Abstract:A tentative analysis is given out for the impotance,favourable condition and the characater to build the protective freostry system for the idea of comprehensive development in the Yangtze River Basin,and six suggestions have been drown for the building of this state eco-pro-jection in this article.

Abstract:In the low hilly and red soil areas of western Zhejiang Province the natural condition is complicated, but the land resources are abundant and the climatic conditions fine,making them good for the comprehensive agriculture demelopment.However, the agricultural struction is unreasonable in the area and without recuperating soil in the land usage,so it breaks doyenA the eco-balance,results in soil and water loss and soil fertilizer becomes exhausted.In order to build a fine eco-circle and develop agriculEure,a herbage base has been built to use the brass, feed the dourest is animals and fishes,to use the excrement manure the fields and to create marsh gas.This experiment has resulted in a good eco-benefit,social benefit and economic benefit。

Abstract:The hilly region of the central part in Sichuan basin is one of the regions with the most serious soil erosion in China. The research on evolutional laws through time and space on the soil erosion is highly important to the work of the soil and water conservation in the hills. This paper deals with those laws and macroecomic analyses of the region. and puts forward control measures. The auther holds that the research and management on gullies is improtant to the work of the soil and water conservation in the hills.

Abstract:Using the principle of geo-chemistry study the present state of water and soil loss on the upper reaches of Wanshui River in Dabieshan Mountains in Yuexi County in western Anhui Province. Rate of soil formation is less than the rate of soil loss,the river water not only transpots quarte but als carrie orthoclase and chemical weathering solid residual of Quarternary. The study area is a serous soil and water loss place

Abstract:The relationship between changes of history and the present condition of forest and grasslands and the loss of soil and water on the Loess Plateau is comprehensively studied first in the paper, based on physical properties (e.g.soil infiltration and anti-scouringbility) in the cultivated and forest soils, The study results show that the plough sole resulted from agriculturally protracted cultivation is the main cause of increasing loss of soil and water on the Loess Plateau.Speeding up the renew of vegetation in the region is the only effective approach of all precipitation inFiltrating on the spot and brings the Huanghe River under the permanent control.

Abstract:By means of Fuzzy methods, the western Shanxi Province can be divided into five gravitation erosion areas as follows:1. the northwestern breakdown area;the intensity in the area of gravitation erosion (for short I)is about 3,200t/km²·y,and accounting for about 2/3 of the total amount of soil erosion(for short m);2.the western slumping, breakdown area, the intensity is about 2,860-4,130 t/km²·y,and m is 45 to 65 percent;3.the central denudation, slumping and break- down area,intensity is about 4,460 t/km²·Y,and m is 16.9 to 34.7 percent; 4.the southern slumping, denudation area, the intensity is about 4,400 t/km²·y, and m is 51 percent; 5.the eastern weak gravitation erosion area, the intensity is less than 500 t/km²·y. Summarily, the amount of gravitation erosion makes up 35 to 46 percent of the total amount of soil erosion in western Shanxi Province.

Abstract:Cultivation of the spring wheat ecotypes with different drought resistances,sterility tolernce and high water use efficiency is an important approach to realize self-supplying of grain food,returning farmland into grassland and woodland,recovery of vegetation,reduction of water loss and soil erosion.Through the study on 21 characters of spring wheat ecotypes with different drought resistances and sterility tolerance,the results shou that the major characters of causing variances of different ecotypes,firstly were the ratios of the number of two-grain spikelets,the number of four-grain spikelets and the number of three-grain spikelets to the total spikelets nmber of an ear respectively;secondly were plant height and the ratio of plant pattern.the basic characters of ecotypes with drought resistances and sterility tolerance were no (or few) four-grain spikelets,a lot of two-grain spikelets,a low grain count,low ratio if plant pattern,relatively plant height great,small flag area and high index of earinternode.It was ontrary to the ecotypes adapted to growing in wet and fertile soil.And it was the two aspects above that intermediated ecotypes.

Abstract:Forsythia suspensa is a good shrub for the economy and conservation of water and soil. First F.suspensa was planted successfully in Ansai in northern Shaanxi in the 1970s. then in Guyuan in Ninxia Hui Autonomous Region in the 1980s. It can be propagated by seeds,layer, cutting,divided plant etc. in the field. After F.suspensa was planted on the hills, it had a high survival rate and quick growth, Using the method of spiral afforestation, an individual can develop into a shrub in the first year, and can quicken closing and conserve soil-water content. After second year of afforestation, the shrubbery began fruit production, the erage yield of the dried fruit was 1,084.5 kg/ha; in the third and fourth year, it was 1,618.5kg/ha; in the fifth year, it was 2,670kg/ha, in seventh year, it has the highest yield of all dried fruit, about 4,000kg/ha.

Abstract:Using rough sediment a.nd tilled loess as samples, the paper compares the advantages and faults, dispersion ability and results between ultrasonic and boiling dispersion method in different power and time. The results show that the ultralsonic dispersion method use time and electric power sparingly, being more complete in dispersion than the boiling method, its dispersion effect is 1.13 to 1.23 times of the boiling one, and that the dispersion abilibty differs from time under same frequency. The conclusion suggests that the way of dispersion at 17.5krh,220V with 500mA electric current in 25 minutes ultrasonic dispersion or 700mA in 15minutes could get better results.

Abstract:According to the principle of multi-factors classification, China was divided into four sections to forecast debris flows from calamitous rainstorm .The debris flow was predicted in these regions according to elatonships between topographical/geological structure,debris flows distribution,rainfall during certain period,and the general characteristic of the climate.A bxeif instruction was also given to each division.

Abstract:The method of pattern recognition is used to distinguish factors which control the development of debris flows in southwestern China, e.g. Sichuan, Yunnan, Guizhou and Guangxi Provinces. The conclusion is that important factor are the firstly features of mother-rock and then the interstring of rainfall, landforms, the covering degree of vegetaton cover. These four factors infuluence the development of debris flows in the region.

Abstract:On July 15,1983,a rainstorm debris flow suddenly,occured on Huashan Mountain, which is one of the five most famous mountains in China After that, the high way traffic, electricnic line and telephone line was destroyed and. a large expanse of fields was coverd.In addition,sisteen tourists were killed by this disaster.Debris flows distributed widely over Huashan Mountain but there had been no previous scientific research. Therefore, great property damage and a serious disaster resulted. In this project,we systematicly studied the pattern of debris distribution from time and space, analysed the contributing factors and put forwand the menthords to protect the Huashan Mountain area.