Climate Change, Dams, and Irrigation Expansion Reshape the Water–Energy–Food Nexus in the Lancang–Mekong River Basin

Effective management of transboundary river basins demands a comprehensive understanding of Water–Energy–Food (WEF) system trade-offs, particularly under growing climate and socio-economic development. In the Lancang-Mekong River Basin, rapid expansion of hydropower infrastructure and irrigated agriculture intensifies competition for limited water resources, with climate variability further complicating system dynamics. However, existing WEF models often overlook the spatial heterogeneity of irrigation demand, limiting their ability to capture water reallocations across interconnected systems. Here, we develop a distributed hydrological model that integrates reservoir operations, irrigation withdrawals, and future climate projections to quantify dynamic WEF feedbacks. A key innovation is the inclusion of a hydraulic infrastructure topology module that uses intelligent remote sensing canal detection technique to detect irrigation canals and establish river–reservoir–field connectivity. Historical simulations reveal that prioritizing hydropower generation can reduce downstream irrigation water availability by up to 14%, with dry-season impacts up to five times greater than those in the wet season. Under future scenarios (2021~2040), irrigation demand is projected to increase by 63~68%, largely driven by expansion of irrigated areas. However, projected increases in dry-season precipitation under future climate change could mitigate these trade-offs, reducing average irrigation shortfalls to 7%. Our findings highlight how WEF system interdependencies are dynamically reshaped by climate and infrastructure development, offering a new framework for evaluating adaptive resource management in transboundary river systems.