Surface and Subsurface Runoff Generation Processes in a Poorly Gauged Tropical Coastal Catchment: A Study from Nicaragua

Hydrological research in humid tropics is particularly challenging because of highly variable hydrological conditions and high socio-economic stresses caused by rapid population increase, as is the case of Nicaragua. The objective of this research is to understand the surface and subsurface runoff generation processes in a poorly gauged coastal catchment in Nicaragua under variable humid tropical conditions. Specifically, it focuses on identifying geomorphological and hydro-climatic controls on catchment response at different spatio-temporal scales and studies the link between hydrological processes and ecosystem conditions (i.e. mangrove forest). Catchment topography, geology and land use control surface and subsurface runoff generation. Spatio-temporal variability of precipitation affects availability of water resources, determines sources of surface runoff generation and induces changes in groundwater-surface interactions. Sustainable water resources management must prevent drastic alterations in catchment structural characteristics defined by forested areas and tidal sand ridges. Catchment response to hydro-climatic and geomorphologic controls supports the mangrove ecosystem freshwater needs. The outcome of this work is a contribution to the hydrological knowledge of poorly gauged catchment in humid tropics. It also provides scientific hydrological insights to support water resources management on the South Pacific coast of Nicaragua.