Validation of TRMM Data in the Black Volta Basin of Ghana

This study was conducted in the Black Volta basin, Ghana, to determine how Tropical Rainfall Measuring Mission (TRMM) satellite-derived rainfall compares with ground-measured values and the possibility of using it to complement ground-measured rainfall. Bilinear interpolation was used to resample 0.25 degrees x 0.25 degrees TRMM 3B42V6 monthly rainfall grids to determine site-specific rainfall of the basin based on rain gauge locations and analyzed statistically. The study showed that the correlation between the monthly datasets ranged from 0.73 to 0.88. A plot of the average monthly data of all the stations gave a correlation coefficient (R) of 0.94. The overall catchment rainfall was well represented by TRMM data. However, the annual station rainfalls were either underestimated or overestimated. The under-estimations and overestimations were mostly below 20% and 10%, respectively, of the raingauge measurements. Although the TRMM rainfall data did not perfectly match with the ground measurements, it can still be used to supplement ground measurements and for estimating rainfalls in ungauged basins. DOI: 10.1061/(ASCE)HE.1943-5584.0000487. (C) 2012 American Society of Civil Engineers.