坦桑尼亚土地利用变化生态环境效应的空间分异特征研究

Study on spatial differentiation characteristics of ecoenvironmental effects of land use change in Tanzania

坦桑尼亚是“一带一路”倡议辐射非洲内陆的重要门户,面临着生态环境恶化及气候变化威胁加剧等问题。基于全球30米空间分辨率地表覆盖数据集及多源社会经济与自然环境数据,综合运用生态环境质量指数、重心迁移分析、热点分析、地理探测器等研究方法,分析了坦桑尼亚2000—2020年土地利用变化及其生态环境效应的空间分异特征。结果表明:①坦桑尼亚土地利用变化速度有所减缓,耕地和人造地表面积持续增加,林地和水体面积不断减少,耕地、林地、草地、灌木地四种地类的相互转化是土地利用变化的主要形式。②生态环境质量指数不断下降,以中央铁路线为界,呈现“南高北低”的分布特征,空间格局相对稳定,重心始终位于首都多多马省域范围内。③生态环境质量变化空间集聚特征显著,2000—2010年间冷点和热点区域分布范围和集聚面积较大,2010—2020年有所减小。耕地、林地和草地之间的相互转化是影响生态环境质量最主要的用地转换类型。④不同影响因素对不同区域生态环境质量的影响程度和显著性均有所差异。社会经济因素大于自然环境因素的影响,而自然环境因素之间的协同增强作用则大于社会经济因素,人口分布明显加强了各自然环境因素对生态环境质量的影响程度。

Tanzania is an important gateway for"the Belt and Road"initiative to reach the interior of Africa.It is faced with the ecological environment deterioration and the increasing threat of climate change.Based on the global 30-meter spatial resolution land cover data and multisource socio-economic and natural environment data,this study comprehensively uses research methods such as eco-environmental quality index,gravity center migration analysis,hot spot analysis,and geodetector to analyze the spatial differentiation characteristics of land use change and its ecological environment effects in Tanzania from 2000 to 2020.The results show that:①The rate of land use change in Tanzania has slowed down,the area of cultivated land and artificial surface continued to increase,while the area of forest land and water body continued to decrease.The mutual transformation of cultivated land,forest land,grassland and shrubland was the main form of land use change.②The eco-environmental quality index has been declining,with the central railway line as the boundary,showing the distribution characteristics of"high in the south and low in the north".The spatial pattern was relatively stable,and the gravity center was always within the scope of the capital city Dodoma.③The spatial agglomeration characteristics of changes in eco-environmental quality were significant.The distribution range and agglomeration area of cold spots and hot spots were large from 2000 to 2010,and decreased from 2010 to 2020.The mutual transformation among cultivated land,forest land and grassland was the main type of land use transformation that affects the quality of ecological environment.④The contribution rate and significance of different influencing factors on eco-environmental quality in different regions were different.The influence of social and economic factors was greater than that of natural factors,while the synergy between natural factors was greater than that of social and economic factors.The population distribution has significantly strengthened the impact of various natural factors on the quality of the ecological environment.