Sandy desertification in the Belt and Road Initiative drylands during 2000–2020: Assessment under the Land Degradation Neutrality framework

Sandy desertification currently poses a severe environmental challenge, hindering the socio-economic development of Belt and Road Initiative (BRI) drylands. However, due to incomplete evaluation systems and unclear driving mechanisms, research on sandy desertification in the BRI drylands remains limited. To address this issue, this study followed the Land Degradation Neutrality (LDN) framework and constructed a new index, called sandy desertification assessment index (SDAI). Based on SDAI, this study assessed the status, evolution, and driving mechanisms of sandy desertification during 2000–2020. The findings are as follows: (1) The year 2006 was identified as the turning point for light and moderate sandy desertification land, whereafter the areas of light sandy desertification increased while the areas of moderate sandy desertification decreased. (2) The transformation patterns of sandy desertification levels were similar in two decades (i.e., 2000–2010 and 2010–2020), with slight differences in conversion areas. (3) The changing trends exhibit regional variability. Notably, reversal was predominantly observed in China, Mongolia, and India, whereas intensification was concentrated in Central Asia. (4) Various factors exerted differing influences on sandy desertification, with annual cumulative precipitation, human footprint, and gross domestic product (GDP) being particularly significant. This study will provide crucial guidance for formulating prevention and control strategies in the BRI drylands.