2015 Volume 21 Pages 503-508
Increase in rainfall intensity due to global warming, reduction of pressure on land use by the population decline, such as requests for conservation of biological diversity, significant changes of river managements are expected in the future. At first I discussed that the river engineering in early-modern era had redundancy and comprehensiveness and had very useful river planning methods and river works technics for the new era watershed management systems. Then I discussed neediness of watershed management for flood control and environmental solution at the time of global warming and population decline. Next I discussed water management system from the viewpoint of water cycle in urban areas. The sustainable, healthy and fundamental integrated watershed management is required in the future.