资源环境科技发展态势分析平台

The rapidly expanding urban population in intertropical African cities that lives in poverty in informal settlements poses major problems for urban health, safety and risk reduction. Such settlements often encroach on floodplains and wetlands, restricting the space available to convey and store flood waters Climate change and the expansion impermeable urban surfaces are contributing to increased magnitude and frequency of flooding. The use of green infrastructure in Africa to alleviate climate change impacts, including for sustainable urban drainage, is widely advocated. Many consider that urban agriculture can be part of such green infrastructure. However, although municipal plans often envisage removal of settlements from floodplains and do not encourage urban agriculture, efforts to bulldoze dwellings and move people from the settlements close to city centres are strongly resisted and can become politically contested. Improvements in urban drainage require participatory, multi-sectoral planning and implementation. In many African cities three different levels of action occur, frequently without considering interests at any other level: municipal drainage and floodplain clearance plans; international NGO and consultant led schemes; and community-based small scale actions for immediate relief and protection. Political allegiances cut across the three levels, showing that without holistic views across all scales of the political, social, economic and environmental aspects of these intertropical African cities, widespread use of floodplain and wetland green infrastructure for flood hazard reduction will be difficult to achieve. (C) 2016 Elsevier B.V. All rights reserved