Wetland reclamation has long been regarded as a strategy to meet growing food demand, given the favorable soil and water conditions of wetlands. However, the trade-off between potentially greater crop production and the ecological cost of lost wetlands—especially involving flood regulation—has not been well understood.
Now, a research team led by Prof. DONG Jinwei from the Institute of Geographic Sciences and Natural Resources Research of the Chinese Academy of Sciences, together with international collaborators, has mapped global croplands reclaimed from wetlands from 2000 to 2022 and evaluated their crop production performance and flood exposure risk.
The study, which was published in Nature Sustainability , found that wetland reclamation provided limited agricultural gains, with no clear yield advantage over existing croplands and only a marginal contribution to global crop production. Nearly half of wetland-reclaimed croplands produced lower yields than existing croplands, especially those used for upland crop cultivation. Globally, these croplands accounted for only 0.1% of total crop production, with their contribution remaining below 1% in 79% of subnational regions.
Meanwhile, a substantial proportion of wetland-reclaimed croplands faced disproportionately high flood exposure. Globally, 52% of these croplands (21,001 km²) were located in regions susceptible to significant flood hazards, with an average flood-exposure probability 23 times that of croplands overall. Moreover, wetland reclamation has increasingly expanded into flood-prone areas, further increasing potential exposure to flood hazards.
The researchers also discovered that 60% of wetland-reclaimed croplands faced “lose–lose” outcomes, in which limited agricultural gains coincided with high flood exposure. These hotspots were concentrated in East and South Asia, North America, eastern South America, and Oceania and were particularly prevalent in food-importing or low-income countries. China, the United States, and India collectively accounted for 34% of these tradeoff hotspots.
The findings provide the first global-scale evidence of the trade-offs between agricultural gains and ecological costs associated with wetland reclamation. According to the researchers, effective interventions are needed to ensure that agricultural expansion does not compromise critical wetland ecosystem services and long-term sustainability.
Nature Sustainability
Limited agricultural gains but high flood risk from global wetland reclamation
9-Oct-2026