The Recession of Spring Hydrographs, Focused on Karst Aquifers

This study constitutes a review of spring hydrograph recession analysis, and it is focused on karst aquifers. The different literature models have been separated into empirical and physically-based models; in the last ones, only analytical models have been considered, as they provide the discharge equation during recession. Under constant geometrical and hydraulic aquifer characteristics, it has been found that the “exponential form” appears to be the most recurrent theoretical type, at least during the long-term flow recession. During this stage, any deviation from the exponential form, may suggest hydraulic anisotropy of actual aquifers, as well as aquifer geometry has a fundamental role in controlling the shape of spring hydrographs. The hydrodynamics of karst aquifer under recession has been described, associating any segment of the hydrograph to a specific hydrologic condition of the aquifer, and also to a specific physical law which control the water flow.