characterizing change of high frequency return periods in urbanizing southern ontario watersheds

Characterizing change of high frequency return periods in urbanizing southern

Ontario watersheds

Peter John Thompson Earthfx Inc.

Dr. William K. Annable

Department of Civil and Environmental Engineering University of Waterloo

CWRA 2014 Canada Water Resources Congress

June 2, 2014

Effects of Urbanization

• Increase in impervious area

• Shorter events

• Larger peak discharge

• Infiltration

• Changes to frequency

• Channelization

• Change in vegetative cover

• Habitat degradation

• Erosion

• Poor water quality

• Failure of engineered structures

2

3

Environment Canada (Water Survey Division) Gauged Catchments

Study Catchments

Environment Canada (Water Survey Division) Gauged Catchments Study Catchments

5

Middle Don River, North York c. 1954-55

Aerial Photographic Analysis

Highway 401 under construction

RCAF Station Downsview


6

Don River at York Mills c. 1955

• Scanned and georeferenced aerial photographs in 8-year intervals from 1954 to 2010

• Identified urbanized areas by hand


7

Don River at York Mills c. 2005

• Two temporal datasets produced: • “Effective Impervious

Area” (EIA)

• Road Density

• Can we relate this observed change to hydrologic variables?

Little Don River at Don Mills (02HC029)

1954

Don River at York Mills

(02HC005)

0 2 4 6 8 10 1 Kilometers

Effective Catchment Area

Road Network - 1954

Forested Cover - 1955

Urbanized Area - 1954

1960


(02HC005)




Road Network - 1960


1970


(02HC005)




Road Network - 1970


1978


(02HC005)




Road Network - 1978


1995


(02HC005)


2005


(02HC005)


Land Use Change Transition from Agricultural to Urban Land Use

0

2

4

6

8

10

12

0

10

20

30

40

50

60

70

80

90

100

1950 1960 1970 1980 1990 2000 2010

Ro

ad D

en

sity

(km

/km

2)

Pe

rce

nt

Are

a

Year

Urbanized Area

Agricultural Area

Catchment Road Density

02HC005 – Don River at York Mills Effective Catchment Area – 95.5 km2

Etobicoke Creek below QEW (02HC030)

1970

• Effective Catchment Area - 204 km2

• Urbanized Area - 45.4 km2 (21%)

• Total Road Length - 718 km

0 4 8 12 2 Kilometers


Road Network - 1970



1978






Road Network - 1978



1995


• Urbanized Area - 100 km2 (47%)




Road Network - 1995



2005






Road Network - 2005


Temporal Land Use Change

Redhill Creek at Hamilton (02HA014)

20

• Effective Catchment Area 57.0 km2

• Urbanized Area ~60%

AAfafdas

Hydrograph Change with Urbanization

Time (T) Time (T)

Rain

fall

(L

)

Dis

ch

arg

e (

L3/T

)

After

Urbanization

Original

Lag time after

urbanization

Hydrograph

of streamflow

Lag time

Center of mass

of runoff

and of rainfall

Dis

ch

arg

e (

L3/T

) Rainfall

•Changes to event hydrograph with urbanization...?

after Leopold (1968)

Daily vs. Instantaneous Data

22

02HA014 – Redhill Creek at Hamilton

• The daily stream flow represents an average, the instantaneous data is made up of 15 minute interval measurements

• Individual events and event peaks can be clearly identified on the 15 minute hydrograph

Instantaneous Stream Flow Data

Manual Chart Digitizing (c. ~1975)

• Need high resolution, high frequency data

• Only data available post-1996

• Joint project with Water Survey of Canada

• Archived electronic records dating from 1969 were processed to create a 15 minute resolution hydrograph

• Much of this data was originally digitized by hand

Daily vs. Instantaneous Data

• Periods of high flow are not captured on the mean daily hydrograph

24

02HC029 – Little Don River at Don Mills

Event Separation Algorithm

25

• Allows individual events to be parsed and analyzed from the instantaneous hydrometric record

• Events are considered over after the Q passes below some ratio of the peak

• Thresholds range from 15% - 50% of peak discharge

02HA014 - Redhill Creek at Hamilton

26


• Most events during the year can be identified

• There is no instantaneous record for backwater periods due to ice or vegetation

• Data lends itself to urban catchments or analysis of warm weather events (May – November)

02HA014 - Redhill Creek at Hamilton

Ba

ck

wa

ter

Du

e t

o Ic

e


27

02HC033 - Mimico Creek at Islington

Ba

ck

wa

ter

Du

e t

o Ic

e

Mann-Kendall Trend (5% CI): Increasing

Peak Event Discharge

Station Name Trend

Duffins Creek above Pickering

East Humber River near Pine Grove

East Oakville Creek near Omagh

Laurel Creek at Waterloo ↑

Redhill Creek at Hamilton

Black Creek near Weston ↑

Etobicoke Creek at Brampton ↑

Etobicoke Creek below QEW ↑

Mimico Creek at Islington ↑

Don River at York Mills ↑

Little Don River at Don Mills ↑

Don River at Todmorden ↑

Rouge River near Markham ↑

Highland Creek near West Hill ↑

Harmony Creek at Oshawa ↑

Peak Event Discharge U

rban

ized

Ru

ral

Frequency Analysis

• Can we relate changes in the urban footprint to changes in return frequency?

• Need to assess hydrologic change in step with catchment land use change

30

Land Use Change

31

Highland Creek near West Hill (02HC013)

Urban Area

Road Density

Space for Time Substitution

32


(Peak Discharge)

Space for Time Substitution

33

(Peak Discharge)


34


Moving Window Weibull Recurrence Interval = Length of Record + 1

Event Rank

35


Return Frequency (7-Year Moving Weibull Plot)


36


37

Don River at Todmorden (02HC024)


38

Rouge River near Markham (02HC022)


Conclusions

• Event based separation allows high resolution datasets to be parsed down to hydrological descriptive variables

• The magnitude of change in storm peaks varies with return frequency, but these changes may not be consistent

• Spatial distribution of build-out critical to understanding hydrologic change

• These data can be used for Partial Peak, and Partial Duration, and Annual Duration methods to fine tune the analysis of higher frequency events in urban catchments

A Nonstationary Analysis of Southern Ontario Storm Events

Identified from High Resolution Streamflow Data;

Nicole L. O’Brien, Peter J. Thompson, Donald H. Burn,

William K. Annable

Session M2C

Acknowledgements

Dr. Herman Goertz Jeanette Fooks

Paula Hunter Carrie-Lynn Green

Water Survey Division, Environment Canada

Tom Arsenault

Aerial Photography Analysis Eco-Hydraulics Co-op

Robert Leonard Tyler Gale

Nikita Tirskikh Victoria Lounder

Chris McKie Ben Plumb

Christina Bright

CompuMOD Dataset Extraction

Ian McLaurin

41

Thank you!

Questions or Comments?

WSC

Station ID Station Name

Area

(km2)

Percent

Urban

(1969)

Percent

Urban

(≈2010)

Percent

Change

02HC019 Duffins Creek above Pickering 93.5 > 5% --

02HC009 East Humber River near Pine Grove 197 > 10% --

02HB004 East Oakville Creek near Omagh 199 > 10% --

02GA024 Laurel Creek at Waterloo 57.5 15 38 23

02HA014 Red Hill Creek at Hamilton 57.0 27 60 33

02HC027 Black Creek near Weston 66.0 55 78 22

02HC017 Etobicoke Creek at Brampton 65.1 1 18 17

02HC030 Etobicoke Creek below QEW 211 20 55 34

02HC033 Mimico Creek at Islington 75.2 43 82 39

02HC005 Don River at York Mills 96.7 30 69 39

02HC029 Little Don River at Don Mills 138 30 68 38

02HC024 Don River at Todmorden 321 43 73 30

02HC022 Rouge River near Markham 181 7 40 33

02HC013 Highland Creek near West Hill 89.0 47 86 39

02HD013 Harmony Creek at Oshawa 42.1 20 45 25

42

Study Catchments

Mann-Kendall Test

• Non-parametric test for monotonic trends

• Independent events assumed to be uncorrelated

• Trends tested to a 95% significance level ( p ≤ 0.025 )

0 if1

0 if0

0 if1

sgn

1

1 1

sgnn

k

n

kj

kj xxS

43

Typical Event Hydrograph

44

Qpeak

Qthreshold

Qstart Qend

Time

Dis

cha

rge

tstart tpeak tthreshold

Trise Tthreshold Ttotal

Vrise

Q75

Q50

T75

T50 Rising Limb

Falling Limb

Recession Limb

Vrecession

Vtotal

tend

• Once an event has be identified on the hydrograph, specific event properties can be analyzed

• Event volume, duration, time to peak, etc. can be calculated directly from the observed hydrograph

• Trends in event parameters can be explored

Peak Event Discharge

Station Name Trend
















Number of Events per Year

Station Name Trend




Laurel Creek at Waterloo


Black Creek near Weston


Etobicoke Creek below QEW

Mimico Creek at Islington



Don River at Todmorden




Event Volume

Station Name Trend





Redhill Creek at Hamilton ↑





Don River at York Mills ↓




Highland Creek near West Hill

Harmony Creek at Oshawa

Total Event Duration

Station Name Trend



East Oakville Creek near Omagh ↓

Laurel Creek at Waterloo


Black Creek near Weston ↓

Etobicoke Creek at Brampton ↓



Don River at York Mills ↓


Don River at Todmorden ↓


Highland Creek near West Hill ↓

Harmony Creek at Oshawa ↓

Event Quick Flow (Direct Runoff) Volume

Station Name Trend




Oakville Creek at Milton ↓

Credit River near Orangeville







Don River at Todmorden



Harmony Creek at Oshawa

MK Trend: Increasing

Event Interflow Volume

Station Name Trend

Duffins Creek above Pickering ↑



Oakville Creek at Milton

Credit River near Orangeville


Etobicoke Creek at Brampton









MK Trend: Increasing

Station Name

Peak

Discharg

e

Time

to

Peak

Event

Duration

Total

Hydrograp

h Duration

Event

Volume

Total

Hydrograp

h Volume

Flashines

s



East Oakville Creek near Omagh ↓

Oakville Creek at Milton ↑ ↓ ↓ ↓ ↓ ↓ ↑

Credit River near Orangeville ↑

Laurel Creek at Waterloo ↑ ↑ ↑ ↑ ↑

Redhill Creek at Hamilton ↑

Black Creek near Weston ↑ ↓ ↑

Etobicoke Creek at Brampton ↑ ↓ ↓ ↓ ↑ ↑ ↑

Etobicoke Creek below QEW ↑ ↑ ↑ ↑ ↑ ↑

Mimico Creek at Islington ↑ ↑ ↑ ↑ ↑ ↑

Don River at York Mills ↑ ↓ ↓ ↓ ↓ ↑

Little Don River at Don Mills ↑ ↑ ↑ ↑ ↑ ↑ ↑

Don River at Todmorden ↑ ↓ ↓ ↑ ↑ ↑

Rouge River near Markham ↑ ↑ ↑ ↑ ↑ ↑

Highland Creek near West Hill ↑ ↓ ↓ ↓ ↑ ↑

Harmony Creek at Oshawa ↑ ↓ ↓ ↑

Summary (Warm Weather Trends)

Mimico Creek at Islington (02HC033)

1970






Road Network - 1970



1978






Road Network - 1978



1995


• Urbanized Area – 53.0 km2 (72%)




Road Network - 1995



2005


• Urbanized Area - 60.2 km2 (81.5%)



Road Network - 2005




1955




0 1 2 3 4 0.5 Kilometers

Topographic Catchment Boundary

Road Network - 1955

Forest Cover - 1955



2010




0 1 2 3 4 0.5 Kilometers

Topographic Catchment Boundary

Road Network - 2010


Change in 1.5 Year Return Discharge

58

Change in Bankfull Discharge

59