پایش و پیش بینی تغییرات کاربری اراضی و گسترش فیزیکی شهر رودسر با استفاده از مدل LCM و CA-Markov (مقاله علمی وزارت علوم)
درجه علمی: نشریه علمی (وزارت علوم)
آرشیو
چکیده
رشد و گسترش تصاعدی شهرها که با فعالیت های ناپایدار شروع شده و به کمبود منابع ضروری می انجامد، باعث آسیب شدید به زیست کره می شود. اگر مصرف بی رویه منابع در داخل و اطراف زیستگاه انسان باشد، باید این تمایلات به طور مرتب پایش شده و اقدامات لازم برای جلوگیری از بهره برداری بیهوده از منابع ارزشمند زمین انجام شود. بر این اساس پژوهش حاضر با هدف پایش و پیش بینی تغییرات کاربری اراضی و بررسی روند گسترش فیزیکی شهر رودسر صورت پذیرفت. به همین منظور از تصاویر سنجنده هایETM+ TM و OLI ماهواره لندست به ترتیب برای سال های 1997، 2010 و 2023 استفاده شد. تصاویر با استفاده از روش طبقه بندی نظارت شده به شش کلاس اراضی کشاورزی، اراضی باغی، اراضی شهری و ساخته شده، پوشش جنگلی، اراضی بایر و رودخانه طبقه بندی شدند. به منظور ارزیابی روند تغییرات کاربری اراضی از مدل LCM استفاده شد. سپس با استفاده از مدل CA-Markov نقشه پیش بینی شده سال 2023 با نقشه واقعی سال 2023 مورد مقایسه قرار گرفت و اعتبارسنجی مدل با مقادیر کاپای بالای 0.75 تأیید شد. نتایج حاصل از بررسی تغییر کاربری اراضی بین سال های 1997 تا 2023 نشان داد که از مساحت اراضی کشاورزی کاسته شده و به مساحت اراضی باغی، اراضی شهری و ساخته شده و نیز اراضی بایر افزوده شده است. پیش بینی تغییرات برای سال 2036 نیز ادامه روند کاهش را برای اراضی کشاورزی و روند افزایش را برای اراضی شهری و ساخته شده تعیین کرده و گسترش فیزیکی شهر را به سمت نواحی ساحلی نشان می دهد. با توجه به اینکه نتایج حاصله، اثرات قابل توجهی بر پایداری اقتصادی – اجتماعی و محیط زیستی منطقه دارد، از اینرو لازم است تا برنامه ریزان تصمیمات مدیریتی مناسبی را در راستای حفظ اراضی کشاورزی و کنترل توسعه شهری داشته باشند.Monitoring and predicting of land use changes and physical expansion of Rudsar city using LCM and CA-Markov model
Introduction The increase in population and the rapid increase in urbanization is one of the key factors of land use change, which leads to the destruction of forests and the conversion of fertile land into urban construction with a significant impact on ecosystems. Land use change is a change in the way land is used, and these changes are shaped by numerous factors, such as politics, management, economics, culture, and the environment. It has serious consequences for the environment. Many cases, such as soil erosion, water scarcity, impact on ecosystem services, decreased biodiversity and habitat loss, and impact on surface temperatures are among the environmental problems caused by land use change. In addition to reducing natural resources, these changes could have serious socio-political consequences in the region by affecting food supply. Hence, recognizing land use change and its driving forces is critical to environmental protection, resource management, land use planning, and sustainable development. To this end, the use of geographic data in combination with land surface modelers (e.g. The LCM and CA-Markov model) offers an effective tool in understanding the dynamics of land use changes in place and time, which can be a guide in formulating policies for the sovereignty of sustainable land. Materials & Methods The present study is applied research, which is prepared by a descriptive-analytical method. In order to prepare a land use map of the studied area, Landsat satellite images sensors of TM, ETM+ and OLI from three time periods, for 1997, 2010 and 2023, respectively, were used by the American Geological Site (USGS). After receiving satellite images, radiometric corrections were performed and then atmospheric corrections were performed using FLAASH command in ENVI 5.3 software. In the next step, points were selected as educational examples in Google Earth Pro software to collect ground information. These samples were collected in six classes: agricultural land, garden land, urban and built land, forest cover, barren land and river. Then, using Maximum Likelihood, which is a supervised classification method, was used to classify the images. In the next step, the maps were entered into ArcGIS 10.7.1 software and necessary calculations such as determining the area of each user were determined. Then, the maps were entered on the IDRISI TerrSet software and the trend of land use changes was investigated using the LCM model. Finally, using the CA-Markov model, land use changes were predicted first for 2023 and then for 2036. Results & Discussion The results showed that from 1997 to 2010, agricultural land increased by 1.8%, garden land by 3.3%, urban and built land by 0.8%, and bareland by 0.75%. But the forest cover shows a decrease of about 6%. In the analysis of time changes between 2010 and 2023, garden land has increased by 2.25%, urban and built land by 9.9%, bareland by 0.85%. Forest cover decreased by 2.36%. During this period, the area of agricultural land has decreased dramatically by about 10%. This decline was caused by the conversion of agricultural land into land (especially Kiwi gardens) and even built land. Also, the gardens and agricultural land that were near the coast, due to the receding of the Caspian Sea, have become urban and built land, and the process of urban development has spread towards the coast. According to the projected land use map of 2036, the area of agricultural use shows a significant decrease compared to 2023. In 2036, 6.48% of the agricultural area used was reduced and added to the area for other uses. These results show that we will see a decline in agricultural land in the coming years, and this is predictable given the annual increase in the price of agricultural tools and inputs, the increase in the problems of farmers in selling crops and the lack of savings in land cultivation, the increase in land prices and the increase in the number of immigrants from the central and southern provinces of the country to this region to buy land and housing, which requires more attention from planners and managers in the decision-making process. Conclusion The results showed that in different years, the area of agricultural land has decreased due to the conversion of this land into garden land and urban and built land. Due to the increase in the price of agricultural inputs in recent years and the lack of sales or sales at low crop prices, in the future, the decrease in agricultural land area will continue at a faster rate, and these lands will either become garden land and built land, or they will increase the area of bareland due to the lack of land cultivation. Over the past years, with the retreat of the Caspian Sea, urban land has expanded towards the coast, and this trend will continue in the future. Therefore, since these changes have significant effects on sustainability, food security, biodiversity and socio-economic vulnerability of the region, it is necessary for planners to make appropriate management decisions to preserve agricultural land and control urban development in the region and prevent the serious damage that will be done to the region following these changes.
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