167 / 2022-02-13 20:23:36

Spatial and temporal intensity of improvement and degradation effects of vegetation cover in the coal mining area of Ordos City

vegetation cover,intensity of spatial-temporal change,coal mining area,Sen + Mann-Kendall trend analysis,Piecewise Linear Regression,ecological restoration

Public Security and Emergency Management > 4. Ecological Security and Land Restoration

In recent years, vegetation in the arid region of Northwest China has maintained a growing trend. However, the impact of high-intensity mining activities on vegetation changes in this region has received extensive attention. The existing research has rarely revealed the impact of coal mining on the intensity of vegetation changes in mining areas. Therefore, this paper uses Sen+Mann-Kendall trend analysis and piecewise linear regression model to research the spatiotemporal intensity of improvement and degradation effect of vegetation cover in the coal mining area of Ordos City. The results show that: (1) From 1998 to 2019, the mean value of NDVI in the study area generally increased with a rate of 0.0053a, and the overall vegetation coverage improved, accounting for 84.38% of the total area of the study area. The vegetation improvement and degradation phenomenon in the open-pit mining area were obvious, while the vegetation improvement in the underground mining area was obvious, and the degradation phenomenon decreased. (2) The vegetation abrupt change in the study area is dominated by improvement mutation, and the mutation years are mainly 2009, 2010 and 2014. The proportion of the abrupt change in the open-pit mining area and the underground mining area is much larger than that in the non-mining area, and the vegetation-improving abrupt change in the open-pit mining area is the most obvious. (3) After the vegetation-improving abrupt change occurred, the average annual vegetation change rate was better than that of the non-mining area in both underground and open-pit mining, indicating that the vegetation construction in the mining area enhanced the vegetation improvement intensity and weakened the vegetation degradation intensity.. (4) The proportion of vegetation-improving abrupt change area in the eastern Ordos coalfield is larger, especially the vegetation-improving abrupt change area of the Jungar coalfield accounts for 46.87% of the total area of the Junger coalfield. (5) During the 20 years from 1998 to 2019 in Ordos, although the overall mining area caused vegetation degradation due to production and construction activities, targeted ecological restoration measures were implemented in different periods, and the effect of vegetation coverage improvement in the open-pit mining area was the strongest. , achieved remarkable results. The research results can provide scientific and technological support for the ecological protection and restoration of the territorial space of the Ordos section of the Yellow River in China.