Abstract:Wind erosion and runoff erosion alternatively take place under the action of wind force and runoff force in copper mine and tailings storehouse with high dam and big storehouse，and with very loose texture and very low resistance to erosion because lack of cement property for tailings sand parts. Soil erosion mudulus reaches 80 OOOt/kmZ.a in the slope of dam meanly，wind erosion mudulus reaches 30 000-40 OOOt/km’in the inside of storehouse.Surface erosion and gully erosion take place easily if the protective works were not carried out well.which will result in harmfullness. To conserve the stabilitydam is the key for secure storaged ahean·lsTsuch as dam structure，of tailingstailings dam and the integrity of slope and top of dam for every sub storehouse. Attention should be paid to every measure for erosionresistance， storehouse protection of dam anddam slopeand Utilization top of suberdam of tailing from the start of storehouse construction.coverin soil on dam protection beneficial measure to control erosion thoroughly around storehouse，and to turn harmfullness popularized and applied in the same mine regions on a big scale.benefity. measures should be popularized and applied in the same mine regions on a big scale.

Abstract:The developing region of Shengfu-dongsheng coalfields is regarded as a independent ecological and geographical unit in this paper. The ways，degree，features and laws of soil erosion and its influence. on the environment in this region have been investigated deeply and analysed comprehensively. Meanwhile，the trend of soil and water loss，wind and sandification, and environmental pollution caused by the coalfields development and construction were forecasted and the countermeasures concerned have been put forward.

Abstract:Ziwuling is a bigger existing secondary forest in the Loess Plateau;also, it is one of the forest areas of conservating water through afforestation in the national plan. The area and comprehensive functions of the forest have been reducing because of over-increasing population，more aggravated production activity, political faults sometimes，and unstrict administrative measures. To this end，the arthors suggested that this region should be classified as one of the key protective regions on national level in order to take some beneficial measures of recovering forest，and to bring its role of conserving soil and water and improving ecological environment into full play.

Abstract:By the end of 1990, there were 522 reservoirs，2666 small reserviors，450 thousand ha irrigation area by pumping, 3893. 0 km² level terraced fields，3407. 9 km² artificial forest and 1085. 7 km` artificial grassland in Weihe watershed. The total area harnessed has reached 8466.7 km²,and the harnessed degree has reached 19.0%. There will be 590 reservoirs to be constructed，2333. 3 ha siltilizing soil with silt arrester，2006. 10 millon m' water storage capacity for control of the key watershed，70. 78 ha irrigation area by pumping，15921. 3 km² the total harnessed area and 36% harnessed degree in the short-term plan. The total harnessed area will reach 40214km² and the harnessed degree will reach 80..4% in the long-term plan. The "laws of Soil and Water Conservation" is used to calculate decreasing the amount of runoff and sediment and its comprehensive benefits for every measures of water conservancy and water conservation. The results show that the comprehensive benefits for decreasing runoff rate is 28. 71%and for decreasing sediment rate is 30. 9 0 o at present. The benefits will be 32. 0 0 o ^r 60.5 0 o and35. 300"84.0%，32.5%~40.7% and 60.0%^-87. 00o in the short-term plan and long-term programm respeclively. Tremendous changes of the trend of runoff and sediment will take place in Weihe watershed in different years (i. e, abundant rainfall year，average rainfall year and exhausted rainfall year).

Abstract:Throngh the practical investigation on gully erosion in the seeond terrace along the bank of Soghuajiang，the formative causes，present situation,, harmfulness and developing trend of gully erosion were analysed. Meanwhile，some control measures have been advanced.

Abstract:The infiltration reducement mechanism of infiltration under surge irrigation were analysed theoretically. The natural laws for the form and development of compact layer have been tested and verified using field experimental data in a large range. The mechanism of reducing water conductivity of infiltration under surge irrigation has been analysed in order to supply beneficial reference for these researchers who work on the surge irrigative techniques and for these administrative personnel who work on water utilization.

Abstract:According to the hydrographical data investigated from Sanguankou hydrologic station in Xiehe basin during 26 years (1966-1991),the mean discharge for every month and the total runoff amount for withered season in this area were predicted with autoregressive model. The predictive precision is improved remarkably.

Abstract:The growth law of root system of Onobrychis Viciaefolia Scop. and the relationship between root systemand overground part were approached systematically, which provides a basis to choose fine leguminous forage grass with strong adaptability and high yield in the arid and semiarid regions of the northwestern China，and it is significant for speeding up basic construction of animal husbandry and for restoring vegetation in the northwestern China.

Abstract:The physical factors such as topography，climate，soil，vegetation were described in this paper. By analysing the present situation and formative reasons of soil and water loss,, the authors 'advanced the principles，basis and system of division of forest for soil and water conservation and forest for water storage according to ecological benefit. Meanwhile，Wujiang watershed‘ (part in Sichuan province) was divided into, four different stereoscopic regions according to degree of soil and water loss a叫landforms in a. large range.

Abstract:Quanjiagou comprehensive experimental area was established by the Institute of the Loess Plateau Control of Shannxi in 1979. The remarkable. changes in ecology and economy have taken place as the structure of land utilization and estate has been rationalized. The mean net income increased from 118 yuan in 1979 to 707 yuan in 1992， the control degree raised from 32 percent in 1979 to 71 percent in 1992，soil erosion mudulus has been reduced from 16 279t/km² before 1979 to 2330 t/km² during "The Seventh Five-year Plan". Ecological environment has been improved remarkably; the farmers' living standards have been improved stably; and remarkable benefits for society and economy have been achieved. But，some notable problems still exist，such as how to stabilize forage area, how to renew low beneficial forest land, and how to manage projectical measures of soil and water conservation. So some ways to resolve these problems were presented in this paper, such as la如ng particular stress on the benefit of soil and water conservation, strengthening scientifical control，adjusting service mechanism，changing free input to return or economic service,etc.

Abstract:The situation of agricultural environment in the Loess Plateau in north Shaanxi and reasons for its worsening were described. It was pointed out that constructing eco-agriculture is the basic strategy for improvement of agri-environment. Paying attention to education is the important way for the improvement of environment. To establish self sufficient grain production and timber forest，.conservational grass and shrub land，commodity animal husbandry and fruit production is the basic principle for development of agricultural economy and improvement of eco-environment in this kind of areas.

Abstract:Althorgh Japan covers only 0. 3 percent area of the world，it provides foods for 2. 5 percent people of the world. Rice，the staple food, can meet itself with a surplus, which is a wonder in the world. Chinese agricnlture,with a dense population and insufficient farmland-only 10 percent of the nationd land，is basically similar to the Japanese，and both the Chinese and Japanese agriculture carry out traditional agriculture which depends on intensive cultivation，applying organic fertilizer, and best field management to increase periese of Japanese modern agriculture has a great reference to Chinese agriculture modernization.