Abstract:The characteristics and mechanism of soil degradation were analyzed, as the case study of Da'an city and Changling county in the west part of Jilin province. Soil degradation in this region mainly expressed decrease of nutrition element and increase of salt and alkali. Soil degradation had been caused by natural factors and human impacts. Natural factors were potential and human activity was to enhance potential soil degradation. With application of GIS and SPSS, it was analyzed that dynamical change and horizontal and vertical distribution of chemical elements. Soil horizon structure was complex. Soil salt content in soil profile expressed T shape, straight trape-zoid, reverse trapezoid, and column shape.

Abstract:A case study to the Xianghai marsh wetlands at downstream of the Huolin river is conducted. Core samples were taken with a gravity corer. Two cores and 78 samples were taken and studied with high-resolution to total sulfur, available sulfur, TOC and pH in different grain size sediments. Results displayed that the high values of total sulfur and available sulfur all existed at granule (silt and clay) in both reed marsh and gleying grassland. Average contents of total sulfur in Xianghai wetlands were close to 700 mg/kg-the average content of total sulfur in world soils. From the top down, contents of total sulfur presented decrease by degrees in different grain size sediments and enriched in the layer of grass roots. Generally speaking, total sulfur and available sulfur increased with TOC.

Abstract:The soil water diversity of typical semi-natural savanna during the middle-end rainy season is researched on the base of lots of trials, including the soil water content spatial and temporal diversity qualities of slimy dry-laterite, the comparison of soil water content spatial and temporal diversity qualities of slimy dry-laterite to loose dry-laterite, the soil water content spatial time diversity qualities of loose dry-laterite under different of vegetation and the soil water content spatial diversity qualities in different landform in valley.

Abstract:Taking the case of Niqiu river and Keluo river, the relation of land use/cover change with river runoff is discussed. When total precipitation increases in Niqiu river watershed, surface runoff decreases. The change of forest cover results in decreasing of evaporative capacity. However, superfluous water has not formed surface runoff but was stored in mire wetland transformed from forest and grass land. The surface runoff was increased in Keluo river watershed because the forest area decreased. Forest change affects surface runoff more than farmland change. The relation of land use /cover change affecting river runoff is complicated, and it is not the result of unique land use/cover change, but the coupling operation of land use/cover change which affects river runoff. In general, the change of marsh is most effective in all the change.

Abstract:According to monitoring data of buried stake, sand-deposited pool and sediment trapping dam; based on the lithology and terrestrial surface substance composition; in terms of slope, the land use and vegetation; the soil erosion intensity in every small valley are analogized. Thus the category result of soil erosion intensity in the demonstrating area of Huajiang is concluded and the influence on soil erosion of topography, landforms, lithology, soil, vegetation and precipitation is analyzed precisely.

Abstract:The general geologic and hydrogeologic conditions of Sangshuping coal mine field are briefly introduced. The aquifers of the field are divided as followings: The Quaternary gravel and sand porous phreaetic aquifers (H1) ; The Permian sandstone fissured confined aquifers (H2); The Carboniferous sandstone and limestone confined aquifers (H3); And the Ordovician limestone confined aquifers (H4); On the basis of analysis of the chemical characterized of groundwater and mine water, it is pointed out that groundwater of the Ordovician limestone aquifer is the main recharge source of mine water. The mine water is characteristic of high hardness, mineralization and SO_4~(2-) content. A purifying method, electric percolation filtration, is proposed to process the minewater.

Abstract:The effect of PAM on the eluviations of N, P and K in the soil is studied. The results showed that the content of N, P and K in the soil soluble liquid decreased strikingly. The accumulative quantities of the N, P and K in soil soluble liquid decreased by 42. 40%, 43. 85% and 68. 19% compared with the accumulative quantity of control. In addition, the accumulative quantity N, P and K in the soil soluble liquid decreased further when the concentration of PAM increased.

Abstract:The information of soil erosion landscape possess horizontal and vertical heterogeneity typicality. The heterogeneity of soil erosion landscape is owing to man's activity, diversity framework of geological body and various altitude zones. The three kinds of model, patch-corridor-matrix model, ring-patch and vertical heterogeneity model are upbuilt based on landscape of soil erosion in Hubei province. The models lay bare the regional location of different grades soil erosion and spatial structural feature, the model can help us to forecast the trend of soil erosion, to have soil and water conservation projects and primary controlling fatcor taped.

Abstract:The effects of coordination complexes of the rare earth (La Nd) chlorides with imidazole and simple chloride salt on bacteria, mold and enzyme activity in field soil are determined in the laboratory. The result of the determination shows that the coordination complexes of rare earth used on experiment, when their concentration is less than 1. 5 mg/g, have little effect on biological activity of the field soil; When their concentration is more than 3 mg/g. they have inhibitory effect on bacteria, mold, catalase and dehydrogenase in soil. In the coordination complexes of the sample soil, whose concentration is 15mg/g, inhibitory effect on bacteria is 47%-63%, on mold is 23%-34%, and on soil-catalase is 9. 5%-38. 7%, dehydrogenase activity obviously decreases; Therefore attention should be paid to the effect of rare earth used in agriculture soil microenvironment.

Abstract:Based on analysis to the causes and laws of soil erosion in Zhaotong prefecture, Yun'nan province, the vegetation coverage percent, land use type and topography slope degree were selected as the key factors for evaluating the degree of soil loss. After fieldwork and analysis to the related materials, the relationship between TM image features and those key factors were established. And the vegetation coverage percent and land use type were extracted from TM accordingly. Combined with the information of slope degree from topography map, the erosion-grading map of Zhaotong prefecture was produced by ARC/INFO 7. 11 and ARCVIEW3. 2 software. Finally, according to the result of statistics from the erosion map, scientific evaluations on the ecological effects were made for the Changjiang river protection forest in Zhaotong prefecture.

Abstract:The conversion between Grid DEMs and TINs is of critical significance in digital terrain analysis which is a key work in the watershed planning of the loess plateau region. Taking Jiuyuan watershed in Suide county of northern Shaanxi province as a test area and 1 :10 000 Grid DEM as a criterion, applying overlay comparative laws and mathematical statistics as basic research methodology, a research on the accuracy of conversion between Grid DEMs and TINs is made. The experiment shows that the conversion accuracy between Grid DEMs and TINs affected by conversion tolerance of TINs directly. The accuracy of Grid DEMs on describing terrain variables (i.e. elevation, slope gradient, channel network etc) decreases with conversion tolerance of TINs increasing, compared to Grid DEM of 1: 10 000. Five meters should be a rational conversion tolerance in the loess hill and gully area.

Abstract:The measurement principle and the mainly components of a dynamic measuring system for sediment concentration and flow rate determination are simply described, including four subsystems such as: the automated sampling subsystem, automated measuring and acquisition subsystem, data analysis/output/retrieve subsystem and operation/control subsystem. Laboratory application experiments and tests of the integrated system indicate that the system has such unique capabilities as short time for high precision measurements, and fast transmission of logged data. The system is so designed that it can be used not only for measuring sediment concentration and flow rate in the laboratory experiments of soil erosion study, but also for field research and for on-site long-term monitoring of soil and water loss from runoff plots.

Abstract:The physiological and ecological properties and planting technique of fine pastures such as Bromus inermis Leyess, Astragalus adsurgens pall, Medicago saliva L, Onobryhis viciae folia scop, and Melilotus albus Desr, are analyzed. The chosen fine pastures are suitable to planting in artificial high-yield and improving pasture, which provided a scientific basis for pasture agriculture and pasture-animal-husbandry development.

Abstract:Due to a little rainfall，which is discordant to supply and demand，lean soil and the long term effect of human activity，the ecological environment in the semi-arid area and semi-moist area inclined to be arid is being degraded. Soil and water loss are becoming more and more serious. Based on the investigation on the spot，the au-thors think that building rainwater catchments is an effective approach to ameliorate the ecological environment and accelerate agriculture in the small watershed. In the case study of Tiewa small watershed，the measurements and management forms of the comprehensive ways in small watershed on the background of rainwater catchment are discussed. The feasibility analysis indicates that the comprehensive ways in small watershed based on rainwater catchments fits the agriculture practice.

Abstract:On the basis of investigation in the middle and lower reaches of Midanjiang Basin, current status and characteristics of soil and water loss were deeply analyzed. In terms of soil and water conservation and ecological construction, prevention and supervision, ecological monitoring and technical support were discussed. Combining the cultivation measure, forest and grass and project measure, construction scope of soil and water conservation and ecological project were put forward. Ecological, economic and social benefits were analyzed in detail, showing the benefits was obvious and the project was feasible in economy.

Abstract:Sustainable agricultural ecosystem are the basic guarantee and condition for the sustainable development of society and economy. The identification of limiting factors is a crucial step to assess the sustainability, to work out the strategies and to implement comprehensive measures for sustainable development of agricultural ecosystem. As a case study, the limiting factors and regulation strategies for the sustainable agricultural ecosystem in Jiangpu county, Nanjing city are analyzed. The results show that the main limiting factors are the decreasing trend of arable land, frequent occurrence of ecological disasters and the weak ability against external perturbation of agricultural ecosystem. The countermeasures for promoting the sustainable development of agricultural ecosystem in Jiangpu county, Nanjing city, including the protection of arable land, the enhancement of the ability against external perturbation, and the control of ecological disasters are suggested.

Abstract:Yun'nan is one of the provinces with serious soil and water loss in China. To strengthen the soil and water loss control, soil and water resources conversion, rehabilitate, rebuild and safeguard ecological environment, are the difficulty and urgent task of Yun'nan province in the course of implementation of the great west development strategy in western China. The current states, endangerment and tendency of soil and water loss in Yun'nan province are introduced based on the analysis of the formative cause of soil and water loss. The counter-measures of implementation of key engineering construction are proposed, which are construction of protecting forest system in great river watershed, conversing cultivated land into forest, protection of natural forest, closing land for reforestation and integrated small watershed management as the main body of eco-environmental construction.

Abstract:Taking the highway project from Tianshi to Chankou section as an example, the requirement and content of replantation project design of soil and water conservation plan at the fessibility research stage are intrduced systematically. (1) According to the requirement of the main project, the distribution and area of plots with different replantation function and requirement are determined, and different management plots need to be delimi-tied; (2) The stand condition of different replanted plot, the factors of different stands need to be rationally classified , therefore, the plant spices to be applied and distribution plan for different replantation plots of different management areas are proposed; (3) The specific requirement of the project in accordance with the general project is studied, and the replanting plan with higher feasibility is put forward, then the typical design is conducted.

Abstract:China and United State of America are greatly suffered from sever soil erosion. On the other hand, achievements on soil and water conservation in both countries have been obtained. Soil erosion situations in both countries are briefly introduced and achievements on soil and water conservation in both countries are summarized. Cooperation research fields in soil and water conservation are suggested.

Abstract:Beryllium-7 is environmental or fallout radionuclide with a half-life of 53. 3 days, which is produced primarily by the bombardment of the earth atmosphere by cosmic rays. It is subsequently transported into the soil surface by wet and dry deposition. It is rapidly and strongly absorbed by soil particles and redistributes with soil particles. Therefore, it ⁷Becan be used as a tracer for studying soil erosion. The recent progress in the use of the environmental radionuclide beryllium-7 (⁷Be) for investigating rates of soil erosion and deposition is introduced, and suggestions for applying it into soil erosion are proposed.

Abstract:Building reservoir is one of the important methods that many countries control the floods and resolve other water problems. Although it can produce much economic interests, it also causes considerable environmental damage, especially on such highly sandy river as the Yellow river. It is because the constantly construction of reservoirs in decades that changed the water and sands conditions of the Yellow river violently. Firstly, the fundamental influence mechanism of water and sands problems of the Yellow river from natural and artificial factors is presented. From the analysis on sediment and water volume of temporal and spatial data of runoff elaborately, the negative effect of the reservoirs (especially Longyangxia reservoir, Liujiaxia reservoir and Sanmenxia reservoir) on water and sands problem of the Yellow river can be recognized, which is that frequency of middle and high water volume was reduced, the sediment accumulation was increased, the current was artificially controlled highly, and the broken current was more severe. Finally the relevant strategy is suggested from the view of sustainable development.