Investigation of river-aquifer interactions in sloping aquifers

Groundwater is a very important water resource, considering its amount on earth and its intended use. While a significant portion of drinking water comes from groundwater, groundwater is also used for various purposes such as irrigation in agriculture, use in production processes in industry, support of underground ecosystems, and geothermal energy production. In addition, correct and sustainable management of groundwater is of great importance in maintaining ecological balance and leaving healthy water resources to future generations. Determining the hydrodynamic behavior of groundwater is of great importance in order to benefit from groundwater in the most efficient way, as it directly affects the hydrological behavior of the region in which it is located, as well as the need for use. There are many factors that affect the hydrodynamic behavior of groundwater. Groundwater flow is directly affected by both the aquifer properties it is in and the other water resources it interacts with. For this reason, it is necessary to investigate groundwater flow in different aquifer properties and understand the interaction of this flow with other sources. In this study, the effect of aquifer slope on groundwater distribution, particle movements and hyporheic flow rate between the river and aquifer in a river-aquifer system was investigated. Visual MODFLOW software was used to conduct this analysis. Models were constructed for two different cases: (i) river-aquifer model in bottomland river valleys and (ii) mountain region river-aquifer model. Groundwater dynamics and surface water-groundwater interactions were examined considering different slope degrees. Areas susceptible to pollution were determined through particle monitoring analyses, and the water level was selected as a sloping water surface profile in accordance with its natural flow. The resulting numerical models were used to evaluate the effects of aquifer slope on groundwater hydrodynamics and surface water groundwater interaction and the pollution threat.