Using satellite-based precipitation for developing intense rainfall equations for ungauged areas of the Southern Bahia Mesoregion

Abstract

Satellite-based precipitation products can be an important alternative for developing IDF equations in ungauged regions, in search for more flood-resilient hydraulic systems. This study evaluated precipitation estimates from the product CHIRPS for developing IDF equations in the Southern Bahia Mesoregion. The statistical metrics used were Percent Bias (PBIAS), Root Mean Square Error (RMSE), Mean Absolute Error (MAE), and the Nash-Sutcliffe Efficiency coefficient (NSE). The results indicate that CHIRPS does not perform satisfactorily in its original state, but it can provide reasonable IDF equations if the data bias is corrected. Based on a linear regression model, a bias correction method was proposed, which can be applied in ungauged areas of the studied region, showing better performance than IDF equations provided by the software Pluvio 2.1 (RMSE 45.27% lower; MAE 46.31% lower).