TOWARD A MAPPING OF GROUNDWATER RECHARGE POTENTIAL:TESTING A DROUGHTY FLOW BASED APPROACH

Abstract

The present study explored physiographic watershed conditions which increase droughty flow in Japanese mountainous watersheds toward the mapping of ground water recharge potential, assuming that higher droughty flow originates higher water recharge potential. The results suggested that a highly elevated watershed underlain by Quaternary rocks, covered by Andosol or farm lands tends to generate higher droughty flow and hence has a higher ground water recharge potential. Then we defined the sum of the satisfied conditions listed above as the "ground water recharge potential index" and mapped it to verify the geographic distribution of the index. Comparison with the geographic distribution of "mega-springs" that generates more than 1.0 m³/s exhibited our ground water recharge potential map is acceptable to some degree.