Studies on key issues in the ecological recovery of seasonal rivers

Liu Xiaobo; Dong Fei; Wang Weihao; Zhang Jiannan; Huang Aiping; Ma Bing; Si Yuan

doi:10.3969/j.issn.1000-1123.2024.21.006

Abstract：Over 50％ of rivers worldwide are seasonal,and this proportion continues to rise due to climate change,extreme weather events,and human activities. In 2023,the Ministry of Water Resources released the "Mother River Recovery Action River and Lake List(2022-2025)",which includes 79 rivers,of which 52 have been dried up. Compared to ordinary rivers,seasonal rivers exhibit unique ecological-hydrological relationships due to their alternating dry and wet hydrological rhythms. Historically,research has primarily focused on perennial rivers,often overlooking seasonal rivers,and findings from perennial rivers are not directly applicable to seasonal ones. Based on a comprehensive literature review,this study examines seasonal rivers in four aspects:their definitions and basic characteristics,ecological and hydrological response relationships,health assessments,and adaptive ecological flow regulation. The study reveals that current research on seasonal rivers lacks a unified definition,in-depth exploration of inherent hydrological conditions and ecosystem processes,consistent methodologies for identifying indicator species,widely applicable ecological health benchmarks,and optimization methods for determining suitable water volume thresholds. In the absence of foundational theories,clarifying the basic concepts,scientifically identifying ecological-hydrological processes,establishing ecological health benchmarks,and developing optimized water threshold regulation methods are essential for addressing the critical issues in the ecological recovery of seasonal rivers. These areas also represent urgent directions for future research.