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Arid Land Geography ›› 2021, Vol. 44 ›› Issue (3): 700-707.doi: 10.12118/j.issn.1000–6060.2021.03.12

• Ecology and Environment of Tarim River Basin • Previous Articles     Next Articles

Ecological responses of ecological water conveyance in the lower reaches of Tarim River for 20 years

LI Yupeng1(),CHEN Yaning1(),YE Zhaoxia1,WANG Fei1,2,SUN Fan1,2,QIN Jingxiu1,2   

  1. 1. State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, Xinjiang, China
    2. University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2021-02-07 Revised:2021-03-07 Online:2021-05-25 Published:2021-06-01
  • Contact: Yaning CHEN E-mail:liyupeng@ms.xjb.ac.cn;chenyn@ms.xjb.ac.cn

Abstract:

An ecological water conveyance project has been implemented since 2001 in the lower Tarim River, Xinjiang, China to replenish its broken river channel and save dying desert communities. The ecological environment of the basin of the river was initially improved, achieving a win-win situation considering both economic and social development and ecological environmental protection of the basin. In this paper, the spatiotemporal changes in the normalized difference vegetation index (NDVI) and vegetation cover in the lower Tarim River were investigated using mathematical statistical methods based on multisource remote sensing data (MOD13Q1 and MCD12Q1) to evaluate the ecological effects of water conveyance in the last 20 years. The results show that the NDVI of the lower reaches of Tarim River increased by 33.3% (from 0.14 in 2000 to 0.21 in 2020) and that the vegetation area increased by 188.0% (from 492 m2 in 2000 to 1423 m2 in 2020). Compared with those in 2000, areas with low, medium, and high vegetation coverage increased by 277 m2, 537 m2, and 132 m2, respectively (increase rates of 20.8%, 448.0%, and 190.0%, respectively). The increases in the vegetation area and vegetation cover in the midstream section were higher than those in the upper and lower reaches. The NDVI and vegetation cover both showed large increases within 2 km from the river banks, which gradually became smaller beyond 2 km. Spatially, about 57.1% of the areas showed a significant increasing trend in NDVI and vegetation cover, and no more than 2.0% of the areas showed a significant decrease. The Hurst index indicates that more than 75.0% of the areas with this greening trend will continue in the future and that only 6.1% of the areas will continue to ecologically deteriorate. A comprehensive assessment of the ecological effects of Tarim River water conveyance project is of great scientific significance for the conservation and restoration management of arid zone deserts and ecological water resource management.

Key words: lower reaches of Tarim River, ecological water conveyance, normalized difference vegetation index (NDVI), vegetation cover