بررسی و پیش بینی روند تغییرات پوشش/ کاربری های اراضی در زیستگاه ساحلی کولاب کیاشهر (مقاله علمی وزارت علوم)
درجه علمی: نشریه علمی (وزارت علوم)
آرشیو
چکیده
یکی از مهمترین تهدیدات انسانی، تغییرات پوشش/کاربری اراضی بوده که منجر به نابودی تنوع زیستی به خصوص در زیستگاه های تالابی شده است. لذا در مطالعه حاضر به بررسی این تغییرات در کولاب بندر کیاشهر طی سال های 2007، 2014 و 2022 با استفاده از تصاویر ماهواره ای لندست تحت سامانه گوگل ارث انجین و طبقه بندی تصاویر به روش جنگل تصادفی پرداخته شد. به منظور پیش بینی روند تغییرات آتی در منطقه، از مدل ترکیبی CA-Markov برای سال 2050 استفاده شد. مطابق نتایج، بیشترین روند افزایشی به اراضی انسان ساخت در سال 2007 (02/588 هکتار) در مقایسه با سال 2022 ( 81/773 هکتار) و کمترین روند تغییرات به کانال دسترسی ( 57/17 هکتار) در سال 2007 در مقایسه با سال 2022 (85/11 هکتار) اختصاص یافت. نتایج مدل CA-Markov نیز نشان داد که جنگل های دست کاشت در بین کاربری های موجود در سال 2050 (48/422 هکتار) در مقایسه با سال 2022 (03/403 هکتار) بیشترین روند افزایشی و اراضی کشاورزی در سال 2050 (48/667 هکتار) در مقایسه با سال 2022 (92/707 هکتار) بیشترین روند کاهشی را خواهند داشت. همچنین در سال 2050 اراضی انسان ساخت، پوشش گیاهی، اراضی بایر، دریاکنار و جنگل دست کاشت روند افزایشی و آب کرانه، اراضی کشاورزی، شاخابه اصلی (سفیدرود) ، کانال دسترسی و پهنه آبی روند کاهشی را نشان می دهند. لذا ضروری است جهت به حداقل رساندن اثرات نامطلوب ناشی از این تغییرات و کنترل تداوم آن در آینده، مدیریتی یکپارچه جهت بهره وری هر چه صحیح تر از این منبع طبیعی اتخاذ شود. همچنین یافته های این مطالعه می تواند به ذینفعان در توسعه راهبردهای مناسب و احیای این زیست بوم تالابی کمک نماید.Investigating and Predicting Trend of Land Cover/Land Use Changes in Coastal Habitat of Kiashahr Lagoon
Background and Purpose: Coastal wetlands are transitional land-to-sea ecosystems that provide a wide range of benefits from ecosystem services, especially in supporting livelihood opportunities for various wildlife species. However, due to human activities, wetlands are continuously being degraded worldwide. The degradation and loss of these natural ecosystems threaten most of the natural resources used by local communities and wildlife-dependent resources. Any change in wetland ecosystems can also affect adjacent, upstream, and downstream ecosystems. For this purpose, examining the extent of changes in these areas is one of the main effective methods to prevent the degradation and loss of these sensitive areas. Therefore, the present study examined the extent of changes in land cover and use around the Kiashahr Lagoon in Boujagh National Park, one of the country's important bird areas and one of Iran's important sites in the Ramsar Convention. Materials and Methods: In this study, the trend of land cover/use changes was examined over 15 years. Landsat 5 (TM) satellite images for 2007 and Landsat 8 (OLI-TIRS) for 2014 and 2022 were classified and analyzed in the Google Earth Engine (GEE) web-based system. For classification, the Random Forest (RF) algorithm was used due to its remarkable accuracy and precision compared to other classification methods. Due to the maximum growth and density of vegetation in the region, satellite images were selected from May to August. In this study, NDVI and NDWI indices were used to better distinguish vegetation and water areas. Finally, validation was performed using the overall accuracy method and the kappa coefficient. The final result included 10 classes of water area, waterside, seaside, the main branch (Sefidrud), access channel, vegetation, hand-planted forest, agricultural land, bare land, and man-made land. To predict and model the changing trend for the year 2050, a combined Markov chain and autonomous cell (CA-Markov) model was used in the Idrisi Terr Set software. Findings and Discussion: According to the results of the changes between 2007 and 2022, the highest increase was related to man-made lands by 25.5 percent and the highest decrease was related to agricultural lands by 98.3 percent, the main reasons for which are the conversion of agricultural land to man-made land and the development of human activities in this area. Likewise, the waterside decreased by 81.3 percent, the water area by 68.2 percent, the main branch (Sefidrud) by 0.42 percent, and the access channel by 0.16 percent in 2022 compared to 2007. These results can indicate the development of human activities and industrialization as well as the trend of climate change in this region during the studied years, which has led to a decrease in the level of water resources, including waterside, seaside, and the main branch (Sefidrud). The forecast results of the CA-Marcove model also showed that by 2050, the highest increase trend among existing land cover/uses will be in hand-planted forests at 0.57 percent. This is while agricultural land will have the largest decline with 1.15 percent. Conclusion: Based on the results, continued land cover/use changes in Kiashahr Lagoon could lead to the destruction and extinction of the region's biodiversity. Given the importance of this area as part of a national park and a highly sensitive coastal marine habitat, minimizing these adverse effects and controlling them in the coming years requires appropriate and integrated planning for the proper exploitation of this natural resource. It is worth noting that the findings of this study could provide an opportunity to advance optimal solutions for the protection of Kiashahr Lagoon and the restoration of this wetland ecosystem, and to further control and monitor human activities in this sensitive coastal area.
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