بررسی روند تغییرات خصوصیات بیوفیزیکی سطح ناشی از فعالیت معدن مس سونگون با تلفیق قابلیت‏ های سنجش از دور انعکاسی و حرارتی

تغییر خصوصیات بیوفیزیکی سطح زمین یکی از مهم‏ترین اثرهای منفی فعالیت‏های انسانی است. هدف از پژوهش حاضر تلفیق قابلیت‏های سنجش از دور انعکاسی و حرارتی برای بررسی و پایش روند تغییرات خصوصیات بیوفیزیکی سطح منطقه معدن مس سونگون ناشی از فعالیت‏های معدنی طی سه دهه گذشته است. بدین‏منظور، از مجموعه داده‏های انعکاسی و حرارتی تصاویر ماهواره‏ای، ایستگاه‏های هواشناسی، و بازدید زمینی استفاده شده است. در این پژوهش، برای طبقه‏بندی کاربری اراضی از الگوریتم طبقه‏بندی بیشترین شباهت، محاسبه دمای سطح از الگوریتم تک‏کاناله و مدل‏سازی خصوصیات بیوفیزیکی روشنایی، سبزینگی، و رطوبت سطح بازه زمانی 13681396 به‏ترتیب از پارامترهای آلبیدو، ndvi، و ndwi استفاده شد. نتایج نشان می‏دهد که بر اثر گسترش و توسعه فعالیت‏های معدنی مساحت جنگل‏ها از 94/995 هکتار به 27/594 هکتار کاهش یافته است. طی بازه زمانی 13681396 مقدار میانگین پارامترهای آلبیدو، ndvi، و ndwi به‏ترتیب 1/0 افزایش، 08/0 کاهش، و 12/0 افزایش یافته است. همچنین، تغییر کاربری جنگل به معدن به‏صورت میانگین سبب افزایش 8/5 درجه کلوین دمای سطح شده است. نتایج پژوهش حاکی از کارایی بسیار بالای تلفیق قابلیت‏های سنجش از دور انعکاسی و حرارتی برای پایش و مدیریت پدیده‏های مختلف انسانی، محیطی، و طبیعی است.

Investigating the Trend of Surface Biophysical parameters Changes due to the Sungun Copper Mine Activities by Integrating Reflective and Thermal Remote Sensing Capabilities

1. Introduction Land use has always been one of the most important indicators that humans through its have been influenced their environment.Nowadays, processed mining and related operations are parts of activities that have potential to harm the environment. Mining is in direct contact with nature and the environment, so this will have important effect on the environment. The negative effects of mining activities on changes in surface biophysical parameters such as greenness, brightness, wetness and land surface temperature (LST) depend on the type of minerals, location of the area, extraction method and other factors. Remote sensing technology provides useful information to understand temporal and spatial changes of land use/cover and land development processes. Sungun is a large porphyry copper mine and extraction method of this mine is open pit mining. The important environmental pollutions in this method of mining are land and landscape degradation, mass production of waste mineral extraction and loss of vegetation covers. Due to Sungun copper mine geographic location which it’s adjacent to the Arasbaran forests and Dezmar protected area, the activities of this mine are environmental impact of great environmental importance.The objective of the present study is integrating reflective and thermal remote sensing capabilities to analyze and monitor changes in the surface biophysical parameters of the Sungun copper mine region caused by mineral activities over the past three decades. 2. Data and methods In the current study, the reflective and thermal bands of satellite images acquired by Landsat 4, 5, 7, and 8 have been used to calculate the LST and biophysical parameters. Also, the water vapor products (MOD07) and the LST products (MOD11) of MODIS sensor of TERRA satellite, the air temperature data measured at the meteorological stations and ground data have been used. In the first step, using reflective bands set of Landsat images, the land use change trends in the study area for the period 1989 to 2017 were extracted and analyzed. Satellite images classified based on maximum likelihood classifier. The cross tab model was used to study land use changes trend. In the second step, the changes in biophysical parameters such as greenness, brightness and wetness caused by mineral activities have been investigated. In order to model the surface biophysical parameters of brightness, greenness and wetness for the period from 1989 to 2017, Albedo, NDVI and NDWI parameters were used, respectively. In the third step, by integrating the reflective and thermal remote sensing capabilities, the LST maps are extracted from different years and the trend of LST changes due to land use changes in different time periods has been investigated. For LST retrieval, a singlechannel (SC) algorithm was applied. Finally, the zonal analysis has been used to analyze the trend of LST changes caused by land use changes in the studied are. 3. Results and Discussion Over the past two decades, with the increase in the activities of Sungun mine, the area of this land use has increased dramatically. The results indicate that the area of the mine class will increase from 13.41 ha in 1993 to 621.54 ha in 2017. During the same period, as a result of the expansion and development of mineral activities, the area of the forests decreased from 995.94 to 594.27 ha. In the period under study, 2295 ha of forest area has changed to mine land use. Also, more than 2632 ha of pasture land has become mine land. The results demonstrate that during the period of 1989 to 2017, the mean values of Albedo, NDVI and NDWI parameters increased, decreased and increased, respectively. The mean of surface albedo values for the study area has been increased from 0.17 in 1989 to 0.25 in 2017. Also, the mean value of the NDVI index has been decreased by almost 0.09 during the period from 1989 to 2017. The major reason for a decrease in NDVI mean values is the reduction of the forest lands and the conversion of them into the mine and pasture lands in past years. In all dates, the lowest and highest LST mean were related to forest and bare land classes, respectively. In these years, the mean value of LST of the forest is, on average, 6.36 °C below the mean value of the LST of the mine land use. The results revealed that land use changes from forest to mine, pasture to mine, forest to pasture, forest to bare land and pasture to bare land have changed the LST 5.8, 0.1, 1.4, 1.6, 3.3, and 0.9 °C, respectively. 4. Conclusions One of the most important negative impacts of human activities is the change in the surface biophysical parameters. Changing the earth's surface biophysical parameters causes a change in many processes and natural cycles of the earth, including the energy billing cycle. The results of this study are a major warning to environmental authorities to provide appropriate plans and solutions to reduce the negative effects of Sungun copper mineral activities. Also, the results of the study indicate the usefulness and efficiency of the integration of reflective and thermal remote sensing capabilities for monitoring and managing various human, environmental and natural phenomena.