Kentsel Yayılma Baskısı Altında Karbon Kaybı ve Karbon Tutulumunun Çevresel İzlenmesi: İstanbul, Türkiye Örneği

Abstract

Hızla büyüyen megakentlerde kentsel yayılma, karasal karbon dinamiklerini önemli ölçüde değiştirmekte; çoğu zaman karbon tutma potansiyelini azaltırken sera gazı emisyonlarını artırmaktadır. Bu çalışma, 2017–2024 yılları arasında İstanbul, Türkiye’de arazi kullanım değişiminin karbon stokları üzerindeki etkilerini, Coğrafi Bilgi Sistemleri (CBS) çerçevesinde Entegre Ekosistem Hizmetleri ve Ödünleşimleri Değerleme Modeli (InVEST) kullanarak değerlendirmiştir. Sentinel-2 uydu görüntüleri ve denetimli sınıflandırma yöntemiyle altı ana arazi örtüsü sınıfı belirlenmiş ve mekânsal-zamansal geçişler nicel olarak ortaya konmuştur. Elde edilen bulgular, yapılı alanlarda %3,72’lik bir artış; tarım (–%2,03), orman (–%0,31) ve çayır-mera (–%0,19) alanlarında ise azalışlar olduğunu göstermiş ve bunun sonucunda –1.117.034,57 tC (yaklaşık –4,1 MtCO₂eşd.) düzeyinde net bir karbon kaybı meydana gelmiştir. Toplam kayıpların %75,7’sini oluşturan toprak organik karbonunun, özellikle tarım alanlarında en kırılgan karbon havuzu olduğu belirlenmiştir. Orman alanlarında gözlenen toprak ve yerüstü karbon kayıpları, ormansızlaşma ve geçirimsiz yüzey artışının olumsuz etkilerini daha da vurgulamaktadır. Bulgular, daha sıkı arazi kullanım düzenlemelerine, ekolojik tampon alanların korunmasına ve kentsel karbon yönetimini güçlendirmek amacıyla yeşil altyapının entegrasyonuna yönelik acil bir gereksinime işaret etmektedir. Bu çalışma, InVEST modelinin kentsel ölçekte karbon izleme ve karbon nötrlüğü hedeflerine ulaşmada karar destek aracı olarak uygulanabilirliğini ortaya koymaktadır.

Keywords

• Karbon stoğu değişimi
• Yeşil altyapı
• InVest modeli
• Arazi kullanım değişimi
• Kentsel Yayılma

Environmental Monitoring of Carbon Loss and Sequestration under Urban Expansion Pressure: A Case Study from Istanbul, Türkiye

Abstract

Urban expansion in rapidly growing megacities significantly alters terrestrial carbon dynamics, often reducing carbon sequestration potential and increasing greenhouse gas emissions. This study assessed the impacts of land-use change on carbon stocks in Istanbul, Türkiye, between 2017 and 2024, using the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model within a Geographic Information Systems (GIS) framework. Sentinel-2 satellite imagery and supervised classification identified six major land cover classes and quantified spatial-temporal transitions. Results revealed a 3.72% increase in built-up areas and declines in agricultural (–2.03%), forested (–0.31%), and rangeland (–0.19%) areas, leading to a net carbon loss of –1,117,034.57 tC (approximately –4.1 MtCO₂eq). Soil organic carbon represented the most vulnerable pool, accounting for 75.7% of total losses, particularly in agricultural lands. Aboveground and soil carbon losses in forested areas further emphasized the adverse impacts of deforestation and impervious surface expansion. The findings highlight the urgent need for stricter land-use regulations, conservation of ecological buffer zones, and integration of green infrastructure to enhance urban carbon management. The study demonstrates the applicability of the InVEST model for urban-scale carbon monitoring and as a decision-support tool for achieving carbon neutrality targets.

Keywords

• Carbon stock change
• Green infrastructure
• InVEST model
• Land-use change
• Urban expansion

References

1. Artmann, M. (2014). Assessment of soil sealing management responses, strategies, and targets toward ecologically sustainable urban land use management. AMBIO, 43(4), 530–541. https://doi.org/10.1007/s13280-014-0511-1
2. Barragán-Escandón, A., Terrados-Cepeda, J., & Zalamea-León, E. (2017). The role of renewable energy in the promotion of circular urban metabolism. Sustainability, 9(12), 2341. https://doi.org/10.3390/su9122341
3. Bekar, M., Yalcinalp, E., & Meral, A. (2020). Analysis of the contribution of rainwater recycling (RWR) to the campus area of KTU, Trabzon Turkey. Fresenius Environmental Bulletin, 29(4), 2112–2122.
4. Budak, M., Kiliç, M., Polat, K., Günal, E., Sırrı, M., & Yolbaş, R. (2025). Assessment of soil organic carbon stock in pistachio orchards established under semi-arid climates of Siirt province, Türkiye. Harran Tarım ve Gıda Bilimleri Dergisi, 29(2), 286–298. https://doi.org/10.29050/harranziraat.1656156
5. Canitez, F., Alpkokin, P., & Kiremitci, S. T. (2020). Sustainable urban mobility in Istanbul: Challenges and prospects. Case Studies on Transport Policy, 8(4), 1148–1157. https://doi.org/10.1016/j.cstp.2020.07.005
6. Churkina, G. (2008). Modeling the carbon cycle of urban systems. Ecological Modelling, 216(2), 107–113. https://doi.org/10.1016/j.ecolmodel.2008.03.006
7. Çorbacı, Ö.L, Özçelik, A.E., Yüksek, F., Yüksek, T., Kara, C.Ö. (2024). Determination of biomass and carbon sequestration capacity of urban trees: Rize province Ziraat Botanical Park. In Climate Change, Carbon Management and Green Space Systems in Architectural Series, Chapter 14: 402-442.
8. Dai, W., & Dai, W. (2019). Effects of urban expansion on environment by morphological study. IOP Conference Series: Earth and Environmental Science, 227(5), 052004. https://doi.org/10.1088/1755-1315/227/5/052004

9. Davies, Z. G., Edmondson, J. L., Heinemeyer, A., Leake, J. R., & Gaston, K. J. (2011). Mapping an urban ecosystem service: Quantifying above‐ground carbon storage at a city‐wide scale. Journal of Applied Ecology, 48(5), 1125–1134. https://doi.org/10.1111/j.1365-2664.2011.02021.x
10. Don, A., Schumacher, J., & Freibauer, A. (2011). Impact of tropical land-use change on soil organic carbon stocks: A meta-analysis. Global Change Biology, 17(4), 1658–1670. https://doi.org/10.1111/j.1365-2486.2010.02336.x
11. Drusch, M., Del Bello, U., Carlier, S., Colin, O., Fernandez, V., Gascon, F., Hoersch, B., Isola, C., Laberinti, P., Martimort, P., Meygret, A., Spoto, F., Sy, O., Marchese, F., & Bargellini, P. (2012). Sentinel-2: ESA’s optical high-resolution mission for GMES operational services. Remote Sensing of Environment, 120, 25–36. https://doi.org/10.1016/j.rse.2011.11.026
12. EPA. (2025, August 6). Greenhouse gas equivalencies calculator. United States Environmental Protection Agency. https://www.epa.gov/energy/greenhouse-gas-equivalencies-calculator
13. FAO. (2020a). Land Husbandry, Water Harvesting and Hillside Irrigation (LWH) Project in Rwanda. Food and Agriculture Organization of the United Nations.
14. FAO. (2020b). The state of the world’s forests: Forests, biodiversity and people. Food and Agriculture Organization of the United Nations.
15. Furberg, D., Ban, Y., & Mörtberg, U. (2020). Monitoring urban green infrastructure changes and impact on habitat connectivity using high-resolution satellite data. Remote Sensing, 12(18), 3072. https://doi.org/10.3390/rs12183072
16. Guo, L. B., & Gifford, R. M. (2002). Soil carbon stocks and land use change: A meta-analysis. Global Change Biology, 8(4), 345–360. https://doi.org/10.1046/j.1354-1013.2002.00486.x
17. Gürel, A., & Gündüz, A. E. (2011). İstanbul’un ekolojik yapısı üzerine bir araştırma. The Journal of Marmara Social Research, 1, 1–12.
18. Hsu, K. W., & Chao, J. C. (2021). Study on the value model of urban green infrastructure development: A case study of the Central District of Taichung City. Sustainability, 13(13), 7402. https://doi.org/10.3390/su13137402
19. InVEST. (2020). User guide: Carbon storage and sequestration. Natural Capital Project.
20. IPCC. (2006). 2006 IPCC Guidelines for national greenhouse gas inventories (Vol. 4). Intergovernmental Panel on Climate Change.
21. Kabisch, N., Korn, H., Stadler, J., & Bonn, A. (Eds.). (2017). Nature-based solutions to climate change adaptation in urban areas: Linkages between science, policy and practice. Springer. https://doi.org/10.1007/978-3-319-56091-5
22. Kang, J., Zhang, B., Zhang, Q., Li, C., Ma, J., Yin, J., Yu, K., Hu, Y., & Bou-Zeid, E. (2025). Global urbanization indirectly enhances the carbon sequestration capacity of urban vegetation. Geography and Sustainability, 6(3), 100268. https://doi.org/10.1016/j.geosus.2025.100268
23. Ketema, H., Wei, W., Chalo, T., Demise, D., Banja, T., Legesse, A., Abaynew, H., Kebede, G., & Bekele, B. (2025). Quantifying urban sprawl and its impact on carbon sequestration for promoting regulated urbanization and a healthy environment in cities. Applied Ecology and Environmental Research, 23(3), 5209–5237. https://doi.org/10.15666/aeer/2303_52095237
24. Kucuker, M. A., Guney, M., Oral, H. V., Copty, N. K., & Onay, T. T. (2015). Impact of deforestation on soil carbon stock and its spatial distribution in the Western Black Sea Region of Turkey. Journal of Environmental Management, 147, 227–235. https://doi.org/10.1016/j.jenvman.2014.08.017
25. Lahoti, S., Lahoti, A., Joshi, R. K., & Saito, O. (2020). Vegetation structure, species composition, and carbon sink potential of urban green spaces in Nagpur City, India. Land, 9(4), 107. https://doi.org/10.3390/land9040107
26. Li, D., & Bou-Zeid, E. (2013). Synergistic interactions between urban heat islands and heat waves: The impact in cities is larger than the sum of its parts. Journal of Applied Meteorology and Climatology, 52(9), 2051–2064. https://doi.org/10.1175/JAMC-D-13-02.1
27. Ma, Z., Duan, X., Wang, L., Wang, Y., Kang, J., & Yun, R. (2023). A scenario simulation study on the impact of urban expansion on terrestrial carbon storage in the Yangtze River Delta, China. Land, 12(2), 297. https://doi.org/10.3390/land12020297
28. Malik, N., Gothi, S., Saini, R., & Aswal, P. (2019). Modelling and monitoring urban landscape dynamics over Haridwar, India. International Journal of Computer Applications, 181(45), 12–15. https://doi.org/10.5120/ijca2019918569
29. Melo, C., Teotónio, I., Silva, C. M., & Cruz, C. O. (2020). What’s the economic value of greening transport infrastructures? The case of the underground passages in Lisbon. Sustainable Cities and Society, 56, 102083. https://doi.org/10.1016/j.scs.2020.102083
30. Meral, A., Özkan, D.G., Demirci, Ö., Yazıcı, İ. (2026). Ex-ACT tabanlı bir yaklaşımla kentsel peyzaj dönüşümlerinin karbon bütçesi değerlendirmesi: Bingöl Genç Millet Bahçesi örneği. İTÜ Dergisi-e Çevre, İklim ve Sürdürülebilirlik, 1791864: 1-9.
31. Meral, A. (2026). Modeling post-disaster urban sprawl trajectories through ANN-based land use/land cover change analysis and scenario projection. Applied Geomatics, 18 (31): 1-15.
32. Meral, A., Vural, H., & Doğan, S. (2021). What our cities can offer after natural disasters. Online Journal of Art and Design, 9(3), 250–259.
33. Natural Capital Project. (2020). InVEST carbon model: Carbon pool data. Stanford University. Nowak, D. J., & Crane, D. E. (2002). Carbon storage and sequestration by urban trees in the USA. Environmental Pollution, 116(3), 381–389. https://doi.org/10.1016/S0269-7491(01)00214-7
34. Oğuztürk, G.E., Çorbacı, Ö.L. (2023) Green infrastructure systems in urban areas the importance of soil permeability. III. International Architectural Sciences and Applications Symposium, September 14-15, 2023. Naples, Italy.
35. Önder, Y.E., Kavzoğlu, T. (2020). Açık kaynak kodlu CBS yazılımları ile trafik kaza yoğunluk analizleri: İstanbul Örneği. Türkiye Coğrafi Bilgi Sistemleri Dergisi, 2(1): 01-09.
36. Poeplau, C., Don, A., Vesterdal, L., Leifeld, J., Van Wesemael, B., Schumacher, J., & Gensior, A. (2011). Temporal dynamics of soil organic carbon after land-use change in the temperate zone: Carbon response functions as a model approach. Global Change Biology, 17(7), 2415–2427. https://doi.org/10.1111/j.1365-2486.2011.02408.x
37. Salamanca, F., Georgescu, M., Mahalov, A., Moustaoui, M., Wang, M., & Svoma, B. M. (2013). Assessing summertime urban air conditioning consumption in a semiarid environment. Environmental Research Letters, 8(3), 034022. https://doi.org/10.1088/1748-9326/8/3/034022
38. Siregar, R. I. (2018). Land cover change impact on urban flood modeling (case study: Upper Citarum watershed). IOP Conference Series: Earth and Environmental Science, 126, 012027. https://doi.org/10.1088/1755-1315/126/1/012027
39. Sivri, N. (2017). Antibiotic Resistance (AR) among enteric bacteria in marine environments of Marmara Sea. Advances in Biotechnology & Microbiology, 6(4). https://doi.org/10.19080/AIBM.2017.06.555694
40. Sürücü, R., & Kiasif, G. Ç. (2022). İstanbul’un kuzeybatı yönündeki büyüme sürecinin sürdürülebilirlik performansına ilişkin algı analizi. Kent Akademisi, 15(2), 681–706. https://doi.org/10.35674/kent.1025957
41. Sütünç, H.S., Çorbacı, Ö.L. (2020). Assessment of basic green infrastructure components as part of landscape structure for Siirt. Düzce University Faculty of Forestry Journal of Forestry, 16(2): 70-88.
42. TUIK. (2024). Toplam nüfus. Turkish Statistical Institute. https://cip.tuik.gov.tr
43. Wang, H., Feng, Y., & Ai, L. (2023). Progress of carbon sequestration in urban green space based on bibliometric analysis. Frontiers in Environmental Science, 11, 1196803. https://doi.org/10.3389/fenvs.2023.1196803
44. Wu, F., & Wang, Z. (2023). Assessing the impact of urban land expansion on ecosystem carbon storage: A case study of the Changzhutan metropolitan area, China. Ecological Indicators, 154, 110688. https://doi.org/10.1016/j.ecolind.2023.110688
45. Wu, Z., Zhao, Z., Gan, W., Zhou, S., Dong, W., & Wang, M. (2023). Achieving carbon neutrality through urban planning and design. International Journal of Environmental Research and Public Health, 20(3), 2420. https://doi.org/10.3390/ijerph20032420
46. Yalçınalp, E., Demirci, Ö., & Meral, A. (2025). Brewing sustainability: Unveiling the potential of coffee ground as green roof media. Urban Ecosystems, 28(2), 80. https://doi.org/10.1007/s11252-025-01684-9
47. Yalçınalp, E., & Meral, A. (2019). Ruderal plants in urban and sub-urban walls and roofs. Ege Üniversitesi Ziraat Fakültesi Dergisi, 56(2), 81–90. https://doi.org/10.20289/zfdergi.478083
48. Yang, H., Ma, J., Jiao, X., Shang, G., & Yan, H. (2023). Characteristics and driving mechanism of urban construction land expansion along with rapid urbanization and carbon neutrality in Beijing, China. Land, 12(7), 1388. https://doi.org/10.3390/land12071388
49. Yener, Ş. D. (2020). Sustainable use of plants in coastal areas of Istanbul. Turkish Journal of Forestry, 21(2), 123–130. https://doi.org/10.18182/tjf.645461
50. Yılmaz, M., Meral, A., Yüksel, A., & Avşaroğlu, M. M. (2025). Nature-based solutions and the carbon cycle: Analysis of Murat River watershed rehabilitation utilising the Ex-Act model. International Journal of Energy and Water Resources. Advance online publication. https://doi.org/10.1007/s42108-025-00234-7
51. Zhao, L., Oppenheimer, M., Zhu, Q., Baldwin, J. W., Ebi, K. L., Bou-Zeid, E., Guan, K., & Liu, X. (2018). Interactions between urban heat islands and heat waves. Environmental Research Letters, 13(3), 034003. https://doi.org/10.1088/1748-9326/aa9f73