Significance of Base Flow in Surface Water–Groundwater Interaction: a Review

Studies on the interaction of surface water with groundwater have gradually gained the attention of hydrologists in recent decades as they play a vital role in the hydrological cycle influencing hydrological and water resources processes. The complexity exhibited in the interaction due to the wide range of heterogeneity in the hydrological and hydrogeological properties of catchment makes it challenging to transfer the results of surface water groundwater (SW-GW) interaction from a point scale to a larger scale. Defining the relationship between groundwater and surface water becomes essential to refine the existing surface water groundwater models to aid the hydrologists in adapting better water management policies and decisions in the future. Before any detailed hydrological modelling to study and simulate the surface water groundwater interaction on a regional or point scale, a thorough understanding of the base flow’s contribution to the streamflow becomes indispensable. A brief review of the existing literature on the role of baseflow in SW-GW interaction and available techniques for characterizing the interaction is summarized here in the context of hydrological and geological conditions and data variability. This paper mainly focuses on three methods of baseflow analysis: Flow duration curve approach, baseflow separation and recession analysis. Identifying the best suitable method for its estimation from a wide range of available methods becomes a challenge as baseflow is a component of the hydrological cycle that is not available for measurement. Comparative study of various baseflow analysis methods, on the other hand, might help us assess the overall accuracy.