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Fine-temporal resolution rainfall is a prerequisite for flood risk-related studies. In recent years, 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. HIGHLIGHTS Evaluation of SPP TRMM_3B42RT for a major flood event using statistical measurements like RB (%), CC, and RMSE (mm/day).; Temporal disaggregation of the DRG data using 3-h SPP TRMM_3B42RT.; Identification of the best approach in terms of hydrologic simulation by using 10 efficiency criteria and the use of the CF technique.;

To evaluate the accuracy and applicability of the TMPA 3B42-V7 precipitation product for the Lancang River basin, we used different statistical indices to explore the performance of the product in comparison to gauge data. Then, we performed a hydrologic simulation using the Variable Infiltration Capacity (VIC) hydrological model with two scenarios (Scenario I: streamflow simulation using gaugecalibrated parameters; Scenario II: streamflow simulation using 3B42-V7-recalibrated parameters) to verify the applicability of the product. The results of the precipitation analysis show good accuracy of the V7 precipitation data. The accuracy increases with the increase of both space and time scales, while time scale increases cause a stronger effect. The satellite can accurately measure most of the precipitation but tends to misidentify non-precipitation events as light precipitation events (<1 mm/day). The results of the hydrologic simulation show that the VIC hydrological model has good applicability for the Lancang River basin. However, 3B42-V7 data did not perform as well under Scenario I with the lowest Nash-Sutcliffe coefficient of efficiency (NSCE) of 0.42; Scenario II suggests that the error drops significantly and the NSCE increases to 0.70 or beyond. In addition, the simulation accuracy increases with increased temporal scale. [ABSTRACT FROM AUTHOR]

The impact of climate change on floods and droughts in Huaihe River Basin is studied using a coupled land-surface hydrology model and continuous wavelet transform technique. Observed temperature in the basin has increased by approximately 0.228 °C per decade since 1951. Observed precipitation and simulated and observed streamflows are used to grade flood and drought events. Two composite grading indices derived from the three series using different weight values are defined for reducing uncertainties caused by errors of observation and simulation and the effect of human activity on observed streamflow. The frequency of flood and drought events is quantified using the Morlet wavelet transform and compared with the trend of average temperature to test for any relationship between climate change and flood/drought frequency. This study shows that flood and drought events have occurred more frequently since the 1980s. The trend of flood and drought events is positively related to climate warming with a coefficient of determination of 0.88 in the Huaihe River Basin. [ABSTRACT FROM AUTHOR]