ABSTRACT
The trial efforts to establish indicators of hydrological cycle in Japan are discussed. There are various and serious problems about hydrological cycle caused by change of the forms of water use, such as reducing runoff discharge at normal times and increasing flood risks. These problems mostly stems from human activities around a river basin, including the change of social activities and land use. To solve these problems and make hydrological cycle healthy, it is necessary for us not only to cope with individual problems, but also to perform countermeasures comprehensively, based on the evaluation of the balance among each element of the hydrological cycle in the watershed. Thus, the issues need tools for comprehensive approaches, including consideration of balance among various needs and social backgrounds of each watershed, in addition to traditional countermeasures.
