18 Jun 2024 --- Due to grave concerns about the effects of groundwater degradation on food security, the International Food Policy Research Institute (IFPRI) conducted a study to identify viable solutions. Groundwater systems in China, India, the US and Iran are considerably depleted, while water resources south of the Sahara, Africa, are underused. We caught up with two of the study’s authors, who provided perspectives on the complex nature of the issue.
“Our analysis employs a simulation modeling approach to compare various scenarios, which offers several advantages over other modeling tools. By leveraging this method, we can assess the effects of eliminating unsustainable groundwater use on key indicators of food security and analyze a range of policy investments designed to mitigate negative food security impacts resulting from sustainable groundwater management,” Vartika Singh, senior research analyst IFPRI New Delhi and co-author of the study, tells Nutrition Insight.
“The simulation model’s capacity to integrate diverse data sources, model complex nonlinear relationships and explore hypothetical scenarios makes it a superior approach for generating robust, reliable forecasts.”
The study, published in Nature Sustainability, reaffirms the world’s growing dependence on depleted groundwater systems. While efforts to slow down this depletion must be accelerated, the researchers note that such efforts could lead to significant food security impacts.
Water food modeling
The researchers find that ending groundwater depletion would lead to sharp declines in food production, mainly rice and wheat, pushing up international rice prices by 7.4% and wheat by 6.7%. Higher food prices can push the number of people at risk of hunger to 24 million, specifically in low and middle-income countries.
A quarter of the world’s river basins are overexploited, including key breadbasket areas in India, Pakistan, China, Iran, the US and Egypt. Climate change pushes more farmers to rely on groundwater as rainfed farming is less viable and surface flows are shrinking.
Singh notes: “Traditionally, water modeling is undertaken on its own without considering water uses, such as food and agricultural production or food modeling is also undertaken on its own, without considering water as a key input.”
“This is suboptimal because more than 80% of human water withdrawals are consumed in agricultural production systems. The combined or joined up water food modeling framework used here integrates biophysical, economic and social systems to analyze agricultural policy and climate change impacts.”
“Using global datasets of historical trends and projections for the future, these models allow us to determine the impacts of key policy changes on water use and associated impacts for agricultural production, food prices and food security. Without joining these models, we could not assess how changes in water allocation and water policy affect global food prices or how such policies change the number of people at risk of hunger,” Singh explains.
The study used IFPRI’s International Model for Policy Analysis of Agricultural Commodities and Trade to simulate the impacts of ending groundwater overdrafts and the effects of measures to counteract negative food security impacts associated with halting groundwater depletion.
IFPRI’s lead modeler on the study, Nicostrato Perez, notes that “no single intervention modeled could fully counteract the negative food security impacts from arresting groundwater depletion. However, investments in agricultural research and development would increase yields of water-constrained irrigated crops through better seed technologies and agronomic practices, potentially lowering global wheat prices by more than 3%.”
South of the Sahara
The IFPR calls for immediate intervention for sustainable groundwater management to secure food sources.
According to the researchers, the region south of the Sahara holds significant potential for food production due to extensive water and land resources and a young population mainly engaged in agri-food systems. However, the region’s growing dependence on food imports vastly limits its potential, while agricultural water management is not taken seriously at higher political levels.
National support is needed to improve water management in rainfed systems and sustainable irrigation development. Roughly 95% of all crops are grown on rainfed lands. While the region has ample water resources, the researchers estimate that less than 10-20% can be converted to irrigation.
Irrigation development has to be handled carefully to avoid some of the pitfalls of Asia, where there is extensive groundwater depletion and water pollution. The region should support farmers in adopting water and soil fertility management that better uses variable rainfall. These efforts should include rainwater harvesting schemes, minimum tillage and mulching to improve soil water storage.
Karen Villholth, a co-author of the study from Water Cycle Innovation, emphasizes the need to support smallholder farmers to sustainably develop groundwater resources for irrigated agriculture.
“Groundwater in this region still holds great potential for securing food production, nutrition and livelihoods for millions of poor people under climate change, but we need to proactively address the risks of overexploitation of the resource,” Villholth says.
Supply-side measures
Policy measures and investments are needed to sustain food production levels in groundwater-dependent regions like India and China because arresting groundwater depletion will negatively affect food prices and agricultural production. A transdisciplinary approach combining regulatory, financial, technological and awareness measures is needed to achieve sustainable groundwater management.
“We cannot ignore groundwater overdraft any longer. The essentiality of groundwater to our food systems has never been greater than today and will continue to increase going forward. If we don’t act today, failing groundwater systems will dramatically increase hunger and undernutrition,” Claudia Ringler, director, Natural Resources and Resilience Unit, IFPRI, tells us.
“However, we cannot improve the sustainability of our groundwater systems without accompanying policy measures to mitigate food price and food insecurity impacts. Carefully crafted policy analysis and interventions need to be designed for the areas where groundwater systems are most degraded such as parts of China, India, the US and Iran.”
According to Ringler, IFPR’s policy scenarios show that improvements can be made through supply-side measures such as investments in agricultural R&D and water management and changing diets. “We have most of the technologies and institutions at our fingertips but also need to be ready to develop new tools,” she urges.
Cost of healthy diets
Singh notes that animal-source foods, vegetables and fruits, which constitute a healthy diet, are either water-intensive or difficult to grow without good water control. Animals, in particular, need access to water at all times and consume large quantities of water through animal feed, including cereals.
“There is clearly a tradeoff between improving the sustainability of our water resources and lowering the cost of healthy diets.”
“Our scenario analysis suggests that more sustainable groundwater use without accompanying policy measures to mitigate food price increases will make it even more difficult to produce healthy diets, but if we can double-down on agricultural research investments, and better incentives and support to rainfed and irrigation systems then we can improve the sustainability of groundwater systems without excessive food price increases,” she explains.
If no action is undertaken, a “peak” groundwater situation will be reached in the coming decades, which some countries have already hit having no further resources to extract. “At these extreme levels of depletion, we expect migration out of rural areas and much sharper increases in food prices,” Singh concludes.
By Inga de Jong
