Abstract:The benefit of a test reformed low beneficial protection forest established on the Huaying mountain has been observed and appraised. The result shows that the hydrologic benefit of reformed low beneficial protection forest is obvious. Having been implemented reformation for five years, the available soil water for various re formative way has increased by 14. 0%～38. 0% over the unstocked forest land. In the portioning of annual precipitation,the storage of soil water was 55. 5%, the surface runoff was merely 1. 8%, the permeant runoff was 8. 7% and the runoff in soil was 23. 7%,the annual runoff coefficient in whole woods was 0. 341 5,it has decreased by 12. 48% under the annual average runoff coefficient determined by Beibei Hydrology Station. The runoff coefficient in the plentiful water period has reduced by 22. 52% as compared with Beibei Station,but in non-plentiful water period,it has heightened by 20. 35%. Therefore,reforming low beneficial protection forest has a very high benefit of storing water,decreasing flood and regulating discharge in rivers.

Abstract:Mengba river watershed is located in the south of Zhijin county, Guizhou province,the upper reaches of Sancha river,a main upper tributary of Wujiang river source.Since 1986, various comprehensive administration measures, including biological ones such as afforestation and closing hillsides to facilitate afforestation and engineering works such as vally dams in the watershed have been designed and implemented. And observations in a hierarchical way to evaluate the effect on hydrologic processes and soil and water conservation have been carried out.

Abstract:The experiment is conducted with three different forage species which have grown for 4 years on newly-built terrace land in loess hilly region to study the effects on raising the content of soil humus and nutrient by cultivations of Bramus inermis,Astragalus adsurgens and Meliotus albus respectly. The resoults show that the soil humus,nitrogen and phosphorus content can be significantly raised by planting the forage species,the best effect on improving soil fertilities can be obtained by planting Bromus inermis. On the other hand,the content of soil trace element changes with the different utilization of the three forage species. Although the treatment of planting Bromus inermis has the best effect,the yield of millet by planting Bromus inermis previously is relatively low. However, the millet by planting Meliotus albus previously has the highest yield among the three treatments.

Abstract:Gully harness and development are a glaring problem demanding prompt solution in mountainous and hilly areas. Owning to the proceeding of gully head, the extending of gully bank,the downcutting of gully bottom,the collapse and the landslide, the gullies were allowed to lie waste. To counter this problem, people in the Water Conservancy Bureau of Pingdingshan City,He'nan Province have conducted an experiment to study the development and utilization of gullies in mountainous and hilly areas. Through the work for 5 years,the new harnessed gullies have reached a area of 13 727ha. The economic benefit obtained in 1995 was 4 647. 38×104 yuan. The study has provided a harness pattern for gully development and utilization in areas of the same kind.

Abstract:Water-rock debris flow is a main type of debris flow in Qinling mountain with a wide distribution,typical development and serious disaster. The movement characteristics of water-rock debris flow and its mechanics of movement starting in Qinling mountain have been analyzed through investigations on the spot.

Abstract:Through discussion on the formation mechanism and the features of debris flow in Sanyanyu gully in Zhouqu county, the seriousness of debris flow disaster and necessity of its prevention are analyzed, A comprehensive controlling program is put forward,which is to take the blocked works as dominant measure, meanwhile to combine debris flow silting ground, draining channel and biological measure. After controlling works finished,there will be 3. 14 million yuan of disaster reductional benefit,and economic benefit will be produced per year, debris flow changes to usual flood flow and its threat to Zhouqu county town will be eliminated at last.

Abstract:In China,drought is the main contravariant that restricts the sustainable agricultural developmemt in arid and semi-arid areas. The ways of the effective usage of rainwater for the sustainable agricultural development and the recent achievements both in theory and practical techniques are discussed. Through analyses to the relevant problems, the results suggest that the strategical acts for sustainable agricultural development in arid and semiarid areas are developing and improving rainwater utilization techniques, establishing the technical systems and speeding up the transformation from research achievements to practical productive forces.

Abstract:The characteristics of urban program of soil erosion and its relation to urban overall plan and urban functions are expanded. The contents and the technicai lines of urban program of soil and water conservation are also explanined.

Abstract:The 8th International Conference on Rainwater Catchment System (ICRCS) was held in Tehran, the captial of Iran,on April, 21 - 25. More than 1 300 representatives from 40 countries attended the conference,and offered 274 papers being published in 4 volums. During the conference, the content of exchange was abundant,there were 10 topio discuss sessions.Meanwhile, 6 study tour lines of postwconference in Iran was arranged to the representatives.There were 19 persons of China participated in the conference, submitted 12 papers, and taken the study tour line B in cool semi-arid region. The 9th ICRCS will be held in Brizil in 1999.