Characterizing the climatic water balance dynamics and different runoff components in a poorly gauged tropical forested catchment,Nicaragua |
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| Authors: | Heyddy Calderon Stefan Uhlenbrook |
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| Institution: | 1. Department of Water Science and Engineering, UNESCO-IHE, Delft, The Netherlands;2. Nicaraguan Aquatic Resources Research Center at the National Autonomous University of Nicaragua (CIRA-UNAN), Managua, Nicaraguaheyddy.calderon@cira-unan.edu.ni;4. Section of Water Resources, Delft University of Technology, Delft, The Netherlands |
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| Abstract: | ABSTRACTThe water balance dynamics and runoff components of a tropical forested catchment (46?km2) on the southwestern Pacific coast of Nicaragua were studied combining hydrometry, geological characterization and hydrochemical and isotopic tracers (three-component hydrograph separation). The climatic water balance was estimated for 2010/11, 2011/12 and 2012/13 with net values of 811?mm year-1, 782?mm year-1 and –447?mm year-1, respectively. Runoff components were studied at different spatial and temporal scales, demonstrating that different sources and temporal contributions are controlled by dominant landscape elements and antecedent rainfall. In forested sub-catchments, permeable soils, stratigraphy and steep slopes favour subsurface stormflow generation contributing 50% and 53% to total discharge. At catchment scale, landscape elements such as smooth slopes, wide valleys, deeper soils and water table allow groundwater recharge during rainfall events. Groundwater dominates the hydrograph (50% of total discharge) under dry prior conditions. However, low soil infiltration capacity generates a larger surface runoff component (42%) under wet prior conditions which dominates total discharge. Our results show that forested areas are important to reduce surface runoff and thus soil degradation, which is relevant for the design of water management plans. Editor D. Koutsoyiannis Associate editor D. Gerten |
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| Keywords: | Tropical hydrology runoff generation groundwater flow poorly gauged catchment forested catchment Nicaragua |
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