Do you know where your catchment ends? The role of inter-basin groundwater flow and hydrogeologic transience in hydrologic processes
A fundamental concept in the hydrologic analysis of watersheds is that the water draining to the outlet of the basin originates within the basin itself. Groundwater hydrologists have long understood the role and impact of inter-basin groundwater flow, defined here as the subsurface transfer of water across topographic boundaries. This inter-basin transfer of water leaves a distinct impact on the hydrologic and solute budgets of the catchments. This talk addresses when and where topographic catchment divides correspond to groundwater divides and how this is affected by climatic variability and geologic heterogeneity. Examples from a range of climates and geologic environments (northern Chile, Great Basin of the United States, Trinidad and Tobago, and coastal Massachusetts) will highlight the relevance of inter-basin flow on hydrologic and geologic processes. Additionally, the coupling of hydrologic transience and changes in groundwater storage is also discussed, since these two processes are often difficult to separate in practice. Finally, I present recommendations and suggestions for new approaches to conceptualization of hydrogeologic watershed boundaries that take into consideration both geologic uncertainty and climate variability.
Relevant Resources
Boutt D.F., Corenthal, LC, Hynek, S.A, Munk, L.A. Extreme imbalance in the modern hydrologic budget of topographic catchments along the west slope of the Andes (21-26oS), In Preparation for Submission to WRR.
Settembrino, M., Boutt, D.F., Ingari, J, DeMars, R., and Bonarigo, A., and U. Maharaj. Groundwater Recharge to a Structurally Complex Island Aquifer System, In Preparation for Submission to Hydrogeology Journal
