A Case Study of Water Quality Modeling of the Gargar River, Iran

Document Type: Research Paper


1 Faculty of Water Science and Engineering, Shahid Chamran University, Ahvaz, Iran

2 Faculty of Physical Geography and Quaternary Geology, Stockholm University, Stockholm, Sweden

3 Faculty of Environmental Health, Ahvaz Jondishapour University of Medical Science, Ahvaz, Iran

4 School of Civil Engineering, College of Engineering, University of Tehran, Tehran, Iran


Human activities in the recent years have considerably increased the rate of water pollution in many regions of the world. In this case study, the main sources of wastewater discharging into the Gargar River were identified. Using river and point source flow rates and water quality parameters measured along the river, the river water quality was simulated using a commonly used, one-dimensional water quality model, the QUAL2K model. Simulated values of DO, CBOD, NH4-N and NO3-N demonstrated the accuracy of the model and despite a significant data shortage in the study area, QUAL2K model was found to be an acceptable tool for the assessment of water quality. Still, for this case study, it was found that the model was most sensitive to river and point source flows and moderate to fast CBOD oxidation, and nitrification rates.


  1. Ambrose, R.B., Connolly, J.P., Southerland, E., Barnwell, T.O., Schnoor, J.L., 1988. Waste allocation simulation models. J. Water Pollut. Control Fed. 6, 1646–1655.
  2. APHA (American Public Health Association), 2005, Standard Methods.
  3. Bowie G.L., M.B. William, Porcella D.B., Campbell C.L., Pagenkopf J.R., Rupp G.L., Johnson K.M., Chan P.W., Gherini S.A and Chamberlin C.E., 1985, Surface Water Quality Modeling. 1985, California, USA.
  4. Brown, L.C., Barnwell, T.O.Jr., 1987. The Enhanced Stream Water Quality Models QUAL2E and QUAL2E-UNCAS: Documentation and User Manual. USEPA, Environmental Research Laboratory, Athens, GA, EPA/600/3-87/007.
  5. Campolo M., Andreussi P., Soldati A., 2002. Water quality control in the river Arno, technical note. Water Res. 36, 2673–2680.
  6. Chapra, S.C., and Canale, R., 2002. Numerical Methods for Engineers, 4th Ed. New York, McGraw-Hill.
  7. Chapra, S.C., Pelletier, G.J., Tao, H., 2006. QUAL2K: A Modeling Framework for Simulating River and Stream Water Quality, Slaughterhouse2.04: Documentation and Users Manual. Civil and Environmental Engineering Dept., Tufts University, Medford, MA.
  8. Cho, J. H., Sung Ryong Ha , 2010, Parameter optimization of the QUAL2K model for a multiple-reach river using an influence coefficient algorithm, Science of The Total Environment, Volume 408, Issue 8, Pages 1985-1991.
  9. Cox, B.A., 2003. A review of currently available in-stream water-quality models and their applicability for simulating dissolved oxygen in lowland rivers. Sci. Total Environ. 314–316, 335–377.
  10. Deksissa, T., Meirlaen, J., Ashton, P.J., Vanrolleghem, P.A., 2004. Simplifying dynamic river water quality modelling: a case study of inorganic dynamics in the Crocodile River, (South Africa). Water Air Soil Pollut. 155, 303–320.
  11. Drolc, A., Konkan, J.Z.Z., 1996. Water quality modeling of the river Sava, Slovenia. Water Resources 30 (11), 2587–2592.
  12. EEC, 1978. Council Directive (78/659/EEC) on the Quality of Fresh Waters Needing Protection or Improvement in order to support fish life, retrieved 20 April 2005 from: http://europa.eu.int/comm/environment/ .
  13. EMECS, 2001. Water Quality Conservation for Enclosed Water Bodies in Japan, International Center for the Environmental Management of Enclosed Coastal Seas (EMECS) retrieved 20 April 2005 from: http://www.emecs.or.jp/.
  14. Fan, Chihhao, Chun-Han Ko, Wei-Shen Wang, 2009, An innovative modeling approach using Qual2K and HEC-RAS integration to assess the impact of tidal effect on River Water quality simulation.
  15. Ghosh, N.C., Mcbean, E.A., 1998. Water quality modeling of the Kali river, India. Water Air Soil Pollut. 102, 91–103.
  16. ICHHTO (Iranian Cultural Heritage, Handicrafts and Tourism Organization), 2008, SHUSHTAR HISTORICAL HYDRAULIC SYSTEM, Tehran, Iran.
  17. IPBO (Iranian Plan and Budget Organization),1992. Drinking Water Quality Standard (3-116), Tehran.
  18. Kannel, P.R., Lee, S., Kanel, S.R., Lee, Y., Ahn, K.-H., 2007. Application of QUAL2Kw for water quality modeling and dissolved oxygen control in the river Bagmati. Environtal Monitoring Assessment 125, 201–217.
  19. Moriasi, D.N., Arnold J.G., Van Liew M.W., Bingner R.L., Harmel, R. D. and Veith, T.L., 2007, Model Evaluation Guidelines for Systematic Quantification of Accuracy in Watershed Simulations Vol. 50(3): 885−900.
  20. Najafzadeh, M. and Azamathulla, H.M., 2013. Group method of data handling to predict scour depth around bridge piers, Neural Comput & Applic, 23:2107–2112.
  21. Najafzadeh, M. and Barani, G.A., 2011, Comparison of group method of data handling based genetic programming and back propagation systems to predict scour depth around bridge piers, Scientia Iranica A, 18 (6), 1207–1213.
  22. Najafzadeh, M., Barani, G.A., Kermani, M.R., 2013, Abutment scour in clear-water and live-bed conditions by GMDH network, Journal of Water Science Technology, 67(5):1121-8.
  23. Novotny, V., 2002. Water Quality: Diffusion Pollution and Watershed Management. Wiley, Hoboken, NJ. Chang, H., 2005. Spatial and temporal variations of water quality in the Han.
  24. International Journal of Air and Water Pollution 161, 267–284.
  25. Owens, M., Edwards, R.W., Gibbs, J.W., 1964. Some reaeration studies in streams. International Journal of Air and Water Pollution 8, 469–486.
  26. Park, S.S., Na, Y., Uchrin, C.G., 2003. An oxygen equivalent model for water quality dynamics in a macrophyte dominated river. Ecological Modeling 168, 1–12.
  27. Park, S.S., Lee, Y.S., 1996. A multiconstituent moving segment model for the water quality predictions in steep and shallow streams. Ecological Modeling 89, 121–131.
  28. Pelletier, G.J., Chapra, C.S., Tao, H., 2006. QUAL2Kw, A framework for modeling water quality in streams and rivers using a genetic algorithm for calibration. Environmental Model. Software 21, 419–4125.
  29. Rasti, M, Nabavi, S.M, Jaafarzadeh N., 2007, Investigation of Fish Farm Wastewater on Gargar River using algae as biologic indicator, 7th IREC, Ahvaz, Iran. (In Persian).
  30. Tao, H, 2008. “Calibration, Sensitivity and Uncertainty Analysis in Surface Water Quality Modelling: Dissertation for doctoral degree”, Tufts University, MA, USA.
  31. Thompson, D.H., 1925. Some observations on the oxygen requirements of fishes in the Illinois River, 111. Natural History Survey Bulletin 15, 423–437.
  32. UNESCO, 2009. Shushtar Historical Hydraulic System, retrieved 24 April 2013 from: http://whc.unesco.org/en/list/1315/documents/ .
  33. USEPA, 1985. Rates, constants and kinetics formulations in surface water quality, second ed. EPA 600/3-85-040, U.S. Environmental Protection Agency, Athens, GA, retrieved 20 October 2006 from: http://www.ecy.wa.gov/.
  34. Zhang, R., Xin Qian, Huiming Li, Xingcheng Yuan, Rui Ye, 2012, selection of optimal river water quality improvement programs using QUAL2K: A case study of Taihu Lake Basin, China, Science of The Total Environment, Volume 431, Pages 278-285.