Numerical simulation of pollutant flow path in groundwater of Birjand plain

Document Type : Complete scientific research article


1 Ph.D. Student of Water Resources, University of Birjand.

2 Corresponding Author, Associate Prof., Dept. of Water Science and Engineering, University of Birjand.

3 Professor, Dept. of Civil Engineering, University of Birjand.


Background and objectives: Groundwater reserves in Iran is one of the main sources of water supply that in recent decades, the emergence of factors such as development, increased groundwater extraction and drought has reduced the quantity and quality of these resources. Therefore, proper management should be done to protect and sustain these valuable reserves and to avoid further negative consequences as much as possible. Lack of proper management in the operation of Birjand aquifer, the necessary conditions for subsidence, an irreparable accident, provides this plain. Therefore, given the importance of these valuable reserves, appropriate strategies for the sustainability of these resources should be considered. By increasing awareness about the quality of groundwater in this area and simulating the transfer of potential contaminants in these waters, we can understand the direction and speed of contamination transfer, determine the areas that are at risk of groundwater pollution in the coming years. Identification and analysis of aquifer status were evaluated in order to evaluate the effects of management scenarios.
Materials and methods: At first, numerical modeling of Birjand aquifer was performed. MODFLOW numerical simulation of Birjand aquifer area was performed in two permanent and non-permanent modes in 2011. Then the hydraulic conductivity calibration was performed on the mentioned date and validated for two years 1391 and 1392. Then, the necessary scenarios for the project, considering different points for wastewater discharge and artificial feeding, were defined. Finally, the effects of reduction, increase and decrease of 20% harvest on pollutant movement were investigated using MODPATH.
Results: The calibration results show that the observed and calculated mid-level error (RMSE) is 1.071 meters, which is desirable. Also, the level calculated by the model indicates the movement of groundwater in the direction of the dominant slope of the region, ie from east and northeast to west and southwest. Also, the way particles move corresponds to the groundwater gradient and in the general direction from east to west. The length of motion of the particle at a given time in the eastern part of the aquifer is less than the western part.
Conclusion:According to the applied scenarios, it can be concluded that increasing and decreasing the withdrawal of Birjand groundwater by 20% does not make a significant difference in the direction and route of pollutant transfer during 10,000 days, but the artificial feeding scheme has a significant effect on the transfer Leaves pollutant particles. Therefore, due to the problems in the groundwater of Birjand, the implementation of artificial nutrition plan for this city is necessary.


1.Akbapour, A., Ghoochanian, E., and Behrooz, E. 2019. Assessment scenarios of water resources management in arid areas (Case Study: Birjand Plain, Iran). Journal of Hydrosciences and Environmeent. 3: 6. 52-62.
2.Akbarpour, A., Aghahoseinali, A., and Azizi, M. 2010. Groundwater exploitation management of Mokhtaran plain using the mathematical model of finite differences in GMS environment. 9th Iran Hydraulic Conference, Tehran, Iran Hydraulic Association, Tarbiat Modares University. (In Persian). 5: 7. 93-114.
3.Akbarpour, A., Etebari, B., and Barzanoni, S. 2011. Groundwater modeling in order to determine the quality of drinking water wells (Birjand case study). Fourth Water Resources Management Conference. (In Persian)
4.Anderson, M., and Woessner, W. 1991. Applied groundwater modeling simulation of flow and advective transport. Academic press. USA. first edition. 6: 5. 202-218.
5.Ansarifa, M.M., Salarijazi, M., Ghorbani, Kh., and Kaboli, A.R. 2019. Spatial estimation of aquifer’s hydraulic parameters by a combination of borehole data and inverse solution. Bulletin of Engineering Geology and the Environment. 79: 1-4.
6.Ansarifa, M.M., Salarijazi, M., Ghorbani, Kh., and Kaboli, A. R. 2020. Simulation of groundwater level in a coastal aquifer.  Marine Georesources & Geotechnology. 38: 3. 257-265.
7.Banzhad, H., Mohebzade, H., Ghobadi, M., and Heidari, M. 2013. Numerical simulation of flow and pollution transfer in groundwater A case study of Nahavand plain aquifer. Journal of Water and Soil, 2: 23. 57-43. (In Persian)
8.Farpour, A., Ramezini, Y.,  . 4: 8. 103-117.
9.Farpour, A., Ramezini, Y., and Akbarpour, A. 2018. Numerical simulation of the trend of chromium changes in the aquifer of Birjand plain. Iranian Journal of Irrigation and Drainage. 5: 12. 1216-1203. (In Persian)
10.Gelahar, L.J., and Axness, C.L. 1983. Three-dimensional stochastic analysis of macrodispersion in aquifers. Water Resources Research. 19: 1. 161-180.
11.Gholizade, H., and Samani, A. 2012. Investigation of surface and groundwater exchange by numerical analysis of well intake zone. National Conference on Water and Wastewater Engineering. March 30-8. Kerman.(In Persian)
12.Groundwater Quality Determination Instruction. 2013. Vice President for Strategic Planning and Supervision, Journal No. 621. (In Persian)
13.Harbaugh, A.W. 2005. The U.S. Geological Survey Modular Ground-Water Model (MODFLOW). U.S. Geological Survey, Reston, .  18: 2. 131-149.
14.Harden, RW. 2000. Brazing Regional Water Planning Area, Carrizo-Wilcox Ground Water Flow Model and Simulation Results. Associates  .6: 1. 93-115.
15.Heng Zhang, Yongxin Xu and Thokozani Kanyerere. 2019. A modelling approach to improving water security in a drought-prone area, West Coast, South Africa. Physics and Chemistry of the Earth. pp. 1474-7065.
16.Kersic, N. 1997. Quantitative Solution in Hydrology and Groundwater Modeling. Lewis Publishers. 461p.
17.Mashhadi, L., and Baghvand, A. 2010. Investigation and modeling of pollution caused by landfill waste on groundwater (Case study of Amanabad aquifer). The fourth conference and specialized exhibition of environmental engineering. Tehran. Faculty of Environment, University of  . 19: 3. 45-60.
18.Nobre, R.C.M., Filho, R., Mansur, W.J., Nobre, M.M.M., and Cosenza, C.A.N. 2007. Groundwater Vulnerability and Risk Mapping Using GIS, Modeling and a Fuzzy Logic Tool. Journal of Contaminant Hydrology. 94: 3-4. 277-92.
19.Pollock, D.W. 1994. User’s guide for MODPATH/MODPATH-PLOT, Version3: a particle tracking post-processing package for MODFLOW, the U.S. Geological Survey finite-difference groundwater flow model. Open-File Report 94-464, U.S. Geological  . 6: 2. 32-51.
20.Rejli, C., Rauber, M., and Huggenberger, P. 2003. Analysis of aquifer heterogeneity within a well capture zone. comparison of model data eith field experiment: acase study from the river Wiese, Switzerland, Aquat.65: 111-128.
21.Shojaie, A., and Samani, A. 2011. Optimization of pumping and treatment methods for groundwater treatment, Shiraz University, Master Thesis in Hydrology. 10: 4. 216-232. (In Persian  )
22.Thorley, M., and Callander, P. 2005. Christhurch city groundwater model. Environment Canterbury Report U05/53. 10p.
23.Wang, H.F., and Anderson, P. 1988. Introduction to Groundwaret Modeling: Finite Difference and Finite Element Methods. Academic Press, San Diego. 237p.
24.Wuolo, R.W., Dahlstrom, D.J., and Fairbrother, M.D. 1995. Wellhead protection area delineation using the analytic element method of ground water modeling. Groundwater.  71-83.