The International Water Management Institute (IWMI) has conducted a global assessment of the feasibility of an innovative solution that addresses widespread water and food insecurity under climate change. The Underground Transfer of Floods for Irrigation (UTFI) approach is based on capturing and storing seasonal floodwater underground, while providing a secure source of water for irrigation in subsequent dry periods and droughts. The report identifies areas with high suitability for implementing the UTFI approach, using a global spatial analysis conducted at a resolution of 0.5o (~ 55 km at the equator). The study uses spatial datasets related to flood and drought risk, water supply and demand, and natural underground water storage conditions to assess global UTFI suitability. The results show that about 11% of global land area (1,580 million hectares), which is home to half the world’s population (3.8 billion) and 40% of all croplands (622 million hectares), has high potential for implementing the UTFI approach. Areas with high UTFI potential include 197 cities, each having a population greater than 0.5 million people. This suggests potential co-benefits of flood risk mitigation in these cities and agricultural production in upstream peri-urban areas. Furthermore, among the river basins with high UTFI suitability, the Awash in Ethiopia, Ramganga in India (one of the major tributaries of the Ganges River Basin) and Chao Phraya in Thailand were selected for an economic analysis in this study. Results indicated high economic viability with internal rate of return values ranging from 20% to 122%. The overall results from this study are intended to provide a first step towards identifying focus areas (at the river basin or country scale), where more detailed investigations could ascertain the technical and economic feasibility of UTFI with greater confidence.
An article recently published on the IWMI website provides further details on this study and also includes a video about the UTFI approach.
Schematic showing the functioning of the UTFI approach in the wet and dry seasons.
