Investigation of seasonal river–aquifer interactions in a tropical coastal area controlled by tidal sand ridges

摘要: Water exchanges between streams and aquifers influence the quantity quality of water in both domains. Seasonal river–aquifer interactions were investigated a tropical coastal area where tidal sand ridges control river discharge to sea. The study site is located southwestern Nicaragua, dominated by humid hydro-climatic conditions. aquifer provides rural town Ostional. Connectivity influences availability for humans downstream estuarine ecosystem. effect stream stage fluctuations on flows pressure propagation adjacent was analyzing high temporal resolution hydraulic head data applying numerical model (HYDRUS 2-D). Tidal at outlet flow direction aquifer. Surface accumulation caused these features induces recharge from river. Simulations show groundwater up 0.2 m 3 h −1 per unit length cross section. Rupture due overtopping causes sudden shift Groundwater exfiltration reached 0.08 immediately after rupture ridges. Simulated bank storage are 0.004–0.06 . These estimates also supported narrow hysteresis loops heads stage. behaves as confined, rapidly transmitting changes fluctuations. However, wave attenuated with increasing distance Therefore, we concluded that dynamic mechanism responsible observed responses. Pressure variation observations modeling useful examine should be coupled future chemical improve process understanding.