非洲Munyaka地区铁皮屋顶时空变化规律研究

Temporal and Spatial Variation of Tin Roof in Munyaka Area of Africa

在非洲,铁皮屋顶的分布能够反映居民的生活水平,对其时空变化分析能够反映当地经济发展状况。采用Sentinel-2研究非洲肯尼亚埃尔多雷特市Munyaka地区铁皮屋顶的光谱特征、遥感指数特征以及纹理特征,利用归一化植被指数和归一化建筑指数与铁皮屋顶的差异剔除农田,构建归一化表面指数且分析纹理特征分别剔除荒地和裸地;建立了多特征决策树提取模型,通过混淆矩阵进行精度评定得到Kappa系数为0.9223,用户精度和制图精度分别为97.79%和91.10%。同时结合埃尔多雷特市政道路工程,对2016~2020年工程前后铁皮屋顶变化进行研究,2018~2020年阶段比2016~2018年阶段,铁皮屋顶面积增加一倍,平均年增长率提升近3%。研究表明该方法能够实现对铁皮屋顶的动态监测,同时说明了“一带一路”建设为解决非洲贫困问题起到推动作用。

In Africa,the distribution of tin roof can reflect the living standard of residents,and the analysis of its temporal and spatial changes can reflect the local economic development.Sentinel-2 was used to study the spec⁃tral characteristics,remote sensing index characteristics and texture features of iron roof in Munyaka area,Eldo⁃ret,Kenya,Africa.The Normalized Difference Vegetation Index(NDVI)and Normalized Difference Building Index(NDBI)were used to remove farmland from the difference of the iron roof.The normalized surface index was constructed and the texture features were analyzed to eliminate wasteland and bare land respectively.The model of multi feature decision tree extraction is established.The Kappa coefficient is 0.9223,and the user pre⁃cision and mapping precision are 97.79%and 91.10%respectively.At the same time,combined with the erdo⁃ret municipal road project,the changes of iron roof before and after the project in 2016~2020 are studied.Com⁃pared with 2016~2018,the area of iron roof in 2018~2020 is doubled,and the average annual growth rate is nearly 3%.Research shows that this method can achieve dynamic monitoring of tin roofs,and illustrates that"The Belt and Road Initiative"construction plays a driving role in solving poverty problems in Africa.