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.
Table of Contents
Chapter 1 Introduction
Chapter 2 Integrating geophysical, tracer and hydrochemical data to conceptualize groundwater flow
Chapter 3 Hydrological and geomorphological controls on the water balance components of a mangrove forest during the dry season
Chapter 4 Characterizing the climatic water balance dynamics and different runoff components in a poorly gauged tropical forested catchment
Chapter 5 Lessons learned from catchment scale tracer tests experiments during rainfall-runoff events in a tropical environment using natural DNA from total bacteria and qPCR
Chapter 6 Investigation of seasonal river–aquifer interactions in a tropical coastal area controlled by tidal sand ridges
Chapter 7 Conclusions and recommendations for future research
Ms Heyddy Calderon is from Nicaragua. She received her BSc. in Chemical Engineering in 2001 from the National University of Engineering in Nicaragua, her thesis was related to experimental determination of infiltration parameters in mine tailings. After completion of her BSc, Ms Calderon received a scholarship from the Canadian International Cooperation Agency (CIDA) to pursue master studies. She received her MSc in Hydrogeology from the University of Calgary in 2004 with a thesis on regional groundwater flow modeling of the most important aquifer of Nicaragua. Starting in 2004, Ms Calderon joined the Nicaraguan Aquatic Resources Research Center at the National Autonomous University of Nicaragua (CIRA-UNAN), where she is now a researcher and adjoined lecturer in hydrology. From 2004 to 2010 Ms Calderon worked in many research projects in Nicaragua related to water resources quality and quantity, groundwater modeling, hydrochemistry and stable water isotope tracers in crater lakes, and water resources management. In 2009 she started her PhD under the guidance of Prof. dr. Stefan Uhlenbrook with the financial support of Nuffic. In 2010 she received a research grant from the International Foundation for Science (IFS). In 2011 she received a 3 year grant from Faculty for the Future Foundation to conduct her PhD. Ms Calderon has several publications in peer-reviewed journals, not all of them relate to the content of this thesis. She is also President of the National Committee of IUGG for Nicaragua and National Correspondent for the International Association of Hydrological Sciences (IAHS) for Nicaragua.