Abstract
Approximately, one billion people across the globe are currently living in informal shack settlements with a large potential fire risk. Due to the small distance between shacks, a single shack fire may spread and could cause a large area of informal settlement to be burnt in a short period of time. In this work, the critical fire separation distance between shacks is first discussed and determined using a simple physics-based theoretical model. Aerial photography within geographic information systems (GIS) is then employed to verify the calculated results based on a real informal settlement burn scar in Masiphumelele, Cape Town, South Africa. The radiative heat fluxes along the centerline of the shack window, at different distances, are calculated to estimate the ignition potential of combustible materials in adjacent shacks. Meanwhile, the potential fire risks, assuming separation distance as a proxy for risk, pre- and post- a known fire in Masiphumelele are obtained and compared. It was established that the heat flux would decay from around 100 kW/m2 within 0.5 m to the value smaller than 0.1 kW/m2 at the distance of 3.5 m away from the shack, which can be considered as a relatively safe distance. The theoretical result agrees well with the minimum effective distance of 3.3 m in real fires occurred in Masiphumelele. However, a GIS analysis of the informal settlement layout in 2015 and 2017 demonstrates that, if the critical fire separation distance is more than 3.0 m, 97% of the settlement could be at risk in a single fire incident. Therefore, more research is required to improve the understanding of fire spread mechanisms in informal settlements.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
References
Habitat, U. (2013). State of the world’s cities 2012/2013: Prosperity of cities, Routledge.
Walls, R., Olivier, G., & Eksteen, R. (2017). Informal settlement fires in South Africa: Fire engineering overview and full-scale tests on “shacks”. Fire Safety Journal, 91, 997–1006.
DMFRS. (2015). Western cape strategic framework for fire and burn injury prevention. In Western cape disaster management and fire rescue services.
Roberts, E. (2017). Migrants without shelter after fire destroys French refugee camp in CNN.
Fire in Germany refugee shelter injures 37 in The Local de (2017).
Walls, R., & Zweig, P. (2017). Towards sustainable slums: Understanding fire engineering in informal settlements. In Advanced technologies for sustainable systems (pp. 93–98). Springer.
Himoto, K., & Tanaka, T. (2008). Development and validation of a physics-based urban fire spread model. Fire Safety Journal, 43, 477–494.
Himoto, K., Tsuchihashi, T., Tanaka, Y., & Tanaka, T. (2009). Modeling thermal behaviors of window flame ejected from a fire compartment. Fire Safety Journal, 44, 230–240.
Wang, Y., & Rush, D. (2018). Determination of critical fallout condition of tempered glass in an enclosure fire. Fire Safety Journal, 101, 18–24.
Law, M., & O’Brien, T. (1989). Fire safety of bare external structural steel. Steel Construction Institute.
Moradi, A. (2016). Fire spreading in South African low-cost settlements “A physics-based model”. Stellenbosch: Stellenbosch University.
Drysdale, D. (2011). An introduction to fire dynamics. Wiley.
Lee, S. W., & Davidson, R. A. (2010). Physics-based simulation model of post-earthquake fire spread. Journal of Earthquake Engineering, 14, 670–687.
Wang, Y., Wang, Q., Su, Y., Sun, J., He, L., & Liew, K. M. (2015). Fracture behavior of framing coated glass curtain walls under fire conditions. Fire Safety Journal, 75, 45–58.
Bergman, T. L., Incropera, F. P., & Lavine, A. S. (2011). Fundamentals of heat and mass transfer. Wiley.
Wang, Y., Li, K., Su, Y., Lu, W., Wang, Q., Sun, J., et al. (2017). Determination of critical breakage conditions for double glazing in fire. Applied Thermal Engineering, 111, 20–29.
Cuzzillo, B. R., & Pagni, P. J. (1998). Thermal breakage of double-pane glazing by fire. Journal of Fire Protection Engineering, 9, 1–11.
Meth, P. (2017). Informal housing, gender, crime and violence: the role of design in Urban South Africa. The British Journal of Criminology, 57, 402–421.
Spearpoint, M. J., & Quintiere, J. G. (2001). Predicting the piloted ignition of wood in the cone calorimeter using an integral model—effect of species, grain orientation and heat flux. Fire Safety Journal, 36, 391–415.
Smith, W. K., & King, J. B. (1970). Surface temperatures of materials during radiant heating to ignition. Journal of Fire and Flammability, 1, 272–288.
Koo, E., Pagni, P. J., Weise, D. R., & Woycheese, J. P. (2010). Firebrands and spotting ignition in large-scale fires. International Journal of Wildland Fire, 19, 818–843.
Acknowledgements
This work is supported by IRIS-Fire project of UK (Engineering and Physical Sciences Research Council Grant no.: EP/P029582/1). Aerial photography was obtained from the City of Cape Town via the Open Data portal (https://web1.capetown.gov.za/web1/opendataportal/DatasetDetail?DatasetName=Aerial%20photography), however, the City of Cape Town does not warrant or guarantee the quality or accuracy of the data, accessed, extracted and/or used from this site.
Author information
Authors and Affiliations
Corresponding authors
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2020 Springer Nature Singapore Pte Ltd.
About this paper
Cite this paper
Wang, Y., Gibson, L., Beshir, M., Rush, D. (2020). Preliminary Investigation of Critical Separation Distance Between Shacks in Informal Settlements Fire. In: Wu, GY., Tsai, KC., Chow, W.K. (eds) The Proceedings of 11th Asia-Oceania Symposium on Fire Science and Technology. AOSFST 2018. Springer, Singapore. https://doi.org/10.1007/978-981-32-9139-3_28
Download citation
DOI: https://doi.org/10.1007/978-981-32-9139-3_28
Publisher Name: Springer, Singapore
Print ISBN: 978-981-32-9138-6
Online ISBN: 978-981-32-9139-3
eBook Packages: EngineeringEngineering (R0)