Conformal PM2.5 Mapping Under Spatial Covariate Shift: Satellite-Reanalysis Fusion for Africa's Green Industrial Transition
Africa's green industrialization imperative demands reliable infrastructure for monitoring air quality. We present a satellite-reanalysis PM2.5 fusion system trained on 2,068,901 records from 404 monitoring locations in 29 African countries (OpenAQ, 2017-2022), combining LightGBM with leakage-resistant spatial cross-validation and conformal prediction to quantify predictions and their geographic applicability limits. Under 5-fold location-grouped spatial cross-validation, LightGBM achieves RMSE = 30.83 +/- 5.07 ug/m3, MAE = 14.54 +/- 1.66 ug/m3, R2 = 0.134 +/- 0.023, and macro F1 = 0.336 +/- 0.018. This R2 is substantially below random-split benchmarks (>0.90) but reflects true geographic generalisation difficulty rather than model failure. Split conformal prediction targeting 90% marginal coverage reveals severe East Africa degradation (actual PICP = 65.3% vs. nominal 90%), consistent with medium-strength covariate shift (humidity KS = 0.2237, sat_pblh KS = 0.2558). We operationalise these findings through regional reliability flags (High/Medium/Low/Unreliable) and a monitor prioritisation score directing infrastructure expansion toward highest-burden unmonitored populations, directly supporting Africa's green industrial transition and SDGs 3.9, 7.1.2, 9, 11.6.2, and 13.
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Computer Science > Machine Learning arXiv:2604.22787 (cs) [Submitted on 5 Apr 2026] Title:Conformal PM2.5 Mapping Under Spatial Covariate Shift: Satellite-Reanalysis Fusion for Africa's Green Industrial Transition Authors:Yaw Osei Adjei (1), Davis Opoku (1), Ephraim Abotsi (1), Kwadwo Owusu Amanqua (1), Oliver Kornyo (1), Elisha Soglo-Ahianyo (1), Cephas Anertey Abbey (1) ((1) Kwame Nkrumah University of Science and Technology, Kumasi, Ghana) View a PDF of the paper titled Conformal PM2.5 Mapping Under Spatial Covariate Shift: Satellite-Reanalysis Fusion for Africa's Green Industrial Transition, by Yaw Osei Adjei (1) and Davis Opoku (1) and Ephraim Abotsi (1) and Kwadwo Owusu Amanqua (1) and Oliver Kornyo (1) and Elisha Soglo-Ahianyo (1) and Cephas Anertey Abbey (1) ((1) Kwame Nkrumah…
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