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Research Articles

Early Access

Stability assessment of Maligcong rice terraces: Linking soil properties and geometry to factor of safety

DOI
https://doi.org/10.14719/pst.8866
Submitted
14 April 2025
Published
01-07-2025
Versions

Abstract

Rice terraces, renowned for their agricultural and cultural significance, are found across Southeast Asia, South America and Africa. Despite their resilience, these landscapes face threats from climate change, land-use changes and declining traditional knowledge. In the Philippines, the Cordillera rice terraces, a United Nations Educational, Scientific and Cultural Organization (UNESCO) world heritage site, suffer from land abandonment, pest infestations and insufficient government support yet technical stability assessments remain limited. The Maligcong rice terraces, like many traditional systems, experience instability, but comprehensive studies on their structural integrity are scarce. This study investigates the stability of these terraces by linking soil properties, terrace geometry and the factor of safety (FoS). Soil characterization revealed predominantly sandy compositions with varying moisture content and hydraulic conductivity across layers. Non-invasive techniques, including portable in-situ soil testing and geophysical methods (geo resistivity), effectively captured soil properties. Drone surveys integrated with Agisoft Metashape and Civil 3D provided accurate geometric modeling. While geometric parameters such as height and width influence terrace design, statistical analysis showed they had minimal impact on FoS. Instead, groundwater fluctuations, particularly water table rise during rainfall, significantly affected stability by increasing pore water pressure and reducing effective stress. Sensitivity analysis confirmed that the most critical stability parameters-cohesion, friction angle and unit weight are concentrated in the surface layer. This study highlights the vulnerability of rice terraces due to soil strength limitations and hydrogeological factors. The findings emphasize the necessity of integrating soil and water assessments into conservation strategies to ensure the long-term sustainability of these culturally and agriculturally valuable landscapes.

References

  1. 1. Sutomo S, Iryadi R, Darma ID, Wibawa IP, Rahayu A, Hanum SF, et al. Short communication: Plant diversity utilization and land cover composition in the Subak Jatiluwih, Bali, Indonesia. Biodiversitas J Biol Div. 2021;22(3):745-50. https://doi.org/10.13057/biodiv/d220345
  2. 2. Jiao J, Wu Y, Yang L, Zhang W. Using a settlement connectivity‐based framework to map the farmland abandonment risk: A case study on the world heritage of Honghe Hani rice terraces. Land Degrad Dev. 2023;34(2):932-44. https://doi.org/10.1002/ldr.4718
  3. 3. Hua H, Liu Z, Wang Y, Wu H. Relationship, discourse and construction: The power process and environmental impact of the Honghe Hani rice terraces as a world heritage site. Int J Environ Res Public Health. 2022;19(24):17100. https://doi.org/10.3390/ijerph192417100
  4. 4. Srivastava A, Kinnaird T, Sevara C, Holcomb JA, Turner S. Dating agricultural terraces in the Mediterranean using luminescence: Recent progress and challenges. Land. 2023;12(3):716. https://doi.org/10.3390/land12030716
  5. 5. Taer A. Shrinking rice bowls. Tracing the decline of Philippine rice lands. Preprint. 2024. https://doi.org/10.21203/rs.3.rs-3927443/v1
  6. 6. Ducusin R, Espaldon M, Rebancos C, De Guzman L. Vulnerability assessment of climate change impacts on a globally important agricultural heritage system (GIAHS) in the Philippines: The case of Batad Terraces, Banaue, Ifugao, Philippines. J Environ Sci Manage. 2019;153:395-421. https://doi.org/10.47125/jesam/153/395-421F
  7. 7. Yang J, Xu J, Zhou Y, Zhai D, Chen H, Li Q, et al. Paddy rice phenological mapping throughout 30-years satellite images in the Honghe Hani Rice Terraces. Remote Sens. 2023;15:2398. https://doi.org/10.3390/rs15092398
  8. 8. Stavi I, Gusarov Y, Halbac-Cotoara-Zamfir R. Collapse and failure of ancient agricultural stone terraces: On-site geomorphic processes, pedogenic mechanisms, and soil quality. Geoderma. 2019;344:144-52. https://doi.org/10.1016/J.GEODERMA.2019.03.007
  9. 9. Chapagain T, Raizada MN. Agronomic challenges and opportunities for smallholder terrace agriculture in developing countries. Front Plant Sci. 2017;8:331. https://doi.org/10.3389/fpls.2017.00331
  10. 10. Negro C. Rice terrace degradation in Ifugao: Causation and cultural preservation [Honors thesis]. Illinois Wesleyan University; 2019. https://digitalcommons.iwu.edu/socanth_honproj/58
  11. 11. Alfat S, Zulmasri L, Asfar S, Rianse M, Eso R. Slope stability analysis through variational slope geometry using Fellenius method. J Phys Conf Ser. 2019;1242:012020. https://doi.org/10.1088/1742-6596/1242/1/012020
  12. 12. Duan Z, Cheng JW, Peng J, Rahman MM, Tang H. Interactions of landslide deposit with terrace sediments: Perspectives from velocity of deposit movement and apparent friction angle. Eng Geol. 2021;280:105913. https://doi.org/10.1016/j.enggeo.2020.105913105913
  13. 13. Kurozumi T, Mori Y, Somura H, O-How M. Organic matter clogging results in undeveloped hardpan and soil mineral leakage in the rice terraces in the Philippine Cordilleras. Water. 2020;12(11):3158. https://doi.org/10.3390/w12113158
  14. 14. Wakai A, Watanabe A, Thang NV, Kimura T, Sato G, Hayashi K, et al. Stability analysis of slopes with terraced topography in Sapa, Northern Vietnam: Semi-infinite slope assumption with specific lengths for slope failure. J Disaster Res. 2021;16(4):485-94. https://doi.org/10.20965/jdr.2021.p0485
  15. 15. Acabado SB, Koller JM, Liu C, Lauer AJ, Farahani A, Barreto-Tesoro G, et al. The short history of the Ifugao rice terraces: A local response to the Spanish conquest. J Field Archaeol. 2019;44(3):195-214. https://doi.org/10.1080/00934690.2019.1574159
  16. 16. Alim MA, Ahmed F, Islam MS. Seepage analysis of Mahananda earthen embankment at Chapai Nawabganj in Bangladesh. Am J Eng Technol Manage. 2017;2(1):1-6. http://dx.doi.org/10.11648/j.ajetm.20170201.11
  17. 17. Brandolini P, Cevasco A, Capolongo D, Pepe G, Lovergine F, Del Monte M. Response of terraced slopes to a very intense rainfall event and relationships with land abandonment: A case study from Cinque Terre (Italy). Land Degrad Dev. 2018;29(3):630-42. https://doi.org/10.1002/ldr.2672
  18. 18. Mori Y, Sasaki M, Tsujimoto K. When do rice terraces become rice terraces? Paddy Water Environ. 2019;17(3):323-30. https://doi.org/10.1007/s10333-019-00727-0
  19. 19. YiLiang Z, Ming L, ZiLong L. Slope stability analysis considering seepage and stress coupling under water level fluctuation. E3S Web of Conferences [Internet]. 2021;276:01028. Available from: https://doi.org/10.1051/e3sconf/202127601028
  20. 20. Soriano MA, Herath S. Quantifying the role of traditional rice terraces in regulating water resources: Implications for management and conservation efforts. Agroecol Sustain Food Syst. 2018;42(80):885-910. https://doi.org/10.1080/21683565.2018.1437497
  21. 21. Karthik AVR, Manideep R, Chavda JT. Sensitivity analysis of slope stability using finite element method. Innov Infrastruct Solut. 2022;7:184. https://doi.org/10.1007/s41062-022-00782-3
  22. 22. Nguyen DH, Pham HD, Do VV, Nguyen VD. Integrating soil property variability in sensitivity and probabilistic analysis of unsaturated slope: A case study. Geomate J. 2023;25(110):132-39. https://geomatejournal.com/geomate/article/view/4011
  23. 23. Bravo-Zapata MF, Muñoz E, Lapeña-Mañero P, Montenegro-Cooper JM, King RW. Analysis of the influence of geomechanical parameters and geometry on slope stability in granitic residual soils. Appl Sci. 2022;12(11):5574. https://doi.org/10.3390/app12115574
  24. 24. Agam MW, Hashim MHM, Murad MI, Zabidi H. Slope sensitivity analysis using Spencer's method in comparison with general limit equilibrium method. Procedia Chem. 2016;19:651-58. https://doi.org/10.1016/j.proche.2016.03.066
  25. 25. Xu Z, Wang X. Global sensitivity analysis of the reliability of the slope stability based on the moment-independent combine with the Latin hypercube sampling technique. Stoch Environ Res Risk Assess. 2023;37(6):2159-71. https://doi.org/10.1007/s00477-023-02385-5
  26. 26. He K, Bao C, Zhao Y. The finite-element analysis of characteristics of soil slope seepage field change in continuous rain condition. Appl Mech Mater. 2012;238:451-56. https://doi.org/10.4028/www.scientific.net/amm.238.451
  27. 27. Bouajaj A, Bahi L, Ouadif L, El Kasri J. Slope stability analysis considering heavy rainfall: A case study. Civil Eng Archit. 2023;11(5A):2986-92. https://doi.org/10.13189/cea.2023.110814
  28. 28. Marrapu BM, Jakka RS. Assessment of slope stability using multiple regression analysis. Geomech Eng. 2017;13:237-54. https://doi.org/10.12989/gae.2017.13.2.237
  29. 29. Chakraborty A, Goswami D. Prediction of slope stability using multiple linear regression (MLR) and artificial neural network (ANN). Arab J Geosci. 2017;10:385. https://doi.org/10.1007/s12517-017-3167-x
  30. 30. Khan MI, Wang S. Slope stability analysis to develop correlations between different soil parameters and factor of safety using regression analysis. Pol J Environ Stud. 2021;30(5):4021-30. https://doi.org/10.15244/pjoes/131203
  31. 31. Nwankwo LI, Olasehinde PI, Osundele OE. Application of electrical resistivity survey for groundwater investigation in a basement rock region: A case study of Akobo-Ibadan, Nigeria. Ethiop J Environ Stud Manag. 2013;6(2):124-34. https://doi.org/10.4314/ejesm.v6i2.2
  32. 32. Ekwe AC, Azuoko GB, Iwuoha DI, Nkitnam E. Aquifer depth determination of low permeability layers using geo-resistivity data: A case study of Enyigba mine area and environs, South Eastern Nigeria. Iraqi J Sci. 2022;63(8):3424-31. https://doi.org/10.24996/ijs.2022.63.8.18
  33. 33. Alshehri F, Abdelrahman K. Groundwater resources exploration of Harrat Khaybar area, Northwest Saudi Arabia, using electrical resistivity tomography. J King Saud Univ Sci. 2021;33(5):101468. https://doi.org/10.1016/j.jksus.2021.101468
  34. 34. Oguama BE, Ibuot JC, Obiora DN, Aka MU. Geophysical investigation of groundwater potential, aquifer parameters, and vulnerability: A case study of Enugu State College of Education (Technical). Model Earth Syst Environ. 2019;5:1123-33. https://doi.org/10.1007/s40808-019-00595-x
  35. 35. Crnogorac L, Gojković Z, Milutinović A, Ganić A, Tokalić R. 3D modeling of terrain and spatial visualization of underground facilities at the 'Crveni Breg' mine. Podzemni Radoni. 2013;33:17-30. https://doi.org/10.5937/PODRAD1833017C
  36. 36. Ahmed R, Mahmud K, Tuya J. A GIS-based mathematical approach for generating 3D terrain model from high-resolution UAV imageries. J Geovisual Spat Anal. 2021;5:24. https://doi.org/10.1007/s41651-021-00094-7
  37. 37. Gonçalves G, Gonçalves D, Gómez‐Gutiérrez Á, Andriolo U, Pérez-Alvárez JA. 3D reconstruction of coastal cliffs from fixed-wing and multi-rotor UAS: Impact of SfM-MVS processing parameters, image redundancy, and acquisition geometry. Remote Sens. 2021;13(6):1222. https://doi.org/10.3390/rs13061222
  38. 38. Tsukamoto Y, Ishihara K, Sawada S. Correlation between penetration resistance of Swedish sounding test and SPT blow counts in sandy soils. Soils Found. 2004;44(3):13-24. https://doi.org/10.3208/sandf.44.3_13
  39. 39. Inada M. Use of Swedish weight sounding tests. Tsuchi-to-Kiso. 1960;8(1):13-18.
  40. 40. Karol R. Soils and soil engineering. Englewood Cliffs (NJ): Prentice Hall; 1960.
  41. 41. Peck RB, Hanson WE, Thornburn TH. Foundation engineering. 2nd ed. New York: Wiley & Sons Incorporated; 1974.
  42. 42. Palacky GV. Resistivity characteristics of geologic targets. In: Nabighian MN, editor. Electromagnetic methods in applied geophysics. Vol. 1. Tulsa: Society of Exploration Geophysicists; 1987. p.13-51.
  43. 43. Chow V, Maidment D, Mays L. Applied hydrology. New York: McGraw-Hill Book Company; 1988.
  44. 44. Rawls WJ, Brakensiek DL, Miller N. Green-Ampt infiltration parameters from soils data. J Hydraul Eng. 1983;109(1):62–70. https://doi.org/10.1061/(ASCE)0733-9429(1983)109:1(62)
  45. 45. Duncan JM, Wright SG, Brandon TL. Soil strength and slope stability. 2nd ed. Hoboken (NJ): John Wiley & Sons; 2014.
  46. 46. Arai M, Minamiya Y, Tsuzura H, Watanabe Y, Yagioka A, Kaneko N. Changes in water table aggregate and soil carbon accumulation in a no-tillage with weed mulch management site after conversion from conventional management practices. Geoderma. 2014;221:50–60. https://doi.org/10.1016/j.geoderma.2014.01.022
  47. 47. Liu J, Song Z, Bai Y, Chen Z, Wei J, Wang Y, Qian W. Laboratory tests on effectiveness of environment-friendly organic polymer on physical properties of sand. Int J Polym Sci. 2018;2018:1–11. https://doi.org/10.1155/2018/5865247
  48. 48. Tarolli P, Rizzo D, Brancucci G. Terraced landscapes: Land abandonment, soil degradation, and suitable management. In: Varotto M, Bonardi L, Tarolli P, editors. World terraced landscapes: History, environment, quality of life. Cham: Springer; 2019. p.195–210. https://doi.org/10.1007/978-3-319-96815-5_12
  49. 49. Martin GR, Finn WDL, Seed HB. Fundamentals of liquefaction under cyclic loading. J Geotech Eng Div ASCE. 1975;101(GT5):423–38. https://doi.org/10.1061/AJGEB6.0000164
  50. 50. Mominul M, Alam Md, Ansary M, Karim M. Dynamic properties and liquefaction potential of a sandy soil containing silt. In: Proc 18th Int Conf Soil Mech Geotech 2013. Eng; Paris, France. p. 1539–42.
  51. 51. Monkul MM, Gültekin C, Gülver M, Akın Ö, Eseller-Bayat E. Estimation of liquefaction potential from dry and saturated sandy soils under drained constant volume cyclic simple shear loading. Soil Dyn Earthq Eng. 2015;75:27–36. https://doi.org/10.1016/j.soildyn.2015.03.019
  52. 52. Gourdol L, Clément R, Juilleret J, Pfister L, Hissler C. Exploring the regolith with electrical resistivity tomography in large-scale surveys: Electrode spacing-related issues and possibility. Hydrol Earth Syst Sci. 2021;25(4):1785–812. https://doi.org/10.5194/hess-25-1785-2021
  53. 53. Hasan MR, Larsen D, Schoefernacker S, Waldron B. Identification of breaches in a regional confining unit using electrical resistivity methods in southwestern Tennessee, USA. Water. 2023;15(23):4090. https://doi.org/10.3390/w15234090
  54. 54. Alsubal S, Sapari N, Harahap ISH. The rise of groundwater due to rainfall and the control of landslide by zero-energy groundwater withdrawal system. Int J Eng Technol. 2018;7(2.29):284–90. https://doi.org/10.14419/ijet.v7i2.29.14284
  55. 55. Ngoc NB. Effect of groundwater level on slopes to construct the SWCC curve for unsaturated soil. Int J Sci Res Arch. 2023;9(1):0482. https://doi.org/10.30574/ijsra.2023.9.1.0482
  56. 56. Bordoni M, Meisina C, Valentino R, Bittelli M, Chersich S. Hydrological factors affecting rainfall-induced shallow landslides: From the field monitoring to a simplified slope stability analysis. Eng Geol. 2015;193:19–37. https://doi.org/10.1016/j.enggeo.2015.04.006
  57. 57. Kim J, Kim Y, Jeong S, Hong M. Rainfall-induced landslides by deficit field matric suction in unsaturated soil slopes. Environ Earth Sci. 2017;76(23):808. https://doi.org/10.1007/s12665-017-7127-2
  58. 58. Tilliger B, Rodriguez-Labajos B, Bustamante JV, Settle J. Disentangling values in the interrelations between cultural ecosystem services and landscape conservation—A case study of the Ifugao rice terraces in the Philippines. Land. 2015;4(3):888–913. https://doi.org/10.3390/land4030888
  59. 59. Wang Q, Yang X, Liu X, Furuya K. Rice terrace experience in Japan: An ode to the beauty of seasonality and nostalgia. Land. 2024;13(1):64. https://doi.org/10.3390/land13010064
  60. 60. Hemid EM, Kántor T, Tamma AA, Masoud MA. Effect of groundwater fluctuation, construction, and retaining system on slope stability of Avas Hill in Hungary. Open Geosci. 2021;13(1):1139–57. https://doi.org/10.1515/geo-2020-0294
  61. 61. Likitlersuang S, Takahashi A, Eab KH. Modeling of root-reinforced soil slope under rainfall condition. Eng J. 2017;21(3):123–38. https://doi.org/10.4186/ej.2017.21.3.123
  62. 62. Taib SNL, Selaman OS, Chen CL, Lim R. Landslide susceptibility in relation to correlation of groundwater development and ground condition. Adv Civ Eng. 2017;2017:4320340. https://doi.org/10.1155/2017/4320340
  63. 63. Lin DG, Chang KC, Ku CY, Chou JC. Three-dimensional numerical investigation on the efficiency of subsurface drainage for large-scale landslides. Appl Sci. 2020;10(10):3346. https://doi.org/10.3390/app10103346
  64. 64. Abd‐Elaty I, Aldeeb H, Vranayova Z, Zelenakova M. Stability of irrigation canal slopes considering the sea level rise and dynamic changes: Case study El‐Salam Canal, Egypt. Water. 2019;11(5):1046. https://doi.org/10.3390/w11051046
  65. 65. Balakrishnan S, Viswanadham BVS. Performance evaluation of geogrid reinforced soil walls with marginal backfills through centrifuge model tests. Geotext Geomembr. 2016;44(3):348–56. https://doi.org/10.1016/j.geotexmem.2015.06.002
  66. 66. Cui W, Xiao M. Centrifuge modeling of geogrid-reinforced and rammed soil-cement column-supported embankment on soft soil. J Test Eval. 2020;48(5):20170603. https://doi.org/10.1520/jte20170603
  67. 67. Onur MI, Tuncan M, Evirgen B, Ozdemir B, Tuncan A. Behavior of soil reinforcements in slopes. Procedia Eng. 2016;143:483–89. https://doi.org/10.1016/j.proeng.2016.06.061
  68. 68. Liu H, Deng A, Chu J. Analysis of strengthening mechanism of the steep slope embankment through centrifugal model test. Shock Vib. 2022;2022:6536257. https://doi.org/10.1155/2022/6536257
  69. 69. Arnedo A, Galve JP, Jiménez-Perálvarez JD, Luque JA, Irigaray C. Assessment of shallow landslide risk mitigation measures based on land use planning through probabilistic modeling. Landslides. 2014;11(6):1007–18. https://doi.org/10.1007/s10346-014-0478-9
  70. 70. Hoque J, Bayezid M, Sharan AR, Mahadi M, Tareque T. Prediction of strength properties of soft soil considering simple soil parameters. Open J Civ Eng. 2023;13(3):479–96. https://doi.org/10.4236/ojce.2023.133035
  71. 71. Bakala TT, Quezon ET, Yasin M. Statistical analysis on shear strength parameter from index properties of fine-grained soils. J Eng Res Rep. 2021;20(4):17291. https://doi.org/10.9734/jerr/2021/v20i417291
  72. 72. Lin H, Bouma J, Wilding LP, Richardson JL, Kutilek M, Nielsen DR. Advances in hydropedology. Adv Agron. 2005;85:1–89. https://doi.org/10.1016/S0065-2113(04)85001-6
  73. 73. Ahmad A. Understanding the correlations and spatial variability of soil properties in predicting slope stability. J Geotech Eng. 2022;25(4):123–35. https://doi.org/10.3390/w13050713
  74. 74. Liangsunthonsit C, Jaroonrat P, Ayawanna J, Naebpetch W, Chaiyaput S. Evaluation of interface shear strength coefficient of alternative geogrid made from para rubber sheet. Polymers. 2023;15(7):1707. https://doi.org/10.3390/polym15071707
  75. 75. Özkal FM. Experimental investigation on the applicability of geogrid: A comparison between conventional and hybrid-reinforced irregular reinforced concrete members. Adv Struct Eng. 2021;24(8):1497–509. https://doi.org/10.1177/1369433218786045
  76. 76. Rossi N, Bačić M, Kovačević MS, Librić L. Fragility curves for slope stability of geogrid reinforced river levees. Water. 2021;13(19):2615. https://doi.org/10.3390/w13192615
  77. 77. Mahmoodzadeh A, Mohammadi M, Ali HFH, Ibrahim HH, Abdulhamid SN, Nejati HR. Prediction of safety factors for slope stability: Comparison of machine learning techniques. Nat Hazards. 2022;111(2):1771–99. https://doi.org/10.1007/s11069-021-05115-8
  78. 78. Gong B. Study of PLSR-BP model for stability assessment of loess slope based on particle swarm optimization. Sci Rep. 2021;11(1):17888. https://doi.org/10.1038/s41598-021-97484-0
  79. 79. Reale C, Xue J, Gavin K. System reliability of slopes using multimodal optimisation. Géotechnique. 2016;66(5):413–23. https://doi.org/10.1680/jgeot.15.p.142
  80. 80. Zhou C, Yin K, Cao Y, Ahmed B. Application of time series analysis and PSO–SVM model in predicting the Bazimen landslide in the three gorges reservoir, China. Eng Geol. 2016;204:108–20. https://doi.org/10.1016/j.enggeo.2016.02.009
  81. 81. Zhao H, Yin S, Ru Z. Relevance vector machine applied to slope stability analysis. Int J Numer Anal Methods Geomech. 2012;36(5):643–52. https://doi.org/10.1002/nag.1037
  82. 82. Liu Z, Shao J, Xu W, Chen H, Zhang Y. An extreme learning machine approach for slope stability evaluation and prediction. Nat Hazards. 2014;73(2):787–804. https://doi.org/10.1007/s11069-014-1106-7
  83. 83. Shiferaw HM. Study on the influence of slope height and angle on the factor of safety and shape of failure of slopes based on strength reduction method of analysis. Beni-Suef Univ J Basic Appl Sci. 2021;10:31. https://doi.org/10.1186/s43088-021-00115-w
  84. 84. Park C, Ahn S. An analytical study on the slope safety factor considering various conditions. J Korean Geotech Soc. 2019;35:31-41. https://doi.org/10.7843/KGS.2019.35.31

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