Alternativas de telhados de habitações rurais para captação de água de chuva no semiárido.

Abstract

he rooftop rainwater catchment system for the human consumption is an increasing practice, especially in áreas without collective water supply, as in a larger part of the brazilian Semi-arid. The rainwater catchment systems installed in this area are based on construction of cisterns to accumulate water catched by means of roofs. In order to contribute for the improvement of the performance of those systems, this work had the objective of studying the problems that obstacle the good operation of that important way of water supply and to propose projectual solutions, adopting appropriate technology to the rural population of the brazilian Semi-arid. A field research was starting point, accomplished in the rural community of Paus Brancos, in the municipality of Campina Grande -PB, during the period from 2002 to 2003. The results showed that 80% of the researched residences have system of catchment water but only 16% store enough water for provisioning during the whole year. It was verified that this lower index is due, mainly, to the precarious installation conditions and maintenance of the subsystems of water transport (gutters and tubes). Considering this data and functional and aestheticformal aspects, five arrangement alternatives of rainwater catchment systems were developed, composed by roofs, gutters and tubes. Looking for simplification and consequent reduction of costs, the gutters supports of were eliminated, resulting earnings in the performance to comparing conventional systems. To test the performance of the proposed alternative was developed in the Laboratory of Ambience and Rural Construction - LACRA/UFCG a reduced scale functional prototype, whose evaluation revealed an excellent performance, with efficiency ranging from 86% to 92%.