Evaluation of sustainable land use in the region with high risk of the flood and waterlogging in the Dongting Lake

Based on analysis of the meaning and characteristics of land use complex system of high risk region, the indicator system for evaluating sustainable land use in the region with high risk of the flood and waterlogging in the Dongting Lake was constructed. The sustainable land use degree of different years and 19 polders of flood storage was evaluated comprehensively in order to analyze the spatial and temporal changes by use of quantitative method. The main evaluation results were as follows: the degree of sustainable land use was increasing and showing the trend of acceleration. The total degree of sustainable land use in the region with high risk of the flood and waterlogging in the Dongting Lake was lower. The trend of increase or reduction among various single indexes was not identical, the index result of product security and natural resources protection decreased from 1985 to 1995. The difference of sustainable land use degree was not evident in various areas, but the sustainable land use degree appeared the distribution law that the degree of sustainable land use was in direct proportion to productivity but in inverse proportion to the risk of the flood and waterlogging disaster. The relationship between the degree of sustainable land use and productivity and the risk of the flood and waterlogging was much more complex. The degree of sustainable land use was higher in the high-productivity areas and lower in the high risk region of the flood and waterlogging.