ارزیابی روند تغییرات پوشش زمین در نوار ساحلی عسلویه شیرینو با استفاده از مدل Lcm

روند افزایشی جمعیّت، توسعه نواحی سکونت گاهی و همچنین کاربری های انسان ساخت، سبب تغییرات پوشش زمین می شود. در این میان، خطوط ساحلی درمقابل تغییرات پوشش زمین حسّاسیت بیشتری دارند؛ به همین دلیل، در پژوهش حاضر روند تغییرات پوشش زمین در جنوب شرقی استان بوشهر از شهر عسلویه تا روستای شیرینو ارزیابی شده است. در نوشتار پیش رو به‌منظور ارزیابی روند تغییرات پوشش زمین از تصاویر ماهواره ای لندست مربوط به سال های 1990،‌ 2000، 2010 و 2019 و مدل lcm استفاده شده است. روش کار به این صورت است که ابتدا نقشه های پوشش زمین تهیه شده و سپس روند تغییرات پوشش زمین به کاربری نواحی انسان ساخت و همچنین روند تغییرات خطّ ساحلی ارزیابی شده است. ارزیابی تغییرات صورت‌گرفته بیانگر این است در طی سال های 1990 تا 2019 تحت تاثیر توسعه فعّالیّت های اقتصادی و به موازات آن توسعه نواحی سکونت گاهی، پالایشگاه ها و همچنین سایر تاسیسات مربوط به شرکت نفت، کاربری نواحی انسان ساخت با تغییرات قابل توجّهی روبه رو شده است. با توجّه به موقعیّت محدوده مطالعاتی و نوع کاربری انسان ساخت (پالایشگاه ها و سایر تاسیسات و زیرساخت های مربوط به شرکت نفت)، روند تغییرات این کاربری بیشتر به سمت نوار ساحلی بوده است و همین امر سبب شده تا در طی این دوره 29 ساله، 2/11 کیلومتر مربع از دریا به خشکی تبدیل شود؛ همچنین با توجّه به توسعه فعّالیّت های اقتصادی و فراهم آمدن شرایط شغلی، نواحی سکونت گاهی در شهر عسلویه و نخل با رشد قابل توجّهی روبه رو شده است و عوامل انسانی بیشتر سبب تغییر ماسه زار ها به کاربری نواحی انسان ساخت شده است.

Assessing the Trend of Landcover Changes in Asaloyeh Shirino Coastline Applying LCM Model

Population growth, development of residential areas, as well as manmade land use, are causing landcover change. Shorelines are more sensitive to landcover change. Therefore, the current study aims to evaluate the trend of landcover changes in the southeast of Bushehr province from Asaloyeh city to Shirino village. The study used Landsat satellite images from the 1990, 2000, 2010 and 2019 and the LCM model to assess the trend of landcover change. The procedure is that first the landcover maps are prepared and then the process of land use change changes, changes in other landcovers to manmade areas and also the coastline change process is evaluated. The assessment of the change indicates that the use of manmade areas has had significant changes in a period from 1990 to 2019 under the influence of the development of economic activities and in parallel with the development of residential areas, refineries, as well as other facilities related to the Gas Company. Depending on the location of the study area and the type of anthropogenic, manmade use (refineries and other facilities and infrastructure related to the gas company), landuse changes mostly direct to coastline. Therefore, 11.2 km2 of the sea has been changed to an arid area during a 29year period. Besides, the development of economic activities and job creation, residential areas in Assaluyeh and Nakhl have experienced significant growth, and this development has further changed the use of sandy lands to the construction of manmade areas.Extended Abstract1IntroductionUrban growth has been accompanied by changes in land use and increased urban activity, which is the result of population growth and economic development. In fact, the horizontal and unplanned expansion of cities with increasing population and growing urbanization leads to land scarcity, changes of adjacent lands, and unprincipled and unplanned use of land and change of land uses. Land use change affects the amount of land demand for agricultural, forestry, industrial, residential, tourism, and landscape diversity and natural areas. One of the most important changes is the change in urban areas. Today, urbanization has become one of the changing factors on the earth surface. Therefore, knowledge of the types of land surface coverings and human activities in its different parts and in other words how to use the land as a basic information for different programs is of special importance which causes possible future developments. Meanwhile, coastlines are more sensitive to land use change, so the present study aims to evaluate the trend of land use change in the southeast of Bushehr province from Asaloyeh city to Shirino.2Materials and MethodsIn order to achieve the desired goals, Landsat satellite images and a 30meterhigh digital model have been used in this study. In the first step, the desired images are prepared; given that the purpose of this study is to evaluate land use changes from 1990 to 2019. In the second stage, land use maps related to the studied years have been prepared. In order to prepare a land use map in ENVI software, first radiometric and atmospheric corrections have been applied to the images and Then, using the maximum probability method and in 5 classes (manmade use, vegetation use, pasture and barren land use, sand use and water zone use), the desired maps have been prepared. In the third step, IDRISI software and LCM model were used to analyze the changes. Therefore, the trend of land use change from 1990 to 2000, from 2000 to 2010, from 2010 to 2019, as well as from 1990 to 2019 has been evaluated.3Results and DiscussionThe results show that land use, especially manmade use of the study area, has undergone significant changes from 1990 to 2019, so that the use of manmade areas has grown by 25.9 km2 over a period of 29 years. The results of the analysis of changes in other uses of humanmade areas indicate that during the years 1990 to 2019, 0.6 km2 of vegetation use, 5.3 km2 of use of pastures and barren lands, 11.6 km2 of sand use and 11.2 km2 of sea has been converted to manmade areas. Spatial analysis of the changes also indicates that most of the changes have taken place near the cities of Asaloyeh, Nakhl and the coastal strip. The study also assessed the trend of coastline changes. The findings reveal that between 1990 and 2000, 1 km2 from sea to land and 0.36 square kilometers from land to sea. Between 2000 and 2010, 8.5 square kilometers of sea became land and 0.1 km2of land became sea. Between 2010 and 2019, 1.7 km2 of land has been converted from land to land and 0.3 km2 from land to sea, according to which from 1990 to 2019, 11.2 km2 from sea to land and 0.8 km2 of land has been turned into a sea.4ConclusionThe assessment of the change indicates that during the years 1990 to 2019, under the influence of the development of economic activities and in parallel with the development of residential areas, refineries and other facilities related to the oil company, the use of manmade areas underwent significant changes. Depending on the location of the study area and the type of manmade use (refineries and other facilities and infrastructure related to the oil company), the trend of land use changes has been more towards the coastal strip leading to the transformation of the 11.2 km2 area from the sea to land during this 29year period. Furthermore, due to the development of economic activities and job creation, residential areas in Assaluyeh and Nakhl have experienced significant growth, and this development has further changed the use of sandy lands to the construction of manmade area.