内蒙古沙尘源空间格局及转化情况分析

Analysis of spatial pattern and transformation of sand and dust sources in Inner Mongolia

我国北方地区春夏季节沙尘天气频发,识别沙尘源区对于沙尘天气预报及区域生态环境治理意义重大。本文以内蒙古自治区为目标区,采用2005、2010、2015和2020年4个年度土地利用/土地覆被数据,分析了内蒙古沙尘源的空间分布格局,并基于土地类型转移矩阵分析了不同类型沙尘源的转化情况。结果显示:内蒙古沙尘源空间格局的时间变化特征并不明显,但通过定量化的分析发现,每种类型沙尘源的面积均随时间波动变化,但总体看,2005—2020年,内蒙古全区沙尘源总面积减少了7771.05km^(2);从内蒙古沙尘源正、逆向转化的分析看,稀树草原、有林草原、落叶阔叶林、农田/自然植被混合区域这几种土地类型是沙尘源转化的活跃区域或者敏感区,要特别给予关注;稀疏的灌木土地类型转化为草原型沙尘源的面积占比降低的事实,从另一个侧面说明内蒙古地区灌木的固沙效果要好;内蒙古荒漠交错带面积广阔,但其生态系统脆弱,为潜在的沙尘源区,应科学划定生态保护区,禁止人为活动。本文研究结果有望为区域生态环境治理及农牧业发展提供科学依据。

Sand and dust weather occurs frequently in spring and summer in the northern region of China,and the identification of sand and dust source areas is of great significance for sand and dust weather forecasting and regional ecological environment management.The spatial distribution pattern of sand and dust sources in Inner Mongo⁃lia was analyzed using land use/land cover data in 2005,2010,2015 and 2020,and the transformation of different types of sand and dust sources was analyzed based on the land type transfer matrix.The results showed that:the tem⁃poral changes in the spatial pattern of sand and dust sources in Inner Mongolia were not obvious,but the quantitative analysis revealed that the area of each type of sand and dust source fluctuated with time,but in general,the total area of sand and dust sources in the whole region of Inner Mongolia was reduced by 7,771.05 km^(2) from 2005 to 2020;From the analysis of the positive and negative transformations of sand and dust sources in Inner Mongolia,savanna,forested grassland,deciduous broad-leaved forest,and mixed farmland/natural vegetation areas are active or sensitive areas for the transformation of sand and dust sources,and special attention should be paid to them;The fact that the percent⁃age of the area of sparse shrub land types transformed into grassland-type sand and dust sources is reduced indicates from another side that the sand fixation effect of shrubs in Inner Mongolia is better;The desert ecotone in Inner Mon⁃golia covers a vast area,but its ecosystem is fragile,and it is a potential dust source area.Ecological protection areas should be demarcated scientifically and human activities should be prohibited.The results of this paper are expected to provide scientific basis for regional ecological environment management and agricultural and animal husbandry de⁃velopment.