Spatial and temporal variability of water quality from reservoir in the semiarid region for irrigation

This study aimed to evaluate the quality of seasonal water use for irrigated agriculture in the reservoir Orós, inserted in the semiarid region of the State of Ceará. The data used in this study were collected between March 2011 and December 2012, 20 points in the reservoir. The study included the following variables: electric conductivity (EC), concentrations of calcium, magnesium and sodium and subsequently calculated the sodium adsorption ratio (SAR). The results showed that the waters of the reservoir presented, both in the dry and rainy, salinity values always below the limit for irrigation (EC