برآورد ارزش اقتصادی خسارات سازه های آبی بر محیط‌ زیست (مطالعه موردی سد زاینده‌رود)

با توجه به تغییرات اقلیمی و عدم توازن در بارندگی در تمام طول سال، کمبود آب یک بحران اساسی در استان اصفهان بوده است، لذا ارائه راهکارها و دستورالعمل‌هایی که منطبق با شرایط اقلیمی کشور می‌باشد کمک شایانی به عبور از وضعیت بحران زای فعلی می نماید. در این راستا طرح‌های آبخیزداری (سد) یکی از راهکارهای مورد استفاده در مقابله با این بحران‌ها بوده است. اما ساخت‌وساز افراطی این سازه در کشور خسارات جبران‌ناپذیری را بر محیط‌زیست وارد ساخته است. هدف از پژوهش حاضر برآورد اثرات زیست‌محیطی سد زاینده‌رود بوده است. به‌منظور محاسبه خسارات وارده به محیط‌زیست از روش آزمون انتخاب بر پایه‌ی ترجیحات اظهار شده استفاده ‌شده است. دادهای تحقیق با استفاده از روش میدانی و طرح دی اپتیمال و توزیع 150 پرسشنامه در مناطق اطراف رودخانه در زمان‌های مختلف به لحاظ باز بودن و بسته بودن آب رودخانه در سال 1396 جمع‌آوری گردید. به‌منظور برآورد الگو از الگوهای لاجیت ساده، شرطی و آشیانه‌ای استفاده گردید. که درنهایت مدل لاجیت آشیانه‌ای به‌عنوان مدل ارجح اثرات انتخاب گردید. مقدار تمایل به پرداخت نهایی محاسبه‌ شده برای بهبود ویژگی‌های تفریحی، حمایت از گونه‌های گیاهی، حمایت از گونه‌های جانوری و حمایت از تالاب گاوخونی به ترتیب 1176، 610، 566، 852 هزار ریال در سال برای هر خانوار برآورد گردید. نتایج نشان می دهد منطقه‌ی مورد مطالعه از اهمیت و ارزش بالایی برخوردار بوده لذا مدیریت و برنامه‌ریزی دقیق جهت کاهش اثرات زیست‌محیطی ضروری می‌باشد.

Estimation of Economic Value of Hydraulic Structures Damages on the Environment (Case Study: Zayandeh Rood Dam)

Introduction: The natural resources in any country are considered as the important infrastructures for economic development; this mainly applies to developing countries. Climate change and imbalance of rainfall over the year has made shortage of water a fundamental crisis in Esfahan Province; therefore, providing strategies and instructions which are in accordance with climate conditions of the country will significantly help to get out of the present critical situation. In this regard, dambuilding projects have been one of the strategies which have been used to face these crises. Lack of attention to consequences of human interventions in environment and lack of considering these damages in considering pros and cons of manmade structures will cause reduction of natural resources and will increase the growing process of dambuilding in the country. Prevention of damages to the environment can increase construction of dams in the country. Materials and Methods: The purpose of this project is environmental analysis of one of the 10 dams of the country using comprehensive management program, so by estimating the damage and its cost, in addition to making managers aware, it is possible to announce maximum support of people for ecosystem management. Results in costprofit analyses of developing Zayanderood Dam and its watering and also authorities ' attention to more investment on the most important performance in view of the people of this province. This method can also be used to reform national accounts. In this method, first, created values of Zayanderood River flowing are considered and then each performance was evaluated. Improving environmental features of building a dam includes reducing public recreational areas (because the river does not flow), destroying some plant species around the river, Gavkhuni Swamp, animal species (such as fishes, water and migrant animals) and also destroying Gavkhuni Swamp (which in general because of no more flowing of the river Zayanderood and lack of watering of this swamp by Zayanderood river, it has been totally dry and destroyed) has been estimated. Similarly, choice experiment was employed for estimation of economic value of recreational areas, some plant species around the river, Gavkhuni Swamp, animal species by means of D Optimal design and distributions of 150 questionnaires in river ward zayanderood district during various seasons (2016) and the nested logit model. Results and Discussion: The results of this research indicated that total value of recreational areas, some plant species around the river, Gavkhuni Swamp, and animal species were estimated 1176,610,852, and 566 thousand rials respectively. Among services damaged of zayanderood rangeland ecosystem, the maximum value belongs to recreational areas and of protection Gavkhuni Swamp. Ignoring and destruction can be the cause of not enough knowledge about the value of the local and natural ecosystem. Sometimes these effects may decrease the remedy of justification of collusion, and cannot evaluate composing dam and gains for local people. All the payment appetency of the family to improve all the properties, computed 320 thousand rials in this year. This research has prepared for estimating environmental effects of composing zayanderood dam and estimating effects of different sides of dam. Final results of the final orientation of the interest of families in paying each environmental feature of Zayanderood Dam determine the environmental damage of this dam and showed that mwtp (marginal willingness to pay) was positive for every recreational, vegetative species, animal species and Gavkhuni Swamp and this means that improving these features increases the average satisfaction obtained by using these dams. Regarding the results of this study, significant amounts of interest in payment for different features of the river showed the strong will of people to exit these conditions of the river. Conclusions: Based on the results of this research, it can be argued that increasing the amount of attention to the various characteristics of the Zayandehrood River is due to the strong determination of people to get out of the current situation. Thus, one of the strategies for improving the environmental conditions of river in the current situation is the general participation of the people of the region. On the other hand, through the development of a coherent program to allocate water between Isfahan and Chaharmahal and Bakhtiari provinces, and also improving water use efficiency, especially in the agricultural sector which is a major consumer of water, the rate of decline in water can be controlled. Obviously, the present research is a preliminary study and a comprehensive assessment of the profittocost ratio is necessary for providing more accurate information on the cost of constructing the dam(s).The finding indicated that the study area had high importance and value therefore it is necessary for accurate administration and planning to increase awareness of the people in the study area. Also the results showed that the studied case zone has a high importance so planning to decrease the remnant of environment is very necessary. Userfriendly and comprehensive studies (especially environmental) are essential for increasing economic plans.