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Earthquake-triggered 2018 Palu Valley landslides enabled by wet rice cultivation

Abstract

The death toll and economic impact of an earthquake can be greatly exacerbated if seismic ground shaking triggers landslides. Earthquake-triggered landslides typically occur in two different contexts: localized failure of steep slopes and resulting landslides that pose a major threat to life in areas below; and lateral spreading of nearly flat sediment plains due to shaking-induced liquefaction, which can damage large areas of critical infrastructure. Unexpected catastrophic landsliding triggered by the 28 September 2018 earthquake at Palu, Indonesia did not occur in either typical context, but produced both destructive outcomes. Here, we show that alluvial ground failure in the Palu Valley was a direct consequence of irrigation creating a new liquefaction hazard. Aqueduct-supported cultivation, primarily of wet rice, raised the water table to near ground level, saturating sandy alluvial soils that liquefied in response to strong ground shaking. Large-displacement lateral spreads occurred on slopes of 1°. Slopes steeper than 1.5° sourced long-runout landslides and debris flows that swept through villages occupying the gentler slopes below. The resulting damage and loss of life would probably not have occurred in the absence of a raised water table. Earthquake-triggered landsliding of gentle, irrigated alluvial slopes is an under-recognized, but avoidable, anthropogenic hazard.

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Fig. 1: Earthquake-triggered landsliding in the Palu Valley, Sulawesi, Indonesia.
Fig. 2: Landsliding was intimately related to agricultural land use and irrigation.
Fig. 3: Profiles across liquefaction-induced landslides showing relationship with agricultural land use.
Fig. 4: Anthropogenic liquefaction and landslide hazard at Palu, and one potential mitigation approach.

Data availability

The data required to reproduce our conclusions are available at the NTU Data Repository (https://researchdata.ntu.edu.sg/). The data included are: horizontal displacements from object tracking and pixel correlation, pixel correlation strain maps, land use classification and mapped geological features. MicMac displacement maps can be found at https://doi.org/10.21979/N9/VTBCFL. Strain rasters can be found at https://doi.org/10.21979/N9/PNYMEQ. Object tracking displacements can be found at https://doi.org/10.21979/N9/WPDFX2. Geological feature KMZ files can be found at https://doi.org/10.21979/N9/BZNMU0. The land use classification map can be found at https://doi.org/10.21979/N9/AFWLAR.

Code availability

The MATLAB function used to calculate horizontal strain components is available at the NTU Data Repository: https://doi.org/10.21979/N9/FLOXET.

References

  1. Bao, H. et al. Early and persistent supershear rupture of the 2018 magnitude 7.5 Palu earthquake. Nat. Geosci. 12, 200–205 (2019).

    Article  Google Scholar 

  2. Socquet, A., Hollingsworth, J., Pathier, E. & Bouchon, M. Evidence of supershear during the 2018 magnitude 7.5 Palu earthquake from space geodesy. Nat. Geosci. 12, 192–199 (2019).

    Article  Google Scholar 

  3. Bellier, O. et al. High slip rate for a low seismicity along the Palu‐Koro active fault in central Sulawesi (Indonesia). Terra Nova 13, 463–470 (2001).

    Article  Google Scholar 

  4. Socquet, A. et al. Microblock rotations and fault coupling in SE Asia triple junction (Sulawesi, Indonesia) from GPS and earthquake slip vector data. J. Geophys. Res. 111, B08409 (2006).

    Google Scholar 

  5. Worden, C. B. et al. Spatial and spectral interpolation of ground‐motion intensity measure observations. Bull. Seismol. Soc. Am. 108, 866–875 (2018).

    Article  Google Scholar 

  6. M 7.5 – 70km N of Palu, Indonesia (United States Geological Survey, 2018); https://earthquake.usgs.gov/earthquakes/eventpage/us1000h3p4/executive

  7. Gempa Bumi M7,4 & Tsunami Sulawesi Tengah (Badan Nasional Penggulangan Bencana, 2019); https://bnpb.go.id/infografis-gempabumi-m74-tsunami-sulawesi-tengah

  8. Dai, F. C. et al. Spatial distribution of landslides triggered by the 2008 Ms 8.0 Wenchuan earthquake, China. J. Asian Earth Sci. 40, 883–895 (2011).

    Article  Google Scholar 

  9. Marano, K. D., Wald, D. J. & Allen, T. I. Global earthquake casualties due to secondary effects: a quantitative analysis for improving rapid loss analyses. Nat. Hazards 52, 319–328 (2010).

    Article  Google Scholar 

  10. Nowicki Jessee, M. A. et al. A global empirical model for near-real-time assessment of seismically induced landslides. J. Geophys. Res. 123, 1835–1859 (2018).

    Article  Google Scholar 

  11. Wang, C. Y. Liquefaction beyond the Near Field. Seismol. Res. Lett. 78, 512–517 (2007).

    Article  Google Scholar 

  12. Bertrand, R. La «Politique éthique» des Pays-Bas à Java (1901–1926). Vingtième Siècle 93, 115–138 (2007).

    Article  Google Scholar 

  13. Kreisel, W., Weber, R. & Faust, H. Colonial interventions on the cultural landscape of Central Sulawesi by “Ethical Policy”: the impact of the Dutch rule in Palu and Kulawi Valley, 1905–1942. Asian J. Soc. Sci. 31, 398–434 (2003).

    Article  Google Scholar 

  14. Metzner, J. Palu (Sulawesi): problems of land utilization in a climatic dry valley on the Equator. Erdkunde 35, 42–54 (1981).

    Article  Google Scholar 

  15. Planet Application Program Interface: In Space for Life on Earth (Planet Team, 2017); https://api.planet.com

  16. Rosu, A. M., Pierrot-Deseilligny, M., Delorme, A., Binet, R. & Klinger, Y. Measurement of ground displacement from optical satellite image correlation using the free open-source software MicMac. ISPRS J. Photogramm. Remote Sens. 100, 48–59 (2015).

    Article  Google Scholar 

  17. Kääb, A., Altena, B. & Mascaro, J. Coseismic displacements of the 14 November 2016 Mw 7.8 Kaikoura, New Zealand, earthquake using the Planet optical cubesat constellation. Nat. Hazards Earth Syst. Sci. 17, 627–639 (2017).

    Article  Google Scholar 

  18. Seed, H. B. Landslides during earthquakes due to liquefaction. J. Soil Mech. Found. Div. 94, 1055–1122 (1968).

    Google Scholar 

  19. Seed, H. B. & Idriss, I. M. Analysis of soil liquefaction: Niigata earthquake. J. Soil Mech. Found. Div. 93, 83–108 (1967).

    Google Scholar 

  20. Bouman, B. A. M., Lampayan, R. M. & Tuong, T. P. Water Management in Irrigated Rice: Coping with Water Scarcity (International Rice Research Institute, 2007).

  21. Carr, M. The water relations and irrigation requirements of coconut (Cocos nucifera): a review. Exp. Agric. 47, 27–51 (2011).

    Article  Google Scholar 

  22. King, G. C. P., Stein, R. S. & Lin, J. Static stress changes and the triggering of earthquakes. B. Seismol. Soc. Am. 84, 935–953 (1994).

    Google Scholar 

  23. Watkinson, I. M. & Hall, R. Fault systems of the eastern Indonesian triple junction: evaluation of Quaternary activity and implications for seismic hazards. Geol. Soc. Spec. Publ. 441, SP441.448 (2016).

    Google Scholar 

  24. Yasuda, S. & Tohno, I. Sites of reliquefaction caused by the 1983 Nihonkai-Chubu earthquake. Soils Found. 28, 61–72 (1988).

    Article  Google Scholar 

  25. Yasuda, S. & Harada, K. Measures developed in Japan after the 1964 Niigata Earthquake to counter the liquefaction of soil. In Proc. 10th National Conference on Earthquake Engineering 11 (Earthquake Engineering Research Institute, 2014).

  26. Wang, C. Y., Cheng, L. H., Chin, C. V. & Yu, S. B. Coseismic hydrologic response of an alluvial fan to the 1999 Chi-Chi earthquake, Taiwan. Geology 29, 831–834 (2001).

    Article  Google Scholar 

  27. Harvey, F. E. & Sibray, S. S. Delineating ground water recharge from leaking irrigation canals using water chemistry and isotopes. Groundwater 39, 408–421 (2001).

    Article  Google Scholar 

  28. Ishihara, K., Okusa, S., Oyagi, N. & Ischuk, A. Liquefaction-induced flow slide in the collapsible loess deposit in Soviet Tajik. Soils Found. 30, 73–89 (1990).

    Article  Google Scholar 

  29. Holzer, T. L., Bennett, M. J., Ponti, D. J. & Tinsley, J. C. Liquefaction and soil failure during 1994 Northridge earthquake. J. Geotech. Geoenviron. 125, 438–452 (1999).

    Article  Google Scholar 

  30. Youd, T. L., Harp, E. L., Keefer, D. K. & Wilson, R. C. The Borah Peak, Idaho Earthquake of October 28, 1983—Liquefaction. Earthq. Spectra 2, 71–89 (1985).

    Article  Google Scholar 

  31. Neumann, K., Verburg, P. H., Stehfest, E. & Muller, C. The yield gap of global grain production: a spatial analysis. Agr. Syst. 103, 316–326 (2010).

    Article  Google Scholar 

  32. Sieh, K. & Natawidjaja, D. Neotectonics of the Sumatran fault, Indonesia. J. Geophys. Res. 105, 28295–28326 (2000).

    Article  Google Scholar 

  33. Naing, T. A. A., Kingsbury, A. J., Buerkert, A. & Finckh, M. R. A survey of Myanmar rice production and constraints. J. Agr. Rural Dev. Trop. 109, 151–168 (2008).

    Google Scholar 

  34. Wessel, P. & Smith, W. H. New, improved version of Generic Mapping Tools released. EOS Trans. AGU 79, 579–579 (1998).

    Article  Google Scholar 

  35. Planet Dump (OpenStreetMap, accessed 23 November 2018); https://planet.openstreetmap.org

Download references

Acknowledgements

Generic Mapping Tools34 was used to produce the figures. This research was supported by the Asian School of the Environment, Nanyang Technological University and the National Research Foundation Singapore and the Singapore Ministry of Education under the Research Centres of Excellence initiative. J.H. was supported by a Singapore National Research Foundation Fellowship (award no. NRF-NRFF2013-06). Part of the research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. This work comprises Earth Observatory of Singapore contribution no. 230.

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K.B., R.M. and J.H. led the analysis and produced the primary results and figures. K.B. led the writing and all authors contributed to writing and editing the manuscript. D.A., E.M., J.M., A.S., B.B. and G.B. made field observations of the landslides and liquefaction. K.B., R.M., J.H., G.F., S.W. and N.D. produced the displacement maps and uncertainty analyses. K.B. and H.A. mapped liquefaction features and produced the land use classification. E.M.H. and S.-H.Y. provided insight into damage mapping, recovery and ground surface deformation at Palu.

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Correspondence to Kyle Bradley.

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Bradley, K., Mallick, R., Andikagumi, H. et al. Earthquake-triggered 2018 Palu Valley landslides enabled by wet rice cultivation. Nat. Geosci. 12, 935–939 (2019). https://doi.org/10.1038/s41561-019-0444-1

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