关键词: 露天煤矿, 荒漠植被, 时空变化, 扰动距离, 气候变化, 降水, 新疆五彩湾

Abstract:

The assessment of desert vegetation damage in large-scale strip coal mining areas is a research hotspot in environment restoration studies in the recent years. The Wucaiwan mining area is located in the western part of the Xinjiang Zhundong coal mining base, most of which is open-pit coal mining. Since the construction of the mining area in 2006, coal mining and coal chemical industry have had a serious impact on the surrounding eco-environment. With 90 scenes of Landsat imagery, the present paper analyzed the spatiotemporal characteristics of Wucaiwan and its surrounding desert vegetation before and after the open-pit coal mining. The aim was to study the disturbance effects of open-pit mineral exploitation from 1990 to 2017, and to quantify the response of vegetation growth to climate change and mining area expansion. Results show that: (1) The vegetation change during 2006-2013 in the mining area presented a trend opposite to that of surrounding areas, with similar trends during 1990-2006 and 2014-2017. Vegetation in the mining area was severely disturbed and experienced an obvious degradation during 2006-2013. (2) Vegetation of the mining area was most flourishing in May or June and fell into decay in July or August, as evidenced by the monthly NDVI during the growing season. This illustrates the typical phenological characteristics of desert ephemeral plants, and it can be seen clearly that vegetation in the central sample area of the mining area has undergone successively degradation and restoration. (3) The disturbance distances of the development of surrounding areas on the growth of surrounding vegetation were -17~21 and -13~23 km along the “west-east” and “south-north” directions, respectively. Besides, the disturbance distance in 2013 was the largest. (4) The precipitation in winter and spring was the main influencing factor on the growth of the Wucaiwan mining area and the surrounding vegetation. Although the mining area has been in an expanding state, the vegetation in the mining area has improved since 2014 (consistent with the surrounding vegetation), thanks to the increase of precipitation and the strengthening of dust protection measures. Our findings provide accurate data for the dynamic monitoring of vegetation changes in open pit coal mining and surrounding deserts in arid areas, informs managers of mining areas to take more effective measures for environmental protection and pollution control.

Key words: strip coal mining, desert vegetation, spatiotemporal variation, distance of disturbance, climate change, precipitation, wucaiwan,xinjiang