introduction of several biological indices for the assessment of river water quality

evaluating the quality and quantity of water resources is crucial for a sustainable development. one of the simplest methods that is able to indicate the conditions of water quality in a short period and at a low cost, compared with the physicochemical methods, is by using the biological water quality indices. identifying the contamination of water resources using biomarkers, especially indices based on macroinvertebrates provides the necessary information for the assessment of the aquatic ecosystems. in this study, five conventional biological indices (bmwp, hfbi, aspt, ept and shannon-wiener) in the river water quality assessment are discussed. according to the conducted survey, the hfbi and aspt indices, which are able to score the water quality based on the strength of benthos in addition to considering the quantitative data population, have better ability to assess the quality of rivers.