A Review on Methods and Models of Surface Water and Groundwater Interaction with Focus on Regional Integrated Models

Surface water (SW) and groundwater (GW) are connected components of the hydrologic system with a dynamic interaction at different local or regional scales. In the first part of this study, the review of principles and general concepts of GW-SW, including the importance of interaction between these two water components is carried out. In the second part, a review of the scientific studies on the interaction of GW-SW at different spatial scales ranging from the point scale to the regional scale is presented. In each of these scales, the differences between the mechanisms of interaction with other scales are investigated and then regional modeling is specifically studied. Regional GW-SW is rarely examined in experimental field studies, which almost exclusively cover small areas. There are various modeling approaches and a few of them can be used in the regional scale but there are still uncertainties about using them. If GW-SW at the regional scale is essentially regarded as the sum of all hydrological processes in a region/catchment, then the most appropriate way to address this seems to be the use of fully coupled, physics-based models. These models attempt to acquire a holistic description of the hydrological cycle and have an ability to connect various processes over a range of spatial and temporal scales. Most authors agree that regional scale integrated modeling is constrained by data availability. Therefore, despite the attractiveness of fully complex schemes, coupling relatively simple models may still provide a suitable approach even if this means an oversimplification in the regional systems.