Abstract:There are two kinds of factors, natural factors and human impacts, affecting cropland conversion and its eco-environment benefit. The human impacts involve three different levels of social-economic activity layer, policy and laws layer, and concept and consciousness layer. The different kind and level factors and their relationship are analyzed. Based on the survey of cropland conversion experiment in Ansai county, it can be seen that the three factors play very important roles in cropland conversion and its eco-environmental benefits. The authors suggest that more experiments on natural factors and human impacts should be carried out to make the conver ting rational for the purpose of better and longer eco-environment benefits.

Abstract:The Xiang hai Natural Reserve is one of the most important natural reserves of China, and it is of great biological, economic, social and cultural significance. Wetland is a essential component of the reserve's landscape, and the Xianghai wet land is one of th e 7 International-importance wet lands in China. The ecoenvironmental and reso urces functions of the Xianghai Reserve wetland are analyzed. The eco-envi ronmental functions mainly include biodiversity maintaining functions, hydrological transition zones, pollutants filter and interception functions, and the resource functions mainly include water and soil resources, biological resources,recreational and educational values, and scientific and cultural fuctions.

Abstract:The changes of loess hilly area erosion intensity in space and time are a comprehensive reflection of changes in natural factors and human factors. The natural factors mainly include ones that affect erosion such as terrestrial surface substance composition, vegetation covering rates, topography , landforms, precipitatio ns, and soon. Human factors mainly refer to human activities affecting erosion acceleration and soil conserv ation control degrees. On the basis of remote sensing investigation on soil erosion, the regularity in relation with the above factors affecting area distinctions of erosion intensity are analyzed.

Abstract:Remote sensing investigation shows that soil erosion area is about 4.1911 million square kilometers for twelve provinces of the west region of China. It is 86.86% of the total soil erosion area of China and 62.31% of total area of west region. It has been the crucial factor to limit the sustainable development of society and economy in the west region. Soil erosion destroys land resource, reduces soil fertility, limits grain increase production, affects water resource envi ro nment , and causes disaster a nd ecology environment imbalance,etc. . It is suggested that some prev ention countermeasures for treating soil erosion, should been token in order to reduce harms of soil erosion to the lowest level

Abstract:Severely eroded purple soil was studied by three different manag ement patterns, which are extensive management , intensive management, enclosing and tending management , at Hekou town, Ninghua county, and the biomass and energy of control community were also investigated. The results showed that the sing let reeaverag e biomass of pinus massonians by intensive management was 37.65 kg , being 2.7 and 13.7 times greater than that of extensive management and the control respectively; and the total biomass of communities was 56.908 t/hm^{2 , being 3.1 and 27.5 times as high as that of extensive management and the control respectively. The gross caloricvalue of different stratum in three management patterns was tree stratum> shrub st ratum> herbage stratum, while for the control, the sequence was tree stratum> herbage stratum.The communi ty energ y o f di fferent manag ement pat terns was mainly accumulated in t ree st ratum. The standing cro p energy of ex tensive manag ement w as 114 764.7 kJ/m2 , being 3.1 and 27.5 times greater than that of extensive manag ement and the control respectively. However, the biomass and the standing crop energy for intensive manag ement were still lower than those of enclosing and tending management, which indicated that the restoration of severely eroded purple soil needed a long time, and the measures of deg raded purple soil control should be taken based on different degradation phase.}

Abstract:the Ming sheng gong landslide, which lies in Lishan mountain, is an old landslide. In order to study the stability of the Ming sheng gong la ndslide, the authors study in details the formation condition based on the plotinvestigation. The Ming sheng gong landslide is caused by synthetic factors, such as layers, precipitation,ground water, physiognomy , slipping belt and crannies. According to the limit balance method, the Ming sheng gong landslide is under an instability situation and has to be dealt with prompt ly.

Abstract:Ten environment indicators are selected as key factors influencing forest soil fertility characteristics in closure area by using the method o f main composi tion analysis. Forest soil fertility is divided into four types in closure area by the way of clustering analysis, and the classi fication result is checked up. On the basis of integ rate evaluation on four types of soil fertility, the measures of vegetation restoration and its management utilization direction are given as the different fertilty type. There are actual produce mea ning so fresearch result to reasonable utilization, soil resource restoratio n and forest construction.

Abstract:The difference and vertical variability of the major nutrition elements contents in Carex lasiocarpa wet land soil and farml and soil are studied. The results show that the major nutrition elements contents inCarex lasiocarpa wet land soil are much more than those in farmland soil (except for to talK content of surface layer),in which the contents of total P and total N in Carex lasiocarpa wet land soil are twenty more than those in farmland soil. The vartical variability of Carex lasiocarpa wetland soilis no table, more than 40% , in which the variabili ty coef ficient of total N is highest, reaching 81.32% . But the verticality variability of farmland soilis not notable, less than 24% , mostly due to the water condition and the organic matter content.

Abstract:The different behavior intention and related phenomena of every economic interest partare explored based on the game theory during the transformation from farm land to reforestation and felling trees forbiddenness in the poverty mountain area. The reasons of policy inefficient implemented are “zero- sum game” of every gamble part, so they could not break away from“prisoners dilemma” . Harmony mechanism whose center is cooperation and aim is in accordance with every part economic interest must be establi shed.

Abstract:Based on the ideology of soil and water conservation and economic coordination development , it is successful for rural economic development pattern adaptation to eco-environment to be practiced in many villages of the middle hilly regions of the loess plateau. In order to expand the little scale successful pattern to larger areas, it is appropriate for a middle scale area to be instanced in Yanergou watershed. The progress and achievement of the industrial basement construct ion and agricultural development of the watershed from1997 to 2000 are mainly analyzed and summarized. After systematically evaluate the eco-envir onmental effect ,economic benefit and development sus tainability of Yanergou watershed's pattern, the authors think it is feasibleto establish rural economic development pattern adaptation to eco-environment in the middle scale areas .

Abstract:After investigating the landslide in Wulong county, the causes of lands lide occurrence are analyzed. On the base of the condition in the neighborhood, the potential landslide hazards in Wulong county are determined. Through contrasting the landslide with other hazards, the countermeasures of controlling hazards are put forward. For the sake of avoiding similar tragedies, sciences popularizatio neducation must best reng thened.

Abstract:With the advantage of neural netw ork in nonlinear problem, aradial basis function is used to improve conventional BP network. According to the condition of inspecting water quality in Dawen river of Huang river,the ANN model of evaluating water quality is put forward. The training stylebook takes 7 polluted target of this water quality as samples , and the water quality is evaluated using the trained network. The calculating results are analyzed and compared. This method is used to speed up the convergence and impove the performance.

Abstract:At present, the environment reconst ruction project in the loess plateau area needs the support of the accurate slope gradient. The slope data are mainly detained from the digital elevation model. Four different test areas are chosen to learn the estimation way of the slope gradient from DEM and set up a slope accuracy simulation math-model by assuming 1∶10000 scale, 5mreso lution DEM as the basis, and applying relation analysis, regression analysis. This model was testified to be available in application, which also present the important way to set up the general model of the national scale

Abstract:坡面径流是土壤侵蚀发生的基本动力 ,径流量计算是定量估算水土流失和进行水土保持效益评价的关键步骤。径流曲线数法是美国农业部开发的计算地表径流量的经验模型 ,它有使用简单、有效 ,且适用于资料匮乏地区等优点。介绍了径流曲线数法的基本原理和计算方法 ,并以陕西安塞 2 5个小区的降雨径流资料 (次降雨 )为基础 ,计算了黄土高原地区不同下垫面条件下的曲线数 (CN )值大小 ,并分析研究了 CN值和各影响因子间的关系 ,对该模型在黄土高原地区使用的有效性也进行了评定。

Abstract:By prospecting the highway of Xi'an to Huang ling, in the light of conserving slope, beautifying environment and embelli shing landscape, the present situation and problems of highway greening are discussed.The result shows that the present g reening situation can not meet the necessity of improving environment,maintaining highway and embodying the features of highway department . As far as reservation zone, middle isolate zone, service district and collecting fees station are considered, the authors desig n the highw ay greening all round and sets forth suggestions of highway greening and management

Abstract:The present situation, causes of formations and damages of soil erosion in Hanshui river valley in Nanyang city are analyzed, which is in the source area of the Middle Line Project of Transferring Water from the South to the North. The measures to control soiler osion in the area are disicussed. The serious soil erosion will have influence on the Middle Line Project . The reasons of soil erosion are natural factors and human factors such as overpopulation pressure caused by the emigrants returning back to the original districts. The countermeasures of soil erosion control include polit ical, economic, legislative measures as well as the way of settling emigrants appropriately.

Abstract:With the economic and social transition from agriculture to industrialization, urbanize and moder nism in the Western Development , the new and hig her demand w ill be put forw ard abo ut the w ater resource exploitation and effective use. Water conservancy is not only the lifeblood of agriculture, but also the lifeblood of industry, cities,and the whole economy and society and even the humanit y's survival. At the same time, the water crisis turns to be severe. It has become a serious problem which caused the human society's general at tention. This point is more prominent and severe in Shannxi province, so it is very necessary to study it.

Abstract:The climate characteristics, soil and water resources, social economy conditions of Feimahe agriculture-fruit compound eco-agriculture experimental and demonstration area, which locates at the urban of Yanan city of Shaanxi province, are investigated. The problems in the agricul ture development, the characteristics of the plants tructure and distribution, technologies applied in the agriculture and the agricultural development orientation were analyzed. This study can give some advices for the agriculture development in the area.

Abstract:The comprehensive control measures implemented in Liuyaotou small watershed suggested a successful way to manage a small watershed in the desert stepperegion. The effective measures adapted to that watershed can be summari zed as: to cont rol the la nd desertification a nd improve the eco-environment;to emphasize on promoting farmer to be rich by developing the shallow underground water; to develop the regional economy and drive the economy towards a sustainability in the watershed for the purpose of raising the land productivity and improving the farmers' living quality by means of combining afforesting and planting grass with confining the mountain.