Hydrologic and Related Environmental Changes in NW Canada: Mackenzie Delta Region

Philip MarshNational Water Research InstituteSaskatoon, Canada

Mackenzie R. basin

Beaufort Sea

Mackenzie Delta Region

treeline

Arctic Environmental Atlas

Alaska

- hydrology influenced by a complex suite of processes including:

- local climate, including temperature, snow, rain, radiation and wind for example.- runoff of the entire MRB;- Beaufort Sea;- changes in vegetation, with vegetation controlled in a complex manor by climate, fire, and possibly the grazing patterns of caribou and reindeer;

Objectives• Provide a few, brief examples of past changes in climate, vegetation

and hydrology in the Mackenzie Delta region over the past 40 years.

• In conjunction with observations of environmental change in this region, we have been carrying out detailed process and model validation studies to improve our understanding of the observed changes. This work has included a number of collaborators, including the Mackenzie GEWEX Study (MAGS) and the Climate Change Action Fund (CCAF).

Tra il Va lle y C k

Ha vikp a k C k.

M a c ke nzie Rive rEa st C ha nne l

C a b in C k.*

M a c ke nzie Rive rPe e l Rive r

Be a ufo rt Se a(3)

Trail Valley CreekMay 13, 1999

Havikpak CreekApril 30, 1999

Climate and hydrology during the last 40 years:

Ice Breakup in the Mackenzie Delta and Discharge of the Mackenzie River

Canadian Mean Temperature Trends (1950-98)

Winter Spring

Summer Autumn

B. Bonsal et al., NWRI

45

35

25

15

5

-5

-15

-25

-35

% ChangeSpring

Precipitation Change (1950-1998)

Summer Autumn

Winter

Barrie Bonsal et al., NWRI

Annual and Seasonal Mackenzie River Discharge

1960 1970 1980 1990

Observed

reconstructed

Dis

char

ge (m

m)

M. Mackay

Mackenzie at Arctic Red: Spring

-0.30-0.20-0.100.000.100.200.300.40

73 75 77 79 81 83 85 87 89 91 93 95

Norm

alised

Q

Mean Spring Q = 12910 cms SD =1775

Year

1950 1960 1970 1980 1990 2000

Pea

k w

ater

leve

l (m

asl

)

3.5

4.0

4.5

5.0

5.5

6.0

6.5

7.0

7.5

1950's

Julia

n D

ay

135

140

145

150

155

160

Annual peak level5-yr running meanBest fit line

May 20

May 25

May 30

June 4

June 91960's 1970's 1980's 1990's

Decadal mean

1950's

Mean = JD 152.5 = June 1 Date of Peak Water

levels

Elevation of peak water level

Mackenzie River East Channel at Inuvik

Year

1970 1975 1980 1985 1990 1995 2000 2005

Julia

n D

ay

130

140

150

160

170

180

190

200Mack. Peak flow E.C. Peak Level Col 1 vs Col 3

Date of East Channel Peak Water Level (Julian Day)

140 160 180 200D

ate

of M

acke

nzie

Riv

er a

t A

rctic

Red

Riv

er (J

ulia

n D

ay)

140

160

180

200

1:1

Date of peak discharge and peak water level is generally simultaneous between Mackenzie River at Arctic Red River

and East Channel at Inuvik

Climate and hydrology during the last 40 years:

Vegetation, snow and runoff in uplands to the east of the Mackenzie Delta

Ann

ual

-4

0

4

Tuktoyaktuk

InuvikA

utum

n

-4

0

4

Win

ter

-404

Spr

ing

-4

0

4

Year

1950 1960 1970 1980 1990 2000

Sum

mer

-4

0

4

(a)

(b)

(c)

(d)

(e)

-9.8oC

-8.9oC

-28.6oC

-13.3oC

11.5oC

Inuvik and Tuktoyaktuk air temperature

Ann

ual

0

100

200

300 Inuvik

Tuktoyaktuk

Aut

umn

0

100

Win

ter

0

50

Spr

ing

0

50

100

Year

1950 1960 1970 1980 1990 2000

Sum

mer

0

100

(a)

(b)

(c)

(d)

(e)

270

136

76

41

4618

4417

100

60

Inuvik and Tuktoyaktuk Precipitation

Increased shrub growth in the Mackenzie Delta Region

• J.R. Mackay presents numerous examples of increased shrub growth the areas north of Inuvik.

• For example, Mackay (1999) reported rapid increase in vegetation in drained lake bottoms since 1980.

• Similar increases observed at sites without drained lakes• Coincided with an increase in winter temperatures and

total snowfall

• However, there have few, if any, systematic studies of changes in vegetation in the Mackenzie Delta region over the last 40 years

Aug 28, 1976 Aug 13, 1993

18 years

J.R. Mackay,1995

Active layer thickness – 1968 to 1993

depressions

hummocks

0.0

1.4

SW

E (m

m)

0

50

100

150

200

250

peak SWEApril 15 SWE

Year1960 1970 1980 1990 2000

Dat

e of

pea

k S

WE

Mar/01

Apr/01

May/01

April 15

mean = 136 mm

Late winter snow cover

Year1950 1960 1970 1980 1990 2000

Dat

e

Apr 03

Apr 17

May 01

May 15

May 29mean = May 17

mean = April 28

air temp. first rises above 0Conset of continuous above 0C air temp. Estimation of the

start of spring melt

Apr 17

May 01

May 15

May 29

Jun 12

Cabin - onset of flowCabin - peak spring dischargeHavikpak - onset of flowHavikpak - peak spring discharge

Year

1980 1985 1990 1995 2000

Cab

in C

r.di

scha

rge

(m

3 /s)

0

10

20

30

Hav

ikpa

k C

r. di

scha

rge

0

1

2

3Cabin CreekHavikpak Creek

Cabin Creek

Apr 17

May 01

May 15

May 29

Jun 12

onset of flowpeak spring discharge

Year

1980 1985 1990 1995 2000

Dis

char

ge (m

3 /s)

0

2

4

6

8

10

Mean peak = May 23

Mean onset = May 16

Trail Valley Creek

Trail Valley Creek

Mean peak = May 29

Mean onset = May 21

Spring snowmelt runoff

Climate and hydrology of the Mackenzie Delta Region:

Process Studies

Trail Valley Creek: Shrub and Tundra Study Sites

Shrub site Tundra site

Shortwave radiation (daily average)

April/May 200321 28 05 12 19 26 N

et s

hortw

ave

(W/m

^2)

04080

120160200

Tundra snowShrub snow

Snow removed from shrub by end of Mayand at the shrub site during first week of

June

Mid-May 2003Mid-April 2003

April/May 200321 28 05 12 19 26 N

et lo

ngw

ave

(W/m

^2)

-100

0

100

200Tundra snowShrub snow

April/May 200321 28 05 12 19 26 N

et lo

ngw

ave

(W/m

^2)

-100

0

100

200Tundra snowShrub snow

Longwave (daily average)

Net Allwave (daily average)

Snow surface radiation

Climate and hydrology of the Mackenzie Delta Region:

Modelling

P-E (225 mm) S (-26 mm)

Qsfc (132 mm) Qtot (247 mm)

(P - E) - S - Qtot = error

(225) - (-26) -247 = 5 mm

CRCM est. of Annual basin water balance

Mackay et al. - MSC

P = 496 mmE = 271 mm

Mackenzie River 1998/99

measured: 2.68 x1011 m3

WATROUTE: 2.70 x1011 m3

WATFLOOD: 2.65 x1011 m3

Basin area = 1.8 million sq km.

Measured = 149 mmWATROUTE = 150 mmWATFLOOD = 147mm

Conclusion• Hydrologic and other environmental changes have occurred in the

MD over the last 40 years• These changes including warmer annual and spring air

temperatures, changes in precipitation and snow cover.• These have contributed to dramatic changes in the timing of spring

freshet and breakup, and in some areas increased shrub growth.• The links between climate, fire, vegetation and hydrology not well

understood• Ongoing process and modelling studies are making progress in

allowing us to better understand some of these past changes, and our ability to consider likely future changes