Abstract:Based on the monitoring net of soil and water conservation at Gaoquan gully small watershed, the relation between natural factors and man-made factor,the laws of time and spacial variation ,the generalized coupling model of sediment at small watersheds were studied systemati-cally,and the mathematic model was established .The results show that the contributing ratio of man-made factor to runoff and sediment reduction was 79.11%, and that of natural factors was 85.69%.The laws of time and spacial variation of loess anti-erodibility and erodibility,and the effects of different indexes on runoff and sediment yield were analysed,the mathematic model on relation between vegetation and soil erosion was also established.According to the generalized coupling model,the effect of“two periods” harness was analysed and evaluated.

Abstract:In the middle reaches of Yellow river basin, a lot of projects have been built.Human activities have changed the land surface and erosion process, they have also alleviated erosion intensity and retained runoff and sediment. Isograms of sediment transportation modulus and coarse sediment modulus are drawn up based on the obtained data. The variation law of sediment and coarse sediment transportation modulus at areas with more and coarse sediment was analysed.

Abstract:The land degradation in Chuxiong city is resulted mainly by water erosion , it is representative of Yunnan-Guizhou plateau .The area of degraded land is 1159.44 km²,it makes up 26.17% of the total area.The harm of land degradation are reducing soil fertility,bursting bridges,aggravating natural disaster and damaging irrigation works.In its formation causes, tattered landform,uneven precipitation and loose land surface matter are the natural factors ;The increased population resulted in slope land under cultivation,forest cut and over-load grazed.

Abstract:In order to analyze the population dynamics of Gansu Zoker(Myosp alax cansus) , It is necessary to know its natality, survivorship rate and mortality,etc.The static life table is set up on the basis of agestructure and sexratio of 515 zokers collected from Xiji county, Ningxia Autunomous Region during Apr.1991-Jun.1993.Some essential population data obtained from the life table are as follows: The net reproductive rate(R₀) was 1.8075.The innate increase capacity(r_m) was 0.4056.It takes about 20 months for its population doubling .The finite increase rate (λ) was 1.0023. The survivorship curve and mortality curve were drawn up. This data indicated that the increment of Gansuzoker in population was slow and stable. The information above will be useful in the zoker population control.

Abstract:Throug hout the controllable analysis of rain resource in semi-arid region,a new waterosmosis plastic membrane was exploited based on validating small rainfall(≤10mm).It can improve rainfall penet ration into soil vertically , modify maximum soil temperature,and ventilate soil,it can also increase soil temperature and block evaporation as conventional membrane does .The patent No.is 97115761.8.In order to raise cropyield in dryland region,small rainfall must be deeply developed.The annual frequency of small rainfall was 70% in semi-arid land in Shanxi province,and the water of it equals to 100mm or more , which has great potentiality of 4tons perhactare land for maize.The tests showed that :the maize covered with water-osmosis plastic membrane had increased by 38.3% in yield,1%～4.5% in soil water than conventional membrane,and 103% in yield than that of no-covered.This new technique can enhance agriculture sustainable development in the 21st century.

Abstract:All the 12 counties in Yulin prefecture of Shaanxi province are poor and severely eroded in the Yellow river basin .Since the new China founded,there has been 378000 ha of irrigated land,soil-saving dam land and terraced land(called“three lands”for short)constructed,which consists of 60% of the total farmland .A regression coefficient of 43.9 of field cropyield to“three lands” area has been drawn by regression analysis,that means the yield of the total farmland increased by 43.9 kg/ha with an increment of each 10000 ha of“three lands”.For the 35 years,“three lands” increased by 906 500 ton of food , and the relevant coefficient is 0.9955, being doubly marked and positively interrelated .Percapita food of villagers was 444 kg in 1996,increased by 1.95 times comparing to that of 150.5 kg in 1949.The sandy area of northern Yulin holds a great potentialin developing irrigated land and food production,and 134000 ha of land can be opened up for well-irrigated farmland.It is predicted that the total food production can reach 1870000 ton,and there will be 521kg food percapita by 2010.

Abstract:The formation and evolution of high mineralized underground water in coastal saline-alkaline region were measured and studied according to the concerned material of oceang raphy,geology,hydrology and meteorology etc.It could play an important role in supervising the exploitation and utilization of coastal land resources.

Abstract:The formative environment of debris flow is analysed by means of investigation in Fangduigully of Wenshui county.It is considered that Fangduigully is a typical complex debris flow gully affected by human actions.There is no clear distinction between areas of solid materials accumulation and passage way.At last,the debris flow of Fang duigully is predicted.The conclusion is that if there is no control engineering,the debris flow will become more serious when storm occurs.

Abstract:Based on many-sided ecologic problems the tea plantation in China faced on,the author presents tentative ideas,that is to adopt the plantation pattern such as intercropping with different crops,to use temporal and spatial variation of plant growing process and bio-chains,so as to increase the utilization ratio of natural resources,and to obtain higher benef its of economy and ecology.

Abstract:At the heavy and coarse sediment region in the middle reaches of the Yellow river basin,because of the high population density,insufficient cereals supplement,deficientfuel,fertilizer and forage resource,and serious soil erosion,the contradiction between population and environment becomes the principle factor which restricts the economic development of this region.The result obtained from management practices at 4 typical small watersheds show that, after comprehensive management for about 4～7 years,the population density could reach a appropriate degree,the contradiction between population and environment could be preliminarily resolved.meanwhile,the environmental population density of this region in the end of the century was predicted.

Abstract:Xishan small basin is located in the source of Pearl river,influenced by social and economic activities of man-kind,the eco-environment of it had been deterioated gradually.Through five years sustained construction,a comprehensive harness system has been set up,and the marked benefits of economy,ecology and society have been achieved by applying eco-economic principle and systematic project,adjusting constructure,utilizing natural resources fully.This is a good type for sustainable development of eco-economic system in mountain areas.

Abstract:Based on the experimental demonstration and investigation,the effects of developing utilization of siltarrester slop on the dam stability,and the protect ing measures were studied.The results show that the dam slop is the most serious erosion beltin view of both gradient and slop length;soil preparation has little influence on slop stability,neither do roots on dam permeated deformation.A fine protective benef it could be obtained by engineering soil preparat ion and plantation,and to establish forest and orchard on dam slop,the social benefit of it is also notable.

Abstract:The authors analysed the extising situation and causes of soil erosion in urban areas,and discussed its influences to the urban construction.Some proposals and countermeasures in soil and water conservation are put forward.

Abstract:A large quantity of abandoned waste rock and dregs and vegetation destroried have been carried out during constructing and coal mining in Huangling coal mine.It results in serious soil and water loss.Based on analysis of designed rainstorms and floods,two waste rock storage dams and two waste rock weirs and other conservative works are designed to control waste rock and dregs and protect the eco-environment in coal field.

Abstract:Agricultural indust rialization is an effective way to solve agricultural principal contradictory and keep up a steady agricultural development.According to the need of keeping up a steady agricultural development in Zhifang gully,the author studied the concept and developing mechanism of agricultural industrialization,and analysed the conditions,the developing course and stages,and the managing forms of agricultural industrialization,then considered that the first stage of agricultural indust rialization may be constructed in Zhifang gully,and approached its industrial structures.

Abstract:The author takes an overview about the varied utilization and research of vetiver(Vetiveria zizanioides) in China,and outline the vetiver planted areas and research regions that its developing tendency from using for extracting root oil in 1950＇s, to keep the soil and water conservation in 1980＇s, up to date, multiple-using for sediment or sandy soil stabilization, wind proof , pollution control, fodder for cattle, plant for mashroom and being utilized for soil engineering project.Vetiver grass can change the solar energy into organic matter or bioenergy, benefit human being,meanw hile improve the environment.So vetiver grass is valuable and worthy of using and research extensively and deeply.

Abstract:A new physically based soil erosion model LISEM, has been developed by the scientists of Netherlands,which can be used to predict soil and runoff and to make soil conservation and landuse plan in small catchment.The varied processes of erosion is incorporated in the model. LISEM is one of the first examples of physically based models that is completely incorporated in a raster GIS and digital remotely sensed data and can be easily applied in larger catchments. A-l though the model has several advantages over other models,it is far from perfect,so more at tention should be paid to the spatial and temporal variability of soil properties and description of soil erosion processes.

Abstract:Scientific theses are reflection of academic study level.The status of Chinese scientific theses in the three large international dataretrieval systems (SCI,EI and ISTP)is introduced , as well as the soil and water conservation periodicals in the“Chinese Science Citation Index”.It is suggested that soil and water conservation periodicals should at tractexcellent academic theses by adopting some practical and effective measures in order to improve its quality and extend its influence.