20世纪是人类有史以来创建最多、也是损失最多、浪费最多的一个世纪。在我国,人们经常用“早、涝、污染”概括现实中的三大水危机。我国600多个城市中,有400多个城市供水不足,110个严重缺水。随着城市化进程的不断加快,水资源的供需矛盾越来越突出。曾有人预言:21世纪是石油让位于水的世纪。雨水对缺水的城市来说,是天上“掉”下来的资源,可以说是天赐之宝。长期以来,我国城市水资源主要着眼于地表水资源和地下水资源的开发,不重视对城市汇聚的雨水的利用,造成大量宝贵的雨水资源流失。随着城市规模的不断扩大,城市地区雨水流失也越来越多。“水”在城市中充当着两个角色,一方面,城市产重缺水,大量开采地下水;另一方面,大量雨水带来城市水涝,城市环境恶化。 The 20th century is the century that mankind has created the most, is the most lost and the most wasted. In our country, people often use “early, floods and pollution” to sum up the three major water crises in reality. Of the more than 600 cities in our country, more than 400 cities have inadequate water supplies and 110 are seriously short of water. With the accelerating process of urbanization, the contradiction between supply and demand of water resources becomes more and more prominent. It has been predicted that the 21st century is a century in which oil has given way to water. Rain on water-scarce cities, is the sky “off ” down the resources, it can be said is a godsend. For a long time, urban water resources in China mainly focus on the development of surface water resources and groundwater resources, and do not attach importance to the utilization of rainwater brought together by the cities, resulting in a great loss of precious rainwater resources. As cities continue to expand in size, there is also a growing loss of rainwater in urban areas. “Water ” plays two roles in the city. On the one hand, the city lacks water and exploits a lot of groundwater. On the other hand, heavy rainfall brings urban waterlogging and the urban environment is deteriorating.