Construction and analysis of future water security resilience network in the middle and lower reaches of Songhua River Basin

Water security constitutes a critical determinant of regional sustainable development, particularly in ecologically sensitive zones. This study develops a water security network framework through the integration of ecosystem service assessment and Minimum Cumulative Resistance (MCR) modeling, focusing on the mid-lower Songhua River Basin—a vital ecological barrier and agricultural base in Northeast China. We systematically simulate land use evolution patterns and water resource supply-demand dynamics under three 2032 scenarios: natural development, cropland protection, and ecological conservation. The findings reveal three critical insights: (1) Land use transformations exhibit scenario-specific characteristics, with built-up areas expanding by 12.7% under natural development, forest cover declining 103.7 km² in cropland protection scenarios, and wetland systems recovering 2118 km² through ecological conservation measures. (2) Spatial heterogeneity in water resource balance manifests through persistent deficits across central plains (18.3–34.6% expansion depending on scenarios), while enhanced water yield services in mountainous areas under ecological conservation extend surplus zones 18.6% toward plains. (3) The proposed "dual-screen, four-zone, multi-corridor, multi-node" resilience framework demonstrates differential performance: natural development and cropland protection scenarios reduce water source areas by 21.3–28.9% with intensified corridor fragmentation, whereas ecological conservation optimizes land use configuration to expand source areas 11.2% and establish new Hegang-Fujin ecological corridors. This research confirms that spatial optimization guided by ecosystem service flows effectively enhances regional water resource carrying capacity, while the developed multi-scenario simulation methodology provides a scientific decision-making framework for optimizing water security patterns in Northeast China's grain-producing regions, balancing ecological integrity with agricultural productivity.