ada-yl2425/Compounding-climate-isolation-across-Africa-s-road-network

# Compounding Climate Isolation Across Africa's Road Network This repository supports the paper **"Compounding climate isolation across Africa's road network"**. The study examines how climate-driven degradation of unpaved roads propagates through African road networks, amplifies travel-time losses, and changes access to healthcare and cities. ## Study overview African road systems are highly exposed to climate stress because a large share of the network is unpaved. The paper defines **compounding climate isolation** as the process by which widespread weather-driven deterioration on unpaved roads is amplified by network structure and translated into unequal accessibility losses for people and places with limited routing alternatives. The analysis combines: - A continent-scale road network for 49 African countries, including paved and unpaved road-surface classification. - Climate stress indicators from precipitation and soil moisture data. - Population, health-facility, administrative-boundary, terrain and populated place datasets. - Weighted road-network models that compare normal and extreme-weather travel conditions. ## Analytical workflow The paper uses a coupled workflow: 1. Estimate climate-conditioned speed and passability for unpaved road segments. 2. Build normal and extreme-weather weighted road-network graphs. 3. Measure travel-time change and network-efficiency loss across international, national and city-scale networks. 4. Evaluate healthcare accessibility using nearest-facility travel time, coverage thresholds and within-country inequality metrics. 5. Identify adaptation bottlenecks by combining climate vulnerability with network importance, then test targeted paving scenarios. ## Key findings - Extreme weather reduces mean road speed by about 10%, but increases travel times by 36.3% across connected international city pairs and 41.0% across within-country city pairs. - Network structure amplifies direct road-level degradation by roughly 3.7- …