Changes in ecosystem processes due to climate change and multiple stressors: contributions to agribusiness and urban expansion in a watershed of the central region of the state of São Paulo

• Grant number: 25/02338-6
• Support Opportunities: Regular Research Grants
• Start date: September 01, 2025
• End date: August 31, 2028
• Field of knowledge: Engineering - Sanitary Engineering - Environmental Sanitation
• Principal Investigator: Maria do Carmo Calijuri
• Grantee: Maria do Carmo Calijuri
• Host Institution: Escola de Engenharia de São Carlos (EESC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Associated researchers: Davi Gasparini Fernandes Cunha ; Julio Cesar Pascale Palhares ; Lívia Maria Fusari ; Paulo Cesar Rocha

Abstract

Since the 1970s until the present day, there seems to be a consensus that using the watershed for water resources management, governance, and conflict resolution is the most appropriate approach. The watershed is a natural landscape unit that represents the definition of an open system. Each watershed is composed of a set of sub-watersheds, and according to the concept of nested sub-watersheds, the effectiveness of water quality management increases as we focus on smaller-scale watersheds before moving to larger ones. The sub-watershed is the ideal unit for integrated planning of natural resource management as an ecosystem. The main objective of this project is to characterize multiple stressors, ecosystem processes, and environmental services in watercourses located within a watershed and its constituent micro-watersheds in the central region of the state of São Paulo, under a gradient of impacts caused by agribusiness, urban expansion, and within the context of climate change. The study site is the Quilombo River watershed, a tributary of the Mogi-Guaçu River, covering an area of 425 km². Its drainage network is located in the municipalities of São Carlos and Descalvado (SP). This watershed contains remnants of native vegetation but is subject to anthropogenic impacts resulting from the intensification of agricultural practices and the prospect of urban expansion. Reference sub-watersheds, as well as those occupied by agriculture, livestock, and urban areas, will be assessed. The methodology combines advanced tools, including the use of UAV (Unmanned Aerial Vehicles) and GIS (Geographic Information Systems) for high-resolution environmental mapping, as well as physical and chemical analyses of water and soil. Hydrological and scenario modeling will be conducted using the HydroPol2D and SWAT-TAMU tools. Monitoring of functional indicators, such as nutrient retention, ecosystem metabolism, and organic matter decomposition, will also be performed alongside macroinvertebrate community analysis to measure the effects of stressors on the structure of lotic systems and the functioning of aquatic biota. The project aims to provide subsidies for the implementation of impact mitigation measures, contributing to the preservation of environmental services and the sustainable use of water. (AU)