نوع مقاله : مقاله پژوهشی
نویسندگان
1 دانشجوی دکترا رشته مهندسی آب، گرایش سازه های آبی دانشکده کشاورزی، دانشگاه شهید باهنر کرمان، کرمان، ایران
2 بخش مهندسی آب دانشکده کشاورزی دانشگاه شهید باهنر کرمان ایران
3 بخش مهندسی آب، دانشکده کشاورزی، دانشگاه شهید باهنر کرمان، کرمان ، ایران.
4 گروه علوم زندگی و محیط زیست، دانشگاه کارلستاد، وارملند، سوئد.
5 بخش مهندسی آب، دانشکده مهندسی آب و خاک، دانشگاه علوم کشاورزی و منابع طبیعی گرگان، گرگان، ایران.
6 بخش مهندسی آب، دانشکده کشاورزی، دانشگاه شهید باهنر کرمان، کرمان، ایران.
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Estimation of the aquatic ecosystems environmental flow is considered important factors to prevent the negative effects of controlling and regulating surface flows on river habitats. The purpose of this research is to evaluate the environmental flow of Zayandehroud river by the Physical Habitat Simulation method in comparison with Tennant and Range of Variability Approach. The study area was determined from the Zayandehroud Dam downstream to the Gavkhuni Wetland and was divided into 3 reaches, which includes 8 hydrometric stations. The flow statistical series used in this research was collected from establishment year begining of hydrometric stations until the last year when data was available from Isfahan Regional Water Department and then normalized and included in calculations. Also, by using average value score of fish species according to the experts, the target species of this research were determined for the upstream, middle and downstream areas, Capoeta damascina, Capoeta aculeata and Aphanius isfahanensis. According to the results, the environmental flow estimated the PHABSIM is 60%, the RVA is 49% and the tennant is 26% of the river average annual flow. The results show that the simultaneous use of the PHABSIM and RVA methods can provide a more accurate method that is more compatible with the ecological characteristics of the Zayandehroud River for estimating environmental flow. Compared to empirical methods such as Tennant, this combination allows for more practical results; however, further evaluation under different hydrological conditions could help strengthen the validity of the results.
کلیدواژهها [English]
The Zayandehroud River, as one of the most important water resources in central Iran, has been severely affected by human exploitation, climate change, and unsustainable development in recent decades, and its base flow has decreased significantly in many time periods. This decrease has not only affected the economic and social functions of the river, but also seriously threatened the sustainability of aquatic habitats and its ecological structure. To respond to this challenge, in this study, with a comparative approach, the performance of several different methods of estimating environmental flow (including hydrological, hydraulic methods, and the physical habitat simulation model) in a section of the Zayandehroud River is evaluated.
Providing the minimum required environmental flow of the Zayandehroud River is considered a requirement for which comprehensive and practical measures and measures must be applied for its management and allocation. The study area in this study is the distance from the Zayandehroud Dam to the Gavkhuni Wetland and is divided into 3 intervals and 8 hydrometric stations. The first station in this study is the Sad-Tanzimi station, and the Varzaneh station, which is the closest station to the Gavkhuni Wetland, is considered as the last study station. In the present study, two hydrological methods, Tennant and RVA, were used for comparison with the physical habitat simulation method to evaluate the environmental flow.
In this study, it was found that the results of Tennant method are often general and non-customized and do not work well for the Zayandehroud River, which has severe hydrological fluctuations, chronic water stress conditions, and a heterogeneous bed. Also, the values proposed by Tennant are either too conservative or are completely impractical in terms of water resources management in dry seasons. The RVA method was able to analyze the flow change patterns and the level of damage to the natural regime of the Zayandehroud River with high accuracy and provided relatively reasonable values for the environmental flow in different months. However, the RVA method lacks a direct assessment of the biological response of species to flow and cannot replace more accurate ecological methods such as habitat simulation.
The physical habitat simulation method, which was implemented in this study using morphological, hydraulic, and biological data, was able to determine the biological value of each flow scenario with high accuracy by considering the real ecological needs of target species and analyzing the habitat response to different flows. The output of this method has high environmental validity and is very valuable for accurate management decisions.
According to the comparison of the methods carried out in this study, the estimated environmental flow in the physical habitat simulation method is 60%, the RVA is 49%, and the Tennant method is 26% of the average annual river flow, respectively.
The RVA and physical habitat simulation methods have both suggested relatively more reasonable and feasible percentages than the Tennant method, which should be taken into account by relevant managers and experts in allocating environmental rights, and it can be said that these methods are capable of protecting the natural flow regime to maintain the ecological values of the Zayandehroud River and establish favorable conditions for the survival of aquatic species. Therefore, the aforementioned methods, considering their advantages and disadvantages and appropriate to the conditions of each project, can be used in management matters and executive plans of engineers and ecohydraulic specialists and help estimate a desirable environmental flow range for the Zayandehroud River and consider it in river management and restoration plans and projects.
Conceptualization, Yousef Rajabizadeh and Kourosh Qaderi; methodology, Yousef Rajabizadeh, Mahboobeh Hajiesmaeili and Mohammad Hasan Naderi; software, Yousef Rajabizadeh, Kourosh Qaderi and Mahboobeh Hajiesmaeili; validation, Yousef Rajabizadeh, Kourosh Qaderi and Mohammad Hasan Naderi; formal analysis, Yousef Rajabizadeh and Mohammad Mehdi Ahmadi; investigation, Yousef Rajabizadeh, Kourosh Qaderi and Mohammad Hasan Naderi; resources, Yousef Rajabizadeh and Mohammad Mehdi Malekpour ; data curation, Yousef Rajabizadeh and Mohammad Mehdi Malekpour; writing—original draft preparation, Yousef Rajabizadeh and Mohammad Mehdi Ahmadi; writing—review and editing, Yousef Rajabizadeh and Mohammad Mehdi Malekpour; visualization, Yousef Rajabizadeh and Mohammad Hasan Naderi; supervision, Yousef Rajabizadeh and Mahboobeh Hajiesmaeili; funding acquisition, Yousef Rajabizadeh. All authors have read and agreed to the published version of the manuscript.” All authors contributed equally to the conceptualization of the article and writing of the original and subsequent drafts.
Data available on request from the authors.
The authors avoided data fabrication, falsification, plagiarism, and misconduct.
The author declares no conflict of interest.
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