42
Geotechnical News • September 2017
GEOHAZARDS
Using the IDF_CC Tool
After selecting a rain-station of inter-
est, users can view information on
that station, including the length of
the data record. To create IDF curves
for future climate change conditions,
users can select a 20-year projection
period for any time between 2006 to
2100, followed by one or multiple
GCM or GCM ensemble options.
After selecting these options, the tool
will automatically downscale GCM
results and apply GCM results to the
local rain station data, providing future
IDF curves in table or graphical for-
mat and allowing the user to compare
the impacts of multiple RCP scenarios
and rainfall return periods, and to
compare historical IDF curves to these
updated curves.
Implications for decision
makers
Increasingly frequent extreme weather
events due to a changing climate
have profound implications for the
planning, design and maintenance of
stormwater management infrastructure
across Canada. The IDF_CC Tool
allows municipalities to more accu-
rately forecast future rainfall events
and make informed planning decisions
that ensure stormwater infrastructure
can handle increased stresses associ-
ated with climate change scenarios.
This stormwater management infra-
structure will help to mitigate the risk
of urban flooding events, leading to
more resilient and sustainable cities
and long-term cost savings. Improved
planning using this tool will help pro-
tect people, property and ecosystems
from the negative impacts of extreme
storms caused by climate change
References
PCIC, (2013) “Statistically down-
scaled climate scenarios”,
last accessed July 12, 2017.
Peck, A., P. Prodanovic, and S.P.
Simonovic, (2012) “Rainfall inten-
sity duration frequency curves
under climate change: City of
London, Ontario, Canada”, Cana-
dian Water Resources Journal,
37(3):177-189.
Sandink, D., S.P. Simonovic, A.
Schardong, and R. Srivastav,
(2016) “A Decision Support
System for Updating and Incor-
porating Climate Change Impacts
into Rainfall Intensity-Duration-
Frequency Curves: Review of the
Stakeholder Involvement Process”,
Environmental Modelling & Soft-
ware Journal, 84:193-209.
Simonovic, S.P., A. Schardong,
D. Sandink, and R. Srivastav,
(2016) “AWeb-based Tool for the
Development of Intensity Duration
Frequency Curves under Changing
Climate”, Environmental Model-
ling & Software Journal, 81:136-
153.
Srivastav, R.K., A. Schardong and S.P.
Simonovic, (2014) “Equidistance
Quantile Matching Method for
Updating IDF Curves Under Cli-
mate Change”, Water Resources
Management: An International
Journal, 28(9): 2539-2562.
Slobodan P. Simonovic,
Ph.D, P.Eng, Member CAE, Fellow
CSCE, ASCE and IWRA
Professor, Department of Civil and
Environmental Engineering
Director of Engineering Works, Insti-
tute for Catastrophic Loss Reduction
The University of Western Ontario,
London, Ontario, Canada N6A 5B9
Tel: (519) 661-4075
Fax: (519) 661-3779
E:
RCPS
DESCRIPTION
CO2
CONCENTRATION
EQUIVALENT (PPM)
PATHWAY
SCENARIO
SEVERITY
2.6
A peak in radiative forcing of approx-
imately 3 watts per square metre (W/
m
2
) before 2100, declining to 2.6 W/
m
2
by 2100
Also referred to as RCP3PD
Peak of ~490 and then
decline by 2100
Peak and decline Lowest
4.5
Stabilization at 4.5 W/m
2
by 2100
without overshoot
650 (stabilized after
2100)
Stabilization
without overshoot
Medium-low
6.0
Stabilization at 6 W/m
2
by 2100 with-
out overshoot
850 (stabilized after
2100)
Stabilization
without overshoot
Medium-high
8.5
Rising pathway resulting in 8.5 W/m
2
by 2100. Radiative forcing continues
to rise beyond 2100
>1,370 in 2100
Rising
Highest
Figure 4. Description of Representation Concentration Pathways (RCPs)
