Automatic Detection of Open and Vegetated Water Bodies Using Sentinel 1 to Map African Malaria Vector Mosquito Breeding Habitats
Automatic Detection of Open and Vegetated Water Bodies Using Sentinel 1 to Map African Malaria Vector Mosquito Breeding Habitats
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DOI：
10.3390/rs11050593
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发表时间：
2019-03-01
期刊：
影响因子：
5
通讯作者：
Thomas, Chris J.
中科院分区：
文献类型：
--
作者：
Hardy, Andy;Ettritch, Georgina;Thomas, Chris J.
提供及时和准确的地表水地图对于绘制疟疾风险图和确定疾病控制干预措施的目标很有价值。雷达卫星遥感有可能提供这一信息，但目前的方法不适合绘制非洲疟疾蚊子水生生境的地图，因为这些生境往往是高度动态的，往往有新兴植被。我们提出了一种新的方法来映射开放和植被水体使用系列哨兵-1图像赞比亚西部。这一地区主要是季节性淹没的上赞比西河洪泛区，面临着一些公共卫生挑战。该方法使用开源分割和机器学习（额外的树分类器），应用于使用免费提供的辅助数据自动导出的训练数据。通过共识方法和大津阈值来实施细化，以消除由于干燥平坦的桑迪地区而导致的误报。结果表明，高精度（平均整体精度92%，标准差3.6）提供了一个易于操作的解决方案，在类似的大型河流洪泛平原无林环境中映射水体。在研究期间，70%的总水映射范围归因于植被水，突出了映射开放和植被水体地表水映射的重要性。
Providing timely and accurate maps of surface water is valuable for mapping malaria risk and targeting disease control interventions. Radar satellite remote sensing has the potential to provide this information but current approaches are not suitable for mapping African malarial mosquito aquatic habitats that tend to be highly dynamic, often with emergent vegetation. We present a novel approach for mapping both open and vegetated water bodies using serial Sentinel-1 imagery for Western Zambia. This region is dominated by the seasonally inundated Upper Zambezi floodplain that suffers from a number of public health challenges. The approach uses open source segmentation and machine learning (extra trees classifier), applied to training data that are automatically derived using freely available ancillary data. Refinement is implemented through a consensus approach and Otsu thresholding to eliminate false positives due to dry flat sandy areas. The results indicate a high degree of accuracy (mean overall accuracy 92% st dev 3.6) providing a tractable solution for operationally mapping water bodies in similar large river floodplain unforested environments. For the period studied, 70% of the total water extent mapped was attributed to vegetated water, highlighting the importance of mapping both open and vegetated water bodies for surface water mapping.