ارزيابي بهترين سيستم آبياري با استفاده از فرآيند تحليل سلسله مراتبي (مطالعه موردي دشت ايذه)

evaluation of the best irrigation system by using Analytical Hierarchy Process (Case study: Plain izeh)

بحران كمبود آب موضوعي است كه باعث ايجاد چالش در مصرف درست و بهينه منابع آب شده‌است. در اين تحقيق تصميم‌گيري چند معياره (MCDM) جهت استفاده درست از منابع آب بكار گرفته‌شد. يكي از روش‌هاي رايج در تصميم‌گيري چندمعياره استفاده از روش تصميم‌گيري تحليل سلسله مراتبي است. اين روش با درنظرگرفتن معيارها و زيرمعيارهايي و باتوجه به اولويت‌بندي معيارها به روش ساعتي (Saaty) و محاسبه وزن‌ معيارها و زيرمعيارهاي انتخابي به روش ميانگين هندسي به سيستم آبياري امتياز مي‌دهد. در اين تحقيق دو معيار اقتصادي-اجتماعي و فيزيك‌ مزرعه براي سيستم‌هاي آبياري سطحي و تحت فشار در منطقه‌ي دشت ايذه درنظرگرفته شد. معيار اقتصادي - اجتماعي به 4 زيرمعيار تجهيزات موجود در منطقه، هزينه، مهارت كارگران و فرهنگ و معيار فيزيك‌مزرعه به 5 زيرمعيار آب، اقليم منطقه، خاك، توپوگرافي و محصول تقسيم‌بندي شدند. در ابتدا معيارها و زيرمعيارها با توجه به جدول امتيازبندي سلسله مراتبي از 1 تا 9 امتيازدهي شدند و پس از محاسبه‌ي ميانگين هندسي وزن نهايي معيارها و زيرمعيارها براي هر گزينه محاسبه شد و سپس درنهايت امتيازها وارد سيستم اطلاعات جغرافيايي مي‌شوند و نقشه‌هاي خروجي براي هر سيستم بدست مي‌آيند. درنهايت سيستم آبياري سطحي بعنوان سيستم مناسب دشت ايذه انتخاب شد.

Introduction Multi-criteria decision making (MCDM) and Geographic Information System (GIS) for accurate decision making about the evaluation parameters used in natural sciences. This selection is influenced by different factors such as production and irrigation system expenses, water availability and quality, soil characteristics, climate conditions, labor skills, and cultural acceptability. The present study was conducted over an area of approximately 11081 ha in the Izeh plain Khuzestan province, south west Iran during 2015-2016. Results of the comparison (for each factors pair) were described in term of integer values from 1 (equal value) to 9 (extreme different) where higher number means the chosen factor is considered more important in greater degree than other factor being compared with. Analytic Hierarchy Process (AHP) is one of Multi Criteria decision making method that was originally developed by Prof. Thomas L. Saaty. In short, it is a method to derive ratio scales from paired comparisons.. The AHP was used for optimization.Spatial analysis to identify susceptible regions for pressurized irrigation systems starts with representing each selected physical sub-criterion by a thematic layer in which each point takes a value (1 to 9) which the samples have been gathered in a laboratory or a qualification according to that criterion. In order to layer all the criteria, data are gathered from satellite images and official sources at different available forms (digital and hard copy maps, tables and charts). Then, they are analyzed and treated using GIS and geostatistical tools. Each layer is obtained in raster data model. Spatial data on water characteristics, topography and climate (temperature map) are obtained from “water and power authority’’ of Khuzestan district, which is the Iranian official source of agricultural spatial database. Data are already available in digital format with 1/150,000 scale.