Regional Monthly Rainfall‐Runoff Model

Abstract

A simple regional model for basins with either linear or nonlinear monthly rainfall‐runoff behavior is presented. The structure of the model depends on two key parameters: (1) An order parameter k; and (2) a memory parameter n, which control the runoff behavior of the basin and the memory of the rainfall‐runoff process, respectively. These parameters are estimated from monthly rainfall‐runoff relationships. The order parameter k is a basin characteristic, whereas the memory parameter n is a characteristic of month, equal to k for months with delayed runoff and zero otherwise. The coefficients of the model are regionalized so that the model may be also used in ungaged sites. Monthly flows may be accurately estimated by using the model and the historical monthly means, and standard deviations are preserved at the 90% confidence level.