Using the WATYIELD water balance model to predict catchment water yields and low flows

摘要

The WATYIELD water balance model is designed to help land and water managers make informed decisions on the effects of landcover changes on catchment runoff. It is a lumped conceptual model of catchment rainfall and runoff. Losses before runoff are calculated from the water balance equation, and water stored in the soil is released as quick or delayed flow to estimate discharge. Input requirements are daily rainfall totals, average monthly reference evapotranspiration, an interception fraction (the amount of rainfall lost through interception), a crop coefficient to convert the reference evapotranspiration to a loss equivalent to transpiration by the vegetation on the site, information on total and readily available soil water, a base-flow index (the proportion of flow as base flow), and a coefficient that defines the rate of baseflow recession.