Improving satellite-based global rainfall erosivity estimates through merging with gauge data

Rainfall erosivity is a key factor that influences soil erosion by water. Rain-gauge measurements are commonly used to estimate rainfall erosivity. However, long-term gauge records with sub-hourly resolutions are lacking in large parts of the world. Satellite observations provide spatially continuous estimates of rainfall, but they are subject to biases that affect estimates of rainfall erosivity. We employed a novel approach to map global rainfall erosivity based on a high-temporal-resolution (30-min), long-term (2001–2020) satellite-based precipitation product—the Integrated Multi-satellitE Retrievals for Global Precipitation Measurement (GPM-IMERG)—and mean annual rainfall erosivity from the Global Rainfall Erosivity Database (GloREDa) stations (n = 3286). We used a residual-based merging scheme to integrate GPM-IMERG-based rainfall erosivity with GloREDa using Geographically Weighted Regression (GWR). The accuracy of the GWR-based merging scheme was evaluated with a 10-fold cross-validation against GloREDa stations. Based on GPM-IMERG-only, the global mean annual rainfall erosivity was estimated to be 1173 MJ mm ha-1 h-1 yr-1 with a standard deviation of 1736 MJ mm ha-1h-1 yr- 1. The mean value estimated via GPM-IMERG merged with GloREDa was 2020 MJ mm ha-1 h-1 yr-1 witha standard deviation of 3415 MJ mm ha-1 h-1 yr-1.

FENTA Ayele Almaw;  TSUNEKAWA Atsushi;  HAREGEWEYN Nigussie;  YASUDA Hiroshi;  TSUBO Misturu;  BORRELLI Pasquale;  KAWAI Takayuki;  BELAY Ashebir Sewale;  EBABU Kindiye;  BERIHUM Mulatu Liyew;  SULTAN Dagnenet;  SETARGIE Tadesual Asamin;  ELNASHAR Abdelrazek;  PANAGOS Panos; 

2023-05-12

ELSEVIER

JRC132567

0022-1694 (online),   

https://www.sciencedirect.com/science/article/pii/S0022169423004973,    https://publications.jrc.ec.europa.eu/repository/handle/JRC132567,   

10.1016/j.jhydrol.2023.129555 (online),