مقايسه كارايي مدل هايMCDM در مكان يابي پخش سيلاب در محيطGIS مطالعه موردي: حوضه آبريز گربايگان

The Comparison of the Efficieny of MCDM Models in site Selection of Flood Spread in GIS Environment (Case Studey: Garabaygan Catchment)

مهم ترين و اولين قدم در انجام پروژه طرح پخش سيلاب مكان يابي مناطق مستعد براي پخش آب و نفوذ دادن آن به داخل سفره هاي زيرزميني است. از اين جهت استفاده از سامانه هاي اطلاعات مكاني (GIS)، براي تعيين مناطق مستعد پخش سيلاب بدون استفاده سامانه تصميم گيري چند معياره (MCDM) مقدور نمي باشد. امروزه در كنار سيستم هاي اطلاعات جغرافيايي، سيستم هاي تصميم گيري چندمعياره به طور گسترده اي براي حل مسايل فضايي به كار گرفته مي شوند. در اين تحقيق از چهار مدل به شرح زيرLogic Boolean, Multi Class Maps, Binary Evidence, AHP در جهت انتخاب مكان هاي بهينه پخش سيلاب با استفاده از سيستم هاي اطلاعات جغرافيايي (GIS) سعي شده و سپس به مقايسه مدل ها پرداخته شده است. در اين تحقيق ابتدا با مطالعات كتابخانه اي و بررسي ميداني 9 پارامتر محيطي موثر انتخاب و سپس از پارامترهاي مذكور، لايه هاي اطلاعاتي در محيط (GIS) با استفاده از نرم افزارهاي9.3 Arc GIS تهيه و كلاسه بندي گرديد. آنگاه با وزن دهي كارشناسان مجرب، وزن هاي به دست آمده براي هر عامل و امتيازهاي كه به خود اختصاص دادند، هريك از نقشه هاي نهايي به 5 كلاس كاملاً مناسب، مناسب، متوسط، نامناسب، كاملاً نامناسب براساس مدل ها در سطح حوضه تهيه گرديد. سپس از روي نقشه هاي به دست آمده مدل ها با هم مقايسه گرديدند. همچنين بررسي دقت مدل ها نشان داده است كه دقت مدل AHP بيش از Multi–Class Maps و مدلBinary-Evidence- است و دقت مدل Binary Evidence و Multi–Class Maps بيشتر از مدل Bool، در تشخيص و كلاسه بندي مكان يابي عرصه هاي مناسب پخش سيلاب در منطقه مي باشد.

The selection of suitable location for implementing of flood spreading project and artificial recharge of aquifers is an important step. To assess this purpose, the Geographic Information System (GIS) conceptual models and decision making systems were used. Regarding different mentioned criteria, it is not possible to use GIS without appropriate Multi-Criteria Decision Making (MCDM) technique. The main aim for this research is to access the suitable location for flood spreading by using the most efficient criteria and classify them into several groups. Consequently, major factors such as slope, geology, geomorphology, hydrology, infiltration rate, cover and environmental impacts of the projects should be considered in the process of selecting appropriate site for artificial recharge through flood spreading. Also evaluating accuracy and application of conceptual models such as Logic Boolean, Multi classmaps, Binary Evidence, the Analytic Hierarchy Process (AHP) have been noticed. In this research, nine physical and environmental efficient variables essential for locating of flood spreading are used. The results indicate GIS-based data combination for ranking suitablelocation of flood spreading by itself, though it is not reliable enough. Also evaluating accuracy of models shows that accuracy of Binary Evidence model for identifying and ranking suitable location of flood spreading is more than that of Boolan model and the Multi class maps model can give better insights to create more realistic output scenarios The most important step in flood spreading process is to define optimal site. The Analytic Hierarchy Process (AHP) is an approach that is suitable for dealing with complex systems related to making a choice from among several alternatives and which provides a comparison of the considered options. In the present research relationship between GIS and Multi-Criteria Decision Making analysis has been investigated in order to find optimal site for flood spreading. The research emphasized the capability of resultant map to be used in site selection for flood spreading.