Interrelationship of environmental indicators of quality in surface waters of the Valle del Cauca

Abstract

In the diagnosis of the present situation and future perspectives for control of pollution and aquatic contamination, one of the aspects of the greatest importance for entities responsible for the management of hydrographic basins is the interpretation of routine Physico-chemical data by means of indices of environmental quality, which include not only physical, chemical and bacteriological parameters, but also biological variables that supply infor­mation factors that affect water quality. Starting in 1990, samples of water and benthic fauna were collected in different stations in the basins of the Cali and Meléndez rivers in the department of Valle. In this work, the water quality index proposed by the National Sanitary Foundation of the United States was used. This index permits, by means of a numerical scale, comparisons of different levels of environmental degradation in bodies of water. In the basins under study, there are variations between 77.2 and 32.5 units, which are correlated with groups of insects at an immature stage, with special emphasis on the orders Ephemeroptera, Plecoptera, and Trichoptera.