بررسی آزمایشگاهی تأثیر دیوار آب‏‏بند بر کاهش نفوذ شوری در آبخوان‏های ساحلی با استفاده از تکنیک پردازش تصویر

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانش‌آموخته کارشناسی ارشد مهندسی عمران، گرایش مدیریت منابع آب، دانشکده مهندسی عمران، دانشگاه صنعتی جندی‌شاپور دزفول.

2 استادیار گروه آب، دانشکده مهندسی عمران، دانشگاه صنعتی جندیشاپور دزفول.

3 استادیار گروه مهندسی عمران، دانشکده فنی و مهندسی، دانشگاه آزاد اسلامی، واحد تهران مرکزی.

چکیده

شناخت مسئله نفوذ آب شور در آبخوان‌‏های ساحلی، نقش مؤثری بر مدیریت منابع آب زیرزمینی مناطق ساحلی دارد. در این تحقیق کاهش نفوذ شوری در یک آبخوان ساحلی در مقیاس آزمایشگاهی با در نظر گرفتن دیوار آب‌‏بند و بدون دیوار آب‏‌بند، محیط همگن و ناهمگن در حالت ماندگار بررسی شده است. برای این منظور، با تعریف سناریوهای مختلف در آزمایشگاه، پارامترهای مؤثر در مسأله در نظر گرفته شده و جهت تسهیل در تحلیل پسرفت شوری، بی‌‏بعد شدند. داده‏‌های آزمایشگاهی با استفاده از تکنیک پردازش تصویر آنالیز گردید و خطوط هم‏غلظت 5%، 95% و ناحیه انتقالی آب‏شور مابین این خطوط (ناحیه پراکندگی هیدرودینامیکی آب شور) مشخص گردید. نتایج نشان داد در محیط ناهمگن‏ میزان پیشروی گوه آب‏‌شور افزایش یافته و میزان تأثیرگذاری اجرای دیوار آب‌‏بند در محیط همگن بیشتر از محیط ناهمگن می‌‏باشد. حداکثر اثرگذاری اجرای دیوار آب‌‏بند در کاهش درصد پیشروی گوه آب شور در محیط همگن 100% و در محیط ناهمگن 92% به‏ دست آمد. بهترین محل قرارگیری دیوار آب‏‌بند در این پژوهش با توجه به ابعاد طولی 1‏ و ارتفاع 0/6 متری مخزن آزمایش، در 0/8 متری از کف و در فاصله 0/2 متری از مرز آب شور به دست آمد. از نمودارهای بی‏‌بعد حاصل می‏‌توان در طراحی بهینه دیوار آب‏‌بند در شرایط واقعی کمک گرفت.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Experimental Investigation on the Impact of Cutoff Wall on Seawater Recession in Coastal Aquifers Using Image Processing Technique

نویسندگان [English]

  • Ali Zohrabi Motlagh 1
  • Mehrdad Shahrbanouzadeh 2
  • S. Sadjad Mehdizadeh 3
1 M.Sc. Graduate in Water Resource Engineering, Department of Civil Engineering, Jundi-Shapur University of Technology, Dezful, Iran.
2 Assistant Professor, Department of Civil Engineering, Jundi-Shapur University of Technology, Dezful, Iran.
3 Assistant Professor, Department of Technology and Engineering, Islamic Azad University, Central Tehran Branch, Tehran, Iran.
چکیده [English]

Understanding the problem of seawater intrusion (SWI) in coastal aquifers plays an essential role in managing groundwater resources in these areas. This research examines seawater recession (SWR) in coastal aquifer in a laboratory scale; considering both homogeneous and heterogeneous environments, with and without a cutoff wall, and in a steady-state condition. For this purpose, different scenarios are defined in the laboratory, and all the effective parameters in the problem are considered and dimensionalized to facilitate salinity analysis. The laboratory data were analyzed using image processing technique and isolines with the concentration of 5%, 95%, and transition zone (Seawater hydrodynamic dispersion zone) were determined. The results showed that in a heterogeneous case, the rate of SWI was higher, and the efficiency of cutoff wall performance was higher in the homogenous case than the heterogeneous case. According to the present study results, the maximum effectiveness of cutoff wall in SWR percentage was obtained in 100% homogeneous and 92% for the heterogeneous case. The best location of the cutoff wall in this study with tank dimensions of 1 and 0.6 meters obtained 0.8 m from the tank bed and 0.2 m from the saline boundary. The achieved graphs helped to design the cutoff wall in actual media optimally.
 

کلیدواژه‌ها [English]

  • Seawater Intrusion
  • Coastal Aquifer
  • Cutoff Wall
  • Freshwater
  • Image Processing Technique
Abarca E, Vazquez-Sune E, Carrera J, Capino B, Gamez D, and Batlle F (2006) Optimal design of measures to correct seawater intrusion. Water Resource Research 42(9):W09415
Abd-Elhamid HF, Javadi AA (2011) A density dependent finite element model for analysis of saltwater intrusion in coastal aquifers. Journal of Hydrology 401:259-271
Abdollahi-Nasab A, Boufadel MC, Li H, and Weaver JW (2010) Saltwater flushing by freshwater in a laboratory beach. Journal of Hydrology 386:1-12
Abdoulhalik A, Ahmed AA (2017) The effectiveness of cutoff walls to control saltwater intrusion in multi-
layered coastal aquifers: Experimental and numerical study. Journal of Environmental Management 199:62-73
Abdoulhalik A, Ahmed A, and Hamill G (2017) A new physical barrier system for seawater intrusion control. Journal of Hydrology 549:416-427
Anwar HO (1983) The effect of a subsurface barrier on the conservation of fresh water in coastal aquifers. Water Research 17(10):1257–1265
Chang SW, Clement TP (2012) Experimental and numerical investigation of saltwater intrusion dynamics in flux-controlled groundwater systems. Water Resource Research 48(9):1–10
Feseker T (2007) Numerical studies on saltwater intrusion in a coastal aquifer in northwestern Germany. Hydrogeology Journal 15(2):267–279
Goswami R, Ambale B, and Clement TP (2008) Estimating errors in concentration measurements obtained from image analysis. Vadose Zone Journal 8(1):108–118
Goswami R, Clement TP (2007) Laboratory scale investigation of saltwater intrusion dynamics. Water Resource Research 43(4)
Gualbert HP (2001) Improving fresh groundwater supply: Problems and solutions. Ocean Coastal Management 44(5–6):429–449
Jakovovic D, Werner AD, and Simmons CT (2011) Numerical modelling of saltwater up-coning: Comparison with experimental laboratory observations. Journal of Hydrology 402(3):261-273
Japan Green Resources Agency (2004) Technical reference for effective groundwater development. Kanagawa Japan
Kaleris VK, Ziogas AI (2013) The effect of cutoff walls on saltwater intrusion and groundwater extraction in coastal aquifers. Journal of Hydrology 476:370-383
Ketabchi H, Mahmoodzadeh D, Ataie-Ashtiani B, and Simmons CT (2016) Sea-level rise impacts on seawater intrusion in coastal aquifers: Review and integration. Journal of Hydrology 535(C):235-255
Luyun JrR, Momii K, and Nakagawa K (2009) Laboratory-scale saltwater behavior due to subsurface cutoff wall. Journal of Hydrology 377(3):227-236
Luyun JrR, Momii K, and Nakagawa K (2011) Effects of recharge wells and flow barriers on seawater intrusion. Ground Water 49(2):239–249
Mahesha A (2009) Conceptual model for the safe withdrawal of freshwater from coastal aquifers. Journal of Environmental Engineering 135(10):980-988
Mahesha A, Lakshmikant P (2014) Saltwater intrusion in coastal aquifers subjected to freshwater pumping. Journal of Hydrologic Engineering 19(2):448-456
Mahmoodzadeh D, Karamouz M (2018) Seawater intrusion in heterogeneous coastal aquifers under flooding events. Journal of Hydrology 568:1118-1130
Mahmoodzadeh D, Ketabchi H, Ataie-Ashtiani B, and Simmons CT (2014) Conceptualization of a fresh groundwater lens influenced by climate change: A modeling study of an arid-region island in the Persian Gulf, Iran. Journal of Hydrology 519(A): 399-413
Mahmoodzadeh D, Ketabchi H, and Ataie-Ashtiani B (2016) Effects of sea level rise and recharge rate variations on seawater Intrusion in confined aquifer. Journal of Hydraulics 10(4):1-15 (In Persian)
Mehdizadeh SS, Werner AD, Vafaie F, and Badaruddin S (2014) Vertical leakage in sharp interface seawater intrusion models of layered coastal aquifers. Journal of Hydrology 519:1097–1107
Mehdizadeh SS, Vafaei F, and Abolghasemi H (2015) Assessment of sharp-interface approach for saltwater intrusion. Environment Earth Science 73(12):8345–8355
Mehdizadeh SS, Vafaei F (2016) Experimental and numerical investigation on saltwater intrusion into unconfined coastal aquifers. Journal of Oceanography 7(25):67-76 (In Persian)
Najmaei M (1990) Engineering hydrology. Amirkabir University Press, 440 p (In Persian)
Osuga K (1997) The development of groundwater resources on the Miyakojima islands. Freshwater Resources in Arid Lands, UNU Global Environmental Forum V. United Nations University Press, Tokyo
Pool M, Carrera J (2010) Dynamics of negative barriers to prevent seawater intrusion. Hydrogeology Journal 18(1):95–105
Potter MC, Wiggert DC, Ramadan B, and Shih TI-P (2012) Mechanics of fluids 4th Edition. Cengage Learning, Inc, 818p
Rezapour A, Saghravani SF, and Ahmadifard A (2018) Study of saltwater intrusion in the coastal aquifers under transient condition using image processing and numerical modeling. Journal of Hydraulics 13(2):69-82 (In Persian)
Robinson G, Ahmed AA, and Hamill GA (2016) Experimental saltwater intrusion in coastal aquifers using automated image analysis: Applications to homogeneous aquifers. Journal of Hydrology 538:304–313
Robinson G, Hamill GA, and Ahmed AA (2015) Automated image analysis for experimental investigations of salt water intrusion in coastal aquifers. Journal of Hydrology 530:350–360
Sugio S, Nakada K, and Urish DW (1987) Subsurface seawater intrusion barrier analysis. Journal of Hydraulic Engineering ASCE 113(6):767–779
Thorenz C, Kosakowski G, Kolditz O, and Berkowitz B (2002) An experimental and numerical investigation of saltwater movement in coupled saturated–partially saturated systems. Water Resource Research 38(6)
Todd DK, Mays LW (2005) Groundwater hydrology. John Wiely and Sons, Inc, Third Edition, 656PP
Wilson JL, Sa da Costa A (1982) Finite element simulation of a saltwater/freshwater interface with indirect toe tracking. Water Resources Research 18(4):1069–1080
Zhang Q, Volker RE, and Lockington DA (2002) Experimental investigation of contaminant transport in coastal groundwater. Advances in Environmental Research 6(3):229-237
Xuan Y, Holly AM (2019) Mechanisms, configuration typology, and vulnerability of pumping-induced seawater intrusion in heterogeneous aquifers. Advances in Water Resources 128:117-128