Sustainability of Groundwater Resources and its Indicators (Proceedings of symposium S3 held during the Seventh IAHS Scientific Assembly at Foz do Iguaçu, Brazil, April 2005). IAHS Publ. 302, 2006, 117-125.

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Alluvial aquifer indicators for small-scale irrigation in northeast Brazil

RAE MACKAY¹ , ABELARDO MONTENEGRO², SUZANA MONTENEGRO³ & JAN VAN WONDEREN⁴

1 School of Geography Earth and Environmental Sciences, The University of Birmingham, Edgbaston, Birmingham B15 2TT, UK

2 Universidade Federal Rural de Pernambuco, Av. Dom Manoel de Madeiros, S/N Recife, Pernambuco,
CEP 50710-470, Brazil

monte@hotlink.com.br

3 Universidade Federal de Pernambuco, Av. Ac. Hélio Ramos, S/N Recife, Pernambuco, CEP 50000, Brazil

4 Mott Macdonald, Demeter House, Station Road, Cambridge CB1 2RS, UK

Abstract The Brazilian northeast is a semiarid area beset by drought and rural poverty. Irrigated agriculture exploits groundwater in the shallow alluvial aquifers in the base of the ribbon valleys. Uncontrolled exploitation and over-irrigation are leading to soil salinization and to degradation of the groundwater. Efforts have been made to promote efficient irrigation methods and to involve the farmers in reducing wastage. However, farm level water resource assessments are not yet undertaken to complement this activity. Farm and community level approaches to monitor and interpret groundwater level and salinity have been proposed. Interpretation has required physical studies to be undertaken in three typical groundwater systems in the region. The studies identify important links between hillslope runoff, groundwater use, subsurface controls and the annual and longer-term variations in water availability and water quality that have important impacts on sustainable groundwater use. Community level management is seen to be essential for sustainability.

Keywords drought alleviation; groundwater management; hillslope processes; monitoring; northeast Brazil; semiarid; small-scale irrigation; sustainability

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