Mathematical Exploration: Quantifying the Impact of Deforestation on Landslip Occurrences
Keywords:
Factor of Safety (FS), Landslide susceptibility, Deforestation, Vegetation recovery, Slope stabilityAbstract
Landslides are a continuing problem in mountainous areas in general and in Baguio City in particular. The presence of high terrain, rainfall intensity, and progressive deforestation contributes significantly to slope instability. The impact of deforestation and re-vegetation on landslide susceptibility is explored here. The quantitative impact of deforestation and re-vegetation on slope stability and hence landslide susceptibility is explored here. The Factor of Safety (FS) derived from computational simulation based on geotechnical principles for slope stability and a geometric progression principle for re-vegetation progression per annum is discussed here. The independent variable is vegetation cover and the dependent variable is Factor of Safety. The findings show that slopes in heavily deforested areas are critically unsafe with FS values less than 1. However, a steady rise in vegetation cover improves slope stability drastically. The findings show that a gradual rise in vegetation cover improves slope stability in two to three years. Rapid re-vegetation translates into significantly high FS. This assumes importance for root resistance and re-vegetation-induced slope stabilization during high rainfall events. The findings are well within the theoretical limits proposed for vegetation slope stabilization in mountainous topography. This paper mainly focuses on re-vegetation, forest protection, and proper management of land use as effective measures to decrease landslide risk. In addition to these, the developed modeling system is also a helpful simplified tool for disaster risk management, land use planning, and further studies related to vegetation, slope stability, and landslide susceptibility.
References
Abancó, C., Bennett, G. L., Matthews, A. J., Matera, M. a. M., & Tan, F. J. (2021). The role of geomorphology, rainfall and soil moisture in the occurrence of landslides triggered by 2018 Typhoon Mangkhut in the Philippines. Natural Hazards and Earth System Sciences, 21(5), 1531–1550. https://doi.org/10.5194/nhess-21-1531-2021
Araza, A. B., Castillo, G. B., Buduan, E. D., Hein, L., Herold, M., Reiche, J., Gou, Y., Villaluz, M. G. Q., & Razal, R. A. (2021). Intra-Annual identification of local deforestation hotspots in the Philippines using earth observation products. Forests, 12(8), 1008. https://doi.org/10.3390/f12081008
Bathurst, J. C., Bovolo, C. I., & Cisneros, F. (2010). Modelling the effect of forest cover on shallow landslides at the river basin scale. Ecological Engineering, 36(3), 317-327.
Biotechnical and soil bioengineering slope stabilization. (n.d.). Google Books. https://books.google.com.ph/books/about/Biotechnical_and_Soil_Bioengineering_Slo.html?id=kCbp6IvFHrAC&redir_esc=y
Depicker, A., Govers, G., Jacobs, L., Campforts, B., Uwihirwe, J., & Dewitte, O. (2021). Interactions between deforestation, landscape rejuvenation, and shallow landslides in the North Tanganyika–Kivu rift region, Africa. Earth Surface Dynamics, 9(3), 445–462. https://doi.org/10.5194/esurf-9-445-2021
Elevation of Baguio, Philippines Elevation Map, Topography, Contour. (n.d.). https://www.floodmap.net/Elevation/ElevationMap/?gi=1728930
Epic Force Project - papers. (n.d.). https://research.ncl.ac.uk/epicforce/papers.htm
Brunsden, D., & Prior, D. B. (1984). Slope instability. John Wiley & Sons.
Home | Food and Agriculture Organization of the United Nations. (n.d.). FAOHome. https://www.fao.org/home/en/?fbclid=IwY2xjawPWpcJleHRuA2FlbQIxMABicmlkETFZajJaUGdKQ0oyeWNkbEF3c3J0YwZhcHBfaWQQMjIyMDM5MTc4ODIwMDg5MgABHjVvBO3jtNeZGf5drYsdhAUAF9AaPkm_JIddARH5ajLe30vzUHRJYKMQvQeA_aem_ywGkdAMyTnJJfeis0MB0cA
Kim, T., Bong, T., & Kim, D. (2025). Probabilistic analysis of infinite slope stability considering variation in soil depth. Applied Sciences, 15(2), 936. https://doi.org/10.3390/app15020936
Klimeš, J., Calvello, M., & Auflič, M. J. (2019). Objectives and main results of “Community Participation for Landslide Disaster Risk Reduction” thematic papers. Landslides, 16(9), 1745–1746. https://doi.org/10.1007/s10346-019-01246-z
Landslides. (n.d.). Google Books. https://books.google.com.ph/books/about/Landslides.html?id=MEPwAAAAMAAJ&redir_esc=y
Lu, N., & Godt, J. (2008). Infinite slope stability under steady unsaturated seepage conditions. Water Resources Research, 44(11). https://doi.org/10.1029/2008wr006976
Libretexts. (2024, March 22). 9.3: Geometric sequences and series. Mathematics LibreTexts. https://math.libretexts.org/Bookshelves/Algebra/Advanced_Algebra/09%3A_Sequences_Series_and_the_Binomial_Theorem/9.03%3A_Geometric_Sequences_and_Series
Manchado, A. M., Ballesteros-Cánovas, J. A., Allen, S., & Stoffel, M. (2022). Deforestation controls landslide susceptibility in Far-Western Nepal. CATENA, 219, 106627. https://doi.org/10.1016/j.catena.2022.106627
Norris, J. E., Stokes, A., Mickovski, S. I., Cameraat, E., Rens, V. B., Nicoll, B. C., & Achim, A. (2008). Slope stability and erosion Control: Ecotechnological solutions. https://doi.org/10.1007/978-1-4020-6676-4
Paringit, M. C. R. (2020). ASSESSMENT OF LANDSLIDE SUSCEPTIBILITY: a CASE STUDY OF CARABAO MOUNTAIN IN BAGUIO CITY. International Journal of Geomate, 19(71). https://doi.org/10.21660/2020.71.9261
Remondo, J., Sánchez-Díaz, M., & Cuesta-Albertos, J. A. (2025). An increasing trend of landslides as a consequence of the global change. Earth Systems and Environment. https://doi.org/10.1007/s41748-025-00685-0
Soil Strength and Slope Stability, 2nd Edition. (n.d.). Wiley.com. https://www.wiley.com/en-us/Soil+Strength+and+Slope+Stability%2C+2nd+Edition-p-9781118651650
Soil Mechanics in Engineering Practice (1996), by Karl Terzaghi & Ralph B. Peck & Gholamreza Mesri : Free download, borrow, and streaming : Internet Archive. (2022, April 2). Internet Archive. https://archive.org/details/soil-mechanics-in-engineering-practice-1996-by-karl-terzaghi-ralph-b.-peck-gholamreza-mesri/page/n3/mode/2up
Slope Stability Analysis. (n.d.). Geoengineer.org. https://www.geoengineer.org/index.php/education/slope-stability/slope-stability-analysis
Xian, J., Zhu, J., Leung, A. K., Wu, C., Feng, S., & Zhang, J. (2025). Using global sensitivity analysis to quantify the uncertainty of root reinforcement in vegetated slope stability. Plant and Soil, 513(2), 1741–1771. https://doi.org/10.1007/s11104-024-07162-z
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Copyright (c) 2026 Angel Y. Tubac, Yesh Markjell L. Besario, Tyra Mae N. Rodriguez (Author)
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