity system areinquired into. It is pointed out that in this system the macroz}ontrol,policy and action of government are the key factor. And also,the main way and significance to improve the social security system are discussed.

Abstract:The method of stud乒ng for interaction between the past man activities and soil and water loss appearing in Holocene is discussed and practiced. The information of the past soil and water loss could be gott-en from the sediment of aver, lake or the bottom of slope according to the measure methods that used in Quaternary. In some degree, that the number of pollen is decr-easing or vanished, the susceptibility is increasing，the elements or compounds transferring difficulty accumulate, or granularity is increasing in the sediment, may suggest that the soil and water loss occurr,d in the past time.The archaeolog-ical site of Hong shan culture is abroad but sparse, and the deposit of culture layer is thin that may be caused by the past soil and water loss during that time in terns of pollen analysis in the sediment of Doling aver in the north of Liaoning province.

Abstract:The characters of outerbar and inner}tre}nn reach in the Yangtze river estuary are presented by analysis of streambed evolu-tion. Based on the value and distribution of flow velocity in construction stage by 2D hydrodynamic mode上the failure mechanism of beach and bank protection works is stud-ied from hydrrodynamic, construction and streambed evolution. At last, the stratag-ies of beach protection and accretion pro-motion in constrution and plan layout of groin and longitudinal dam are presented.

Abstract:Based on the stochastic theories of soil wind erosion, a stochastic model for soil wind erosion isfounded, and the stochastic probability distributions, expectations and variations for stun a kinds erodible soil particles at any time are calculated. Com-pared with the former researches, the model do not need to limit the length of the time,and classified the factors which influence the wind erosion as different kinds. And through those can analysis for single factor or through calculating the joint probability density distributions of those factors and analysis the relations-hips of those factors synthetically.

Abstract:A dual-box system(one is rill box and the other isf der box) with 15 gradient and clay loss is used to quantify effects of runoff and sediment from up-slope on down-slope rill erosion and sedunent under different sediment concentrations and rainfall intensities.The experiment results show,d that the sedunent from up}lope was completely transport,d, runoff from up-slope caused the additional sedunent deliv-ery at down}lope rill erosion channel. Sedunent regune in rill erosion process was always detachment一transport.The additional sediment delivery caused by up}lope runoff increased with a decrease of sediment concentration in up-silope runoff or an in- crease of rainfall intensity.

Abstract:Abstract The relationship of thevegetation index and soil erosion was discussed by the spatial overlay statistics of the soil erosion and vegetation data.The vegetation index is gotten from NOAAAVHRR,and classified eight grades.The soil erosion data is by visual inter-preting LANDSAT TM imagery. It is show classified eight that wind soil erosionaccounts for 80.7% of all kind of erosion in vegetation grade 1, congeliturbation erosion and wind erosion dominate in vegetation grade 2 respectively acxeounting for 46.9%and 42.2%，and water erosion dominates from vegetation grade 3 to grade 8. Wester erosion above very heavy dominates in vegetation grade 3.Wind erosion with very heavy dominates in vegetation grade 1.

Abstract:水资源承载力涉及到整个资源、经济、环境大系统,水资源承载力与社会、经济、环境可持续发展是否协调是全球关注的重大问题。在充分理解水资源承载力概念、水资源承载力影响因素的基础上建立了水资源承载力评价指标体系及评价方法,并以典型缺水的关中地区为例进行了研究,得到了关中水资源可持续利用的满意方案.

Abstract:Herbage benefiting to the Eco-economy，grain production meeting the food demand, and the afforest-ation having the ecological function detemine their roles and development orientation in the hilly agricultural economy. Based on the regional ecological condi-tion and the resources characteri-stics, the measures to improve the hilly eco}nvironment should be multiply arranged by following the strategical rules and the techni-que requiremerits which are planting grass and tr s sparsely, growing the crops and fruit trees in the terrace, rotationally cutting the grass, using the forest by rationally graziery, and making the soil and water consemation industrialization. Combination of,eco-environment constmction and the economy development in the hilly area is the crucial way to realize the healthy development of agriculture and soil and water consemation.

Abstract:The main studying objects were the rainstorms which had happened since 1980'5 and aroused landslide in Weibei area. the formation reasons of rainstorms were inquired in suitable disposition and interaction, environmental conditions and physical,chanism for weather systems of large, middle and small scales, at high, middle and low lati tucdes and altitudes.

Abstract:The further harnessing based on the soil and water consemation means to further harness, protect, develop, and use the soil and water resources that had been harnessed. The sustainable harne-ssing means the sustamable harnessing process by following the sustainable development theory. These practices should focus on keeping the biocliver-sity, harnessing thefamyard environment, establishing techni-que service network, and adjusting the structure of the land use according to the sustainable, economic, and comprehensive rules, which can promote the development of the soil and water conservation by the innovation of the system and technique. Based on these approaches, the strategies on harnessing the loess plateau were developed, which is to grow the crops on the flat land by the aver; to plant the grass on the hill, and plant thefruit trees on the terrace; trap the sediment and the water in the channeh and close the hills or rotate the grazing on the hi1Ls.

Abstract:The necessity of systematically studying land degradation and its control from the point of view of sociall conomy was expounded. The main studied content of the sociall conomy theory of land degradation and its control is emphatically discussed, which are the study of sociall conomy causes and aftereffect of land degrada-tion, economic evaluation, macro-accounting，the study of ethical land use, the study of cost-benefit analysis of land degradation control, legistation and administration,economy prompting and social organizing.

Abstract:Based on the field monitoring data of newly-eultivatECl su}areane soil water in environmental immigrants settlement area of northwest Guangxi province from March 1997 to Dec. 1999, the yearly dynamic of soil water was made clear.The available water of soi1 was investigated after raining.

Abstract:Taking Jiuyuan watershed in Suide county of northern Shaanxi province，a test area, applying overlaidand cxun parative laws as a basic research m ethodology and 1:10 000 DEM as a cntenon, a research on the errors simulation and the rectify method in deriving slope gradient from 1:50 000 scale DEMs was made A gradient correction down}caling model obtained can effectively rectify the slope statistical values in the hill and gully area of the loess plateau, which is of great significance in enacting related standards in the fields of both soil erosion monitoting and soil conservation.

Abstract:Based on micro-scale DEM datum, optimum size of analysis windows of relief，which is 5km×5km, is defined by means of windows analysis and sample statistical method. Relief in soil erosion of China has been extraded using ARC/INFO software and mapp,d using Arcview.Applicalality of relief was analyzed and initially application of reli,f factor in assessment of Chinese potential soil and water loss is studied.

Abstract:Desertification is one of the most serious environment and socio-economic problems in the world and China today. Land of sandy desertification almost covers everywhere in Ejina Banner(a county，Inner M ongolia Autonomous Region. Using remote sensing method can expediently acquire some inf}omation such as desertification status and effect of harnessing desertification. The ecological change situation from 1986 to 2000 in Ejina onsis is researched. The result is as followes(1) Area of water body of lakes on the northern and eastern are distinctly reduced.(2) Area of the oasis is rapidly shrunk. From 1986 to 2000, the area is r,duced 61.48%，average 4.39% annually.(3) condition of oasis quality is declined. The oasis ecological environment trends to be bad.Its main reason is that human activities exc ded the load capacity of natural resources such as wester and land. By means of selfstorative ability of natural vegetation and human scientific conservation,that the oasis,cosystem maintains dynamical balance and the environment remains relatively stable is possible.

Abstract:Sediment feeding hopper is an most important technique for researches of sediment transport capacity and soil erosion model building. One self-controlled s,diment feeding hopper was developed and the structure and working theory were discussed in detailed. The stability and relationship between running sp d and sediment rate were tested. The results indicted that the kind hopper had very high stability and the maximum relative error was less than 15.5%.There is every fine linear correlation existing between motor conning sped and sediment feeding rate. Sediment fe,ding rate increased as motor running sped increasing. The range of sediment feeding rate was 0-1120g/s and should be used in the researches of relative fields, such as sediment transport capacity of overland flow.

Abstract:Taking small watershed as a unit, acxeording to the allocating feature of mountainous protection forest system,and adopting locating and semi-locating research technique, the function of water accumulation and soil conservation of mountainous protection forest system was monitor,d and analyzed in hierarchical way. The research results are as follows. The difference of soil and water conserative effectis relatively large in different land types, different land use methods and different forest types. The main source of sand producing is the bare area of central Guizhou plateau and cultivated slopeland in drainage area, The erosion quantity of cropland is 18.7-36.0 times than that of forest land; The erosion quantity of bare land is far larger than that of cultivated slopeland, and is as high as about 100 times than that of forest land. After the protection forest system was established, the protection effect was obvious, the mlulus of soil erosion reduced following the increase of forest cover rate The modulus of soil erosion decreased 36% when the forest cover rate of drainage area increased from 18.6% to 42.4%.After the construction of plantation in sloping field, the surfac, mnoff decreased from 79.4% to 96.9%，and the silt amount d,creas,d from 87.8% to 99.9%;In order to control soil and w ester loss of small westershed in mountainous region, forest cover rate must be more than 30%.

Abstract:According to natural resource character in arid area of south Ningxia Hui Autonomous Region the present condition of animal husbandry development is analyzed. It is pointed out that developing animal husbandry in the development of the west parts of China must first improve ecological environment and plant grasses, optunize animal structure and enhance anunal and poultry unprovement, improve basic conditions upon which anunal development depends, optimize resources using and raise the comprehensive benefits of livestock operation, set up overall service system and follow a sustainable development approach.

Abstract:Based on the soil and water resources and environment, the problems of exploiting soil and water resources in Yulin valley are studaed.A new exploiting methods is put forward.The actual effect of exploiting soil and water resources is analyzed.

Abstract:That reclaiming in steep slop land extend the area of dry sloping fied plays an most importment role in soil and water loss and forest eco-environment serious poor in karst area of Guizhou province. On the bases of dry sloping fields structure and its damages. the countermeasures of conversion from farmland to forest in steep slop land are pointed out on sustainable development, that is to program the plan of conversion of famland to forest and using to use the steep slop land reasonably of conversion from farmland to forest, to promote village's development; to follow the way of sustainable intensive agriculture development; to popularize the successful models of conversion from farmland to forest in steep slop, make the policy of village's development,etc