Hydrological Drivers on Carbon Storage and Habitat Quality Under Land‐Use Change

ABSTRACT

Rapid urbanisation and resource exploitation have reshaped land‐use patterns in Bohai Bay (BB), altered hydrological processes, and placed increasing pressure on ecological functions and restoration planning. Most existing studies have primarily relied on static assessments or single ecosystem services, whereas scenario‐based evaluations of coastal carbon storage (CS) and habitat quality (HQ), together with their hydrological drivers, remain limited. This study assessed CS and HQ in BB from 2000 to 2020, analysed their dominant hydrological drivers, and projected their trajectories to 2040 under three land‐use scenarios: natural development (Q1), ecological protection (Q2), and urban development (Q3). Between 2000 and 2020, CS decreased by 58.00 million tons, while mean HQ declined from 0.50 to 0.48, primarily due to the expansion of impervious and the reduction of cropland and grassland. Compared to 2020, Q2 was associated with the least deterioration in CS (2.72%) and HQ (3.45%), indicating that coordinated protection and restoration can partially buffer development‐driven losses. Shapley additive explanations (SHAP) analysis showed that digital elevation model (DEM), distance to rivers, and plant available water content (PAWC) were the dominant drivers of both CS and HQ, jointly contributing more than 80% to their spatial variation. Groundwater storage provided an additional positive effect, indicating that groundwater support is an important foundation for maintaining coastal ecological functions. Integrated CS‐HQ zoning revealed a distinct pattern of ‘higher in the west and north, lower in the east and south’, broadly corresponding to areas with higher elevation, lower disturbance, and stronger water‐retention capacity. Under Q2, very important and important zones accounted for the largest combined proportion (69.22%) among the three scenarios. These findings indicate that the ecological consequences of land‐use change in coastal regions depend not only on the amount of ecological land retained but also on how land‐use trajectories modify water redistribution, soil‐moisture availability, groundwater support, and hydrological connectivity.