Use of gridded climate data for hydrological modelling in the Zambezi River Basin, Southern Africa

Abstract

The Zambezi River Basin is among many basins in Southern African region with inadequate, low resolution, poorly maintained and distributed network of hydrometeorological stations. This scenario entails scarcity of hydrological data in the basin and subsequently leads to poor assessment of water resources. This paper investigates alternative technologies in the assessment of the hydrology and water resources in the basin. The high-resolution gridded climate data together with land use and soil data were used as inputs into SWAT model to simulate hydrological processes. Calibration and validation of model were performed using SWAT-CUP. Comparison of average monthly rainfall data for gridded and observed shows 97% correlation. The statistics show NS to be 0.73 while R2 was 0.73. The uncertainty analysis was determined with a P-factor at 0.75 while the R-factor was 0.75. Therefore, use of gridded climate data for hydrological modelling in data scarce regions could be a useful tool to estimate the main hydrological parameters and water resources of an area with satisfactory accuracy.