Hydrological response of a headwater catchment in Southeast Brazil-Threshold patterns of stormflow response

Autor(es)

Chittolina, Mariane ; da Rocha, Humberto Ribeiro ; Domingues, Leonardo Moreno ; Lobo, Gre de Araujo

• Tipo de documento: Artigo Científico
• Fonte: Hydrological Processes; v. 37, n. 5, p. 15-pg., 2023-05-01.

Resumo

Headwater catchments are essential water sources for sustaining low flow in downstream rivers. The montane region of Serra da Mantiqueira in Southeast Brazil is the largest water supplier for the densely populated area of Sao Paulo, where we investigated the hydrological response of a subtropical catchment and four of its sub-catchments. We discussed the relationships between rainfall, streamflow, baseflow, stormflow, soil moisture, and water table depth using high-frequency field observations over 4 years. Baseflow accounted for most of the streamflow during the dry season and for half of streamflow in the wet season. In contrast, the variations in soil moisture were dampened, with increases in the early wet season preceding the increase in streamflow and decreases in the late wet season following the decrease in streamflow. The mean runoff coefficient and baseflow index varied from 23% to 37% and from 62% to 75% across the catchments, respectively. At the event scale, all catchments had a pronounced threshold behaviour, where stormflow increased sharply when event precipitation reached similar or equal to 10 mm, soil moisture reached similar or equal to 51% and water table depth decreased to similar or equal to 135 cm. The event stormflow coefficient was highly variable, with a maximum of 25%. The temporally integrated stormflow coefficient was low for conditions below a soil moisture threshold (similar or equal to 3%-10%) and high above a soil moisture threshold (similar or equal to 8%-15%). Our estimates of flows and threshold behaviours were consistent across the various study catchments, improving our understanding of runoff generation at a catchment scale. This information should help improve the management of water resources focused on water and food security in a context of climate change. (AU)

• Processo FAPESP: 16/16358-0 - Balanço hídrico em uma sub-Bacia do Ribeirão das Posses, Extrema, Minas Gerais
• Beneficiário: Mariane Chitolina
• Modalidade de apoio: Bolsas no Brasil - Doutorado Direto
• Processo FAPESP: 19/17179-0 - O papel das águas subterrâneas e do solo na disponibilidade hídrica superficial nas cabeceiras do sistema de reservatórios da Cantareira: uma investigação experimental de campo em uma bacia hidrográfica multi-instrumentada
• Beneficiário: Mariane Chitolina
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Doutorado Direto
• Processo FAPESP: 20/04060-1 - Processos hidrometeorológicos em uma bacia multi-instrumentada na Serra da Mantiqueira
• Beneficiário: Mariane Chitolina
• Modalidade de apoio: Bolsas no Brasil - Doutorado Direto
• Processo FAPESP: 15/50682-6 - Investimentos pró-climáticos inteligentes em bacias de montanhas tropicais da América do Sul (ClimateWise)
• Beneficiário: Humberto Ribeiro da Rocha
• Modalidade de apoio: Auxílio à Pesquisa - Programa de Pesquisa sobre Mudanças Climáticas Globais - Temático
• Processo FAPESP: 19/23853-5 - Riscos e oportunidades regionais de mudanças do uso da terra e das mudanças climáticas aos serviços ecossistêmicos hídrico-climáticos: investigação para bacias na Caatinga e na Mata Atlântica do Sudeste
• Beneficiário: Humberto Ribeiro da Rocha
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 21/11762-5 - Centro para Segurança Hídrica e Alimentar em Zonas Críticas
• Beneficiário: Humberto Ribeiro da Rocha
• Modalidade de apoio: Auxílio à Pesquisa - Centros de Ciência para o Desenvolvimento