26. Knowledge Assessment on Climate Change and Urban and Peri-urban Agriculture in Dakar, Senegal

This chapter examines the biophysical, socio-economic, environmental and human health dimensions of urban and peri-urban agriculture in Dakar city (Senegal) and identifies structural threats to urban agriculture, including those already induced, or have the potential to be induced, by climate change. Urban agriculture, which provides an important source of fresh vegetables and other fresh products for the city is being increasingly marginalised due to a combination of factors including diminished soil and water quality, increasing temperatures and reduced rainfall, urban encroachment and pollution from industrial sources. A lack of clearly defined roles and responsibilities between local and national governments hinders the ability to protect urban agricultural land from urban encroachment and a lack of access to credit by farmers adds to their ability to cope with the multitude of other pressures. Dakar is bordered by the Atlantic Ocean on the northern, western and southern sides with no room for expansion, including any potential expansion of urban agriculture. Ground water in this urban zone is steadily deteriorating due to nitrate pollution of shallow groundwater in soil aquifers combined with increasing saltwater intrusion. Recycling of untreated wastewater for use in urban agriculture, a common practice in Dakar and other cities in Africa has increased the incidence of food-borne contamination. For example, recent microbial sampling of water showed a very high proportion of sites (87 %) with contamination levels above World Health Organisation standards for irrigation without restriction. Solid and liquid waste management is one of the biggest problems Dakar is facing as are many other cities of developing countries. Climate change will further impact urban agriculture. Shortening of cold periods favorable to vegetable cropping in semi-arid areas, increasingly hotter summers, more frequent flooding and drought periods, and higher incidence of pest and diseases are among the potential impacts of climate change. Coastal zones of the city are particularly under threat due to the rising sea level with negative consequences of coastal erosion and salt-water intrusion in lowlands. Projection models show a strong warming trend in the region. Conversely, there is no agreed trend of rainfall prediction at present but deficits are anticipated by general circulation models. Adaptation strategies of farmers include lifting the ground surface with landfill in order to better cope with flooding (specifically for flower cultivation), development of soil and soilless micro gardens in boxes, crop diversification and use of hybrid seeds. Urban agriculture has the potential to contribute to climate change adaptation through reinforcement of urban agricultural systems resilience, water recycling, buffering thermal and hydraulic shocks, providing safe and nutritious food, recycling wastes and conserving biodiversity. Despite its huge potential to reduce poverty and make the city more resilient to impacts from climate change, urban agriculture is not high on the urban planning agenda. Recommendations are formulated towards taking into consideration urban agriculture in national and local planning, strengthening capacities of stakeholders and awareness at all levels of society on the economic, social and environmental role of urban agriculture can play in sustainable development and greening of the city and its economy.