Spatiotemporal monitoring of rainfall erosivity in Morocco using free satellite data

Abstract

This study aims particularly to overcome the lack of rainfall measurements and to demonstrate the usefulness of open satellite data rainfall-erosivity estimation in Morocco. For this purpose, a short time series of two satellite products, namely CHIRPS (Climate Hazards Group InfraRed Precipitation with Station data) and TRMM (Tropical Rainfall Measuring Mission). were used and correlated to in-situ measurements of a period of 17 years (2000- 2016). This analysis revealed a relatively better correlation between monthly CHIRPS product and in-situ measurements. the coefficient of determination is arround 0.81. After its calibration using regression equations, this product were used to estimate the rainfall-erosivity over Morocco according to Renard and Freimund equation. The result showed a geographical disparity and an annually weak evolution of erosivity. Likewise, the study pointed out a significant difference in the estimated erosivity across seasons. This imply a reduction of 3% in summer and 15% in spring and a remarkable increase of 33% in autumn and 39% in winter. The prominent change of the seasonality of rainfall erosivity is very significant in the course of agricultural practices’ evolution and the adoption of adequate measures of soil protection.

Keywords

• Erosion
• erosivity
• rainfall
• modelling
• CHIRPS
• TRMM
• Morocco