Cistern Project for Domestic Water use in Semi-Arid Regions

Abstract

Water scarcity in semi-arid regions compromises the quality of life, principally human health, in these regions. The use of cisterns with adequate dimensions, that ensure the minimum of water required to meet human needs, is a practice recommended for these regions. This paper aims to estimate, considering the regional variability of precipitation, the most appropriate relationship between the capacity of cistern and the catchment area to ensure access to water considering the minimum recommended by WHO. A case study is presented for the Brazilian semi-arid region. A curve representing the relationship between these two variables was created for each region with similar precipitation conditions. In regions with low annual average precipitation, increasing the cistern capacity was found less efficient if there was no increase in the catchment area, while in areas with higher annual precipitation and longer periods of drought, the increased cistern capacity was the best alternative. Large differences in the relation between the cistern capacity and the catchment area were obtained in regions where the total precipitation and seasonal variability of precipitation throughout the year showed an intermediate behavior.