생태융합환경공학연구실

논문 초록 (Abstract)

Uncertainties in climate change and precipitation patterns reduce the predictability of groundwater and surface watermanagement. In the process of constructing groundwater flow models for existing groundwater management, large-scalewatersheds are typically the primary focus. However, in watershed environments with complex boundary conditionswhere coastal lagoons and rivers coexist, it is necessary to establish conditions distinct from those of large-scalewatersheds. This study, targeting the Songji lagoon watershed on the east coast, determined that defining boundaryconditions in small-scale basins can significantly influence the predictive stability of the model and the results ofsensitivity analysis. It quantitatively investigated the impact of boundary condition settings on the calibration andpredictive accuracy of groundwater flow models. To this end, nine scenarios were constructed by stepwise combination ofhydraulic conductivity, river, lake, and drainage conditions. Steady-state simulations using MODFLOW and parametercalibration based on PEST were performed to simulate groundwater flow for each scenario. Analysis results indicated thatthe scenario employing a stepwise calibration method, where river and lake water levels (stage) and conductance were setfirst, yielded the most effective water level prediction accuracy (R2 = 0.998 and RMSE = 0.138). This demonstrates that,in small coastal basins, a boundary-focused calibration strategy is an effective approach that reduces spatial uncertaintyand enhances model reliability compared to traditional parameter calibration.