Ecohydrological Modeling and Scenario Impact Assessment in Rural Rio de Janeiro

Understanding hydrological process dynamics is a crucial requirement for river basin management and environmental planning. Possible future climate changes raise questions about their impact on human livelihoods, which strongly depend on water availability and quality, soil fertility, and other ecosystem services. This chapter presents a physically based, spatially distributed ecohydrological model that was applied within three meso- to macroscale watersheds in the hinterland of Rio de Janeiro. While an increasing population and a fast-growing industrial sector create a high demand for water supply, the study region faces serious problems of forest fragmentation, overexploitation, and soil degradation, which create increasing pressures on water resources. This situation is further intensified by the climate conditions with distinct wet and dry periods that can cause floods and landslides in the rainy season and water shortages during dry periods, especially affecting the agricultural and domestic supply sectors. Recent water shortages raise questions how future climate changes will impact the hydrological dynamics and if river basin management needs to take appropriate counteractions. The results show that the developed models allow simulating hydrological processes at a high spatiotemporal resolution. Given the fact that their process representation is physically based, these models can help answer questions about hydrological dynamics under changing environmental conditions.