The changes of vegetation cover in Ejina Oasis based on water resources redistribution in Heihe River

• Published in: Environmental earth sciences Vol. 64; no. 7; pp. 1965 - 1973
• Main Authors: Yaobin, Wang, Qi, Feng, Jianhua, Si, Yonghong, Su, Zongqiang, Chang, Haiyang, Xi
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.12.2011; Springer; Springer Nature B.V
• Subjects: Applied geophysics; Arid zones; Biogeosciences; Earth and Environmental Science; Earth Sciences; Earth, ocean, space; Ecosystems; Environmental Science and Engineering; Exact sciences and technology; Freshwater; Geochemistry; Geology; Hydrology; Hydrology. Hydrogeology; Hydrology/Water Resources; Internal geophysics; Land use; Local government; Original Article; Remote sensing; Rivers; Terrestrial ecosystems; Terrestrial Pollution; Vegetation cover; Vegetation mapping; Water resources; Far East; Asia; Northwest China; China; China, People's Rep; LUCC; Ejina Oasis; Vegetation cover; Northwest China; Water resources redistribution in Heihe River; rivers; models; Thematic Mapper; Space remote sensing; Landsat; arid environment; vegetation; water resources; land use; ecosystems; land cover
• ISSN: 1866-6280; 1866-6299
• DOI: 10.1007/s12665-011-1013-0

The Ejina Oasis (EO), located in arid northwest China, is a typical arid area in the world. The ecosystem in the oasis has become worse since the 1990s. However, it began to improve after the Chinese government took the mandatory measure to redistribute the water in Heihe in 2000. To understand this change, the remote sensing images in 1990, 2000 and 2006 were selected, and exertion related Land Use/Cover Change (LUCC) model was employed. Results showed that: (1) non-vegetation cover was the main body of the vegetation cover in oasis, showing a trend of increase at the beginning and diminution later, while low, medium and high vegetation cover was the other way around; (2) the area of low, medium and high vegetation cover in 2006 was less than that in 1990; the status and trend index P t of oasis vegetation cover was 0.62 in 1990–2000, which means that the oasis ecosystem of Ejina was getting worse and was under an unbalanced status; P t was 0.27 in 2000–2006 indicating that the oasis ecosystem was restored obviously and the whole system tended to be balanced; (3) all of these changes should be attributed to the water resources redistribution in Heihe River, which played a leading role, as well as the measures and relevant policies taken by the local government, which promoted the rapid recovery of the medium and high vegetation.