1- دانشجوئ
Abstract: (15264 Views)
Based on the macro-invertebrate community and physico-chemical indices, water quality of the Tajan River in 6 stations along 80 km of the river length was assessed. Monthly sampling was conducted for one year (September 2011 to August 2012), using a surber with 30.5 × 30.5 cm dimensions and a 60μ mesh net for the benthic invertebrates sampling. The identified macro-invertebrates belonged to 31 families, 12 orders and 5 classes, the highest and the lowest abundance of which belonged to Psychodidae and Chironomidae, respectively. Based on Hilsenhoff Family Biotic Index, the research stations were classified into 4 qualitative categories, viz. excellent, good, fair, and fairly poor. Stations 1 and 5, respectively, showed the highest and lowest HFBI index. The highest and the lowest values for the Shannon–Weiner index were recorded in station 1 and station 2, respectively. The results of physicochemical parameters indicated reduced dissolved oxygen in the stations 2 and 5, and increased TDS in station 2 and 1 and increased nitrite and ammonium in station 3. Results of Spearman correlation coefficients between biotic indices and physicochemical variables revealed significant relationship between DO, TDS, EC, PO4 and water flow with HFBI and Shannon-Weiner indices. This study showed, generally pollution in stations 2 and 5 has reduced water quality in these station's.
Received: 2014/04/21 | Published: 2015/02/20