A GIS-based Decision Support System to Identify Potential Sites for Soil and Water Conservation Measures (Case Study: Kakhk Watershed)

Document Type : مقاله پژوهشی

Authors

• Mahmood Azari
• Adel Sepehr

Ferdowsi University of Mashhad

10.22067/geo.v7i2.66301

Abstract

1 Introduction
Water crises and soil erosion are some of the most important challenges threating food security around the world, and Iran is no exception in this case. Watershed management measures are common practices for soil and water conservation. Identifying and prioritizing suitable sites for implementing soil and water conservation measures in a watershed is, in fact, an important decision in watershed management. To this end, the analysis of spatial data and comparison with technical standards of conservation practices is primarily required. Multi Criteria Decision Making (MCDM) analysis methods are a commonly used method of analysis combining data from various criteria. The Analytical Hierarchy Process (AHP) is a MCDM tool widely applied in order to identify the potential sites for flood water spreading, artificial discharge and rainwater harvesting. Terrace and channel terrace are historical measures in soil and water conservation in Iran. Both of these measures are commonly used for upland area to reduce steepness of hill slope. The present research aims to present a GIS-based decision support system for the site selection of terrace and channel terrace in Kakhk Watershed located in the Eastern part of Iran. Finally, the results derived from AHP are compared with the current terrace and channel terrace implemented in the watershed.
2 Materials and Methods
The case study of this research is Kakhk Watershed. Kakhk is located between 58° 31′ 22′′–58° 38′ 01′′ E and 34° 02′ 25′′–34° 06′ 14′′ N  in Khorasan Razavi Province in the Southwest of Gonabad. The above mentioned watershed drains an area of 37.8 km2. The major land uses of this watershed include Rangelands and agricultural lands. The mean of annual rainfall in this region is about 279 mm; 58.4% of this rainfall takes place during the winter.
The main criteria for allocating terrace and channel terrace were achieved through the review of past literature in the field. Based on previous studies undertaken in this field, slope, rainfall, runoff, soil depth, soil texture, distance to drainage network and economic issues were the main factors affecting the site selection of terrace and channel terrace. Therefore, spatial data were acquired and processed through Arc GIS 9.2. Software. Rainfall-elevation equation was derived through analyzing eight climatic stations near the watershed used for preparing the annual rainfall map. In order to estimate the direct runoff, the Soil Conservation Service (SCS) Curve Number (CN) method was applied. The weight of each map and classes were derived using AHP and entered in each map and classes. The AHP is a widely used multi-criteria decision-making tool which assists decision makers in planning, selecting the best alternative, and resource allocations. The selected criteria were prioritized based on the decision-making process which, in fact, judges the dominance of one criterion over another. Consistency ratio (CR) was used to assess the consistency in the comparative importance judgment. Final weights derived for each criterion were assigned and calculated in Arc GIS. Then, rasterized maps were used for producing suitability maps. Suitability levels for each map were categorized based on the obtained results from both the field survey and literature review. In order to test the applicability of the approach developed in the study, the locations with existing soil and water conservation measures were compared with locations obtained through AHP.
3 Results and Discussion
The results of the AHP analysis reveal that slope and runoff criteria have the highest weight, while the distance to drainage network has the least weight in the allocation of terrace and channel terrace. The results also indicate that 4% and 7% of the watershed are highly suitable highly for terracing. Twenty nine percent and 47% of the watershed area in the West and Southwest have low suitability and are not suitable for terracing, respectively. In addition, the results for channel terrace show that 5% and 14% are suitable and highly suitable for channel terrace. Thirty one percent and 25% of the watershed area with high slope and low depth soil have low suitability and are not suitable for channel terrace, respectively. Highly suitable sites were mainly located near the main outlet due to the existence of deep soils with suitable texture. Upland areas of the studied watershed were mainly located at the unsuitable level although the amount of rainfall was considered to be proper for conservation measures due to the limitations in slope and soil properties.
A comparison between the obtained results and the implemented measures in the watershed reveals that 59% of the area with channel terrace and 21.8% of the area with terraces are located at highly suitable levels. The mismatch between the obtained results using implemented measures may be due to not taking into account the other criteria such as social and economic issues and also people participation during the process of implementation.
4 Conclusion
The current study aims to apply a combined GIS and MCDM approach to allocate and prioritize sites for the implementation of terrace and channel terrace within the Kakhk Watershed in west of Iran. The obtained results in the present study suggest that decision support system may assist local watershed managers in soil and water conservation. Using further criteria in site selection and using more MCDM methods are also recommended for future studies.

Keywords

• Site Selection
• watershed Prioritization
• AHP
• GIS
• Kakhk Watershed

20.1001.1.23221682.1398.8.1.4.5

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References

ابراهیمی محمدی، شیرکو؛ آذری، محمود؛ انتظامی، هیرش؛ 1390. بررسی نهشته‌های کواترنر دشت دهگلان در سنندج جهت تعیین مناطق مستعد پخش سیلاب. چاپ در مجموعه مقالات اولین کنفرانس ملی سیستم‌های سطوح آبگیر باران ایران. مشهد. صص 14-1.

اداره کل منابع طبیعی و آبخیزداری خراسان رضوی؛ 1386. مطالعات ارزیابی اقدامات آبخیزداری حوزه کاخک گناباد. 187ص.

آذر، عادل؛ معماریانی، عزیزالله؛ 1373.AHP تکنیکی نوین برای تصمیم گیری گروهی. فصل‌نامه دانش مدیریت. شماره 27 و 28. صص32-22.

اسمعلی، اباذر؛ عبداللهی، خدایار؛ 1389. مدیریت آبخیزداری و حفاظت خاک. انتشارات دانشگاه محقق اردبیلی.

آل شیخ، علی اصغر؛ سلطانی، محمد جعفر؛ هلالی، حسین؛ 1381. کاربرد GIS در مکان‌یابی عرصه‌های پخش سیلاب. فصل‌نامه تحقیقات جغرافیایی. شماره 4. صص38-22.

پیرمرادی، رضا؛ نخعی، محمد؛ اسدیان، فریده؛ 1389. تعیین مناطق مناسب برای احداث سد زیرزمینی با استفاده از GIS و AHP. حوضه دشت ملایر در استان همدان. مجله جغرافیا محیطی. شماره 8. صص66-51.

چابک بلداجی، مسلم؛ حسن زاده نفوتی، محمد؛ ابراهیمی خوسفی، زهره؛ 1389. مکان‌یابی عرصه پخش سیلاب با استفاده از روش تحلیل سلسله مراتبی (AHP) در حوضه عشق آباد طبس. مجله علوم مهندسی و آبخیزداری ایران. شماره 13. صص8-1.

چزگی، جواد؛ مرادی، حمید رضا؛ خیرخواه، میرمسعود؛ 1389. مکان‌یابی محل‌های مناسب جهت احداث سد زیرزمینی با استفاده از روش تصمیم‌گیری چندمعیاره با تاکید بر منابع آب درحوضه غرب استان تهران. مجله علوم مهندسی و آبخیزداری ایران. شماره 13. صص68-65.

حبیبی، علی؛ 1391. تلفیق فرآیند تحلیل سلسله مراتبی (AHP) و سیستم اطلاعات جغرافیایی (GIS) در مکان‌یابی محل‌های مناسب جهت تغذیه مصنوعی آب‌های زیرزمینی در حوضه خلیج گرگان. دانشکده علوم کشاورزی و منابع طبیعی گرگان. دانشگاه گرگان.

خاشعی سیوکی، عباس؛ قهرمان، بیژن؛ کوچک زاده، مهدی؛ 1390. ارزیابی پتانسیل استحصال آب از آبخوان از روش فرآیند تحلیل سلسله مراتبی فازی در دشت نیشابور. مجله پژوهش آب ایران. شماره 9. صص180-171.

خیرخواه آرزو؛ محمدی فاطمه؛ معماریان هادی؛ ۱۳۹۴. تعیین مناطق مستعد استحصال و ذخیره سازی آب باران با استفاده از تحلیل سلسله مراتبی در محیط GIS (مطالعه موردی: حوزه آبخیز رود سراب شهرستان خوشاب استان خراسان رضوی. چاپ در مجموعه مقالات کنفرانس ملی سیستم‌های سطوح آبگیر باران ایران. مشهد. ص 1-14.

رمضانی مهریان، مجید؛ ملک محمدی، بهرام؛ جعفری، حمیدرضا؛ رفیعی، یوسف؛ 1390. مکان‌یابی محل‌های انجام عملیات تغذیه مصنوعی آب‌های زیرزمینی با بکارگیری روش‌های تصمیم‌گیری چند معیاره و سیستم اطلاعات جغرافیایی در دشت شمیل و آشکارا هرمزگان. مجله علمی_ پژوهشی علوم مهندسی و آبخیزداری ایران. شماره 14. صص1-10.

سازمان جنگل‌ها، مراتع و آبخیزداری کشور؛ 1387. مبانی طراحی و راهنمای اجرای سازه‌های کنترل فرسایش (دستورالعمل و ضوابط فنی طراحی و اجرای بانکت بندی). نشریه شماره 1-450. جلد اول.

سازمان جنگل‌ها، مراتع و آبخیزداری کشور؛ 1388. مبانی طراحی و راهنمای اجرای سازه‌های کنترل فرسایش (دستورالعمل و ضوابط فنی طراحی و اجرای تراس‌بندی). نشریه 3-450. جلد سوم.

قدسی پور، سید حسن؛ 1384. فرآیند تحلیل سلسله مراتبی. انتشارات دانشگاه صنعتی امیرکبیر.

ملکی، امجد؛ حصادی، همایون؛ نادریان، پروین؛ 1388. مکان‌یابی تغذیه مصنوعی آبخوان حوضه آبریز مرگ. تحقیقات جغرافیایی. شماره 1. صص 87-53.

مهدوی، عاطفه؛ نوری امامزاده‌یی، محمدرضا؛ مهدوی نجف‌آبادی، رسول؛ طباطبائی، سیدحسن؛ 1389. مکان‌یابی عرصه‌های مناسب تغذیه مصنوعی سفره‌های زیرزمینی به روش منطق فازی در حوضه آبریز دشت شهرکرد. مجله علوم و فنون کشاورزی و منابع طبیعی، علوم آب‌وخاک، شماره 56، صص78-63.

مهدوی، محمد؛1381. هیدرولوژی کاربردی. انتشارات دانشگاه تهران.

نادری، نگاه؛ محسنی ساروی، محسن؛ ملکیان، آرش؛ قاسمیان، داوود؛ 1390. فرایند تحلیل سلسله مراتبی تکنیکی برای تصمیم‌گیری در حوضه‌های آبخیز. مجله محیط‌زیست و توسعه. شماره. صص41 -50.

Critchley, W., Siegert, K., Chapman, C., & Finket, M., 2013. Water harvesting: A manual for the design and construction of water harvesting schemes for plant production. Scientific Publishers.

De Winnaar, G., Jewitt, G. P. W., & Horan, M., 2007. A GIS-based approach for identifying potential runoff harvesting sites in the Thukela River basin, South Africa. Physics and Chemistry of the Earth, Parts A/B/C, 32: 1058-1067.

FAO., 1990. Guidelines for soil description. 3th edition.

Gruma, B., R. Hesseb, and A. Kesslerc. K. Woldearegayd. E. Yazewe. C. Ritsemac. V. Geissen., 2016. A decision support approach for the selection and implementation of water harvesting techniques in arid and semi-arid regions. Agricultural Water Management، 173: 35–47.

Hudson, N., 1987. Soil and water conservation in semi-arid areas. Food and Agriculture Organization of the United Nations. Vol 57.

Hunink, J. E., P. Droogers. and S. Kauffman. B. M. Mwaniki. J. Bouma., 2012. Quantitative simulation tools to analyze up- and downstream interactions of soil and water conservation measures: Supporting policy making in the Green Water Credits program of Kenya. Journal of Environmental Management. 111: 187-194.

Jaiswala, R. K., N. C. Ghoshb. And R. V. Galkatea. T. Thomas., 2015. Multi Criteria Decision Analysis (MCDA) for watershed Prioritization.Aquatic Procedia 4: 1553 – 1560.

Krois, J., A. Schulte. 2014. GIS-based multi-criteria evaluation to identify potential sites for soil and water conservation techniques in the Ronquillo watershed, northern Peru. Applied Geography. 51:131-241.

Madan, K.J., V. M. Chowdary. And Y. Kulkarni. B. C. Mal., 2014. Rainwater harvesting planning using geospatial techniques and multicriteria decision analysis.Resources, Conservation and Recycling. 83: 96– 111.

Mbilinyi, B. P., S. D. Tumbo. And H. F. Mahoo. F. O. Mkiramwinyi., 2007. GIS based decision support system for identifying potential sites for rainwater harvesting. Physics and Chemistry of the Earth. 32: 1074–1081.

Mendoza, G. A., H. Martins., 2006. Multi-criteria decision analysis in natural resource management: A critical review of methods and new modelling paradigms. Forest Ecology and Management. 230: 1–22.

Prinz, D., & Singh, A., 2000. Technological potential for improvements of water harvesting. Gutachten für die World Commission on Dams.

Saaty, T. L., 1980. The analytic hierarchy process: Planning, priority setting, resource allocation.

Tumbo, S. D., Mbilinyi, B. P., Mahoo, H. F., & Mkiramwinyi, F. O., 2006. Determination of suitability levels for important factors for identification of potential sites for rainwater harvesting. In Proceedings of the 7th WaterNet-WARFSA-GWP-SA Symposium, Lilongwe, Malawi.