Abstract
When an early rainfall precedes the main rainfall in a river basin,the runoff analysis must consider the change in the soil’s runoff characteristics due to non-rainfall periods and the rainfall’s scale.This study investigates how these factors influence the recovery level of the soil storage capability and proposes a new storage function model. In this paper, we consider the recovery of storage capability in the storage function model constants R and F to improve the conformity of the calculated flow discharges and the observed data.Based on our analytical results of the Honmyo River Basin in Nagasaki Prefecture, the calculated values and the observed data are in good agreement after changing both R and f. In addition,the calculated results are greatly influenced by the difference in the scale of the rainfall used to determine the initial model constants and the main rainfall which is the target of runoff analysis.
