Methodology

Two-parameter monthly water balance model

The TWBM was applied in this study to simulate the catchment rainfall-runoff relationship. The TWBM was developed by Xiong & Guo (1999) and has been widely applied worldwide to simulate monthly runoff (Guo et al., 2005; Zhang et al., 2013; Deng et al., 2016). The model inputs are potential evapotranspiration (PET) and precipitation (P ), both of which are readily available or can be estimated from routine meteorological observations (Xiong & Guo, 1999).
Monthly actual evapotranspiration (\(E_{i}\)) is estimated in TWBM as: