Estudo econômico simplificado de cinco diferentes tipos de revestimento de canais de irrigação.

Abstract

The present work was developed in the Center of Science and Technology of the Federal University of Paraíba in Campina Grande, Paraíba. The objectives of this study were to analyze the behavior of some types of channel coating, aiming to minimize water losses by infiltration, to test these coatings for their resistance to the erosive action of water and finally to make an economic feasibility study of them. In order to study water losses through infiltration, four static channels coated with soil plastic cement, gravel 19, compacted natural soil (control) and plastic (polyethylene) membrane were constructed. It was adopted the ponding method, to determine the infiltration of the water in the channels. The experimental time for the static channels was 103 days, distributed between dry and wet periods alternately. No significant influence was observed in the infiltration of the channels, as a consequence of this variation. Erosion was determined at the end of the flow of each flow through readings made on the exposed parts of the steel pickets installed in the base and the slopes of the channels. In this work, some information about bentonite coatings was published, a study by Queiroga & Ferreira (1974), not yet published. The method used for the feasibility study of the coatings tested was as recommended by SP South of the Bureau of Reclamation, Sal t Lake City, Utah, USA. During the period that the channels remained wet (63 days), there was an infiltration accumulated of 0,0; 23.3; 16 5.7; and 457.1 cm / day for plastic-coated, plastic-soil, gravel and compacted natural soil, respectively. In the dynamic channels, only the control was affected by the movement of the water, reaching an accumulated erosion of 37 mm. Among the coatings studied, the plastic cement soil was the one that presented the best results. Next were the crushed stone linings, then the plastic.