Characterizing Change in Baseflow Interactions with Urbanization Through Event-Based Hydrograph Separation and Analysis

Characterizing change in baseflow interactions with urbanization through

event-based hydrograph separation and analysis

Peter John Thompson Earthfx Inc.

Dr. William K. Annable

Department of Civil and Environmental Engineering University of Waterloo

IAH 2012 Congress

September 21, 2012

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

AAfafdas

Hydrograph Change with Urbanization

Time (T) Time (T)

Rain

fall

(L

)

Dis

ch

arg

e (

L/T

3)

After

Urbanization

Original

Lag time after

urbanization

Hydrograph

of streamflow

Lag time

Center of mass

of runoff

and of rainfall

Dis

ch

arg

e (

L/T

3)

Rainfall

•Changes to event hydrograph with urbanization...?

after Leopold (1968)

Study Catchments

4

Environment Canada (Water Survey Division) Gauged Catchments

0 2 4 6 8 101Kilometers

Effective Catchment Area

Road Network - 1954

Forested Cover - 1955

Urbanized Area - 1954

Little Don River at Don Mills (02HC029)

1954

Don River at York Mills

(02HC005)



Road Network - 1960


1960


(02HC005)




Road Network - 1970


1970


(02HC005)




Road Network - 1978


1978


(02HC005)




Road Network - 1995


1995


(02HC005)




Road Network - 2005


2005


(02HC005)


Land Use Change (“De-farming”/Urbanization)

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

Urban Stream Flow Data

• Need high resolution, high frequency data

• Joint project with Water Survey of Canada

• Extracted archived stream flow data to create a complete hydrometric record from 1969 to present

12

Daily vs. Instantaneous Data

Daily vs. Instantaneous Data

15

Event Separation Algorithm

• Suite of hydrograph visualization and analysis tools written in VB .net

16

Event Separation Algorithm

Typical Event Hydrograph

Qpeak

Qend

Qstart Qreg

Time

Dis

cha

rge

Qpivot

tstart tpeak tend treg

Trise Tevent Trec

Vevent

Q75

Q50

T75

T50 Rising Limb

Falling Limb

Recession Limb

17

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

18

Peak Event Discharge

MK Trend: 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 ↑

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 York Mills ↑


Don River at Todmorden




Event Volume

Station Name Trend




Laurel Creek at Waterloo ↑

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 ↓

Hydrograph Separation

Qpeak

Qstart

Qreg

Time

Dis

cha

rge

Qpivot

tstarttpeak

treg

Quick (Direct)Flow

Inter Flow

Base Flow

Constant Slope Method Inflection Point Solver

• Find inflection point on falling limb via non-linear curve fitting

• Separate linear storage volumes

Hydrograph Separation

25

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


Event Interflow Volume

Station Name Trend

Duffins Creek above Pickering ↑



Oakville Creek at Milton

Credit River near Orangeville

Black Creek near Weston ↑

Etobicoke Creek at Brampton










Zombie Science?

28

“Results from these comparisons show that depending on the method used, automated baseflow separation underestimates the simulated baseflow by as much as 28%, or overestimates it by up to 74%, during rainfall events.” (Partington et al., 2012)

Conclusions

• While direct runoff increases in urbanizing catchments, event contribution to shallow system may increase or decrease

• Hydrograph separation methods have relevance in modern hydrology, more work required

• Must work towards integrated SW/GW definitions

• Canada has an large database of high resolution, instantaneous hydrometric data spanning from 1969 onwards

29

Acknowledgements

Dr. Herman Goertz Jeanette Fooks

Paula Hunter Carrie-Lynn Green

Eco-Hydraulics Co-op

Tyler Gale

Victoria Lounder

Ben Plumb

Christina Bright

Water Survey Division, Environment Canada

Tom Arsenault

Aerial Photography Analysis

Robert Leonard

Nikita Tirskikh

Chris McKie

31

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 56.3 27 60 33

02HC027 Black Creek near Weston 58 55 78 22

02HC017 Etobicoke Creek at Brampton 63.2 1 18 17

02HC030 Etobicoke Creek below QEW 204 20 55 34

02HC033 Mimico Creek at Islington 70.6 43 82 39

02HC005 Don River at York Mills 88.1 30 69 39

02HC029 Little Don River at Don Mills 130 30 68 38

02HC024 Don River at Todmorden 316 43 73 30

02HC022 Rouge River near Markham 186 7 40 33

02HC013 Highland Creek near West Hill 88.1 47 86 39

02HD013 Harmony Creek at Oshawa 41.6 20 45 25

32

Study Catchments

Summary (Warm Weather Trends)

Station Name Peak

Discharge

Time to

Peak

Event

Duration

Total

Hydrograph

Duration

Event

Volume

Total

Hydrograph

Volume

Flashiness



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 ↑ ↓ ↓ ↑

Partial Flow Duration Curve

1970 1985 2010