The Effect of Urban Activities on Some Benthos Population: A Case Study of Zayanderood River (1997-2010)
This study aimed to assess the effects of urban activities in Isfahan city on the water quality of Zayanderoud River during the years 1997-2010. In this study, we investigated: 1) the changes in physicochemical parameters such as river discharge, pH, and EC in this period (1997-2010) in three locations: before the city, within the city and after the city; 2) the changes in the density of the four different macrobenthos families as Chironomidae, Lumbricidae, Lumbriculidae and Tubificidae in this period and in the aforementioned locations. Data were analyzed using the statistical software MiniTab 15 using Regression. The result showed that during 1997-2010, physicochemical and biological parameters have changed significantly. Besides, the amount of discharge has significantly declined in this period. The findings showed that by increasing the distance from the Zayanderoud dam wall, discharge and pH significantly decreased but EC increased and, in consequence, macrobenthos density increased significantly by time. Considering the biological features and habitats specification, this issue was indicative of the undesirable quality of water in the river while the river passes the city. This can result from recent global climate change by decreasing precipitation, discharging different wastewater to river and increasing water transfers to other areas.
Keywords: Zayanderoud River, Benthic Communities, City Effect