Changes in Lake Wetland Inundation and Shrinkage Within the Framework of Rivers–Lake Interactions

ABSTRACT The Dongting Lake (DTL) area constitutes a naturally interconnected lake wetland. Alterations in river–lake relationships are poised to profoundly modify the ecological condition of the lake region. This study aims to investigate the hydrological interactions and ecological response mechanisms involving the Yangtze River, the Four Rivers within the DTL basin (DFR), and DTL itself during extreme hydrological events. Amidst the trajectory of wetland contraction, the impact of shifts in river–lake relationships on the wetland's state remains unclear. Thus, we employ cross‐wavelet transformation and the multifractal method to establish a framework for the hydrological interactions between rivers and the lake. Through this framework, we analyze the varying progression of hydrological relationships within the river–lake system and their corresponding responses. The findings reveal that instances of low‐water events in DTL predominantly manifest during winter and spring. These low‐water events exhibit a propensity to occur frequently and irregularly, except during July–August in most statistical years, coinciding with the Yangtze River's flood regulation period. Additionally, the DFR–DTL system exhibits a broader range of significant resonance periods and indicates a strong and consistent correlation between the hydrological events in the river and lake systems. The DFR–DTL system serves as the principal impetus behind the ecological evolution of DTL. Simultaneously, alterations in the inundation status across DTL regions display an ascending trend from west to east. The outcomes of this study provide a scientific foundation for elucidating the evolutionary dynamics of river–lake connectivity and informing effective ecological restoration strategies within the DTL region.