Massive road and rail projects could be Africa’s greatest environmental challenge
▻https://theconversation.com/massive-road-and-rail-projects-could-be-africas-greatest-environmen
If completed in their entirety, the corridors will total over 53,000 kilometres in length, crisscrossing the African continent. Some individual corridors are over 4,000 kilometres long.
Will these corridors generate key social and economic benefits, or will they cause great environmental harm? To address this question, we looked at three factors, focusing on a 50-kilometre-wide band laid over the top of each corridor.
First, we assessed the “natural values” of each corridor, by combining data on its biodiversity, endangered species, critical habitats for wildlife, and the carbon storage and climate-regulating benefits of its native vegetation.
Second, we mapped human populations near each corridor, using satellite data to detect nightlights from human settlements (to avoid lands that were simply being burned, we included only places with “persistent” nightlights). We then combined the natural-value and population data to generate a conservation-value score for each corridor, reasoning that sparsely populated areas with high natural values have the greatest overall conservation value.
Finally, we estimated the potential for new roads or railroads to increase food production. Areas that scored highly had soils and climates suitable for farming but large yield gaps, were within several hours’ drive of a city or port, and were projected to see large future increases in food demand.
