https://jgrs.kgut.ac.ir/ دوفصلنامه علمی سنجش از دور زمین شناختی fa daily 1 Thu, 01 Aug 2024 00:00:00 +0330 Thu, 01 Aug 2024 00:00:00 +0330 https://jgrs.kgut.ac.ir/article_209811.html Land use and land cover (LULC) play a crucial role in studying the ongoing worldwide environmental changes This study employs TM, ETM+, and OLI images acquired from the Landsat satellite over a thirty-year period (1990-2020) to analyze changes in land use. The Support Vector Machine (SVM) algorithm is utilized for land use classification, and a Median filter in the ENVI software was applied to the SVM algorithm results to produce smoother images. The study area is located in Kerman Province, Iran, encompassing the cities of Kerman, Zarand, Bardsir, and parts of Rafsanjan, Ravar, and Sirjan counties. An area with hot and dry climate. Due to the vastness of the consider region and the difficulty of detailed investigation owing to the decrease in accuracy four classes were selected for SVM classification: built-up areas, vegetation, water resources, and bare land (comprising soil and rock formations). The results indicated that the classification of OLI data performs better in terms of overall accuracy (more than 80%) and the kappa coefficient (more than 0.7). Specifically, the analysis revealed a 1.88% decrease in vegetation cover, a 0.19% increase in urban areas, and a 0.005% change in surface water bodies over the 30-year period. These changes are attributed to the influence of human activities, drought, poor management practices, and climate change on the dynamics of land use in the region. https://jgrs.kgut.ac.ir/article_224481.html Mining activities are a major contributor to heavy metal pollution, presenting a serious risk to the surrounding environment. Human activities, particularly mining, can adversely affect soils in the impacted regions. In older mining sites, the use of outdated and inefficient techniques often results in waste materials with elevated metal concentrations. When exposed to atmospheric conditions, these metals can be released into the soil and water systems. Soil, as a critical element of the life cycle, exhibits diverse physical and chemical properties due to the weathering of rocks and minerals in the Earth's crust. Lead and zinc mines are particularly hazardous to the environment because of their high levels of toxic elements. Given the economic significance of mining, it is essential to conduct environmental assessments to mitigate pollution and safeguard human health. Heavy metal pollution is a worldwide issue, as these metals are chemically stable, persist in the environment, enter the food chain, and exert toxic effects on living organisms. The toxicity and bioaccumulation of heavy metals in food chains pose significant environmental and health challenges in contemporary societies. Lead and zinc deposits are potential sources of environmental contamination due to their high concentrations of toxic elements and heavy metals. In Kerman province, most lead and zinc mines are situated in the northern region, particularly in the Ravar area, with the Gojer lead and zinc mine being a prominent example. This study employed statistical methods such as Principal Component Analysis (PCA), Factor Analysis (FA), and environmental indices to evaluate the degree and distribution of soil and stream sediment pollution in the Gojer mine area. Statistical analysis demonstrated a strong correlation among heavy metals. Furthermore, the Enrichment Factor (EF) and Potential Ecological Risk Index (RI) indicated varying levels of heavy metal pollution in the mine area. The primary sources of contamination were identified as lead and arsenic, both of which pose significant risks to human health. The severity and spatial extent of contamination were also notable. Pollution levels were highest in close proximity to the mining site, with the presence of Gossan linked to lead and zinc mineralization. As the distance from the mining area increased, pollution levels gradually declined. https://jgrs.kgut.ac.ir/article_231129.html Geological lineaments are an essential component of geological structure on the surface, and they are used in resource exploration for hydrocarbons, groundwater, and minerals. This study aims to extract lineaments from satellite images and magnetic data in the Zivah 1:100000 geological sheet. The lineaments were extracted using manual and automatic methods. Directional filters in different directions and hillshade technique were applied to manually extracted lineaments. Lineaments were automatically extracted using principal component analysis on the panchromatic band of Landsat 8, followed using the Segment Tracing Algorithm (STA). Magnetic data were used to extract basement faults and lineaments. The study observed that most fractures and lineaments in the region have an East-West trend and are extremely consistent in orientation with the basement faults in the Zivah area, suggesting that the systematic fault systems at the basement in the study area have been reactivated many times. The correlation between surface linear features and probable subsurface oil and gas traps (Anticlines) was also assessed, and the implication of using surface lineament and fracture analysis for delineating hydrocarbon reservoirs in the area was discussed. The highest density of faults and fractures was found in the central areas of Zivah, indicating that the areas might be a suitable bed for the accumulation of hydrocarbons. Therefore, the study recommends the use of surface lineament and fracture analysis as a cost-effective tool for hydrocarbon exploration in other parts of the basin. https://jgrs.kgut.ac.ir/article_231958.html امروزه، رشد جمعیت و توسعه اقتصاد، محرّک­های اصلی تغییرات کاربری و پوشش زمین در سراسر جهان است که این تغییرات در محیط­های شهری بیش از سایر مناطق بوده است. یکی از تأثیرات این تغییر کاربری‌ها در اقلیم شهری بروز می‌کند، به نحوی که شهرهای گرم‌تر آسایش و زندگی انسان‌ها را با مشکل مواجه کرده است. گرمایش شهری تحت عناوینی مانند جزایر حرارتی شهری در دنیا نمود یافته است؛ بنابراین بررسی وضعیت پراکندگی جزایر حرارتی و ارتباط آن با نوع کاربری‌ها در شناخت میکرواقلیم شهری اهمیت دارد. در شهر عسلویه به دلیل ایجاد و توسعه کاربری‌های صنعتی شامل انواع پالایشگاه‌های بخش نفت، گاز و پتروشیمی، تغییر در خرداقلیم آن مشاهده می‌گردد که باعث ایجاد مشکلات زیست محیطی شده است. یکی از این تغییرات، پیدایش جزایر حرارتی شهری است. در تحقیق حاضر با بهره‌گیری از سنجش ‌از دور، به بررسی وضعیت توزیع این جزایر در شهر عسلویه و اراضی حاشیۀ آن (بندر عسلویه) در ارتباط با کاربری و پوشش زمین پرداخته ‌شده است. بدین منظور از تصاویر لندست 7 و8 در روزهای 15/4/2000، 11/4/2010، 14/4/2020 استفاده و با استفاده از آنها نقشه‌های دمای سطحی، شاخص نرمال شده تفاوت پوشش گیاهی (NDVI)، شاخص مناطق ساخته‌شده (NDBI) و نقشۀ کاربری اراضی تهیه ‌شد. بر اساس نتایج نقشه‌های دمای سطح تهیه‌شده از سال ۲۰۰۰ تا ۲۰۲۰، گسترش مناطق صنعتی-کارگاهی و استقرار آنها در مناطق شهری منجر به ایجاد سطوح سخت مانند آسفالت، جاده‌هایی برای ماشین‌آلات سنگین و افزایش استفاده از بتن و آجر شده است. افزایش این سطوح عواقبی از جمله تغییرات کاربری اراضی، بالا رفتن دمای آن منطقه و تشکیل جزایر حرارتی، افزایش NDBI، کاهش NDVI به دلیل کم شدن فضا برای پوشش گیاهی را به دنبال دارد. این پدیده در سطح شهر عسلویه به دو کاربری وابسته است که شامل کاربری شهری و مناطق صنعتی که رابطه مثبت دارد و در این مناطق دما به نسبت اراضی بایر افزایش‌یافته است. همچنین در پهنه‌های دارای پوشش گیاهی و مناطق ساحلی دما کاهش‌ یافته و رابطه منفی با جزیره حرارتی دارد.