Assessing surface water-groundwater interactions in the seasonal lake-wetland system of Lake Poyang

洪泛系统具有复杂动态的水文环境，在季节性洪水脉冲影响下，地表-地下水交互转化对洪泛区水循环和生态环境保护等方面具有重要意义.本文采用野外试验、统计分析和达西定律等研究方法，开展了鄱阳湖洪泛区碟形湖湿地系统（河流-洲滩湿地-碟形湖）地表-地下水文学特征、相互作用和交换通量研究.数据资料显示，在地形地貌影响下，研究区洲滩地下水位明显低于碟形湖水位，但总体上略高于周边河流水位，统计结果进一步表明，在控制洪泛湿地的地下水动态方面，河流水文情势变化对地下水的影响作用要强于碟形湖水文变化.就河流-地下水转化关系而言，研究区湿地系统的地下水与周边河流水体之间存在动态转化关系，地下水对河流的补给通量以及河流对地下水的补给通量分别约为0.4和0.2 m/d.就湖泊-地下水转化关系而言，碟形湖一般来说补给周边滩地的地下水系统，但两者之间的交换通量基本小于0.1 m/d.在年尺度上，研究区地表-地下水之间的累积交换通量变化约介于7.5~48.2 m/a，其中河流-地下水的累积交换通量约是碟形湖-地下水的4~7倍，且秋、冬季的累积交换通量要明显大于春、夏季.本文研究结果可为洪泛区河湖系统的水资源联合管理、水环境整治和生态环境保护等方面提供科学支撑.;Floodplain systems are affected by seasonal shifts between dry and wet cycles, therefore cause marked changes in surface water groundwater flow regimes. Surface water-groundwater interactions rarely investigated large floodplain systems, where few data obtained or monitored. This study used field observations, statistical analysis, Darcy's law approach to explore dynamics, interactions, the associated fluxes a geographically complex river-floodplain wetland-seasonal lake system (Lake Poyang, China). Results indicate that wetland is more sensitive variations river levels than lakes. Groundwater generally lower those of lakes, but slightly higher surrounding levels, due influence topography. Statistical analysis further reveals hydrology tends play significant role controlling relative Generally, shows gaining conditions (i.e., recharges river) occasionally losing groundwater) with variable Darcy up 0.4 0.2 m/d, respectively, while lakes likely show (<0.1 m/d). Additionally, annual accumulated flux rates range from 7.5 m/a 48.2 for system. The rate river-groundwater around four seven times lake-groundwater interactions. Also, autumn winter spring summer on scale. findings this have important implications improving understanding resources joint management, quality, eco-environmental protection both lake.