The purpose of this paper is to develop regional multivariate regression models which relate low~flow to watersheds characteristics in mountainous watersheds. Normally, a multiplicative model structure is imposed and multivariate statistical procedure...
The purpose of this paper is to develop regional multivariate regression models which relate low~flow to watersheds characteristics in mountainous watersheds. Normally, a multiplicative model structure is imposed and multivariate statistical procedures are employed to select suitable watersheds characteristics and to estimate model parameters. Since such procedures have met with only limited success, we take a different approach. A simple conceptual stream~aquifer model is extended to a watershed scale and evaluated for its ability to approximate the low-flow behavior of unregulated catchments in Mankyoung, Sumjin and Youngsan river basin.The conceptual watershed model is then adapted to estimate low-flow using multivariate regional regression procedures. Our results indicate that in the river basins, low-flow are highly correlated with the product of watershed area, average basin slope and base flow recession constant, with the base flow recession constant acting as a surrogate for both basin hydraulic conductivity and drainable soil porosity.