18世纪中叶以来不同时段的中国水灾格局

Chinese flood patterns in different periods since the middle of the 18th century

以县域为基本统计单元，以年均水灾次为基本指标，在数字地图技术支持下，编制了一套信息来 源不同、时段相对连续的中国水灾格局图。分析表明：中国水灾格局以胡焕庸线为界，呈现东西分异； 水灾高值区呈现团块分布，与地貌格局关系密切；近百年来全国水灾中心呈现由黄淮海平原向东北、西 部和南方转移的趋势；近５０年来，华北成为水灾低值区，水灾由东向面形成４个梯度区。这些研究为 揭示水灾格局对水灾过程影响机制的研究提供了科学依据。

Based on the average flood times per year(AFT) with the statistic unit 'county', this paper presented the Chinese flood disaster spatial patterns from the digital flood disaster maps of China, which come from different information sources and divided into different periods. The paper gets also some conclusion as follows: the flood disaster spatial pattern of China is separated into east and west parts by the HU Huan-yongs Line, the areas with high AFT value show mosaic distribution, which is controlled by the landform of China, the high AFT areas in China show the trend of moving from Huang-Huai Plain to Northeast, West and South China during the last 100 years, in the last 50 years, North China has become the lower AFT areas, and the flood disaster spatial pattern shows four belts from the east to west parts of China.