DEVELOPING A WATER QUALITY MANAGEMENT MODEL FOR KARUN AND DEZ RIVERS

The karun and dez rivers basin are the largest rivers basin in iran which are situated in the south west ofthe country. karun river originates from zagros mountain ranges and passing through khuzestan plain,reaches the persian gulf. several cities lie along its pat h of them the most important is ahvaz, the centerof khuzestan province. to achieve water quality goals in karun and dez rivers, a water qualitymanagement model has been developed through the gis approach and a mathematical water quali tymodel. in karun and dez rivers, water quality has decreased due to heavy pollut ion loads from khuzestanprov ince cities and surround ing areas. ln this survey , pollution sources, land use, geographic features andmeasured water quality data of the river basin were incorporated into the arc-view geographicinformation system datab ase. with the database, the mode l calculated management type and cost for eachmanagement project in the river basin . until now, river management policy for polluted rivers in lran hasbeen first of all to get pena lties from pollution sources and secondarily, to construct treatment plants forthe pollut ion sources whose wastewater is released untreated and for which the wastewater quality goal ofthe iranian department of the environment is not met. different management projects with a timeprogram were proposed and they were compared with the results of the river quality without anymanagement approach. it became clear that the results based on the management approach were muchbetter than those for the unmanaged condition from the viewpoint of the achieve ment of water qua litygoals and cost optimization.