| According to the newly revised "Law of the People’s Republic of China on Soil and Water Conservation", the delimitation of Soil and Water Loss-prone Areas is significance and necessary for the new Soil and Water Conservation Program. It could be used as a basis for Soil and Water conservation planning of Jiangsu Province, and a scientific basis for soil and water conservation supervision of the administrative departments as well. Moreover, it could give workarounds for the problem of Soil and Water Loss-prone Areas delimitation, especially for the delimitation in areas with high development and construction. It’s different between assessment on "Sensitivity to Soil and Water Loss" and "Soil and Water Loss-prone Areas".In rapid urbanization areas, the artificially pressure should be emphasized in the research of Soil and Water Loss-prone Areas.The plain area of Jiangsu Province is determined to be the studied area which is around 8.21 km2. Based on the "Pressure-State-Response" conceptual model, an index system is established to delimiting Soil and Water Loss-prone Areas. Then the indices weight is obtained with the improved classical analytical hierarchy processes. Each index is classified into several classes with regard to their changing in Jiangsu and the existing research results, and each class is valued with 1/3/5/7/9 according to their impacting degree on soil and water loss. In this thesis, soil and water conservation planning and soil conservation division of Jiangsu Province thematic database is applied as the main data sources, and each index map is converted into grid format with size 250m×250m. Through digitizing, the spatial database including the index’s map and their attributes data is built in ArcGIS software. Subsequently the values of the indices classes are multiplied by derived weights for each index and then are summed together. Furthermore, the evaluation and analysis is made separately from the three sub-level indices of pressure, state, response and the general index. Finally, by selecting one hundred evaluation units which have erosion intensity data, preliminary consistency test is carried out between the delimitation results and the status.The main achievements of the thesis are as follows:(1) An index system based on PSR conceptual model to delimiting Soil and Water Loss-prone Areas:The artificially pressure index consists of land-use intensity of human disturbance, population density, fixed-asset investment, distance to the city, distance to major transportation routes. The natural pressure index is composed of average annual precipitation, slope, soil erodibility K-factor, vegetation coverage, and river density. The state index is made up of the ratio of soil and water loss areas. The response index is defined as the areas protected by the Ecological Red Line.(2) The distribution of the pressure which would cause soil and water loss is common in the plain area of Jiangsu Province. The area of III degree and above pressure accounts for 40.75%, and artificially pressure is greater than the natural pressure both in grade and area. The area of Ⅰ,Ⅱ,Ⅲ,Ⅳ degree Soil and Water Loss-prone Areas accounts for 10.12%,42.90%,25.73% and 1.24%. There is no IV degree Soil and Water Loss-prone Areas. Finally, the regions confirmed as the Soil and Water Loss-prone Areas of Jiangsu Province accounts for 26.97% of the total area, mainly distributing in the regions such as the urban district and suburb of the city and the county, urban area of the town, and development zones, as well as the Coastal Plain Sandy Area, the High-content Sands in Tongnan Area, and the Disused Sandy Districts of the Yellow River.(3) The evaluation results of the units which have soil and water loss data are consistent with the actual situation. Through the preliminary consistency test, the Kappa coefficient is 0.726, indicating that the results can basically reflect the characteristics and statue of soil and water loss in Jiangsu Province. |
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