A methodology for temporal disaggregation of daily rain gauge data using satellite precipitation product for improved accuracy in hydrologic simulation

Abstract

Abstract High-temporal resolution rainfall is a prerequisite for flood risk-related studies. Recently, satellite precipitation products (SPPs) have gained some attention in the hydro-meteorology field, but the application of these products for hydrological studies is still uncertain. This study discusses the methodology for temporal disaggregation of daily rain gauge (DRG) data using SPP for improved accuracy in hydrologic simulation. The objectives of this research article are (i) to temporally dis-aggregate the DRG data using 3-h SPP TRMM_3B42RT; (ii) to suggest the best approach in terms of hydrologic simulation capabilities using the compound factor (CF) technique. The hydrologic simulation in HEC-HMS was performed for various temporally disaggregated rain gauge (TDRG) data and results were analyzed using 10 efficiency criteria. The best approach was selected using the CF technique. The lowest CF of 2.4 reveals that peak discharge can be computed with less than 8% deviation using the TDRG data, which utilizes the least error tile/grid/pixel from rain gauge rainfall value out of four nearby tile/grid/pixel. This study concluded that flood volume can be computed with less than 5% deviation using DRG data but it failed to reproduce the flood peak. This approach has overcome the insufficiency of sub-daily rainfall observation.