Evaluating the Performance of Drainage System in Dropping Water Table Elevation in Shiraz Plain

Document Type : Research Paper

Authors

1 Science Assistant, Dept. of Civil Eng., Payam Noor University of Shahrekord

2 Assoc.Prof. Dept. of Civil Eng., Shiraz University, Shiraz

3 M.Sc. Student of Soil Physics and Conservation, Callege of Agriculture, Shahrekord University, Shahrekord

Abstract

Shiraz plain is facing elevated groundwater level problem in its south and south-eastern regions due to increasing population, conversion of farmlands and gardens into residential areas, and destruction of old Qanats that used to drain the plain. To overcome this problem, construction of three drainage aqueducts in the plain started since 2003. So far, more than half of one main aqueduct, with a length of ~15 km, has been constructed at eastern Shiraz. In this study, performance of the drainage system in dropping groundwater level in the plain has been evaluated under different scenarios. First, the hydraulic behavior of Shiraz plain aquifer was modeled using PMWIN. Besides the main aqueducts, measured precipitation and evaporation, recharge and discharge from the aquifer by remaining old aqueducts, wells, and Khoshk and Chenar-Rahdar rivers, and returned wastewater were all considered in the model. After model calibration and verification, the required parameters were determined and groundwater level in the plain was predicted for different scenarios at the end of aqueduct construction. Results reflect a good performance for aqueducts in all scenarios as evidenced by large volumes of drained water in comparison to other inflow and outflows of water in the aquifer. As expected, the lowest inflow, outflow, and drained water were observed in the plain during the drought (3rd scenario), and the highest flows during the wet years (4th scenario). Results indicate that in order for groundwater level to drop to the expected extent, lateral aqueducts should also be constructed otherwise the water drained by aqueducts will be less than half of the expected value.

Keywords


1- Bakker, M. (1999). “Simulating groundwater flow in multi-aquifer systems with analytical and numerical Dupuit models.” J. of Hydrology, 222, 55-64.
2- Anderson, E.I. (2005). “Modeling groundwater-surface water interactions using Dupuit approximation.” J. of Advances in Water Resources, 28, 315-327.
3- Knowles, I., and Yan, A. (2007). “The reconstruction of groundwater parameters from head in an unconfined aquifer.” J. of Computational and Applied Mathematics, 208, 72-81.
4- Mukhopadhyay, A., Al-Sulaimi, J., and Barrat, M. J. (1994). “Numerical modeling of groundwater resource management options in Kuwait.” Groundwater, 32(6), 917-928.
5- Ramireddygari, S. R., Sophocleous, M. A., Koelliker, J. K., Perkins, S. P., and Govindaraju, R. S. (2000). “Development and application of a comprehensive simulation model to evaluate impacts of watershed structures and irrigation water use on stream flow and groundwater: The case of wet walnut Creek watershed, Kansas, USA.” J. of Hydrology, 236 (3), 223-246.
6- Rezaei, H., and Mousavi, S.A. (2003). “Study of Bajgah plain groundwater situation using the finitedifference there dimensional modular Modflow model.” Proc. of the Second National Student Conf. on Water and Soil Resources, Shiraz University, 907-916. (In Persian)
7- Kamali, G. (2003) “Investigating caases of groundwater uplift in urban aeras and its adverse environmental consequences (with due attention to shiraz Plain).” Proc. of the 8th National Seminar on Irrigation and Evaporation Reduction, Shahid Bahonar University, Kerman. (In Persian)
8- Jiao, J. J., and Leaner, D. N. (1996). “Using sensitivity analysis to assist parameter zonation in groundwater flow model.” Water Resources Bulletin, 32(1), 75-78.
9- Osman, Y. Z., and Bruen, M. P. (2002). “Modeling stream-aquifer seepage in an alluvial aquifer: An improved loosing- stream package for MODFLOW.” J. of Hydrology, 264, 69-86.
10- Johannes, H. A. (2004). “Modeling water balance in Rio Turbio aquifer, Mexico.” M.Sc. Thesis, Wagenin Gen University Mexico.
11- Samani, N., Kompani-Zare, M., and Barry, D. A. (2004). “MODFLOW equipped with a new method for the accurate simulation of axisymmetric flow.” J. of Advances in Water Resources, 27, 31- 45.
12- Rodriguez, L. B., Cello, P. A., Vionnet, C. A., and Goodrich, D. (2008). “Fully conservative coupling of HEC-RAS with MODFLOW to simulate stream-aquifer interactions in a drainage basin.” J. of Hydrology, 353, 129-142.
13- Rosemary, W. H. C., Greg, M. P., Earman, S., and Ronald, L. H. (2008). “A comparison of groundwater fluxes computed with MODFLOW and a Mixing model using Deuterium: Application to the eastern Nevada test site and vicinity.” J. of Hydrology, 361, 371- 385.
14- Rahimi, A., and Sedehi, M. (2005). “Predication of groundwater level changes in the plain of hamedan-Bahar using time series model.” J. of Water and Wastewater, 51, 42-49. (In Persian)
15- Alkhamis, R., Kariminasab, S., and Aryana, F. (2007). “Investigating the effect of land subsidence due to groundwater discharges on well casing damage.” J. of Water and Wastewater, 60, 77-87. (In Persian)
16- Safari, H., Afshar, A., Ghaheri, A., Abrishamchi, A., and Tajrishi, M. (2007). “A quality- quantity simulation model for stream-aquifer interaction.” J. of Water and Wastewater, 61, 2-14. (In Persian)
17- Asghari Moghadam, A., Nourani, V., and Kord, M. (2009). “Using genetic algorithm of estimate hydraulic parameters of unconfined aquifers.” J. of Water and Wastewater, 69, 73-79. (In Persian)
18- Fars Regional Water Organization. (1996). Reports on Shiraz plain, studies, Shiraz. (In Persian)
19- Tehran, K., and Nabavi, H. (1985). Brochures for stratigraphic geology and Zagros geological reports, Iran Surving Organization, Tehran. (In Persian)
20- Parab Consulting Eng. Co. (1993. Feasibility studies on water table drawdown in southeastern Shiraz and its transfer to Sarvestan Plain, Vol. 3, Shiraz. (In Persian)