Mapping desertification degree and assessing its severity in Al-Ahsa Oasis, Saudi Arabia, using remote sensing-based indicators

Abstract

Desertification in Saudi Arabia is cause for environmental and socio-economic concern, as it has severe and problematic impacts. This study aimed to map desertification and the degree of its severity over the date palms-dominated Al-Ahsa Oasis in the Eastern Province of Saudi Arabia using Landsat-8 OLI imagery acquired in December 2019. Based on linear regression analysis, correlations between the normalized difference vegetation index (NDVI) and albedo (α), tasseled cap wetness (TCW), brightness (TCB), and greenness (TCG) were obtained. These indicators were generated by employing the tasseled cap transformation method (TCT). The results revealed a strong negative association between TCW and TCB (r = − 0.91). In contrast, NDVI–α exhibited a weak negative relationship (r = − 0.53) as a desertification identifier. Thus, the desertification degree index (DDI) was applied to the TCW–TCB relationship. The findings indicated that 83% of the oasis exhibited desertification, which was further classified based on the degree of severity into 14.2% extreme, 19.3% severe, 23.9% moderate, and 25.6% low. Overall, the study illustrates the capability of remote sensing data and techniques in mapping and assessing the degree of desertification and its severity by applying the DDI index.