پديد آورندگان :
بوستاني، فردين نويسنده استاديار دانشگاه آزاد اسلامي، واحد شيراز , , گوهرگاني، احسان نويسنده دانشآموختهي كارشناسي ارشد مهندسي كشاورزي (سازههاي آبي)، واحد علوم و تحقيقات فارس، دانشگاه آزاد اسلامي، فارس، ايران ,
چكيده لاتين :
Beshar River is one of the most valuable water sources in the Kohgilooye and Boyerahmad province, which has special economical and ecological values and conditions, but it is encountered with danger of discharges from Yasuj wastewater treatment plant, wastewater of sugar, glucose, and starch factories, agricultural drainage, municipal garbage, and the surface water collecting network of Yasuj town.
In the current research, QUAL2K software was used to identify and understand changes and to predict water quality of Beshar river for its future urban, agricultural, and industrial plans.
For this reason, at first, the statistical data and information were collected and their accuracy and their qualities were studied; including weather data such as temperature, dew point temperature, wind velocity, cloud coverage, the percentage of the river which is in shadow, and date related to sunshine, water measurement including discharge data and water quality, river hydraulic including data of the beginning point to the ending point of each river profile with equal hydraulic specifications such as their distances, their longitudes and latitudes, their digital elevation at the beginning and at the end points, the form of their cross sections, and the hydraulic coefficients, contaminant sources including the place they were entered the river and their qualities, and the synthetic coefficient. Then by field studies, 4 appropriate points between Tang-e Sorkh to Mokhtar Bridge were determined for sampling.
Water temperature, electrical conductivity, dissolved oxygen, biochemical oxygen demand (BOD), nitrate nitrogen, organic phosphorus, and acidity parameters were measured by collecting and analyzing samples, in September and March months which have the lowest and the highest water amounts in the year, The data measured at field and the analyzed results of samples in the lab, were used for calibrating the model.
Model simulation of biochemical oxygen demand parameters showed that the values in September were more frequent than in March, because of the entered urban wastewater, agricultural drainage, and the aquacultures wastewater in that month. The minimum and the maximum BOD simulated by the model in September were 4.6 and 8.4 mg/l, respectively; however, the simulated values in March were 1 to 7 mg/l.
Real and simulated results showed relatively high dissolved oxygen concentrations in Beshar River, which indicated its high assimilative capacity. Also pH of the river was generally basic, and almost equal. The river interval from Dehno village to Mokhtar bridge showed the highest contamination, and the quality after Mokhtar bridge had the worst condition in September month, but appropriate assimilative capacity of the river caused the quality of the river current to be improved in 10 km. Finally comparing values simulated by QUAL2K model to real data showed that it can be used for qualitative investigations and management of Beshar River.
