A team of economists from UC Berkeley, the World Bank, the University of Wisconsin, and Gaston Berger University reported on Mar. 5 that irrigation infrastructure in the Senegal River Valley has led to significant increases in agricultural cultivation and reduced vulnerability to temperature shocks. Their findings were published in the February issue of the Journal of Development Economics.
The study is important as sub-Saharan Africa faces rapid population growth and a changing climate, with food systems largely dependent on rain-fed agriculture. Improving crop yields is seen as a critical priority for food security in the region.
The researchers analyzed more than 3,000 Landsat satellite images from 1985 to 2019 and combined this data with records from 871 irrigation projects completed between 1988 and 2019. They found that cultivation rates increased substantially after irrigation projects were completed, remaining nearly seven times higher for two decades. The benefits persisted even after twenty years, especially during dry seasons when cultivation rates exceeded pre-irrigation levels by over fifty percentage points. Vegetation greenness also improved consistently following project completion.
Despite these gains, many farms used irrigated land only intermittently or at below-average rates. As of 2019, about a quarter of irrigated land remained unused due to water access issues or financial constraints such as an inability to afford pumps needed for drawing water from canals. “It was important for us to evaluate how these large-scale projects perform on the ground in Africa, and we were pleasantly surprised by the persistence and improvement in land-use rates over time,” said Marco Gonzalez-Navarro, George Pardee Jr. Professor of International Sustainable Development at UC Berkeley’s Department of Agricultural & Resource Economics.
Gonzalez-Navarro said maintaining existing infrastructure is crucial for addressing water access problems and emphasized expanding financial services like lines of credit to improve land utilization.
Rausser College of Natural Resources aims to analyze natural and human systems through biological, ecological, economic and social science lenses while developing inclusive strategies to safeguard Earth’s resources and foster sustainability, according to the official website. The college operates in environmental sciences fields such as resource management, ecology and nutritional studies according to its official website. It also supports equitable access to resources through community programs while advancing research into climate solutions and biodiversity protection according to its official website.
