Quality indicators and potential of rainwater harvesting on paved roads in semiarid Bahia

Abstract

The low rainfall and the irregularity in the distribution of annual rainfall in the Brazilian semiarid region are among the factors that cause the instability of agricultural production. Thus, the present study aimed to obtain quality indicators of rainwater harvested on asphalt, as well as to estimate the potential catchment runoff on paved roads semiarid region in the State of Bahia. For physico-chemical and microbiological analysis, samples were collected in tanks filled with raim water runoff arising from the roads paved with asphalt inside the Federal Institute Senhor do Bonfim Campus in Bahia. The potential water catchment was estimated from the ratio of the total catchment area and mean annual precipitation for the semiarid region of Bahia State. The study showed that rainwater captured on asphalt roads was classified as of severe degree of restriction for use in irrigation, with respect to infiltration in the soil. However regarding the clogging of emitters in irrigation systems, the water is of low risk except for the Fe ion showing moderate degree of restriction of obstruction and the highways in semiarid Bahia have high potential for harvesting rainwater for non-potable purposes.