Monitoring land sensitivity to desertification in Central Asia: Convergence or divergence?

Liangliang Jiang; Anming Bao; Guli Jiapaer; Hao Guo; Guoxiong Zheng; Khusen Gafforov; Alishir Kurban; Philippe De Maeyer

doi:10.1016/j.scitotenv.2018.12.152

Monitoring land sensitivity to desertification in Central Asia: Convergence or divergence?

Sci Total Environ. 2019 Mar 25:658:669-683. doi: 10.1016/j.scitotenv.2018.12.152. Epub 2018 Dec 12.

Authors

Liangliang Jiang¹, Anming Bao², Guli Jiapaer³, Hao Guo¹, Guoxiong Zheng⁴, Khusen Gafforov⁵, Alishir Kurban³, Philippe De Maeyer⁶

Affiliations

¹ State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China; University of Chinese Academy of Sciences, Beijing 100049, China; Department of Geography, Ghent University, Ghent 9000, Belgium; Sino-Belgian Joint Laboratory of Geo-information, Urumqi 830011, China; Sino-Belgian Joint Laboratory of Geo-information, Ghent 9000, Belgium.
² State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China; Sino-Belgian Joint Laboratory of Geo-information, Urumqi 830011, China; Sino-Belgian Joint Laboratory of Geo-information, Ghent 9000, Belgium. Electronic address: baoam@ms.xjb.ac.cn.
³ State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China; Sino-Belgian Joint Laboratory of Geo-information, Urumqi 830011, China; Sino-Belgian Joint Laboratory of Geo-information, Ghent 9000, Belgium.
⁴ State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China; University of Chinese Academy of Sciences, Beijing 100049, China.
⁵ State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China; University of Chinese Academy of Sciences, Beijing 100049, China; Research Institute of Irrigation and Water Problems, Tashkent 100187, Uzbekistan.
⁶ Department of Geography, Ghent University, Ghent 9000, Belgium; Sino-Belgian Joint Laboratory of Geo-information, Urumqi 830011, China; Sino-Belgian Joint Laboratory of Geo-information, Ghent 9000, Belgium.

PMID: 30580221
DOI: 10.1016/j.scitotenv.2018.12.152

Abstract

In Central Asia, desertification risk is one of the main environmental and socioeconomic issues; thus, monitoring land sensitivity to desertification is an extremely urgent issue. In this study, the combination of convergence patterns and desertification risk is advanced from a technical perspective. Furthermore, the environmentally sensitive area index (ESAI) method was first utilized to monitor the risk of desertification in Central Asia. In the study, the spatial and temporal patterns of desertification risk were illustrated from 1992 to 2015 using fourteen indicators, including vegetation, climate, soil and land management quality. The ESAI spatial convergence across administrative subdivisions was explored for three time intervals: 1992-2000, 2000-2008 and 2008-2015. The results indicated that nearly 13.66% of the study area fell into the critical risk of desertification from 1992 to 2008. However, the risk of desertification has improved since 2008, with critical classifications decreasing by 19.70% in 2015. According to the mutation year detection in the ESAI, 25.89% of the pixels with mutation years from 1992 to 2000 were identified, and this value was higher than that during the other time periods. The convergence analysis revealed that the desertification risk for 1992-2000 tended to diverge with a positive convergence coefficient of 0.13 and converge over the 2000-2008 and 2008-2015 time periods with negative convergence coefficients of -0.534 and -0.268, respectively. According to the spatial convergence analysis, we found that the divergence patterns in northern Central Asia from 1992 to 2000 resulted from the effects of the Soviet Union collapse: cropland abandonment in northern Kazakhstan and rangeland abandonment in Tajikistan, Kyrgyzstan and eastern Kazakhstan. In contrast, most areas from 2000 to 2008 experienced increased sensitivity to desertification with the convergence pattern caused by decreased precipitation, especially in northern Central Asia. However, convergence patterns were found in most regions for 2008-2015 with regard to augmented precipitation, which resulted in decreased sensitivity to desertification. Moreover, the low sensitivity areas were more likely to converge under increased precipitation. In this region, the findings of our study suggested that spatial convergence and divergence acted as related predictors of climate change and human activities, respectively. Thus, the ESAI convergence analysis was considered to provide an early warning of potential desertification.

Keywords: Climate change; Convergence analysis; Desertification risk; Environmental sensitivity area index; Human activities.