内蒙草原区植被覆盖度时空演变及其驱动力分析
Spatial-temporal evolution of vegetation coverage and its driving force analysis in Inner Mongolia grassland
[目的]内蒙草原具有丰富的自然植被和矿产资源。以内蒙草原区为参考确定适宜的植被覆盖度并了解其分布特征和驱动因素,可为其矿山生态修复工作提供有益的思路和建议。[方法]本研究基于Landsat5/7/8 NDVI数据,采用像元二分模型反演植被覆盖度。通过Sen+MK和Hurst指数对该地区植物覆盖度的稳定性、空间分布和未来演变趋势进行了全面的研究。并且使用最优参数地理探测器(OPGD)来探究植被覆盖度空间分异的驱动因素。[结果]1)2006-2020 年内蒙草原区植被覆盖度呈增长趋势,整体呈现东高西低的空间格局,以高波动为主;2)从变化趋势分析,植被具有轻微或明显改善的区域(64.8%)远多于轻微或严重退化区域(23.2%),12%的区域无明显变化。与过去 15年相比,未来植被改善区域的面积将会减少至 36.6%,中部草原区的锡林郭勒盟市和乌兰察布市中部,东部草原区呼伦贝尔市的西部和鄂尔多斯市的西部以及西部草原区乌海市都有退化风险,应重点关注;3)降水q平均值为 0.35,是内蒙草原区空间分异性的主导因素,其与土壤类型、土地利用和气温 3个因子的q值介于 0.40～0.63之间,协同作用最显著。
[Objective]Inner Mongolia grasslands are rich in natural vegetation and mineral resources.Taking the grassland area of Inner Mongolia as a reference to determine the appropriate vegetation coverage and understand its distribution characteristics and driving factors can provide useful ideas and suggestions for its mine ecological restoration work.[Method]Based on the Landsat5/7/8 NDVI data,this study uses the pixel binary model to invert the vegetation coverage.The stability,spatial distribution and future evolution trend of plant coverage in this area were comprehensively studied by Sen+MK and Hurst index.And the optimal parameter geographic detector(Optimal Parameters Geographical Detector)was used to explore the driving factors of the spatial differentiation of vegetation coverage.[Result]1)From 2006 to 2020,the vegetation coverage in the Inner Mongolia grassland area showed an increasing trend,and the overall spatial pattern was high in the east and low in the west,with high fluctuations;2)From the analysis of the change trend,the vegetation has slightly or significantly improved areas(64.8%)are far more than slightly or severely degraded areas(23.2%),and 12%of areas have no significant change.Compared with the past 15 years,the area of the future vegetation improvement area will be reduced to 36.6%,the central part of Xilinguole League City and Ulanqab City in the central grassland area,the western part of Hulunbeier City in the eastern grassland area,and the western part of Ordos City in the eastern grassland area and Wuhai City in the western grassland area have degradation risks,which should be focused on;3)The average q value of precipitation is 0.35,which is the dominant factor of spatial differentiation in the Inner Mongolia grassland area,and its relationship with the three factors of soil type,land use,and temperature The q value is between 0.40 and 0.63,and the synergistic effect is the most significant.Key Words:Vegetation coverage;Inner Mongolia grassland;Optimal Parameters Geographical Detector;Spatiotemporal evolution;Driving force
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