Impacts of future climate and landuse on water resources in Espírito Santo, Brazil

Abstract

Increasing temperature and precipitation changes are expected to bring fundamental changes to the country of Brazil as predicted by Global Climate Models (GCMs) (IPCC, 2007). Potential effects of climate change in Brazil suggest changes of 4-4.5°C in surface temperature as a result of increased CO2 concentrations. In plantation states such as Minas Gerais and Espírito Santo, a much drier climate is predicted to be a result of global warming and/or reduced water vapor transport from Amazonia. However, the responses of regional and local streamflow to these changes are still not well quantified, particularly in data-sparse regions and where hydrologic studies have not been thoroughly explored, making it difficult for water managers to plan for uncertainties associated with a changing climate. The overarching goal of this dissertation is to address a set of management issues related to local climatology and land use change and to present the results on a platform that helps improve understanding and communication between water managers, stakeholders and decision makers. The specific science questions that this dissertation will answer are: how does the long-term climate affect water availability in the region, how do changes in weather and landuse alter water flow and affect the mobilization of sediments, and how can these results be described in a way that helps water managers make decisions? More specifically, this dissertation will study the linkages between streamflow, precipitation and temperature through the use of a macroscale land surface hydrology model for the entire State of Espírito Santo. I also use a sensitivity-based approach to estimate future streamflow in the region. At a finer resolution, I apply a hydrology-soil-vegetation model to simulate effects of increased eucalyptus and agriculture on the Jucu and Santa Maria watersheds and investigate how changes in land use and water management issues will impact sediment flow. I also describe the integration of the results into a decision support system or dynamic information framework (DIF) that can be easily transferable to tropical regions and other areas with similar climatology to Espírito Santo. This study will be particularly useful in helping water managers assess changes in land surface water availability due to climate and land cover change and to plan for ensuing uncertainties.