Computer Science Department, Stanford University, Stanford, CA 94305.
Emmett Interdisciplinary Program in Environment and Resources, Stanford University, Stanford, CA 94305;
Proc Natl Acad Sci U S A. 2021 Apr 27;118(17). doi: 10.1073/pnas.2018863118.
Improving compliance with environmental regulations is critical for promoting clean environments and healthy populations. In South Asia, brick manufacturing is a major source of pollution but is dominated by small-scale, informal producers who are difficult to monitor and regulate-a common challenge in low-income settings. We demonstrate a low-cost, scalable approach for locating brick kilns in high-resolution satellite imagery from Bangladesh. Our approach identifies kilns with 94.2% accuracy and 88.7% precision and extracts the precise GPS coordinates of every brick kiln across Bangladesh. Using these estimates, we show that at least 12% of the population of Bangladesh (>18 million people) live within 1 km of a kiln and that 77% and 9% of kilns are (illegally) within 1 km of schools and health facilities, respectively. Finally, we show how kilns contribute up to 20.4 μg/[Formula: see text] of [Formula: see text] (particulate matter of a diameter less than 2.5 μm) in Dhaka when the wind blows from an unfavorable direction. We document inaccuracies and potential bias with respect to local regulations in the government data. Our approach demonstrates how machine learning and Earth observation can be combined to better understand the extent and implications of regulatory compliance in informal industry.
提高环境法规的遵守率对于促进清洁环境和健康人群至关重要。在南亚，砖制造是主要的污染源，但主要由小型、非正规的生产者主导，这些生产者难以监测和监管，这是低收入环境中的一个常见挑战。我们展示了一种低成本、可扩展的方法，用于从孟加拉国的高分辨率卫星图像中定位砖窑。我们的方法以 94.2%的准确率和 88.7%的精度识别出窑炉，并提取了孟加拉国每个砖窑的精确 GPS 坐标。利用这些估计值，我们表明，至少有 12%的孟加拉国人口（超过 1800 万人）居住在距离窑炉 1 公里以内的地方，而 77%和 9%的窑炉分别（非法）位于学校和卫生设施 1 公里以内。最后，我们展示了当风向不利时，窑炉在达卡会排放高达 20.4μg/[Formula: see text]的[Formula: see text]（直径小于 2.5μm 的颗粒物）。我们记录了政府数据中与当地法规有关的不准确性和潜在偏差。我们的方法展示了机器学习和地球观测如何结合使用，以更好地了解非正式产业法规遵守情况的程度和影响。
