Sao Francisco River Basin

Recent economic development in the Sao Francisco basin in Brazil has brought major benefits to its primarily urban population of 16 million people. The price, however, has been high. Pollution and land degradation threaten not only natural habitats but also people’s livelihoods, water supplies and health.

Urban sewage, industrial effluents and agrochemicals (mainly in irrigated areas) have seriously polluted some of the major tributaries of the Sao Francisco river. The region’s traditional fishery is in decline due to lower fish populations, and reports of conflicts over competing uses of water are becoming more frequent as the quality and quantity of the available supply decreases. There is also a drastic reduction of water in the dry periods. Moreover, land degradation is undermining the region’s rich biodiversity of both plants and animals and is adversely affecting agricultural production.

Brazilian authorities and scientists are fully aware of these problems and anxious to reverse the decline. The necessary political will, institutional framework, and funding mechanisms for rehabilitating the Sao Francisco river basin are well established and provide a conducive environment for research and development under the Challenge Program for Water and Food.

Researchers are examining a range of social and biophysical factors—from rural poverty, water flows and crop production to pollution, threats to biodiversity and the decline of fish populations.

lhbassoi@cpatsa.embrapa.br

Sao Francisco Basin Overview

Basin area: 640,000 km²

Population: 16 million

Percentage urban: average, 77% (49% in lower basin, 96% upper basin)

Poverty indicators: Human Development

Index (HDI) varying from 0.343 to 0.806 (national average = 0.830)

Mean annual rainfall: 1,000 – 2,000 mm (upper basin) and 350 – 800 mm (lowermiddle basin)

Annual evapotranspiration: 1,000 – 1,600 mm

Climate: Mix of semi-arid and savanna-like conditions (latter is less dry, with rain from October to March)

Irrigated area: 333,000 ha (mostly fruit crops and horticulture and some soybeans)

Major crops: banana, mango, coconut, grape, guava, acerola, melon, vegetables, soybeans

Rainfed agriculture: Mostly annual crops (maize, beans, rice), cassava and pasture

Basin water demand: 7.06 billion m3/year. Urban supply, 12.5%; irrigation, 71.4%; livestock, 3.1%; industry, 13%.