Abstract:Based on the analysis to the natural and artificial factors affecting the soil erosion of the mountainous region in western Guizhou province,it is thought that the region has been one of the areaswith the most serous soil and water loss in Guizhou province,which would harm the comprehensive exploitation serously to the watersheds of Wujiang river,meanwhile,threatening the developement of the national economy in the region and the safety of lives and properties.Having expounded the cause and harmness of several major types of erosion in the place,it points out that to strengthen the harmness of soil erosion of the region is the task of great urgency.

Abstract:The hillrock collaping is a pricipal type of erosion in the south of China.In Guangdong province it is characterized with great rainfall.intensive storm,rough texture of soil,and weak ability to resist to the scouring and eroding,it is said that that the artificial activity is fierce is the main factor to cause the collapsing of the hillrock,the scouring of runoff,collapsing and slopeslide,water and gravitational erosion are effected each other.The paper divides the hillrock collapsing into fou types and there stages in decelopement.

Abstract:This paper is based on the data of the field investigations on the debris flow of urban Maerkang county made in May and October,1987.Having studied the four debris flow valleys in this area and its relative natural factors ,the state of the calamity and its potential dangers,the author brings about the principles,projects,and cencret measures to control the problems of this four debris flow valleys.

Abstract:To give full play to the function of connotation of soil and water conservation and to reinforce the harness of soil erosion is required in the increase of harness benefit,the augment of agricultural staying power and the development of commercial economy.It raises some cenceptions on the establishment of soil and water conservtionsystem of science,including:1.to stress "consciousness effect"in teh leading mind;2.wielding "entirety effect"to stress the working mechanism of the soil and water conservation system;3.using "comprehensive effect"to stress the quality standard of technics about prevention,harness,management and utilization;4.to take small watershed as unit is an important method in the system;5.with "legal effet"to harness in society is connected closely to the system of the soil and water conservation science.

Abstract:The paper analyses the characters of soil and water loss in Zhujiang watershed at first,Based on the summary of the experiences and lessons in the comprehensive harness of watershed in many years,it is raised that while the expriment area of comprehensive harness for small watershed is conducted well the active harnessing in large area should be underlined,At last it is suggested to solve the key problems in six aspects be the focal point for the soil and water conservation work to be done well.

Abstract:The soil and water censervation departments in districts of Shandong province summarized and explores the experiences of the comprehensive harness taking small watershed as the basic unit,based on inestigation in recent years.Then,the "Comprehensive model of disposition with nine combination"and the harness policy supported by local masses is popularized in teh province,which makes the preponderance of comprehensive harness in small watershed give full play,and strongly promots the developement of soil and water censervation work widely and deeply.

Abstract:In some areas of China new soil and water loss are being exacerbated increasingly due to the effects of unreasonable activities in society and economy.According to the factual conditionof Qixia county,sets of mesures have been adopted to control new soil and water loss,including those of organization,legal institution,etc.,especially the principle of "people who makes soil and water loss must harness it,and who creates harm conpensate"is carried out seriously.The range and norm of damages are stiqulated,The practice of the comprehensive measures in Qixia county for several years has gotten better results initially.

Abstract:The rim line of present gully can be deemed as a boundary to divide land of stduy area into two sections,namely,the ridge-land above this line,and the gully-land below it.But it is not very often to get the actual proportion because of some subjective reasons and/or some complex objective local characteristics.In this paper,we used aerial photograghs to divide the area into four different regions,selectd typical samples rir-photos,interpreted the rim line of gully,we can get the following conclusions.1)The proportions have some regional differences,but no zonal regularuty in this area.2)This propertions are not only restricted by palaeo-topography,but also impacted by human activities.3)Ridge-land amounts to about 35% in the region where deep-level land slip appears very commonly,45% in rivers source area and 40% in the rest areas.

Abstract:The type of development of Heilu soil are related to nonexchangeble potassium in Heilu soil of loess region.The present paper deals with prelimiary study on the genetic characteristics and nonexchangeable potassiumof profle in major soil types of Heilu soil.The results obtained are summarized as follows:The distribution of nonexchangeable potassium on soil profile in lisht-textured soil,ortho Heilu soil and resty Heilu soil accord with expaonental equation.It is one principle feature in Heilu soil of stepperegion.The distribution of nonexchangeable potassium on profile of argillic Heilu soil is "S"formed.It is the transitional form of forest-steppe region soil from the lou soil of forest region to light textured soil or the Heilu soil rusty Heilu soil of steppe region,The form of them has some features of the distribution as nonexchangeable potassium in the lou soil profile,but the contents are different.The distribution of nonexchangeable potassium on the profile are same of on the Heilu soil of the forest-steppe region in the gully land,gully plain land and river platform of the stppe region.

Abstract:The main content studied in the paper is evaluating eleven kinds of grass fields with optimization of multi-objectives from the stratetegic points of view of current grass field and its development on the entire loess plateau,providing scientific evidence for rational and efficient utilization of the natural grass field and the developement of husbandry.

Abstract:Through the investigation it is thought that there are great potentiality in the utilization of ridge in Shaanxi province except few counties and communes the ridges on the farmland of most districts are bare.To mitigate the contribution between man and land,among forest,grain and fruit,the full and rational use of ridge land is important.The paper expounds the obvious effects of rational use of ridge to increase the benefits in ecology,economy and society with examples.

Abstract:By means of experiment on the foresting technics to resist drought in the loss hilly region of west Guyuan county,the initial experiences are explored as follows,1.to select the varieties of tree having drought-resisting avility;2.to prepare soil in advance;3.to forest with film;4.to forest with cut stem;5.to soak and dip in mud;6.to protect root in wet stat;7.to forest in autum.Those indicated above provide acientific evidence for the forestry production on the loess hilly region of the arid and semi-arid area in south Ningxia Hui Autonomous Region.