برآورد نیازآبی اکولوژیک تالاب‌های بین‌المللی بختگان و طشک و سهم عوامل اقلیمی و انسانی در خشکیدگی آنها

نوع مقاله : مقاله پژوهشی

نویسندگان

1 بخش مهندسی منابع طبیعی و محیط زیست، دانشکده کشاورزی، دانشگاه شیراز، شیراز، ایران

2 اداره کل حفاظت محیط زیست فارس، شیراز، ایران

چکیده

تالا‌ب‌ بین‌المللی بختگان و طشک یکی از بزرگترین سایت‌های تالابی ایران است که در سال‌های اخیر خشک شده است. این تحقیق با هدف برآورد نیاز آبی اکولوژیک تالاب بختگان انجام شد. بدین منظور ابتدا تغییرات درازمدت داده‌های پایه شامل بارش در ایستگاه‌های منتخب، شاخص خشکسالی و تغییرات آورد رودخانه‌های کر و سیوند بعنوان منابع اصلی تغذیه تالاب‌های بختگان و طشک آنالیز شد. برای برآورد نیاز آبی اکولوژیک ابتدا تغییرات مساحت تالاب در درازمدت بررسی شد. همچنین تغییرات گونه‌ی فلامینگو بعنوان گونه شاخص تالاب هم‌راستا با تغییرات تالاب بررسی شد. میزان حقابه‌ی اکولوژیک مورد نیاز برای حفظ کارکردهای اکولوژیک تالاب‌های بختگان و طشک از رودخانه کر-سیوند در محل ورود به تالاب در شرایط خشکسالی، نرمال و ترسالیبه ترتیب 700 میلیون متر مکعب، 826 میلیون متر مکعب و 1037 میلیون مترمکعب برآورد گردید. بهترین زمان رهاسازی حقابه تالاب از منابع آبی بالادست به ترتیب اولویت، ماه‌های بهمن، اسفند و فروردین پیشنهاد می‌گردد. مهمترین عوامل موثر در خشکیدگی تالاب‌ها، افزایش سطح زیرکشت بالادست حوضه در اثر افزایش بیش از اندازه‌ی جمعیت حوضه، ، مدیریت ناصحیح و ناپایدار منابع آبی، احداث سدهای جدید در بالادست حوضه، کاهش بارندگی و افزایش شدت خشکسالی در دو دهه‌ی اخیر در منطقه بوده است.

کلیدواژه‌ها


عنوان مقاله [English]

Estimation of ecological water flow requirements of Bakhtegan and Tashk internationally important wetlands and contribution of climatic and anthropogenic factors in their drought

نویسندگان [English]

  • Arya Vazirzadeh 1
  • Sasan Kafaei 2
1 Department of Natural Resources and Environmental Engineering, School of Agriculture, Shiraz University, Shiraz 71441-65186, Iran
2 Fars Department of Environment, Shiraz, Iran.
چکیده [English]

Bakhtegan and Tashk internationally important Wetland is one of the largest wetland sites in Iran that has dried up in recent years. This study was conducted to estimate the ecological water requirements of this wetland site. For this purpose, first the basic data including long term trend of rainfall, SPI and flow rates of Kor and Sivand rivers as the main feeding sources of wetlands were analysed. Then, to estimate the ecological water requirement, changes in the wetland area in the long run were investigated. Also, changes in Flamingo species as an ecologic index were studied in line with wetlands surface changes. The results showed that the amount of ecological water required to maintain the ecological functions of Bakhtegan and Tashk wetland from the Kor-Sivand River at the entrance of the wetland in dry, normal and wet yearsare 700, 826 and 1037 million cubic meters, respectively. The best times to release the water from upstream sources are February, March and April, respectively. The most important factors contributing in the drought of wetlands include   increase of agrilands to fed excessive increase of the basin population, non-sustainable management of water resources, construction of new dams in watershed, significant reduction of rainfall and increasing of dry seasons during last two decades.

کلیدواژه‌ها [English]

  • Bakhtegan
  • Tashk
  • wetland
  • Climate
  • ecological water requirements
Amarasinghe, A. G. (2020). Analysis of long-term rainfall trends in sri lanka using chrips estimates. American Journal of Multidisciplinary Research & Development (AJMRD)2(11), 34-44.
Bagheri, M.H., Bagheri, A, Sohooli, Gh. A. (2016). Analysis of changes in the Bakhtegan lake water body under the influence of natural and human factors. Water Research of Iran, 12 (3), 1-11. In Farsi.
Ebrahimi-Khusfi, Z., Nafarzadegan, A. R., Ebrahimi-Khusfi, M., & Zandifar, S. (2022). Monitoring the water surface of wetlands in Iran and their relationship with air pollution in nearby cities. Environmental Monitoring and Assessment194(7), 1-20.
Fennessy, M. S., Jacobs, A. D., & Kentula, M. E. (2007). An evaluation of rapid methods for assessing the ecological condition of wetlands. Wetlands27(3), 543-560.
Hamidifar, H., Akbari, F., & Rowiński, P. M. (2022). Assessment of Environmental Water Requirement Allocation in Anthropogenic Rivers with a Hydropower Dam Using Hydrologically Based Methods—Case study. Water14(6), 893.
Harbor, J. M. (1994). A practical method for estimating the impact of land-use change on surface runoff, groundwater recharge and wetland hydrology. Journal of the American Planning Association60(1), 95-108.
Jensen, M. E. (2010). Estimating evaporation from water surfaces. In CSU/ARS Evapotranspiration Workshop, Fort Collins, CO (pp. 1-27).
Jin, X., Yan, D., Wang, H., Zhang, C., Tang, Y., Yang, G., & Wang, L. (2011). Study on integrated calculation of ecological water demand for basin system. Science China Technological Sciences54(10), 2638-2648.
KhanAhmadi, H., Saghafian, B., & Daneshkar, A. P. (2021). Forecasting the area of the Bakhtegan and Tashk Lake using remote sensing and climatic factors. Iran Water Resources Research 17(1)-151-165.
Mozafari, M, Hosseini, Z, Fijani, E. (2021). The impacts of Mollasadra and Sivand dams on the drought of Bakhtegan and Tashk, the fortieth Symposium of Earth Science, Tehran, Iran.
Rawat, K. S., Singh, S. K., & Szilard, S. (2021). Comparative evaluation of models to estimate direct runoff volume from an agricultural watershed. Geology, Ecology, and Landscapes5(2), 94-108.
Rooyan consulting Co (2008). Environmental study of Bakhtegan and Tashke lakes. Fars Regional Water Co. 137 pp. In Farsi.
Sajedipour, S., Zarei, H., & Oryan, S. (2017). Estimation of environmental water requirements via an ecological approach: a case study of Bakhtegan Lake, Iran. Ecological engineering100, 246-255.
Tarazkar, MH, Zibaei, M., Soltani, Gh. (2016). Identification and ranking of Bakhtegan International Wetlands restoration strategies with Fuzzy TOPSIS approach. Wetland Ecobiology, 8(27)-23-40.
Teymoorey, I., Pour Ahmad, A., Habibi, L., & Salarvandian, F. (2011). Using the fuzzy C-means classification method for the need water determination of Lakes Bakhteghan & Tashk. Physical Geography Research Quarterly43(77), 21-37.
Tiner, R. W. (1996). Wetland definitions and classifications in the United States. JD Fretwell, JS Williams, and P. J. Redman (compilers) National Water Summary on Wetland Resources. US Geological Survey, Reston, VA, USA. Water-Supply Paper, 2425, 27-34.
Torabi, Gh., Aghamohammadi, H., Behzadi, S. (2018). Monitoring of Bakhtegan lake and sourended lands using satellite images and computational intelligence. Ecohydrology, 5 (1). 263-269. In Farsi.
 Vazirzadeh, A. (2021). The impact of human activities on the diversity of wetland ecosystems in fars province: a look at the way we have traveled and the road ahead. 1st Fars Biodiversity Conference, March 2021, Shiraz University, Iran, 227-237. In Farsi.
Wittmann, F., Householder, E., De Oliveira, A., Lopes, A., Junk, W., & Piedade, M. (2015). Implementation of the Ramsar convention on South American wetlands: an update.