Document Type : Original Article


Department of Environmental Engineering, Faculty of Environment and Energy , Islamic Azad University, Science and Research Branch, Tehran, Iran


Rivers are among the major water resources and important and vulnerable inland ecosystems (Hayatolgheib et al., 2016). Today, the quality of such water resources has been threatened due to the irregular consumption of water and pollution of rivers by unnatural and human resources (Li et al., 2009). The Peer-bazar River and Anzali International Wetland has been subjected to severe eutrophication  over the past two decades (Zebardast and Jafari, 2014). As a reuslt evaluation and estimation of changes in water quality the mouth area of the main feeding river  estuary in the Anzali wetland (the Peer-bazar River) is in the first priority.
Materials and methods:
The present study aimed at evaluating the eutrophication status and prediction of temporal-spatial changes in nutrients concentrations, such as ammonium-nitrogen (N-NH3), nitrate (N-NO3), total nitrogen (TN), phosphorous (PO4-3), TP, in the estuary of Pir-Bazar river as the main and most important stream feeding the Anzali International Wetland. Sampling was performed from 10 points of the drainage basin within 18 months from December 2014 to June 2016. In this research, zoning maps were prepared and the status of present and future water quality parameters of the basin were accurately estimated using a researchers software-developed application and the five interpolation methods of Kriging, S-PLUS, polynomial regression, inverse distance to power, and local polynomial; and finally the optimal method was selected through a root-mean-square error (RMSE) based cross validation approach. 
Result and discussion:
The results showed that in this drainage basin, the second order quadratic polynomial regression (with a mean RMSE of 0.2075 for TN and of 0.1475 for TP) and the topical polynomial with power of 10 (order of 3) (with a mean RMSE of 0.331 for TN and of 0.22 for TP) were the best and the worst methods for estimation of nitrate and phosphate levels in the drainage basin, respectively, as compared to other methods. In order to prepare the zoning map, monthly and seasonal maps of spatial distribution of nitrate and phosphate concentrations were created, and temporal (seasonal) changes in nutrients at the wetland entrance (estuary of Pir-Bazar river) were expressed. The results showed that the mean levels of nutrients in Pir-Bazar river water (0.616 mg/L for TN and 0.325 mg/L for TP) were higher than the allowed limits, according to the European directive 80/778/EEC and the OECD standard, (in normal conditions, the limits are 0.1-0.5 mg/L for TN and 0.01-0.1 mg/L for TP in fresh water). Also, according to the results of software, the mean TN to TP ratio at the wetland entrance was maximally 33.7 that exceeded the limit of 16. Therefore, the region’s water is subject to an advanced and critical eutrophication. Considering the positive and high values of the coefficient of performance for TP and TN between 0.87 and 0.918 (mean 0.894), it can be argued that phosphorus and nitrogen in this water basin are likely to share the same source; meanwhile the coefficient of performance varied between 0.187 and 0.721, showing the best performance for nitrate and phosphate, respectively. 
The results predicted by this software show that the mean annual concentration of ammonium, nitrate, nitrite, phosphate, and dissolved salts in this river will increase about 1.2%, 3.2%, 32%, 5%, and 7%, compared to the current situation in 2020. These figures will be about 3.4%, 9%, 87%, 14%, and 16.5% in 2030; this is a new finding and a reliable innovation in water quality management in the wetland. 


  1. Aliverdi, A.R. and Eslami, H., 2014. Modeling quality parameters nitrate and ammonia in the river between the bridge Elhayi using software WASP6:
  2. European Directive 80/778/EEC relating to the quality of water intended for human consumption, 1994.
  3. Forsythe, K.W., Paudel, K. and Marvin, C.H., 2010. Geospatial analysis of zinc contamination in lake Ontario sediments. Environmental Informatics. 16(1), 1-10.
  4. Haji, A.H., Mirbagheri, S.A. and Javid, A.H., 2013. A wavelet support vector machine combination model for daily suspended sediment forecasting. International Journal of Engineering Transaction Aspects. 27(6), 855.
  5. Hasani Pak, A.A., 2013. Geostatistical. Tehran University Published, Tehran, Iran.
  6. Hayatolgheib, M., Gheshlaghi, A., Jafari, H. and Forghani Tehrani, G., 2016. Measure performance and efficiency of water consumption Tehran by data envelopment analysis. Journal of Natural Environment. 68(4), 619-628. (In Persian with English abstract).
  7. JICA (Japan International Cooperation Agency), 2012. Zoning plan in the Anzali wetland, Anzali wetland ecological management project in Islamic Republic of Iran. Report number: 2, p. 95.
  8. Kazemi, S.M. and Hosseini, S.M., 2014. Comparison of spatial interpolation methods for estimating heavy metals in sediments of Caspian Sea. Expert Systems with Applications. 38, 1632–1649.
  9. Lee, J., Jang, C., Wang, S. and Liu, C., 2011. Evaluation of potential health risk of arsenic-affected groundwater using indicator kriging and dose response model. Science of the Total Environment. 384, 151–162.
  10. Liu, S., Gu, S., Tan, X. and Zhang, Q., 2009. Water quality in the upper Han river basin, China: The impacts of land use land cover in riparian buffer zone. Journal of Hazardous Materials. 165, 317-324.
  11. Marofi, C., Tornjiyan, A. and Zarabyaneh, H., 2012. Evaluation of geostatistical methods for estimating electrical conductivity and pH water drainage channel Hamedan-Bahar plain. Journal of Soil and Water Conservation researches. 16(2), 41-53. (In Persian with English abstract).
  12. Ministry of Energy., 1998. An extensire plan for monitoring of water quality in Anzali Watershed. p. 15, 48.
  13. Mirbagheri, S.A. and Tanji, K.K., 1981. Sediment characterization and transport modeling in Colusa Drain. California. University of California at Davis, Department of Land, Air, and Water Resources.
  14. Mirbagheri, S.A., Tanji, K.K. and Krone, R.B., 1988a. Sediment characterization and transport model in Colusa Basin Drain. ASCE. Journal of Environmental Engineering. 114(6), 1257-1273.
  15. Mirbagheri, S.A., Tanji, K.K., Krone and R.B., 1988b. Simulation of suspended sediment in Colusa Basin Drain, California. Journal of Environmental Engineering ASCE. 114(6), 1275-1294.
  16. Mirbagheri, S.A. and Hashemi, S.A.H., 2008. Nutrient transport model in Chah nimeh manmade reservoir. Proceedings of the 8th conference on systems theory and scientific.
  17. Mirbagheri, S.A., Nourani, V. and Rajaee, T., 2010a. Neuro-fuzzy models employing wavelet analysis for suspended sediment concentration prediction in rivers. Hydrological Science Journal. 55(7).
  18. Mirbagheri, S.A., Nouri, J., Farokhian, F. and Jafarzadeh, N., 2010b. Water quality variability and eutrophic state in wet and dry years in wetlands of the semiarid and arid regions. Environmental Earth Science. 59(7), 1397-1407.
  19. Mirbagheri, S.A., Mahmodi, S. and Khezri, S.M., 2011. Simulation modeling of nitrogen and phosphorous change in Chalous river. Civil and Environmental Engineering University of Tabriz. 40(3), 47-59. (In Persian with English abstract).
  20. Mirbagheri, S.A., Sadrnejad, S.A. and Hashemi, M. S. A., 2012. Phytoplankton and zooplankton modeling of Pishin Reservoir by means of an advection-diffusion drought model. International Journal of Environmental Research (IJER), 6(1).
  21. Mousavi, G., 2010. Water Engineering. Hafiz Published. 2(1), p.78.
  22. Naseri, S. and Ghaneian, M.T., 2004. Quality management lakes and tributary rivers. Nas Publishers, One Edition. p. 54.
  23. Nejatkhah Manavi, P., Passandi, A., Sogholi, M., beheshtinia, N. and Mirshekari, D., 2010. Evaluation of nitrate and phosphate in the south-eastern basin of the Caspian Sea in the spring and summer. Journal of Researches Marine Science and Technology. 4(3), 27-35. (In Persian with English abstract).
  24. OECD, Vollenweider, R. A. and Kerekes, J., 1982. Eutrophication of waters. Monitoring, assessment and control. OECD Cooperative programme on monitoring of inland waters (Eutrophication control). Environment Directorate, Paris. p.154.
  25. Ouyang, Y., Nkedi-Kizza, P., Wu, Q.T., Shinde, D. and Huang, C.H., 2006. Assessment of seasonal variations in surface water quality. Water Research. 40(20), 3800-3810. (In Persian with English abstract).
  26. Pirasteh, K. and Eimandel, B., 1997. Investigation the effects of industrial pollutant sources on the water quality of Siahroud river. Proceeding of the third Conference on Potable Water Conservation, Iran. pp. 55-58.
  27. Rafiee, M., Akhond Ali, A.M., Moazed, H., Jaafarzadeh, N. and Zahraie, B., 2013. A Case Study of water quality modeling of the Gargar River, Iran. Journal of Hydraulic Structures. p. 10-22. (In Persian with English abstract).
  28. Salmani, M.H. and Salmani Jajaei, E., 2016. Forecasting models for flow and total dissolved solids in Karoun river-Iran. Hydrology. 535, 148–159.
  29. Shoaei, S.M., Mirbagheri, S.A. and Zamani, A., 2015. Seasonal variation of dissolved heavy metals in the reservoir of Shahid Rajaee Dam, Sari, Iran. Desalination and Water Treatment. 56(12), 3368-3379.
  30. Standard Methods Handbook for water and wastewater., 2005. Publications Washangton DC, APHA, ANWA. WPCE press. 20th edition, ISBN: 0875532357, Standard No. 1020 B. & 1020 C., pp. 39-53 & 111-119.
  31. Taghizadeh Mehrjardi, R. A., Zare'ian Jahromi, M., Mahmoudi, S., Heidari, A. and Sarmedian, F., 2013. Investigation of spatial interpolation methods for spatial variation of groundwater qualitative properties of Rafsanjan plain. Science and Engineering Watershed of Iran, Volume 2, No. 5, pp. 23-31. (In Persian with English abstract).
  32. Zarrati, A.R., Tamai, N. and Islam, G.M.T., 2001. Huang G. Prediction of water surface elevation in a channel with continuous bends. Proceedings of 29th IAHR Congress, Beijing, China. pp. 95-104
  33. Zebardast, L. and Jafari, H.R., 2014. Evaluation process changes in Anzali wetland using remote sensing and providing management solution. Environmental Studies. 37(57), 57-64. (In Persian with English abstract).