雨水作为一种极有价值的水资源,早已引起日本的重视,并在多领域进行了回收利用,其各项雨水利用技术达到了世界领先水平。日本是个水资源比较缺乏的国家,目前全国水资源利用率已达到20%左右,新辟水源所需的投入越来越大。为此,日本政府除了采取开源措施和提高水的利用率、鼓励全社会利用循环水外, As an extremely valuable water resource, rainwater has drawn great attention from Japan and has been recycled in many fields. Its rainwater harvesting technology has reached the advanced level in the world. Japan is a country that lacks water resources. At present, the utilization rate of water resources in the country has reached about 20%, and the investment required for the development of new water resources is getting bigger and bigger. To this end, apart from adopting open source measures and improving the utilization rate of water, the Japanese government encourages the whole society to use recycled water,