Future Projections of the Aridity Index in the Brazilian Territory

• Grant number: 24/13670-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2024
• End date: October 31, 2025
• Field of knowledge: Engineering - Civil Engineering - Hydraulic Engineering
• Principal Investigator: Edson Cezar Wendland
• Grantee: Eduardo Silva Alexandre
• Host Institution: Escola de Engenharia de São Carlos (EESC). Universidade de São Paulo (USP). São Carlos , SP, Brazil

Abstract

This project aims to study the potential changes in aridity in Brazil under the current scenario of global climate change. The concept of aridity refers to the water availability necessary to sustain life in terrestrial environments, and this concept is influenced by the balance between the demand and supply of water in the atmosphere. The trend of increasing aridity in various regions of the globe, including Brazil, may have serious implications for water resource management and ecosystem maintenance. In this context, the main objective of the project is to evaluate how different formulations of Potential Evapotranspiration (5C585G) influence the estimation of projected changes in the future Aridity Index (5) and its relationships with hydrological flows in Brazil. To achieve this, the project will assess the impact of different 5C585G formulations on the characterization of future aridity and the projected changes in the aridity index across different temporal and spatial scales nationally. The study will be conducted in three main stages: calculating the monthly Aridity Index using various 5C585G formulations, evaluating the expected changes in aridity across the national territory on monthly, seasonal, and annual scales in regions, states, biomes, and hydrographic units (UGHRs), and finally, analyzing the correlation between the projected changes in the aridity index and climatic variables such as precipitation (5C), evapotranspiration (5C585G), water deficit (5C585G - 5C), and seasonality. This will help to understand the influence of each of these variables on the projected changes in aridity, as well as the relevance of the aridity index for characterizing the hydroclimatological state of a given environment. For this purpose, climate data from the CLIMBra database will be used, which includes raw and bias-corrected climate simulations for the historical period (1980-2013) and the future period (2015-2100). The project is expected to provide detailed maps of the projected changes in the aridity index at the various scales assessed. These maps will help support water resource and ecosystem management policies by providing accurate information on the areas most vulnerable to climate change in Brazil. Additionally, analyzing the correlations between aridity and climatic variables will allow for a deeper understanding of the mechanisms controlling future aridity changes, contributing to the development of more effective adaptation and damage mitigation strategies.