Variations of the water quality of the Carrizal River in Manabi

The purpose of this work is to determine the physical-chemical variations in the water quality of Carrizal River (Manabi), in 21 sampling stations, covering an area of 51 km. Seven points were sampled in (i) the micro-basin, 5 points in (ii) La Esperanza reservoir and 9 points in (iii) the sub-basin of Carrizal river. Samples were taken according to an experimental design of random blocks with factorial arrangement, and according to the results, there's a correlation between the parameters and the different geographical positions monitored. Thus, we calculate a new water quality index called hardness index, which relates the alkalinity, oxide-reduction potential hardness, conductivity, suspended solids, and total solids. According to this index, it is evident that the concentration of minerals of calcium, magnesium, sulphates and carbonates increased along with the concentration of solids in the water, as well as the REDOX potential and electrical conductivity, increased from the upper basin to the lower basin of Carrizal river. This correlation between physical-chemical parameters of the water and the different geographical positions monitored is probably influenced by anthropogenic activities.