نوع مقاله : مقاله پژوهشی

نویسندگان

• سید نعیم امامی ¹
• صالح یوسفی ²
• محمد نکوئی مهر ³
• معصومه منصوری ⁴

¹ دانشیار بخش حفاظت خاک و آبخیزداری، مرکز تحقیقات و آموزش کشاورزی ومنابع طبیعی استان چهارمحال وبختیاری، سازمان تحقیقات، آموزش وترویج

² 2- استادیار بخش حفاظت خاک و آبخیزداری، مرکز تحقیقات و آموزش کشاورزی ومنابع طبیعی استان چهارمحال وبختیاری، سازمان تحقیقات، آموزش

³ مرکز تحقیقات وآموزش کشاورزی ومنابع طبیعی استان چهارمحال وبختیاری

⁴ مرکز تحقیقات و آموزش کشاورزی ومنابع طبیعی استان چهارمحال وبختیاری، سازمان تحقیقات، آموزش وترویج کشاورزی،شهرکرد،ایران.

چکیده

بندهای زیرزمینی سازه‌هایی هستند که جریان طبیعی آب‌های زیرسطحی یا جریان‌های زیرقشری را مسدود نموده و سبب ایجاد ذخایر آبی در زیر زمین می‌شوند .فواید اصلی ذخیره آب در این بندها میزان بسیار کم تبخیر، کاهش خطر آلودگی، عدم وجود مشکل زیر آب رفتن زمین‌های کشاورزی، پایداری سازه‌ای بسیار بالا و هزینه پایین ساخت می‌باشد. مهمترین چالش درفرآیند احداث بندهای زیرزمینی، شناسایی و تعیین مکان‌های مناسب و مستعد جهت احداث این بندها می‌باشد. این پژوهش با هدف تعیین معیارهای مناسب مکانیابی جهت احداث بندهای زیرزمینی و به صورت موردی درسطح شهرستان بن استان چهار محال وبختیاری به انجام رسیده است. دراین تحقیق ازمنطق بولین (Boolean)جهت تعیین محدوده های مناسب بهره گیری شد وآنگاه با استفاده از عکس‌های هوایی وتصاویر ماهواره ای لندست، 10 محور مناسب احداث بند در محدوده‌های شناسایی شده مشخص گردید. درادامه و به‌منظور اولویت‌بندی محورها، با استفاده از روش سلسله مراتبی (AHP) ابتدا معیارها، زیرمعیارها و شاخص های اولویت‌بندی تعیین و سپس محورهای شناسایی شده براساس معیارهای منتخب به ترتیب از 1تا10اولویت‌بندی گردیدند. براساس نتایج حاصله، به‌ترتیب معیارهای هیدرولوژی با وزن 5.0 عوامل اقتصادی- اجتماعی با وزن 30.0، مخزن با وزن 13.0 و محور با وزن 058.0 دارای اولویت اول تا چهارم هستند. در تعیین ارزش شاخص‌ها، کمیت آب (ارتفاع رواناب) با وزن 833.0، بیشترین وزن را به خود اختصاص داده است و به‌عنوان مهم‌ترین شاخص و بعد از آن عمق آبرفت با وزن 743.0 دارای وزن و اهمیت بیشتری نسبت به سایر شاخص‌ها می‌باشند. براین اساس ازبین محورهای شناسایی شده دومحور 1(باشناسهB) و محور 2(باشناسهA) به عنوان اولویت‌های اول ودوم تعیین و به بخش اجرا معرفی گردیدند.

کلیدواژه‌ها

• آب زیرقشری
• منطق بولین
• به گزینی
• AHP

موضوعات

• آب های زیرزمینی

عنوان مقاله [English]

Site selection of underground dams in Ben Township, Chaharmahal and Bakhtiari province

نویسندگان [English]

• sayed naeim Emami ¹
• saleh yousefi ²
• mohammad nekooeimehr ³
• masoumeh mansoori ⁴

¹ Agricultural and Natural Resources Research and Education Center, Chaharmahal and Bakhtiari, Agricultural Research and Education Organization, Shahrekord, Iran.

² Assistant professor, Soil Conservation and Watershed Management Research Department, Chaharmahal and Bakhtiari Agricultural and Natural Resources Research and Education Centre, AREEO, Shahrekord,

³ Agricultural and Natural Resources Research and Education Center, Chaharmahal and Bakhtiari, Agricultural Research and Education Organization, Shahrekord, Iran.

⁴ Agricultural and Natural Resources Research and Education Center, Chaharmahal and Bakhtiari, Agricultural Research and Education Organization, Shahrekord, Iran.

چکیده [English]

Extended Abstract
The construction of underground dams is a method of controlling and storing water in wet periods for use in dry periods. Underground dams are structures for blocking water under the surface of the earth. Although the underground dam is considered a new method for water extraction, satisfactory results of their implementation have been reported in different parts of the world. This research was conducted with the aim of determining the appropriate site selection criteria for the construction of underground dams in Ben County, Chaharmahal and Bakhtiari province, Iran. The most important problem in the development and construction of underground dams is the complexity of determining suitable places for their establishment. Determining the most important criteria for identifying the suitable places, selecting the most suitable decision-making method in the integration of information layers, and ranking the vulnerable areas have greatly helped in the implementation of these structures.
The investigated area includes Ben township with an area of 14327 hectares, which is located in the north to northwest of Chaharmahal and Bakhtiari province. Ben, Vardanjan, and Yancheshmeh cities are located in this area. The research employed Boolean logic, aerial photos, and Landsat satellite images to identify 10 suitable axes for dam construction. Also the study utilized the Analytic Hierarchy Process (AHP) to prioritize the axes based on hydrological, economic-social parameteres. After specifying the axes in the first stage and determining their criteria and value, using the MADM method and based on the AHP decision-making method, the suitable points for the construction of the underground dam were prioritized. According to the studied area conditions and the available information, 4 main criteria, 3 sub-criteria and 17 indicators were used in the process of AHP. In the following, using the relative values ​​determined by the binary comparison method for these indices and criteria, the appropriateness index was calculated for each axis.
In the hierarchical analysis method, inappropriate areas were eliminated in the first step using Boolean logic, and three elimination criteria: slope, land use and geology. Then with the field survey in the determined areas and using the Boolean method, 10 suitable axes were selected for the construction of the underground dam. To establish the priorities MADM method was employed based on the decision-making flow, also the AHP method was applied and questionnaire was analyzed using the Delphi method, to consider expert opinions. According to the value of the main criteria and indicators, hydrological factors are given priority with a weight of 0.51, followed by economic-social factors with a weight of 0.30, reservoir with a weight of 0.13, and axis with a weight of 0.058. The study identified the quantity of water (runoff height) and the depth of alluvium as the most critical indicators, with weights of 0.833 and 0.743, respectively. Subsequently, axis 1 (identified as B) and axis 2 (identified as A) were determined as the first and second priorities for consideration by the implementation department. The results showed that the quantity of water is more important than the quality. That is because in the absence or lack of subsurface flows, the reservoir of the underground dam is not completely drained, leading to many problems, including difficulties in suppling the water needs of the residents. According to the results, the higher the water quality (water hardness) has the greater relative importance.  The downstream areas of pollution sources were considered as unsuitable places and removed. The results indicated that a larger reservoir volume will make it more suitable. The best places to construct an underground dam in a river are the gorges withthe highest reservoir level in the upstream areas. By the results of the reservoir depth factor, the best areas were the alluviums with a depth of less than 10 meters. The outcomes of the this investigation indicated that most of the waterways 3 and 4 were located on slopes of less than 5%, which were suitable areas for the construction of underground dams, because the slope factor has an inverse relationship with the volume of the reservoir and the amount of permeability. The depth and length of the dam axes are the most important economic factors in an underground dam, and due to the limitations in the axes drilling depth compared to the length of the axes, this criterion cocidered as the first priority. The suitable axes were those that, in addition to having a suitable reservoir for storing water upstream, had the minimum possible depth and length for the implementation of the wall. Shorter axes had more value and importance than other axes. Among the socio-economic sub-criteria, the factor affecting the water resources -especially the downstream qanats- was more important, because the change in the qanat water supply causes local challenges. The results revealed that the index of distance from the village was more important than the distance from the road. The existence of a road in the construction site of the underground dam increases the access and reduces the costs related to the construction and maintenance of the structure.
 

کلیدواژه‌ها [English]

• Subsurface water
• Boolean logic
• site selection
• AHP