Change and spatial pattern of flood disaster risk
区域洪水灾害风险格局演变分析——以马来西亚吉兰丹州为例

Flood disasters are among the world's most frequent and damaging types of disaster. Flood hazard, flood risk and disasters are the products of an interaction between environmental and social processes. Accurate comprehension of the condition and rule of flood disaster risk change is of critical importance for early warning and flood disaster administering.The study area, situated in the northeast of Kelantan Delta in Malaysia, is the main flood disaster area. In the other papers, the maps and data of flood disaster risk zones and flood risk index have been calculated using the Fuzzy Comprehensive Assessment (FCA) method. In this paper, the condition and rule of risk change in the past decade are analyzed based on risk zone data and risk index data of flood disasters in 1990 and 2000. The risk data of the two phases are overlaid and areas of risk zone changes are summarized. Risk dynamic degree, transition matrix of risk zone change, risk index change, and the mean of change are calculated. Some conclusions are drawn as follows: (1) The variation of risk zones is significant in the spatial pattern and time change from 1990 to 2000. (2) Highest risk zone and higher risk zone are increasing. Moderate risk zone and lower risk zone are decreasing. (3) Conversion among risk zones is lopsided. It is the main reason for the variation taking place in the spatial pattern of risk zones.(4) Mean risk index of 2000 is higher than that of 1990 in the whole area. Risk change is different in the local zones. (5) The change process of flood disaster risk is self-organized and complex. The self-organized character of flood disaster system is significant to reveal the internal universal phenomenon and mechanism.