تحلیل روند سری‌ زمانی تصاویر پوشش گیاهی (MODIS-NDVI) و ارتباط آن با تغییرات کاربری اراضی در استان گلستان

نوع مقاله : مقاله پژوهشی

نویسندگان

گروه مهندسی آب، دانشکده مهندسی زراعی، دانشگاه علوم کشاورزی و منابع طبیعی ساری، ساری، ایران.

چکیده

مقدمه: تغییرات اقلیمی و فعالیت‌های انسانی تأثیر مستقیم در پوشش سطح زمین‌ دارند. تغییرات کاربری اراضی در شمال کشور از مهم‌ترین علل تخریب پوشش گیاهی در جنگل‌های هیرکانی بوده که در دهه‌های اخیر، به‌دلیل فعالیت‌های انسانی، به وقوع پیوسته است. تغییرات پوشش گیاهی در استان گلستان، با تنوع اقلیم و پوشش سطحی، نشان‌دهندۀ تأثیرات این فعالیت‌هاست. بر‌این‌اساس نظارت بر پویایی پوشش گیاهی نیازی اساسی، برای درک بهتر دربارۀ چگونگی واکنش پوشش گیاهی به فشارهای انسانی، درجهت حفظ جنگل‌های هیرکانی است.
مواد و روش‌ها: بررسی و پایش پوشش گیاهی با بررسی نمایۀ نرمال‌شدۀ تفاضل پوشش گیاهی (NDVI) انجام شد. برای تحلیل روند پوشش گیاهی در استان گلستان، از داده‌های سری زمانی ترکیبی شانزده‌روزۀ MODIS-NDVI به‌نام MOD13Q1، با قدرت تفکیک مکانی 250 متر در دورۀ بیست‌ساله استفاده شد. در این پژوهش، پیش‌از بررسی روند تغییرات پوشش گیاهی در منطقه، ابتدا تصاویر خام NDVI با فرمت HDF محصول از سایت ناسا دانلود و ازلحاظ آماری، بررسی و تحلیل شدند. بدین‌ترتیب 920 تصویر سری زمانی شانزده‌روزۀ پوشش گیاهی نمایۀ NDVI در نرم‌افزار GIS، پس‌از موزاییک‌سازی، به 460 تصویر تبدیل و با استفاده از ضرب فاکتور مقیاس تصاویر، به‌حالت استاندارد بین 1- تا 1+ درآمدند. برای ارزیابی روند سری در نرم‌افزار IDRISI TerrSet، ابتدا تصاویر با استفاده از بی‌هنجاری مؤلفۀ فصلی حذف شد. فرایند تحلیل روند ‌تغییرات ‌فعالیت‌ پوشش ‌گیاهی‌ و‌ معنی‌داری ‌آن ‌به‌روش غیرپارامتری من‌ـ کندال‌ انجام‌ شد‌.
نتایج: نتایج نشان داد که 20% از مساحت منطقۀ مورد مطالعه دارای روند کاهشی در پوشش گیاهی است؛ درحالی‌که 80% روند افزایشی داشته است. از‌این‌میان، 5% دارای کاهش معنادار و 50% دارای افزایش معنی‌دار پوشش گیاهی و مابقی بدون روند هستند. طی بیست سال گذشته، 4088 کیلومترمربع از پوشش گیاهی از دست ‌رفته است. تحلیل تأثیر فعالیت‌های انسانی در این تغییرات با استفاده از نقشه‌های موقعیتی شهرستان‌ها و مسیرهای اصلی انجام ‌شد. نتایج نشان داد که در دشت‌های شمالی گلستان، به‌دلیل دسترسی آسان‌تر به زمین‌ها برای فعالیت‌های انسانی، تغییر کاربری اراضی و توسعۀ شهرنشینی، کاهش پوشش گیاهی بیشتری رخ داده است. بیشترین افزایش معنی‌دار پوشش گیاهی در شهرستان‌هایی مانند کردکوی، بندر گز، آق‌قلا، گرگان، آزادشهر، رامیان و بیشترین کاهش معنی‌دار در شهرستان‌های بندر ترکمن، گنبد کاووس، مینودشت و کلاله مشاهده ‌شده است. مسیرهای اصلی منتهی به استان گلستان شامل گرگان‌ـ بجنورد، گرگان‌ـ ساری، آزادشهرـ سمنان، جادۀ غربی اینچه برون و جادۀ شرقی اینچه برون است که همگی شاهد روند کاهشی در پوشش گیاهی در اطراف خود بوده‌اند. ازآنجاکه استان گلستان از تنوع اقلیمی چشمگیری برخوردار است، تغییرات پوشش سطحی در نقاط منتخب با کاهش معنی‌دار پوشش گیاهی نیز بررسی شد.
بحث و نتیجه‌گیری: براساس نتایج این تحقیق از سال 2001 تا 2020، مناطق مرتفع استان گلستان، به‌ویژه ارتفاعات غربی شاهد افزایش پوشش گیاهی بوده‌اند که احتمالاً با افزایش دما براَثر گرمایش جهانی و بهبود شرایط دمایی برای گیاهان در این ارتفاعات مرتبط است. در مقابل، پوشش گیاهی مناطق کم‌ارتفاع واقع در دشت‌ها، نوار ساحلی، ارتفاعات پایین‌تر و به‌خصوص حاشیۀ شهرها و جاده‌ها درحال از دست رفتن است. فعالیت‌های انسانی، مانند تغییر کاربری اراضی و توسعۀ شهرنشینی در دشت‌های شمالی گلستان به کاهش پوشش گیاهی دامن زده‌اند. این تغییرات نشان‌دهندۀ کاهش پوشش گیاهی انبوه و افزایش تأثیرات منفی انسانی و طبیعی‌اند. در ارتفاعات، به‌رغم روند آرام‌تر کاهش پوشش گیاهی درقیاس با مناطق پایین‌دست، نگرانی‌هایی بابت تخریب پوشش گیاهی در مناطق بکر جنگلی وجود دارد. تحولات یادشده نیازمند توجه و اقدامات فوری، برای مدیریت پایدار منابع طبیعی و سازگاری با تغییرات اقلیمی است.

کلیدواژه‌ها


عنوان مقاله [English]

Trend Analysis of MODIS-NDVI Time Series and Its Relationship with Land Use Changes in Golestan Province

نویسندگان [English]

  • Morteza Dastigerdi
  • Mehdi Nadi
  • Bahareh Shamgani Mashhadi
Department of Water Engineering, Faculty of Agricultural Engineering, Sari Agricultural sciences and Natural Resources University, Sari, Iran.
چکیده [English]

Introduction: Human activities and climate change directly affect the earth's surface cover. In the northern part of the country, land use changes have emerged as a significant factor contributing to the destruction of vegetation in Hyrcanian forests. Unfortunately, this destruction has persisted over the past few decades due to human activities. Golestan province, known for its diverse climate and surface cover, has experienced noticeable changes in vegetation, illustrating the impacts of these activities. Therefore, it is crucial to monitor the dynamics of vegetation in order to gain a better understanding of how vegetation respond to human pressures. This knowledge is essential for preserving the Hyrcanian forests.
Materials and Methods: The investigation and monitoring of vegetation cover in Golestan province involved the use of the Normalized Difference Vegetation Index (NDVI). To analyze vegetation trends over a 20-year period, 16-day combined MODIS-NDVI time series data (MOD13Q1) with a spatial resolution of 250 meters, were utilized. The research began with the acquisition of raw NDVI images in HDF format from the NASA website. These 920 images, from the 16-day time series, were then analyzed statistically. To standardize the images and facilitate further analysis, they were converted into 460 images through mosaicing and scaling between -1 and +1. The evaluation of serial trends was performed in IDRISI TerrSet software, where the images underwent a preprocessing step to remove seasonal anomalies. The changes in vegetation activity and their significance were subsequently analyzed using the non-parametric Mann-Kendall method.
Results and Discussion: The results indicate that 20% of the studied area experienced a decrease in vegetation, while 80% exhibited an increase. Out of these, 5% had a significant decrease, and 50% showed a significant increase in vegetation, while the remaining had no discernible trend. Over the past 20 years, a total of 4088 square kilometers of vegetation has been lost. To analyze the impact of human activities on these changes, location maps of cities and main routes were utilized. The findings revealed that the northern plains of Golestan exhibited a greater reduction in vegetation due to easier land access for human activities, changes in land use, and urban development. The cities of Kordkoy, Bandar Gaz, Aqqala, Gorgan, Azadshahr, and Ramian experienced the most significant increase in vegetation cover, whereas the cities of Bandar Turkman, Gonbadkavoos, Minoodasht, and Kalaleh witnessed the most significant decrease. The main routes leading to Golestan province, including Gorgan-Bujnoord, Gorgan-Sari, Azadshahr-Semnan, Incheh Brun West Road, and Incheh Brun East Road, all showed a decline in vegetation in their vicinity. Due to the significant climatic diversity in Golestan province, surface cover changes were examined at specific locations where a substantial reduction in vegetation cover was expected.
Conclusion: Based on the research conducted from 2001 to 2020, it can be concluded that the highlands of Golestan province, particularly the western highlands, have witnessed an increase in vegetation. This phenomenon is believed to be correlated with the rise in temperature resulting from global warming, which has created more favorable conditions for plant growth in these highland areas. In contrast, low-altitude regions such as plains, coastal areas, lower elevations, and especially areas surrounding cities and roads, have experienced a decline in vegetation cover. This decline can be attributed to human activities, including changes in land use and urbanization in the northern plains of Golestan. These changes signify the loss of extensive vegetation and the exacerbation of detrimental impacts from both human activities and natural factors. Although the reduction in vegetation in the highlands has been relatively slower compared to the lower regions, concerns arise regarding the destruction of vegetation in pristine forest areas. These developments highlight the urgent need for immediate attention and implementation of measures for sustainable management of natural resources and adaptation to climate change.

کلیدواژه‌ها [English]

  • Keywords: : Land use change
  • Vegetation degradation
  • Man-Kendall
  • Destructive human activities
  • MOD13Q1
Abbasnezhad Alchin, A. & Darvishsefat, A.A, 2023, Investigating the Trend of Vegetation Changes (Greening and Browning) Using MODIS-NDVI Time Series in Mazandaran Province, Journal of Wood and Forest Science and Technology, 30 (1), PP. 125-140, 10.22069/JWFST.2023.20755.1991.
Abdi, O., Shirvani, Z. & Buchroithner, MF., 2018, Spatiotemporal Drought Evaluation of Hyrcanian Deciduous Forests and SemiSteppe Rangelands Using Moderate Resolution Imaging Spectroradiometer Time Series in Northeast Iran, Land Degrad Dev, 29, PP. 2525-2541,
 
Abdolalizadeh, Z., Ebrahimi, A. & Mostafazadeh, R., 2019, Landscape Pattern Change in Marakan Protected Area, Iran, Reg Environ Change 19, PP. 1683-1699, https://doi.org/10.1007/s10113-019-01504-9.
Afzali Kurd, P. & Behzadi, M.S., 2023, Investigating Vegetation Changes and NDVI Index in the South of Golestan Province Using Satellite Images, The Third National Conference on Protection and Protection of Forests and Pastures in Iran, Tehran.
Colditz, R.R., Ressl, R.A. & Bonilla-Moheno, M., 2015, Trends in 15-Year MODIS NDVI Time Series for Mexico, In 8th International Workshop on the Analysis of Multitemporal Remote Sensing Images (MultiTemp), Jul. 22-24 Annecy, France, PP. 1-4, https://doi.org/10.1109/Multi-Temp.2015.7245766.
Dastigerdi, M., Nadi, M., Raeini Sarjaz, M. & Kiapasha, Kh., 2022, Vegetation Trend Analysis Using NDVI Time Series of Modis Satellite in the Northeast of Iran, Journal of Water and Soil Conservation, 29(1), PP. 135-150, DOI: 10.22069/ jwsc.2022.20208.3554.
Dastigerdi, M., Nadi, M., Sarjaz, M.R. & Kiapasha, K., 2024, Trend Analysis of MODIS NDVI Time Series and Its Relationship to Temperature and Precipitation in Northeastern of Iran, Environmental Monitoring and Assessment, 196(4), P. 346.‌
De Jong, R., de Bruin, S., de Wit, A., Schaepman, M.E. & Dent, D.L., 2011, Analysis of Monotonic Greening and Browning Trends from Global NDVI Time-Series, Remote Sensing of Environment, 115(2), PP. 692-702, https://doi.org/10.1016/j.rse.2010.10.011.
Dubovyk, O., Landmann, T., Erasmus, B.F.N.; Tewes, A. & Schellberg, J., 2015, Monitoring Vegetation Dynamics with Medium Resolution MODIS-EVI Time Series at Sub-Regional Scale in Southern Africa, Int. J. Appl. Earth Obs. Geoinf, 38, PP. 175-183, https://doi.org/10.1016/j.jag. 2015.01.002.
Fan, X., Gao, P., Tian, B., Wu, C. & Mu, X., 2023, Spatio-Temporal Patterns of NDVI and Its Influencing Factors Based on the ESTARFM in the Loess Plateau of China, Remote Sensing, 15(10), P. 2553,‌ https://doi.org/10.3390/rs15102553.
FAO, 2015, Global Forest Resources Assessment 2015, Food and Agriculture Organization of the United Nations, http://www.fao.org/3/i4808e/i4808e.pdf.
Guan, Q., Yang, L., Pan, N., Lin, J., Xu, C., Wang, F. & Liu, Z., 2018, Greening and Browning of the Hexi Corridor in Northwest China: Spatial Patterns and Responses to Climatic Variability and Anthropogenic Drivers, J. Remote Sensing, 10(8), PP. 1270-1290, https://doi.org/10.3390/rs10081270.
Gutiérrez-Girón, A., Díaz-Pinés, E., Rubio, A. & Gavilán, R.G., 2015, Both Altitude and Vegetation Affect Temperature Sensitivity of Soil Organic Matter Decomposition in Mediterranean High Mountain Soils, Geoderma, 237, PP. 1-8,‌ https://doi.org/ 10.1016/j.geoderma.2014.08.005.
Hashemi Dareh Badami, S., Nouraeisefat, I., Karimi, S. & Nazari, S., 2015, Development Trend Analysis of Urban Heat Island Regarding Land Use/Cover Changes Using Time Series of landsat Images, RS & GIS Techniques in Natural Resources, 6(3), PP. 15-28.
Jafari, S.M., Zarre, S. & Alavipanah, S.K., 2013, Woody Species Diversity and Forest Structure from Lowland to Montane Forest in Hyrcanian Forest Ecoregion, Journal of Mountain Science, 10, PP. 609-620, https://doi.org/10.1007/s11629-013-2652-2.
Kalbi, S., Fallah, A. & Shataee, SH., 2014, Estimation of Forest Attributes in the Hyrcanian Forests, Comparison of Advanced Space-Borne Thermal Emission and Reflection Radiometer and Satellite Poure I’observation de la terre-high Resolution Grounding Data by Multiple Linear, and Classification and Regression Tree Regression Models, Journal of Applied Remote Sensing, 8, P. 083632, https://doi.org/10.1117/1.JRS.8.083632.
Karimi, A., Abdollahi, S., Ostad-Ali-Askari, K., Eslamian, S. & Singh, V.P., 2021, Predicting Fire Hazard Areas Using Vegetation Indexes, Case Study: Forests of Golestan Province, Iran, Journal of Geography and Cartography, 4(1), PP. 1-6.‌
KC, A. & Ghimire, A., 2015, High-Altitude Plants in Era of Climate Change: A Case of Nepal Himalayas, Climate Change Impacts on High-Altitude Ecosystems, Springer, PP. 177-187, https://doi.org/ 10.1007/978-3-319-12859-7-6.
Kendall, M.G., 1948, Rank Correlation Methods, New York, NY: Oxford University Press.
Keybondori, S., Abdi, E., Deljouei, A., Lázaro-Lobo, A., Ervin, G.N., Shakeri, Z. & Borz, S.A., 2023, Effect of Forest Roadside on Vegetation Characteristics in the Hyrcan-ian Temperate Forest, European Journal of Forest Research, 142(2), PP. 455-473,‌ https://doi.org/10.1007/s10342-023-01535-2.
Kiapasha, K., Darvishsefat, A.A., Zargham, N., Attarod, P., Nadi, M. & Schaepman, M., 2017a, Greening Trend in the Hyrcanian Forests Using NOAA NADVI Time Series during 1981-2012, Forest and Wood Products, 70(3), PP. 409-420, https://doi.org/ 10.22059/jfwp.2017.206833.748.
Kiapasha, K., Darvishsefat, A.A., Julien, Y., Sobrino, J.A., Zargham, N., Attarod, P. & Schaepman, M.E, 2017b, Trends in Phenological Parameters and Relationship between Land Surface Phenology and Climate Data in the Hyrcanian Forests of Iran, IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 10(11), PP. 4961-4970,‌ DOI: 10.1109/JSTARS.2017.2736938.
Kim, J.Y., Rastogi, G., Do, Y., Kim, D.-K., Muduli, P.R., Samal, R.N., Pattnaik, A.K. & Joo, G., 2015, Trends in a Satellite-Derived Vegetation Index and Environmental Variables in a Restored Brackish Lagoon, Glob Ecol. Conserv., 4, PP. 614-624, https://doi.org/10.1016/j.gecco.2015.10.010.
Liu, J., Wei, L., Zheng, Z. & Du, J., 2023, Vegetation Cover Change and Its Response to Climate Extremes in the Yellow River Basin, Science of The Total Environment, 905, P. 167366,‌ https://doi.org/ 10.1016/j.scitotenv.2023.167366.
Luo, L., Ma, W., Zhuang, Y., Zhang, Y., Yi, S., Xu, J. & Zhang, Z., 2018, The impacts of Climate Change and Human Activities on Alpine Vegetation and Permafrost in the Qinghai-Tibet Engineering Corridor, Ecological Indicators, 93, PP. 24-35, https://doi.org/10.1016/j.ecolind.2018.04.067.
Mann, H.B., 1945, Nonparametric Tests against Trend, Econometrica, 13, PP. 245-259.
Masihpour, M., Darvishsefat, A.A. & Rahmani, R., 2019, Long-Term Trend Analysis of Vegetation Changes Using MODIS-NDVI Time Series during 2000-2017 (Case Study: Kurdistan Province), Forest and Wood Products, 72(3), PP. 193-204, https://doi.org/ 10.22059/jfwp.2019.277944.995.
Mehrani, A., Riazi, B., Mirbagheri, S.A. & Khorasani, N., 2021, Monitoring of Vegetation Changes in Golestan Province and a Collection of International Wetlands (Alma Gol, Alagol and Aji Gol) and the Reasons Are Based on a Two-Time Analysis of NDVI, Journal of Plant Environ-mental Physiology, 16(64), PP. 97-110, https://doi.org/10.30495/iper.2022.679550.
Miles, V.V. & Esau, I., 2016, Spatial Heterogeneity of Greening and Browning between and within Bioclimatic Zones in Northern West Siberia, J. Environmental Research Letters., 11(11), P. 115002, DOI: 10.1088/1748-9326/11/11/115002.
Mirahsani, M., Salman Mahiny, A., Soffianian, A., Moddares, R., Jafari, R. & Mohammadi, J., 2018, Evaluation of Vegetation Supply Water Index through Time-Series Images of MODIS Products in Drought Monitoring over Gavkhuni Basin, Iranian Journal of Applied Ecology, 6(4), PP. 31-47, DOI: 10.29252/ijae.6.4.31.
Nadi, M., Dastigerdi, M., Shamgani Mashhadi, B., Hatamipour, M. & Mahdavi Amrei, O., 2024, Analysis of Vegetation Trend in Mazandaran Province with Emphasis on Land Use Changes Using MODIS NDVI Time Series, Journal of Watershed Management Research, 15(30), PP. 212-225.
Naqinezhad, A. & Zarezadeh, S., 2013, A Contribution to Flora, Life Form and Chorology of Plants in Noor and Sisangan Lowland Forests, Journal of Taxonomy and Biosistematics, 4, PP. 31-44.
Pan, N., Feng, X., Fu, B., Wang, S., Ji, F. & Pan, S., 2018, Increasing Global Vegetation Browning Hidden in Overall Vegetation Greening: Insights from Time-Varying Trends, Remote Sensing of Environment, 214, PP. 59-72, https://doi.org/10.1016/j.rse. 2018.05.018.
Sagheb-Talebi, K., Sajedi, T. & Pourhashemi, M., 2014, Forests of Iran: A Treasure from the Past, a Hope for the Future, 15325, Sprimnger Netherlands.
Shamsipour, A.A. & Rodger Safari, V., 2020, Investigating the Consequences of Climate Change with a Focus on Spatial Analysis of Drought Severity in Golestan Province with Statistical Indicators and Remote Sensing, Climate Change Research, 1(3), PP. 65-76.
Wang, J., Xie, Y., Wang, X., Dong, J. & Bie, Q., 2019, Detecting Patterns of Vegetation Gradual Changes (2001–2017) in Shiyang River Basin, Based on a Novel Framework, Remote Sens., 11, P. 2475, https://doi.org/10.3390/rs11212475.
Willis, K.S., 2015, Remote Sensing Change Detection for Ecological Monitoring in United States Protected Areas, Biological Conservation, 182, PP. 233-242, https://doi.org/ 10.1016/j.biocon.2014.12.006.
Wu, D., Wu, H., Zhao, X., Zhou, T., Tang, B., Zhao, W. & Jia, K., 2014, Evaluation of Spatiotemporal Variations of Global Fractional Vegetation Cover Based on GIMMS NDVI Data from 1982 to 2011, Remote Sensing, 6(5), PP. 4217-4239, https://doi.org/10.3390/rs6054217.
Yin, T., Zhai, Y., Zhang, Y., Yang, W., Dong, J., Liu, X. & Wang, R., 2023, Impacts of Climate Change and Human Activities on Vegetation Coverage Variation in Mountainous and Hilly Areas in Central South of Shandong Province Based on Tree-Ring, Frontiers in Plant Science, 14, P. 1158221, https://doi.org/10.3389/fpls. 2023.1158221.