关键词: 气候变化, 土地利用/地表覆盖变化, 人类活动, 洪水灾害, 长江中下游

Abstract: The flood disaster in the middle and lower reaches of the Yangtze River is the combined consequence of its geography and human activities. The structure of water system and the geographical characteristics decide its floodprone, and the climate variability and land use/land cover changes make the water circulation change greatly; whereas the construction of a number of reservoirs and dikes and the development of urbanization cause the flood process verified remarkably. Therefore, under the influence of these factors, the flood disaster in the middle and lower reaches of the Yangtze River occurs frequently in recent years. This paper summed up the impact of climate variability on precipitation in the middle and lower reaches of the Yangtze River, discussed the relationship between water system properties and flood disasters, and analyzed the laws of influence of human activities on flood disasters. Based on these studies, the rainstormflood simulation under the variational condition has been developed. We took the Nantiaoxi of Dongtiaoxi Valley as a study area to verify dynamically the precipitationrunoff process. In one word, all of the works provide the support for flood proofing and disaster reduction in the middle and lower reaches of the Yangtze River.

Key words: climate variability, land use/land cover change, human activities, flood disaster, middle and lower reaches of the Yangtze River