تحلیل حساسیت روش‌های هیدرولیکی نسبت به روش‌های تأمین اطلاعات هیدروموفولوژیکی برای تعیین نیاز محیط زیستی

نوع مقاله : مقاله پژوهشی

نویسنده

دانشیار گروه مهندسی آب، دانشکده فنی و مهندسی، دانشگاه بین‌المللی امام خمینی (ره)، قزوین

چکیده

در این مقاله به اهمیت استفاده از روش‌های هیدرولیکی در تعیین جریان محیط زیستی پرداخته شد. روش هیدرولیکی برای تعیین نیاز محیط زیستی وابسته به مقاطع عرضی رودخانه است؛ ولی علی‌رغم استفاده گسترده، تاکنون پژوهشی در مورد ضوابط استخراج اطلاعات از این مقاطع صورت نگرفته است. در این پژوهش نشان داده شد که عمق مقاطع عرضی بر روی نتیجه حاصل از روش هیدرولیکی بسیار تأثیر‌گذار است. با در نظر گرفتن ماهی به‌عنوان گونه شاخص زیستگاه، لازم است عمق استخراج اطلاعات از مقطع عرضی به یک متر محدود شود. دومین عامل مهم در این روش، انتخاب میزان افزایش عمق در هر مرحله یعنی y∆ مناسب برای استخراج مشخصات هندسی و هیدرولیکی برای توسعه منحنی دبی- محیط خیس شده است، که در این پژوهش 1 سانتی‌متر به‌دست آمد. میزان عدم قطعیت دبی محیط زیستی محاسبه شده توسط روش هیدرولیکی برای تصمیم‌گیری در مورد تخصیص آب در مناطق پرتنش دارای اهمیت است. ضریب مانینگ یکی از مهم‌ترین عوامل مؤثر در تعیین جریان رودخانه است. با مطالعه انجام شده در محدوده‌ای معادل سه برابر انحراف از معیار ضریب مانینگ برای منطقه مطالعاتی ثابت شد که تأثیر این ضریب در تعیین دبی محیط زیستی در مقابل تخمین دبی رودخانه بسیار کمتر است.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Sensitivity Analysis of Hydraulic Methods Regarding Hydromorphologic Data Derivation Methods to Determine Environmental Water Requirements

نویسنده [English]

  • Alireza Shokoohi
Associate professor- Water engineering department- Faculty of technical and engineering- International University of Imam Khomeini
چکیده [English]

This paper studies the accuracy of hydraulic methods in determining environmental flow requirements. Despite the vital importance of deriving river cross sectional data for hydraulic methods, few studies have focused on the criteria for deriving this data. The present study shows that the depth of cross section has a meaningful effect on the results obtained from hydraulic methods and that, considering fish as the index species for river habitat analysis, an optimum depth of 1 m should be assumed for deriving information from cross sections. The second important parameter required for extracting the geometric and hydraulic properties of rivers is the selection of an appropriate depth increment; ∆y. In the present research, this parameter was found to be equal to 1 cm. The uncertainty of the environmental discharge evaluation, when allocating water in areas with water scarcity, should be kept as low as possible. The Manning friction coefficient (n) is an important factor in river discharge calculation. Using a range of "n" equal to 3 times the standard deviation for the study area, it is shown that the influence of friction coefficient on the estimation of environmental flow is much less than that on the calculation of river discharge.

کلیدواژه‌ها [English]

  • Environmental flow
  • Hydraulic Method
  • Maximum Curvature
  • Sensitivity and Uncertainty Analysis
1- Tharme, R.E. (2003). “A global perspective on environmental flow assessment: Emerging trends in the development and application of environmental flow methodologies for rivers.” J. of River Research and Applications, 19, 397-442.
2- Tharme, R.E. (1996). Review of international methodologies for the quantification of the instreamflow requirements of rivers, Water Law review Final Report for Policy Development for the Department of Water Affairs and Forestry, Pretoria, Freshwater Research Unit, University of Cape Town, South Africa.
3- King, J.M., Tharme, R.E., and De Villiers, M. (2000). Environmental flow assessments for rivers: Manual forthe building block methodology, Water Research Commission Technology Transfer Report No. TT 131/00. Pretoria, South Africa.
4- Arthington, A.H., King, J.M., O’Keeffe, J.H., Bunn, S.E., Day, J.A., Pusey, J., Bluhdorn, D.R., and Tharme, R.E. (1992). “Development of a holistic approach for assessing environmental flow requirements of riverine ecosystems.” Proc. An International Seminar and Workshop on Water Allocation for the Environment: The Centre for Water Policy Research, University of New England, Armidale, 69-76.
5- Tennant, D.L. (1976). “Instream flow regimens for fish, wildlife, recreation and related environmental resources.” J. of Fisheries, 1(4), 6-10.
6- Gippel, C.J., and Stewardson, M.J. (1998). “Use of wetted perimeter in defining minimum environmental flows.” J. of Regulated Rivers: Research and Management, 14, 53-67.
7- Jowett, I.G. (1997). “Instream flow methods: A comparison of approaches.” J. of Regulated Rivers: Research andManagement, 13, 115-127.
8- Shokoohi, A., and Hong, Y. (2011). “Using hydrologic and hydraulically derived geometric parameters of perennial rivers to determine minimum water requirements of ecological habitats (case study: Mazandaran Sea Basin-Iran).” J. of Hydrological Processes, 25, 3490-3498.
9- Shokoohi, A., and Hong, Y. (2011). “Determining the minimum ecological water requirements in perennial rivers using morphological parameters.” J. of Environmental Studies, 37(58), 117-128.
10- Smakhtin, V.U., Shilpakar, R.L., and Hughes, D.A. (2006). “Hydrology-based assessment of environmental flows: an example from Nepal.” J. of Hydrological Sciences, 51(2), 207-222.
11- Bovee, K.D. (1986). Development and evaluation of habitat suitability criteria for use in the instreamflow incremental methodology, USDI Fish and Wildlife Service Instream Flow Information Paper #21 FWS/OBS-86/7. 235 p, Washington, DC
12- Annear, T.C., and Conder, A.L. (1984). “Relative bias fisheries instream flow methods.” North AmericanJ.of Fisheries Management, 4, 531-539.
13- Kelly, M., Munson, A.B., Morales, J., and Leeper, D.A. (2007). Proposed minimum flows and levels fortheupper segment of the Braden river, from linger lodge to lorraine Road. Southwest Florida Water management district, USA.
14- Richardson, B.A. (1986). “Evaluation of instream flow methodologies for freshwater fish in New South Wales.” Campbell I.C. (EDs.), Stream protection, the management of rivers for instream uses, Water Studies Centre, Chisholm Institute of Technology, Caulfield, 143-167.
15- Goodman, A.W. (1980). Analytical geometry and the calculus, 4th Ed., Macmillan Pub. Co. Inc., NewYork.
16- Ab Energy Mohit. (2009). Comprehensive project of west of Mazandaran river engineering project;Hydrology Report, Co-consulting engineers Khazarab-Ab Energy Mohit, Mazandaran Regional Water Company, Energy Ministry of Iran. (In Persian)
17- Ab Energy Mohit. (2009). Comprehensive project of west of Mazandaran river engineering project; Environmental Recognition Report, Co-consulting engineers Khazarab- Ab Energy Mohit, Mazandaran Regional Water Company, Power ministry of Iran. (In Persian)
18- Abdoli, A., and Naderi, M. (2008). Khazar Sea southern basin fish biodiversity, 1st Ed., Abzian Scientific Pub., Tehran, Iran. (In Persian)
19- USACE. (1996). Risk-Based analysis for flood damage reduction studies, Manual No. 110-2-1619, USA.
20- Breine, J., Simoens, I., Haidvogl, G., Melcher, A., Pont, D., and Schmutz, S. (2005). “Manual for the application of the European Fish Index-EFI. A fish-based method to assess the ecological status of European rivers in support of the Water Framework Directive.” <http://fame.boku> (Sep. 7, 2012)
21- Hatfield, T., Lewis, A., Ohlson, D., and Bradford, M. (2003). Development of instream flow thresholds as guidelines for reviewing proposed water uses, Biritish Columbia Instream Flow Guidelines for Fish, BC.