Tecnologias sociais de captação de água da chuva e suas relações com o desenvolvimento rural de Barra de Santana – PB

Abstract

The low amount and irregularity in the distribution of rainfall, coupled with the lack of water alternative to supply the countryside of Barra de Santana, in the micro-region of Cariri, come invalidating coexistence the population and the development of small business agriculture. The use of social technologies of rainwater catchments has allowed increasing water availability with the same amount of rain. In this context, it was necessary to conduct a study that would allow diagnosing these social technologies and link them to rural development Barra de Santana, PB, and these determinations the main objectives. The study was conducted at the site Barriguda and Mororó District, located in Barra de Santana, PB, applying questionnaires with several questions related to the social, environmental, technological and economic dimensions for a universe of 30 small farmers benefited from programs one Million Cisterns (P1MC) and one Land and Two Waters (P1+2). Dates mmonthly and annual rainfall were provided by the Executive Agency for Water Management, AESA, Campina Grande, PB. By statistical criteria, data were pooled and calculated the measures of central tendency and dispersion and established local rainfall patterns. To estimate the water uptake of annual rainfall, was adopted six scenarios with total rainfall, equivalent to median, the driest years and the wettest and the levels of 25, 50 and 75% probability. Potential volumes of rainwater catchments for the areas of roofs homes and/or cement soil (for tanks boardwalk type and flood) were determined depending on the rainfall regime and their catchments areas. Results indicated that the rainfall distribution is irregular and asymmetric and, therefore, the median is the measure of central tendency recommended. Still, there is a high potential to capture rainwater, which will increase the water supply, with the same amount of rainfall. Small producers have declared that social water technologies P1MC and P1+2 are promising. Catchments areas less than 40 m² has the potential to capture a volume of less than 16.000 liters, for the four storm scenarios, although it is not recommended to set a single volume value for the tank without establisher local rainfall patterns and water volume necessary for consumption and small agricultural production. A greater supply of water collected and stored rainwater in cisterns, for use in productive activity resulted in increased household income. Underground dams emerge as an alternative to fruit plantations, grasses and forage cactus. The benefits of these social technologies are still recent and, therefore, the results are still incipient. Therefore, there is need to continue this study in order to quantify the potential of rainwater harvesting, depending on the volumes of water required to meet the human and animal consumption needs (P1MC) and production activities, which depend, exclusively, local rainfall patterns and the size of the catchments area.