@article { author = {Hayatgheibi, F. and Shahnoushi, N. and Ghahreman, B. and Samadi, H. and Ghorbani, M. and Sabouhi, Mahmood}, title = {Environmental Flow Assessment of Karun River in Upstream and Downstream of Beheshtabad Dam}, journal = {Water and Soil}, volume = {35}, number = {3}, pages = {319-333}, year = {2021}, publisher = {Ferdowsi University of Mashhad}, issn = {2008-4757}, eissn = {2423-396X}, doi = {10.22067/jsw.2021.67064.0}, abstract = {Introduction: The development of water resources in many cases has led to increased economic welfare, improved living and health standards, food production, etc. However, in some cases due to the insufficient attention to all aspects of these projects, the irreparable environmental effects and subsequent social and economic effects have been imposed on society. Paying attention to environmental water requirements is one of the most important issues in decision making in water resources development plans. The objective of this study is to assess river environmental water requirements in upstream and downstream of Beheshtabad Dam. Beheshtabad Dam has designed to build on the Karun River for water transfer from Karun to Zayanderood basin. But it has not been implemented due to the various problems and challenges. Materials and Methods: Protecting and restoring river flow regimes and hence, the ecosystems they support by providing environmental flows has become a major aspect of river basin management. Environmental flows describe the quantity, timing, and quality of water flows required to sustain freshwater,estuarine ecosystems,the human livelihoods, and well-being that depend on these ecosystems. Over 200 approaches for determining environmental flows now exist and used or proposed for use in more than 50 countries worldwide. In the present study, hydrological methods have been used. These methodes include Tennant and modified Tennant, Flow Duration Curve (FDC) and FDC shifting (for different environmental management classes). For this purpose, four hydrometric stations (three stations upstream and one station downstream of the dam) have been selected. Results and Discussion: The results of the study showed that the river water flow had not been sufficient to meet environmental water requirements in several cases, especially in years when the region was experiencing mild to moderate drought conditions. According to the Tennant method, the minimum environmental flow requirement averages based on Beheshtabad, DezakAbad, Kaj, and Armand stations data were 3.80, 5.06, 6.99, 22.01 m3/s, respectively. Using the mentioned stations data, , the minimum environmental flow requirement averages were 3.62, 6.07, 7.91, 23.67 m3/s based on the modified Tennant method. According to the flow duration curve method, minimum environmental flow requirements (Q95) were 1.96, 5.1, 8.32, 30.62 m3/s, using data collected from Beheshtabad, DezakAbad, Kaj, and Armand stations, respectively. The results of the flow duration curve shifting method indicated that the river water flow did not meet the river environmental water requirements in different environmental management classes in some months and years. Comparative results of different methods revealed that the minimum environmental flow requirement of Beheshtabad River upstream of Beheshtabad Dam was 1.22-16.75 m3/s from September to April (based on FDC shifting method, class C). The estimated minimum environmental flow for Koohrang River was 3.69-16.81 m3/s from September to April. The downstream of the dam, Karun River requires a minimum flow rate of 20.8-73.29 m3/s from September and October to April (based on FDC shifting method, class E). Conclusion: According to the results of various methods used in this study, the Karun River flow is not enough to meet the minimum river environmental water requirements in some years and months. Therefore, decision-makers must pay attention to the environmental water requirements in decisions related to the development plans and water transfer from this river. It should be noted that the river environmental water requirements have not been met completely when the region has experienced moderate or mild drought, which would be more acute in cases of more severe drought conditions. Therefore, the current surplus water of this basin may not be a sustainable source to transfer to another basin.}, keywords = {BeheshtAbad Dam,Environmental water requirement,Hydrological methods,Karun River,Water transfer}, title_fa = {برآورد حداقل جریان آب زیست‌محیطی مورد نیاز رودخانه کارون در بالادست و پایین‌دست سد بهشت‌آباد}, abstract_fa = {هرچند توسعه منابع آبی در موارد متعددی به افزایش رفاه اقتصادی، بهبود استاندارهای زندگی و بهداشتی، تولید غذا و غیره منجر شده است، اما در برخی از موارد به‌دلیل عدم توجه کافی به گستردگی حوزه‌ی تأثیرگذاری این طرح‌ها، آثار زیست‌محیطی و متعاقب آن اجتماعی و حتی اقتصادی جبران‌ناپذیری بر جامعه تحمیل شده است. توجه به نیاز آب زیست‌محیطی رودخانه‌ها یکی از موارد بسیار مهم در تصمیم‌گیری‌های مربوط به طرح‌های توسعه منابع آب می‌باشد. بنابراین در مطالعه حاضر تلاش شده است با استفاده از روش‌های هیدرولوژیکی، نیاز آب زیست‌محیطی در بالادست و پایین‌دست محل درنظر گرفته شده برای احداث سد پروژه جدید انتقال آب بهشت‌آباد، محاسبه گردد. براساس نتایج حاصل در بالادست محل سد، حداقل جریان زیست‌محیطی مورد نیاز رودخانه بهشت‌آباد بین 22/1 مترمکعب بر ثانیه برای شهریور تا 75/16 متر مکعب بر ثانیه برای فروردین برآورد شده است. حداقل جریان زیست‌محیطی برآورد شده برای رودخانه کوهرنگ نیز از 69/3 متر مکعب بر ثانیه برای شهریور تا 81/16 متر مکعب بر ثانیه برای فروردین متغیر می‌باشد. همچنین در پایین‌دست سد در محدوده ایستگاه ارمند، رودخانه کارون به حداقل جریان 8/20 متر مکعب بر ثانیه برای ماه‌های شهریور و مهر تا 29/73 مترمکعب بر ثانیه برای ماه فروردین نیاز دارد. نتایج حاصل نشان می‌دهد در موارد متعددی به‌ویژه در سال‌هایی که منطقه با خشکسالی خفیف تا متوسط مواجه بوده، جریان آب مشاهداتی رودخانه برای تأمین حداقل نیازهای زیست‌محیطی آن کافی نبوده است. بر این اساس، به نظر می‌رسد منابع آب محدوده مورد بررسی نمی‌تواند به عنوان منبع پایداری برای انتقال آب درنظر گرفته شود.}, keywords_fa = {انتقال آب,رودخانه کارون,روش‌های هیدرولوژیکی,سد بهشت‌آباد,نیاز آب زیست‌محیطی}, url = {https://jsw.um.ac.ir/article_39910.html}, eprint = {https://jsw.um.ac.ir/article_39910_6289816886d87453b977b1667f5ca9fc.pdf} }