A Preparatory Investigation Toward Estimating Flow Durartion Curves From Physiographic Characteristics in Japanese Mountainous Watersheds

Abstract

 The present study explored the effects of physiographic watershed characteristics on the index-flows of 95 days flow, 185 days flow, 275 days flow, and 355 days flow toward estimating the shapes of flow duration curves based on physiographic watershed characteristics in Japanese mountainous watersheds. A multiple regression analysis showed the 95, 185, and 275 days flows increase with annual rainfall. The 185, 275, and 355 days flows increased with Andosol coverage ratio and decreased with building coverage ratio. The obtained regression equations successfully estimated the index-flows only in the mountainous watersheds located between the Kii peninsula and the Kyushu region in Japan.