ارزیابی روند توسعه فیزیکی شهر سقز به سمت مناطق مستعد وقوع سیلاب مقاله

روند افزایشی جمعیت و توسعه فیزیکی نواحی شهری سبب شده است تا در طی سال‌های اخیر، بخش زیادی از نواحی جمعیتی به سمت مناطق سیل‌خیز حرکت کنند. اهمیت موضوع سبب شده است تا در این تحقیق به بررسی روند توسعه فیزیکی شهر سقز به سمت مناطق مستعد وقوع سیلاب پرداخته شود. در این تحقیق از تصاویر ماهواره لندست، لایه‌های رقومی اطلاعاتی و مدل رقومی ارتفاعی 30 متر SRTM به‌عنوان مهم‌ترین داده‌های تحقیق استفاده شده است. ابزارهای تحقیق شامل ArcGIS، ENVI و IDRISI می‌باشد. مدل‌های مورد استفاده در تحقیق نیز شامل مدل تلفیقی منطق فازی و AHP و همچنین مدل LCM می‌باشد. این تحقیق در دو مرحله انجام شده است که در مرحله اول، به ّا استفاده از مدل Fuzzy-AHP به شناسایی مناطق مستعد وقوع سیلاب پرداخته شده و در مرحله دوم، با استفاده از مدل LCM، روند افزایشی نواحی سکونتگاهی به سمت مناطق سیل‌خیز ارزیابی شده است. نتایج تحقیق بیانگر این است که بخش‌های میانی محدوده مطالعاتی به دلیل نزدیکی به رودخانه، ارتفاع و شیب کم، دارای پتانسیل سیل‌خیزی بالایی است. همچنین نتایج ارزیابی (مدل LCM) روند توسعه فیزیکی شهر سقز به سمت مناطق مستعد وقوع سیلاب بیانگر این است که در سال 1369 حدود 8/3 کیلومترمربع در معرض سیلاب قرار داشته است که این میزان در سال 1399 به 2/7 کیلومترمربع افزایش یافته است. با توجه به موارد مذکور، بخش زیادی از شهر سقز در طی سال‌های اخیر به سمت مناطق مستعد وقوع سیلاب حرکت کرده است که بیانگر عدم نظارت بر توسعه فیزیکی این شهر بوده است.

1- Introduction In recent years, the increasing trend of the population has caused urban areas to face a lot of physical development, the share of developing countries has been higher than that of developed countries. Physical development in many areas has caused rapid changes in land use and increased environmental degradation. Therefore, the physical development of cities is considered as one of the main factors that change the surface of the earth. Studies have shown that the urban areas of Iran, due to their unlimited and unplanned expansion, have encroached on the natural environments and destroyed them, which has increased the potential for natural hazards such as floods in these areas. Has been considering the mentioned cases, more supervision should be done on the physical development of cities, especially flood-prone cities. Saghez city in Kurdistan province is one of the flood-prone cities that have faced a lot of physical development in recent years. Due to its economic and social situation, this city has faced a large population growth in recent years, which has caused the significant physical development of this city and as a result, the development of residential areas into flood-prone areas. Considering the importance of the topic, in this research, the physical development of Saghez city towards flood-prone areas has been investigated. 2- Methodology In this research, in order to achieve the desired goals, descriptive-analytical methods have been used. The research data includes topographic maps 1:50000 and geological maps 1:100000, a digital elevation model of 30 meters, as well as Landsat satellite images (Table 1). Research tools include Arc GIS, ENVI and IDRISI. The models used in the research also include the integrated model of fuzzy and AHP (in order to identify flood-prone areas) as well as the LCM model (in order to evaluate the physical development process of Saghez city towards flood-prone areas). This research has been done in two stages. In the first stage, in order to prepare the flood potential map of the study area, 6 parameters of height, slope, slope direction, distance from the river, and type of lithology and land use have been used. In the second stage, in order to evaluate the process of physical development of Saghez city towards flood-prone areas, the LCM model has been used. At this stage, after preparing the land use maps, the prepared maps were entered into the IDRISI software and using the LCM model, the trend of land use changes in the study area was evaluated. 3- Results The results of the flood zoning of Saghez city have shown that the middle areas of the range have the highest flood potential due to the proximity to the Saghez River, low altitude and slope. Also, the results obtained from the satellite images have shown that the city of Saghez had an area of about 6.5 square kilometers in 1369, which increased by 1.1 square kilometers to 7.6 square kilometers in 2000. In continuation of the physical development process of this city, the area of residential areas increased to 10.2 and 16.6 square kilometers by 2019 and 2019, respectively. Based on this, the maximum amount of physical development with 5.5 square kilometers was related to the time period of 1389 to 1399. Also, the results of the physical development of cities towards flood-prone areas show that in 1369, 3.8 square kilometers of residential areas were exposed to the risk of flooding, and from this amount to 1379, 1389 and 1399, respectively, 3 It has increased by 4.1, 5.1 and 2.7 square kilometers. Based on this, the highest amount of development towards flood-prone areas with 1.9 square kilometers was related to the time period from 2010 to 2020 4- Discussion & Conclusions The increasing trend of population and physical development of urban areas has caused a large part of population areas to move towards flood-prone areas in recent years. The results of this research have shown that the middle parts of the study area have a high flood potential due to their proximity to the river, low altitude and slope. The results of the evaluation of the physical development of the city of Saghez also indicate that this city has faced a lot of development during the years 1369 to 1399, and based on the results, the city of Saghez had an area of about 6.5 square kilometers in 1369, which is 2019 has increased to 16.7 square kilometers. The results of the evaluation of the physical development process of Saghez towards flood-prone areas indicate that in 1369, about 3.8 square kilometers were exposed to floods, which increased to 2.7 square kilometers in 1399. Also, the results of the evaluation of land use changes indicate that during the studied time period, 8.8 square kilometers of pastures, 0.6 of agricultural lands and 0.8 of pastures have been converted into residential areas, the highest amount of which is related to It was the eastern areas of Saghez city. According to the mentioned cases, a large part of the city of Saghez has moved towards flood-prone areas in recent years, which indicates the lack of monitoring of the physical development of this city.

همچنين نتايج ارزيابي (مدل LCM) روند توسعه فيزيکي شهر سقز به سمت مناطق مستعد وقوع سيلاب بيانگر اين است که در سال ١٣٦٩ حدود ٣/٨ کيلومترمربع در معرض سيلاب قرار داشته است که اين ميزان در سال ١٣٩٩ به ٧/٢ کيلومترمربع افزايش يافته است . همچنين در اين تحقيق از مدل تلفيقي منطق فازي و AHP١ (به منظور شـناسـايي مناطق مسـتعد وقوع سـيلاب ) و مدل LCM٢ (به منظور ارزيابي روند توسـعه فيزيکي شـهر سـقز به سـمت مناطق سـيل خيز) استفاده شده است . اين تحقيق در دو مرحله انجام شده که در ادامه به تشريح آن ها پرداخته شده است : جدول ١: مشخصات تصاوير مورد استفاده رديف تاريخ ماهواره سنجنده ١ ١٣٦٩/٤/٤ لندست ٥ TM ٢ ١٣٧٩/٤/٨ لندست ٧ ETM ٣ ١٣٨٩/٤/٤ لندست ٧ ETM ٤ ١٣٩٩/٤/٧ لندست ٨ OLI -مرحله اول (شـناسـايي مناطق مسـتعد وقوع سـيلاب ): در اين تحقيق به منظور تهيه نقشـه پتانسـيل سـيل خيزي محدوده مطالعاتي از ٦ پارامتر ارتفاع ، شـيب ، جهت شـيب ، فاصـله از رودخانه ، نوع ليتولوژي و کاربري اراضـي اسـتفاده شـده اسـت (انتخاب پارامترها 1 . همچنين نتايج روند توسعه فيزيکي شهرها به سمت مناطق سيل خيز بيانگر اين است که در سال ١٣٦٩، ٣/٨ کيلومترمربع از نواحي سکونتگاهي در معرض مخاطره سيلاب بوده است که از اين ميزان تا سال هاي ١٣٧٩، ١٣٨٩ و ١٣٩٩ به ترتيب به ٤/٣، ٥/١ و ٧/٢ کيلومترمربع افزايش يافته است . Assessing the physical development of cities and extending to geomorphological prohibited areas Using Land Change Modeler (Case Study: Sanandaj City).