河流的游水地是建造在河流旁边的一种防洪设施,在日本得到了广泛的应用。集中暴雨时,可以用它来暂时储存河流中急增的水量,以防止下游发生洪涝灾害。这是日本在重要河流的防洪除涝中采用的对策之一。颇具特色的是,在规划设计河流游水地时,常常除了用作防洪除涝以外,还兼有其它用途,也就是在集中暴雨时,河流游水地起着蓄洪削峰的重要作用,而平时,它又作为运动场、网球场、停车场和公园等供广大市民使用。这在土地资源十分紧缺,土地价格十分昂贵的日本有着重要的意义。一、鹤见川及流域概况1.自然状况鹤见川源于东京都町田市,流经多摩丘陵,在横滨市的鹤见区流入东京湾。其干流长度为42.5km,流域面积达235km~2,属日本国 River water is built on the river next to a flood control facilities in Japan has been widely used. When concentrated heavy rains, it can be used to temporarily store the surge in river water to prevent flooding downstream. This is one of Japan’s countermeasures for flood control and waterlogging in major rivers. Distinctively, when planning and designing rivers and lakes, they are often used for other purposes in addition to flood control and waterlogging. In other words, during heavy rainstorms, river water plays an important role in flood peak reduction. In normal times, It is also used as a playground, tennis courts, parking lots and parks for the general public. This is of great significance in Japan, where land resources are scarce and land prices are very expensive. I. Tsurumi River and Watershed Overview 1. Natural Conditions Tsurumi River originates in Machida City, Tokyo, flows through the Tama Hills and flows into Tokyo Bay in Tsurumi-ku, Yokohama-shi. The main stream length of 42.5km, drainage area of ​​235km ~ 2, is a Japanese country