# Optical remote sensing for monitoring soil erosion in sub-Saharan grassland biomes: a systematic review

## TL;DR

This paper reviews how optical and radar satellite technologies can monitor soil erosion in sub-Saharan grasslands, highlighting gaps in research and validation.

## Contribution

The study systematically evaluates remote sensing methods for soil erosion monitoring in sub-Saharan grasslands, identifying research gaps in SAR sensor applications.

## Key findings

- Gully development is closely linked to topography, including river flow networks and slope gradients.
- Optical remote sensing techniques are widely used, but SAR sensor effectiveness for erosion monitoring remains under-researched.
- There is insufficient validation of SAR-derived erosion models with ground-truth data in the region.

## Abstract

The Sub-Saharan African region is experiencing the effects of climate change and rapid population growth. The current population, together with the impacts of climate change, has a negative effect on soil resources; hence, implementing land conservation and sustainable land management methods is essential throughout the region. Policymakers require spatial information on soil erosion hotspots to make decisions because soil erosion has high negative impacts on agricultural lands. The study aimed to systematically review the literature on integrating optical and Synthetic Aperture Radar (SAR) systems and multiplatform satellite-based systems to monitor soil erosion in sub-Saharan grassland biomes. The review followed the PRISMA guidelines, and a bibliometric analysis was conducted to identify and evaluate relevant studies. In this study we include thirty-four articles for data extraction. Data was extracted and evaluated based on the techniques used to monitor soil erosion. The study reveals that the development of gullies varies and is closely linked to topography, specifically river flow networks and slope gradients. The findings highlighted the applications of different remote sensing techniques for monitoring soil erosion in the grasslands of sub-Saharan Africa. There is limited research on the effectiveness of SAR sensors for detecting the progression of soil erosion in grasslands, and there is insufficient validation of SAR-derived erosion models with ground-truth data in sub-Saharan Africa.