نوع مقاله : مقاله کامل علمی پژوهشی
نویسندگان
1 بخش مهندسی آب، دانشکده کشاورزی، دانشگاه شهید باهنر کرمان، کرمان، ایران
2 دانشیار دانشگاه شهید باهنر کرمان
3 دانشجوی فوق دکتری، گروه علوم محیطی و زیستی، دانشگاه کارلستاد، سوئد
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Background and objectives: Environmental flow allocation of rivers is an overlooked factor in the sustainable water resources management in Iran and an undeniable necessity to preserve the ecosystems in the country's watersheds and also to prevent the destruction of wetlands and rivers leading to lakes. In Iran, there is a need for many researches in order to use new, advanced and accurate methods in order to environmental flow evaluation and determine the validity of its use for rivers inside the country, especially for rivers with high biological value species. The objective of this research is environmental flow evaluation of the Zayandehroud River using the RVA method and compare it with the hydrological methods of Tennant, Arkansas and the hydraulic method of the wetted perimeter in order to determine and suggest the best environmental flow evaluation method in different areas of the Zayandehroud River.
Materials and methods: In the present research, the environmental flow evaluation of Zayandehroud river was done using the RVA method and compared with the methods of Tennant, Arkansas and wetted Perimeter with the curve slope algorithm. The study area between Zayandehroud Dam and Gavkhouni Wetland was determined and divided into 3 parts, which includes 8 hydrometric stations along Zayandehroud River. The flow statistical series used in this research is considered from the beginning of the establishment year of hydrometric stations to the last year when data were available, i.e. 2018, and the mean daily flow values for all existing hydrometric stations in Zayandehroud River were collected from Isfahan Regional Water Department. The flow data in this research was normalized for each station from the year of its establishment to the last year when the flow data was available and included in the calculations.
Results: Based on evaluation of the results, the estimated environmental flow in the hydraulic method is 70%, Arkansas 60%, RVA 49% and Tennant 26% of the mean annual flow. Tennant's method practically considers a small percentage of the river flow for the river environmental flow and it is definitely not enough. The methods of wetted perimeter and Arkansas also theoretically suggest reliable percentages for the river environmental flow, but in terms of implementation and considering the water fair allocation among all stakeholders, these two methods are almost impossible to do. The RVA method provides a better plan and has suggested a relatively more reasonable and feasible flow percentage than other methods, which should be considered by managers and experts for the allocation of environmental flow.
Conclusion: The suggested values of environmental flow with the methods carried out in this research, especially the RVA method, for each area of river, are able to protect the flow natural regime to maintain the river ecological values and provide favorable conditions for aquatic species to live. Therefore, the mentioned methods can be used in the management affairs and executive programs of ecohydraulic engineers and specialists according to their advantages and disadvantages and according to the conditions of each project. Also, the results of this research help to estimate a suitable environmental flow range for the Zayandehroud river and consider it in the river restoration projects.
کلیدواژه‌ها [English]
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