Hydraulic and water quality simulation in steep-slope rivers: a case study of Dohezar river, Tonekabon

Document Type : Research Paper

Authors

Department of Civil Engineering, Faculty of Civil Engineering and Environment, Shahid Beheshti University, Tehran, Iran.

10.22059/jwim.2025.384294.1186

Abstract

The growth of pollutants in surface water resources has significantly increased, causing adverse effects on the environment and human communities. As a result, the use of mathematical models to simulate river water quality and evaluate various scenarios has become essential. This study utilizes the HEC-RAS model to assess the spatial and temporal distribution of pollutants in mountainous rivers with steep slopes and a step-pool structure, as well as to examine changes in pollutants at sections above and below the step. Four main sections on the Dohezar River in Tonekabon, located upstream, downstream, upstream of the step, and downstream of the step, were studied. Qualitative samples for dissolved oxygen, nitrate, inorganic phosphorus, and water temperature were collected and tested over an eight-month period. The simulation results during calibration and validation periods showed that the mean minimum and maximum total relative errors were 1.05 percent for temperature and 10.18 percent for inorganic phosphorus, respectively, indicating acceptable accuracy of the HEC-RAS model in simulating water quality parameters. Overall, due to stable flow and reduced turbulence, errors were lower in upstream and downstream sections, while error increased in areas downstream of the step due to enhanced turbulence and movement of settled quality parameters. Another reason for increased error in these areas is the model's use of hydrostatic pressure instead of hydrodynamic pressure, which reduces accuracy in turbulent flows. The results indicate that the HEC-RAS model performs well in simulating water quality in mountainous rivers, and improving the simulation of settled quality parameters and nitrate and phosphorus processes can further enhance the model's accuracy.

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References

  1. Abed, B. S., Daham, M. H., & Al-Thamiry, H. A. (2020). Assessment and modelling of water quality along Al-Gharraf River (Iraq). Journal of Green Engineering, 10, 13565-13579.
  2. Chow, V. T., Maidment, D. R., & Mays, L. W. (1988). Applied Hydrology. McGraw-Hill.
  3. Environmental Protection Agency. (2021). Nutrient Pollution.
  4. Environmental Protection Organization of the Islamic Republic of Iran. (2019). Report on the status of surface water in Iran. In Persian.
  5. Hydrologic Engineering Center. (2016). HEC-RAS user manual. S. Army Corps of Engineers.
  6. Jung, W. S., & Kim, Y. D. (2019). Effect of abrupt topographical characteristic change on water quality in a river. KSCE Journal of Civil Engineering, 23(5), 1981-1990.
  7. Kalathil, R., & Chandra, S. (2021). The influence of different morphological units on the turbulent flow characteristics in step‑pool mountain streams. Scientific Reports, 11, 199564. doi:10.1038/s41598-021-99564-7.
  8. Karimi Gashnei, A., & Salaridaragi, M. (2014). Qualitative classification of river water (Case study: Karun, Dez and Karkheh rivers). Journal of Environment and Development, 5(10), 29-38. (In Persian).
  9. Kraemer, B. M., Pilla, R. M., Woolway, R. I., et al. (2022). Lakes in hot water: The impacts of a changing climate on aquatic ecosystems. BioScience, 72(11), 1050-1066.
  10. Mafinge, K., Hai-Long, Y., & Kongolo, K. (2022). Development and application of integrated catchment and surface water quality model in river network area: A review. International Journal of Scientific and Research Publications (IJSRP), 12(4), 93-102.
  11. Mat Saad, A., Abu Hassan Asari, F. F., Affandi, S., & Zid, A. (2022). River pollution: A mini review of causes and effects. Journal of Tourism, Hospitality and Environment Management, 7(29), 139-151.
  12. Moghiminezhad, S., Ebrahimi, K., & Kerachian, R. (2018). Investigation of seasonal self-purification variations of Karun River, Iran. Amirkabir Journal of Civil Engineering, 49(4), 621-634. (In Persian).
  13. Paixao, M. A., & Kobiyama, M. (2019). Relevant parameters for characterizing mountain rivers: A review. Journal of Mountain Science, 16(7), 1500-1515.
  14. Pourfallah Koushali, H., Mastuori, R., & Khaledian, M. (2023). A modelling approach for flooding effects on water quality of Zarjoob River using HEC-RAS. Iranian Journal of Irrigation and Water Engineering, 52(4), 403-422. (In Persian).
  15. Prabu, S., Suriyaprakash, T. N. K., Kandasamy, R., & Rathinasabapathy, T. (2016). Effective waste water treatment and its management. In Handbook of Research on Waste Management Techniques for Sustainability (pp. 321-347). IGI Global.
  16. Radfar, M., & Alipour Nasirmahale, F. (2024). Modeling and investigation of annual nitrate pollution trend of Tajan River with QUAL2Kw and HEC-RAS. Irrigation Sciences and Engineering, 47(2), 87-104. (In Persian).
  17. Ramlau-Hansen, C. H., Bay, B., & Knudsen, U. B. (2020). Association between drinking water nitrate and adverse reproductive outcomes: A systematic PRISMA review. Water, 12(8), 2287.
  18. Roshangar, K., & Davodi, S. (2023). Modeling dissolved oxygen using deep learning and advanced prediction methods. Journal of Water and Irrigation Management, 13(1), 157-170. (In Persian).
  19. Soleimani, P. (2021). Modeling the water quality of Doiraj River using HEC-RAS. Master's thesis, Water Science and Engineering - Water Structures. )(In Persian.
  20. Taralgatti, P. D., Pawar, R. S., Pawar, G. S., Nomaan, M. H., & Limkar, C. R. (2020). Water quality modeling of Bhima River using HEC-RAS software. International Journal of Engineering and Advanced Technology (IJEAT), ISSN: 2249-8958.
  21. Torabizadeh, A., Tahershamsi, A., & Tabatabai, M. R. M. (2018). Measurement of dimensionless Chezy coefficient in step-pool reach (Case study of Dizin River in Iran). Flow Measurement and Instrumentation, 64, 190-193.
  22. Ward, M. H., deKok, T. M., Levallois, P., Brender, J., Gulis, G., Nolan, B. T., & VanDerslice, J. (2005). Workgroup report: Drinking-water nitrate and health—Recent findings and research needs. Environmental Health Perspectives, 113(11), 1607-1614.
  23. Ward, M. H., Jones, R. R., Brender, J. D., de Kok, T. M., Weyer, P. J., Nolan, B. T., Villanueva, C. M., & van Breda, S. G. (2018). Drinking water nitrate and human health: An updated review. International Journal of Environmental Research and Public Health, 15(7), 1557.
  24. World Health Organization (WHO). (2022). Guidelines for Drinking-Water Quality: Fourth Edition Incorporating the First and Second Addenda (4th ed.). Geneva, Switzerland: World Health Organization.
  25. Xiao, L., Chen, Z., Zhou, F., Ben Hammouda, S., & Zhu, Y. (2020). Modeling of a surface flow constructed wetland using the HEC-RAS and QUAL2K models: A comparative analysis. Wetlands, 40(6), 2235-2245.
Water and Irrigation Management
Volume 15, Issue 1
May 2025
Pages 19-36

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