Hydrological responses to climate changes in a headwater watershed

Lívia Alves Alvarenga,Luz Adriana Cuartas,Carlos Rogério De Mello,Sin Chan Chou,Alberto Colombo

doi:10.1590/1413-70542016406027716

Abstract

ABSTRACT Climate change impacts need to be considered in water resource planning. This work aims to study of the impacts climate change on Lavrinha headwater watershed, located in the Mantiqueira Range, southeastern Brazil. The impacts from climate change (RCP 8.5 scenario) in the Lavrinha watershed runoff were analyzed based on the "Distributed Hydrology Soil Vegetation Model" (DHSVM), forced with the climate simulated for this future climate change scenario. These simulations, in turn, were generated by the Eta regional climate model coupled to Global Climate Model (GCM) HadGEM2-ES for the 2011-2040, 2041-2070 and 2071-2099 periods. The results of this study showed that the runoff is very sensitive to rising temperatures and reduced precipitation, both projected for the RCP 8.5 scenario. The hydrological simulation projected a reduction in the monthly streamflow between 20 and 77% over the twenty-first century (2011-2099), corresponding to drastic reductions in the runoff behavior and consequently in the water production capacity of the region.

Highlights

Low water availability can cause catastrophic economic, social and environmental problems
Climate projections of the fifth report of the Intergovernmental Panel on Climate Change (IPCC) (AR5) is based on Representative Concentration Pathways (RCPs) and these scenarios were used for new simulations with climate models made by the project Coupled Model Intercomparison Project Phase 5 (CMIP5)
The objective of this study is to evaluate the hydrologic impacts on the streamflow of Lavrinha watershed using the Distributed Hydrology Soil Vegetation Model (DHSVM) simulations associated with future climate-RCP 8.5 scenario designed by the Eta regional climate model, which in turn is based on the downscaling of the HadGEM2-ES model projections (Chou et al, 2014a, b)

Summary

Introduction

Low water availability can cause catastrophic economic, social and environmental problems. The Atlantic forest in these areas is an important biome threatened with extinction. In this context, it is important to highlight water shortages that occurred in southeastern of Brazil in hydrological years 2013/2014 and 2014/2015 which caused water supply problems for the population (Coelho et al, 2015). Climate projections of the fifth report of the Intergovernmental Panel on Climate Change (IPCC) (AR5) is based on Representative Concentration Pathways (RCPs) and these scenarios were used for new simulations with climate models made by the project Coupled Model Intercomparison Project Phase 5 (CMIP5). Global AR5 models, when compared to models of the fourth IPCC report (AR4), showed improvements in the rainfall simulation, especially for tropical latitudes (Flato et al, 2013)

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Methods

Conclusion