Abstract:An unbalance development of regional economy is a projecting character in current economic operating in our country，and it is a main problem which requires to be solved in Shaanxi province.Through fully analysis to the economic situation in the countryside and con-trasring the three major regions in Shaanxi province with principal indexes of agriculture economics, the key factors which limit the balance development among regions were found, and the approachs to accelerate the regional economy development were given.

Abstract:In the study and practice of comprehensive harness in loess plateau region, the studying on economic problems are strengthened.The status, the studying ways and the substance of the economic problems concering comprehensive harness in loess plateau region are analyzed.

Abstract:The principle of replacement weighting method has been used in the total sediment load monitoring.Through using the specially designed digits sensor and the computer-based digits collection system, the monitoring device has a wide sediment concentration measurement range, it can monitor and record sediment concentration processes automatically and can be used in very low runoff discharge.The observation precision of the device can't be affected by sediment partical size in runoff.The device is available for rainfall erosion experiment.

Abstract:During the period of 1992^ 1994, the study on remaking of low-middling yield farmland, which is regarded as a part of Hongni river valley, was carried through transforming ecological environment, improving agricultural productive condition and applying agrotechniques.By combining ecology .production with science and technology, the structure of ecosystem, the productive function of farmland and economic effect in Hongni river valley has been improved obviously.Basing on that, the direction and measures to be taken in the further remaking of lowmiddling yield farmland were suggested.

Abstract:Soil erosion resistance is studied with liner model theory in loess low hill area.The principal factors to affect erosion resistance are found out, and the effects of various land types to erosion resistant ability are analysed.At the same time, a predicting model of soil resistance ability to erosion is constructed.These provide some theoretical bases for comprehensive managing in loess low hill area.

Abstract:Crossing loess plateau from south to north·wind erosion energy water erosion energy and gravity erosion energy attached with terrain are calculated in water erosion region, wind water erosion region and wind erosion region.The results indicate that in wind-water erosion region, wind erosion energy makes up the decrease of water erosion energy, wind erosion energy, water erosion energy and gravity erosion energy attached with terrain make wind-water erosion region be an area of high erosion energy environment and potential erosion intensity. With transition from water erosion region to wind erosion region total erosion energy increases, especially wind erosion energy increases abruptly.Additionally, the results also show that the fragility of earth surface in wind一water erosion region is the main course of severe soil erosion in this region.

Abstract:A mathematical method of judging ecological fragility in loess plateau region is given, and the fragility indexes at 105 counties are calculated.Three types of eco-environmental fragility at those major erosion countries, i.e.intense fragility region, intermediate fragility region, slight fragility region, are divided on their fragility indexes.Thus, a new basis for comprehensive control in loess plateau region is provided.

Abstract:It needs a long complex process to establish an artificial froest ecosystem in the fragile natural environment with serious soil and water loss in loess hilly area, Because the artificial forest should be steady and productive within a very shorter period than that of natural forest needs, we should study the ecological relationship of natural system.The system we built should have as less as possible of resistant and competitation in it, so that the system could be efficient.Therefore the structure and function of those artificial system is the key in their erecting process.We had made a wrong step in land harnessing and afforesting for our overlooking to the natural law.

Abstract:After having tackled the key problems of science and technology for ten years, the industrial structure of Wangdong gully watershed has had a distinct change.It goes through one way structure which put stress on historic planting industry to two-way structure which put stress on both planting industry and side occupation in the seventh five-year plan.Now it has been developed to three-way structure of planting industry, fruit industry and industrial sideline.This structure increases agro-ecosystem adversity-resistance.In the climatic condition of succes lively arid, grain yield developer continuously, the peasant revenue increases doubly, eco-envi-ronment have been improved obviously and economic, social and ecological benefits have been achieved at the same time.

Abstract:The consumption law of soil moisture in wheat fields in the eastern part of Weibei rainfed highland was analyzed by using the farmland water balance method.The results show that the actual water consumption by wheat was 291.5~365.9mm, the rate of average moisture to meet wheat requirement was 64.9%.A mathematical model for wheat yields and farmland evapotranspiration is established through the statistics analysis.The agronomic measures such as accumulating and conservation moisture techniques, soil fertility and drought-proof chemicals are put forward.

Abstract:The land forming factors at Haiyuan experimental area were analysed at first.Based on the land quality characteristics and differences, the land types were classified, the morphologic feature and productive properties of various land types were also expounded.By metes of the land survey and analysis, the present condition and characteristics of landuse were mastered.And the major problems existed in landuse present condition were brought to light.Finally, according to the land quality and the ecological conditions of vegetation, the models of the land rational development and its implemental method were pointed out.

Abstract:In the low一hill areas of loess plateau in eastern Qinghai province, the serious accele rated soil erosion has caused many crucial problems such as the imblance of ecosystem, the unsteady developing of agriculture and the slow advancing of economics.And then, people in those areas have been plunged into poverty.It is proved by practices, that the effective measures to prevent accelerated soil erosion are controlling mountains, rivers, farmland, forests and roads in a comprehensive way.Thus, the condition in those areas could be completely improved, the soil and water loss could be controlled, and the land productivity could be developed.