Towards an improved flood preparedness system in China

摘要

In many areas of the Globe, floods have recently become more destructive, causing material damage of many billions (10~9) of US$ as well as thousands of fatalities annually. Floods constitute a substantial category of catastrophic weather events, which have exhibited a rapid upward trend: average annual material losses, in inflation-adjusted dollars, increased tenfold between the 1950s and the 1990s (IPCC, 2001). Flood losses are determined by a simultaneous occurrence of two elements: the abundance of water inundating areas beyond the river bed and the presence of damage potential in the inundated area. Growth in flood risk can be attributed to a number of factors. Changes in socio-economic systems include land-use change (e.g. urbanization), increasing exposure and growing damage potential (flood-plain development, increasing accumulation of population and wealth in flood-prone areas). Changes in terrestrial systems lead to a growth in impermeable areas and reduction of storage, e.g. by the loss of natural inundation areas (lakes, wetlands, flood plains). In the past, only extremely heavy precipitation caused destructive flooding. Nowadays, less extreme rain may lead to a serious flooding disaster. Finally, there have been adverse flood-hazard changes due to climate change, e.g. increasing potential for intense precipitation in the warming world.