Water deficit risk for forest and fruit species in the State of Rio Grande do sul, southern Brazil

Abstract

The aim of this study was to identify, in the State of Rio Grande do Sul, Southern Brazil, homogeneous zones regarding water deficit risk and thus to contribute to studies of climate risks in agriculture, livestock and forestry. The regions were delimited by cluster analysis, being the classificatory variables defined by the availability of water resulting from the difference between the rainfall (P) and the potential evapotranspiration (ETP), considering the water reserve in the soil with a storage capacity (CAD) of 50, 75 and 100 mm of water. The analysis allowed the recognition of six zones with homogeneous risk in the State of Rio Grande do Sul. The Southern State has a higher risk of water deficit in the summer, especially in West Frontier with Uruguay and Argentina, while the Northeast has the lowest risk. In the spring, the risks are intermediaries and in the fall, the risks are low, continuing the trend of increased risk in the Southern State, mainly in West Frontier. In winter, the risk is virtually null throughout the state.