Satellite observations of surface water dynamics and channel morphology in the Pearl River

 

 

In recent decades, global watershed surface processes have undergone significant alterations due to a complex interplay of factors, including global warming and human-induced stressors. Changes in river morphology serve as crucial indicators of the long-term dynamic evolution of rivers and their associated environmental impacts.

 

Existing studies have predominantly focused on changes in river morphology, with limited attention given to regions exhibiting lateral stability. This study introduces a novel river morphology change index and applies it to overlay analysis of river morphology in the Pearl River basin spanning several decades. By quantifying areas of stable, expanding, and diminishing river morphology, the study unveils the patterns of morphological change in the region. The findings reveal a trend of increasing stability in the Pearl River's morphology, extending from its source to its mouth, driven by progressive human intervention. While such interventions enhance river stability in the short term, the hardening of channels may reduce their effectiveness in managing floods during extreme climatic events (e.g., heavy rainfall), potentially exacerbating flood risks.

 

Through a case study of the Pearl River Basin, this paper underscores the vital importance of retaining wide river corridors and restoring natural riverbed morphology configurations in maintaining natural geomorphology. It further proposes recommendations for optimizing river management and disaster prevention and mitigation.