پایش تغییرات کاربری اراضی و تأثیر آن بر روند تخریب زمین و بیابان زایی با استفاده از تصاویر ماهواره ای لندست (مطالعه ی موردی: شرق ایران، دریاچه ی هامون) (مقاله علمی وزارت علوم)
درجه علمی: نشریه علمی (وزارت علوم)
آرشیو
چکیده
امروزه فنّاوری های سنجش ازدور و سامانه ی اطلاعات جغرافیایی به عنوان دو عنصر اصلی در پایش کاربری اراضی و تغییرات پوشش گیاهی مورد استفاده قرار می گیرد. به کارگیری این روش به عنوان یکی از منابع مهم دریافت اطلاعات مربوط به تغییرات سطح زمین، نقش مهمی را در مدیریت زیست بوم ها ایفا می کند. تحقیق حاضر باهدف بررسی روند تغییرات کاربری اراضی، پویایی پوشش گیاهی و گرایش زیست بوم تالاب های هامون هیرمند و هامون صابری در یک دوره ی هفت ساله صورت گرفته است. بدین منظور از تصاویر ماهواره ای لندست 7 در سال 2006 میلادی و لندست 8 در سال 2013 میلادی و در ماه آوریل استفاده شده است. پس از انجام تصحیحات لازم، با استفاده از روش طبقه بندی نظارت نشده و با تکیه بر خصوصیات طیفی پدیده ها در باندهای مختلف نقشه ی کاربری اراضی منطقه ی تهیه شد. به منظور بررسی درصد تغییرات کاربری اراضی، هر کدام از کاربری های به دست آمده در سال 2006 به طور جداگانه بر روی نتایج طبقه بندی سال 2013 قرار داده شد و مقدار تغییرات هر کلاس در دوره ی موردنظر به دست آمد. صحت روش به کار گرفته شده با تکیه بر پژوهش های میدانی انجام شده در سال 2010 میلادی که شاخص تعدیل کننده ی خاک (SAVI) را به عنوان شاخصی با بالاترین ضریب همبستگی با ویژگی های منطقه ی معرفی می کند، مورد بازبینی قرار گرفت. نتایج بیانگر این است که استفاده از خصوصیات طیفی پدیده ها در این نوع طبقه بندی صحت قابل اعتمادی را ارائه می دهد. با توجه به نتایج به دست آمده، کلاس های پوشش گیاهی و آب کاهش چشم گیری را در دوره ی موردمطالعه داشتند و بر مساحت کلاس اراضی بایر افزوده شده است که نشان از گرایش منطقه ی موردمطالعه به سمت بیابانی شدن دارد. سیر قهقرایی زیست بوم هامون سبب چالش های زیست محیطی متعددی من جمله آلودگی ناشی از گردوغبار، از دست رفتن مشاغل وابسته به دریاچه هم چون ماهیگیری و دامداری و نیز افزایش مهاجرت از این منطقه ی شده است.Monitoring Land Use Change and its Impacts on Land Degradation and Desertification Trend Using Landsat Satellite Images (Case study: East of Iran, Hamoon Wetland)
Introduction
Nowadays, remote sensing and GIS technologies are used as the two main elements in monitoring of land use and vegetation changes. Using this method as one the main sources receiving and updating information on the Earth's surface changes, plays an important role in the management of ecosystems. The present study aims to investigate the trend of land use change, vegetation dynamics and the bio monitoring trend of Hamoon wetland between 2006 and 2013 using of Landsat images. After making the necessary corrections, using the unstructured classification method and based on the spectral characteristics of the phenomena in different bands, the regional map of the region was prepared. In order to evaluate the percentage of land use change, each of the uses obtained in 2006 was separately allocated to the 2013 classification results and the amount of changes in each class was obtained in the desired period. The accuracy of the methodology used was based on field studies conducted in 2010, which introduced the Soil Adjusted Vegetation Index (SAVI) as an index with the highest correlation coefficient with regional features was revised. The results indicate that the use of spectral properties of phenomena in this type of classification presented a reliable reliability. According to the results vegetation and water classes have significantly declined during the study period and the area of bare land classes have been added that show the trend towards desertification in the studied area. The demolition of the ecosystem has caused many environmental challenges, including pollution from dust, the loss of lake dependent businesses such as fishing and livestock, as well as increased immigration from the area.
Introduction
Acquiring knowledge about the health of soil cover and soil plays an important role in managing the ecosystems of arid regions. Access to information for assessing and monitoring ecosystems on a global and regional scale is often difficult and limited. n the meantime, remote sensing knowledge plays an important role in the monitoring and management of these areas, which can be used to determine the spatial patterns of land use and land cover by creating a broad and integrated view of the area. Remote sensing technologies and GIS technologies are now used as the two main elements in land use monitoring and land cover changes. Using this method as one the main sources of receiving and updating information on the Earth's surface changes, plays an important role in the management of ecosystems. The main features of digital satellite imagery are the ability to analyze images based on the reflectivity of objects and ground phenomena. Classification is one of the main goals of satellite image processing processes, with the final result of which is usually the creation of subject-matter maps of land cover with specific land use features. The aim of present study is to investigate land use change, vegetation dynamics and trend of Hamoon wetland between 2006 and 2013 using of Landsat images.
Materials and Methods
After making the necessary corrections, using the unstructured classification method and based on the spectral characteristics of the phenomena in different bands, the regional map of the region was prepared. In order to evaluate the percentage of land use change, each of the uses obtained in 2006 was separately allocated to 2013 classification results and the amount of each class change was obtained in the desired period. The accuracy of the methodology used was based on field studies conducted in 2010, which introduced the Soil Adjusted Vegetation Index (SAVI) as an index with the highest correlation coefficient with regional features was revised. The results indicate that the use of spectral properties of phenomena in this type of classification presented a reliable reliability.
Discussion and Results
The results were compared in order to determine the amount of land use change. According to the results vegetation and water classes have significantly declined during the study period and the area of bare land classes have been added that show the trend towards desertification in the studied area. The demolition of the ecosystem has caused many environmental challenges, including pollution from dust, the loss of lake dependent businesses such as fishing and livestock, as well as increased immigration from the area.
تبلیغات
