Suitability of satellite-based rainfall products for estimating rainfall erosivity in areas with contrasted climate and terrain properties: Example of west-central Morocco

Abstract

This study aims to assess the accuracy of three satellite-derived products (IMERG-F, CHIRPS and PERSIANN CDR) in quantifying the erosivity of rainfall. A network of 14 gauge stations is utilized to estimate the R-factor in west-central Morocco between 2001 and 2020. This evaluation is conducted at the basin, and the pixel scale is based on five statistical metrics. The present research showed that rainfall intensity and the topographic characteristic of terrain could highly affect the performance of SPPs in estimating the R-factor; the results show that the estimations become less accurate either in high altitudes or in high rainfall intensities. Furthermore, the findings indicate that CHIRPS outperforms the other datasets, particularly at the basin scale where the relative bias is close to 0, with a minimum error and a Nash coefficient of about 0.62, followed by the IMERG-F product, while PERSIANN CDR has the lowest performance. Overall, this study’s outcome yields valuable insights into the applicability of CHIRPS product in estimating rainfall erosivity factor in scarcely gauged areas characterized by a complex climate and topography.

Research highlights

• The rainfall erosivity factor was calculated using three satellite precipitation products.

• CHIRPS product exhibited the best performance in estimating rainfall erosivity in Tensift watershed.

• The performance of SPPs in estimating R factor is highly affected by the altitudes and the climatic caracteristics of the study area.

• The vulnerability maps were created to identify regions threatened by water erosion according to the three products.