Climate Change and Heavy Rainfall-Related Water Damage Insurance Claims and Losses in Ontario, Canada

Chad Shouquan Cheng, Qian Li, Guilong Li, Heather Auld

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Science Section, Operations-Ontario, Meteorological Service of Canada, Environment Canada, Toronto, Canada.

DOI: 10.4236/jwarp.2012.42007                

Abstract

The objective of this paper was to project possible impacts of climate change on heavy rainfall-related water damage insurance claims and incurred losses for four selected cites (Kitchener-Waterloo, London, Ottawa, and Toronto) located at Ontario, Canada. To achieve this goal, the future climate change scenarios and rainfall simulations, at local scale, were needed. A statistical downscaling method was used to downscale five global climate model (GCM) scenarios to selected weather stations. The downscaled meteorological variables included surface and upper-air hourly temperature, dew point, west-east and south-north winds, air pressure, and total cloud cover. These variables are necessary to project future daily rainfall quantities using within-weather-type rainfall simulation models. A model result verification process has been built into the whole exercise, including rainfall simulation modeling and the development of downscaling transfer functions. The results of the verification, based on historical observations of the outcome variables simulated by the models, showed a very good agreement. To effectively evaluate heavy rainfall-related water damage insurance claims and incurred losses, a rainfall index was developed considering rainfall intensity and duration. The index was evaluated to link with insurance data as to determination of a critical threshold of the rainfall index for triggering high numbers of rainfall-related water damage insurance claims and incurred losses. The relationship between rainfall index and insurance data was used with future rainfall simulations to project changes in future heavy rainfall-related sewer flood risks in terms of water damage insurance claims and incurred losses. The modeled results showed that, averaged over the five GCM scenarios and across the study area, both the monthly total number of rainfall-related water damage claims and incurred losses could increase by about 13%, 20% and 30% for the periods 2016-2035, 2046-2065, and 2081-2100, respectively (from the four-city seasonal average of 12 ± 1.7 thousand claims and $88 ± $21 million during April-September 1992-2002). Within the context of this study, increases in the future number of insurance claims and incurred losses in the study area are driven by only increases in future heavy rainfall events.

Keywords

Climate Change; Statistical Downscaling; Rainfall-Related Flooding Risks; Water Damage;Insurance Claims; Canada

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	PSEPC, “Canadian Disaster Database Version 4.4,” Public Safety and Emergency Preparedness Canada, 2006.
[2]	G. R. Brooks, S. G. Evans and J. J. Clague, “Floods,” Geological Survey of Canada Bulletin 548—A Synthesis of Geological Hazards in Canada, 2001, pp. 101-143.
[3]	K. Pal, “Assessing Community Vulnerability to Flood Hazard in Southern Ontario,” Canadian Water Resources Journal, Vol. 27, No. 2, 2002, pp. 155-173. doi:10.4296/cwrj2702155
[4]	MNR, “Flood Damages in Ontario,” Technical Report, Ontario Ministry of Natural Resources, apuskasing, 2004.
[5]	IPCC, “Summary for Policymakers,” In: S. Solomon, D. Qin, M. Manning, Z. Chen, M. Marquis, K. B. Averyt, M. Tignor and H. L. Miller, Eds., Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the 4th Assessment Report of the Intergovernmental Panel on Climate Change, Cambridge University Press, Cambridge, 2007.
[6]	IPCC, “Climate Change 2001: Impacts, Adaptation, and Vulnerability,” Cambridge University Press, Cambridge, 2001.
[7]	D. I. Smith, “Greenhouse Climatic Change and Flood Damages—The Implications,” Climate Change, Vol. 25, 1993, pp. 319-333. doi:10.1007/BF01098379
[8]	E. C. Penning-Rowsell, J. Handmer and S. Tapsell, “Extreme Events and Climate Change: Floods,” In: T. E. Downing, A. A. Olsthoorn and R. S. J. Tol, Eds., Climate change and Extreme Events: Altered Risk, Socio-Eco- nomic Impacts and Policy Responses, Vrije Universiteit, Amsterdam, 1996, pp. 97-127.
[9]	D. I. Smith, “Urban Flood Damage and Greenhouse Scenarios—The Implementation for Policy: An Example from Australia,” Mitigation and Adaptation Strategies for Global Change, Vol. 4, No. 3-4, 1999, pp. 331-342. doi:10.1023/A:1009623925591
[10]	J. W. Hall, E. P. Evans, E. C. Penning-Rowsell, P. B. Sayers, C. R. Thorne and A. J. Saul, “Quantified Scenarios Analysis of Drivers and Impacts of Changing Flood Risk in England and Wales: 2030-2100,” Global Environmental Change Part B: Environmental Hazards, Vol. 5, No. 3-4, 2003, pp. 51-65. doi:10.1016/j.hazards.2004.04.002
[11]	Environment Canada, “Flooding Events in Canada— Ontario: Hurricane Hazel,” 2000. http://www.ec.gc.ca/water/en/manage/floodgen/e_ont.htm#hazel
[12]	Environment Canada, “Remembering Hurricane Hazel 1954—50th Anniversary,” 2004. http://www.atl.ec.gc.ca/weather/hurricane/hazel/en/index.html
[13]	J. Klaassen and M. Seifert, “Extreme Rainfall in Ontario: The Summer 2004 Storms Study,” Environment Canada, 2006.
[14]	C. S. Cheng, G. Li, Q. Li and H. Auld, “A Synoptic Weather Typing Approach to Simulate Daily Rainfall and Extremes in Ontario, Canada: Potential for Climate Change Projections,” Journal of Applied Meteorology and Climatology, Vol. 49, No. 5, 2010, pp. 845-866. doi:10.1175/2010JAMC2016.1
[15]	C. S. Cheng, G. Li, Q. Li and H. Auld, “A Synoptic Weather-Typing Approach to Project Future Daily Rainfall and Extremes at Local Scale in Ontario, Canada,” Journal of Climate, Vol. 24, No. 14, 2011, pp. 3667-3685. doi:10.1175/2011JCLI3764.1
[16]	C. S. Cheng, G. Li, Q. Li and H. Auld, “Statistical Downscaling of Hourly and Daily Climate Scenarios for Various Meteorological Variables in South-Central Canada,” Theoretical and Applied Climatology, Vol. 91, No. 1-4, 2008, pp. 129-147. doi:10.1007/s00704-007-0302-8
[17]	Bank of Canada, “Inflation Calculator,” 2006. http://www.bankofcanada.ca/en/rates/inflation_calc.html
[18]	Environment Canada, “DATA,” 2006. http://www.cccma.bc.ec.gc.ca/data/data.shtml
[19]	PCMDI, “WCRP CMIP3 Multi-Model Dataset,” 2006. http://www-pcmdi.llnl.gov/ipcc/about_ipcc.php
[20]	J. G. Galway, “The Lifted Index as a Predictor of Latent Instability,” Bulletin of the American Meteorological Society, Vol. 37, 1956, pp. 528-529.
[21]	J. J. George, “Weather Forecasting for Aeronautics,” Academic Press, London, 1960.
[22]	R. C. Miller, “Notes on Analysis and Severe Storm Forecasting Procedures of the Air Force Global Weather Central,” Technical Report 200(R), Headquarters, Air Weather Service, USAF, 1972.