Coupled modelling of soil thaw/freeze dynamics and runoff generation in permafrost landscapes,

Upper Kolyma, RussiaLebedeva L.1,4, Semenova O.2,3

1Nansen Environmental and Remote Sensing Centre2Gidrotehproekt Ltd

3St. Petersburg State University4State Hydrological Institute

St. Petersburg, Russia

The study is partially supported by Russian-German Otto Schmidt Laboratory for Polar and Marine research

Bare rocksBush tundra

Larch forest

Riparian vegetation

Variety of landscapes and complex process interactionsVariety of landscapes and complex process interactions

Deep active layerSubsurface runoff

Shallow active layer, surface runoff

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Motivation•variety of landscapes and dominated flow formation

mechanisms•sparse hydrometeorological network in North-Eastern Russia

and nearly absence of research stations•observed environmental changes impact differently in diverse

landscapes

- analysis of active layer formation and flow generation mechanisms in mountainous permafrost landscapes of the Kolyma Water Balance Station (North-Eastern Russia)

- simulate thaw/freeze depths and runoff in homogenious landscape typical for North-Eastern Russia using the Hydrograph model

- develop and verify unified approach for hydrological modelling in changing permafrost environments of North-East of Russia

Objectives

Study area: Kolyma water-balance station•Mean air temperature is -11,40С•Mean annual precipitation 320 mm•Elevation ranges 800-1700 m•Variety of landscapes •Continuous permafrost with the thickness up to 400 m•Representative for the vast territories of Upper Kolyma River Basin

Creek Area, km2

Average (and maximum) elevation, m

Average (and maximum) slope, º

Area occupied by a certain landscape, %

Rocky talus

Mountain tundra

Sparse trees

Forest and bogs

Morozova 0.63 1370 (1700) 33 (50) 98 2 0 0

Severny 0.33 1020 (1300) 21 (40) 24 63 0 13

Yuzhny 0.27 985 (1100) 17 (30) 5 17 56 22

Kontaktovy 21.2 1070 (1700) 25 (50) 34 27 12 27

List of measurements conducted at KWBS

Scheme of the typical landscapes

Bush tundra

Bare rocks

Sparse forest

Larch forest

The Hydrograph model

Process-based (explicitly includes all processes)

Observable parameters, no calibration (can be obtained apriori)

Common input daily data (air temperature and moisture, precipitation)

Free of scale problem (from soil column to large basin)

initially developed by Prof. Yury Vinogradovinitially developed by Prof. Yury Vinogradov

www.hydrograph-model.ru

Physical ground properties that drive the processes of active Physical ground properties that drive the processes of active layer formationlayer formation

www.hydrograph-model.ru

Moss andlichen

Peat Clay withinclusion of

rocks

Bedrock

Density, kg/m3 500 1720 2610 2610Porosity, % 90 80 55 35Water holding capacity, % 60 20-40 13 7Infiltration coefficient,mm/min

10 0.0005-0.5 0.0005 0.05-1

Heat capacity, J/(kg oC) 1930 1930 840 750Heat conductivity,W/(m oC)

0.8 0.8 1.2 1.5

Wilting point, % 8 6-8 4 2-3

Soil thaw/freeze processes and runoff formationSoil thaw/freeze processes and runoff formationType 1 – peaty soils and surface flowType 1 – peaty soils and surface flow

1 2 3 4 5 6 7 8 9

01.0901.0801.0701.0601.05

P (

mm

)

20

10

0

De

pth

(m

)

0

-0.2

-0.4

-0.6

-0.8

SW

E (

mm

)

100

80

60

40

20

0

T (d

egre

e C) 20

10

0IN

F (

mm

)

2 0

15

10

5

0

Q (

m3

/s)

0.05

0.04

0.03

0.02

0.01

0.00

Flo

w (

mm

)

20

15

10

5

0

observed runoffsimulated runoffsnow water equivalent

infiltration into soilsurface flowobserved soil thaw depthsimulated soil thaw depth

Peaty soil is fully saturated with ice during snow melt. It thaws slowly and surface flow occurs.

moss and lichen

peat

bedrock

clay inclusion of rocks

100

90

80

70

60

50

40

30

20

10

cm

Larch forestSparse forest

Bush tundraBare rocks

Soil thaw/freeze processes and runoff formationSoil thaw/freeze processes and runoff formationType 2 – rocky stratum and subsurface flowType 2 – rocky stratum and subsurface flow

1 2 3 4 5 6 7 8

01.0901.0801.0701.06

P (

mm

)

30

20

10

0

De

pth

(m

)

0.0

-0.5

-1.0

Wa

ter

de

pth

(m

m)

200

150

100

50

0

T (d

egre

e C)

20

15

10

5

0

Ice

co

nte

nt

(mm

) 2 50

200

150

Q (

m3

/s)

0.25

0.20

0.15

0.10

0.05

0.00

observed runoffsimulated runoffsnow water equivalent

liquid water content in soilice content in soilsimulated soil thaw depth

moss and lichen

peat

bedrock

clay inclusion of rocks

100

90

80

70

60

50

40

30

20

10

cm

Larch forestSparse forest

Bush tundraBare rocks

Snowmelt water is re-frozen in soil. Only subsurface flow is formed.

Stages of the soil thawing and spring flow formation (Bantsekina, 2003)

Data of ice content in the rocky stratum don’t exist. According to literature each year in freshet period 40-60 mm ground ice are formed. Modelling results for 1969-1990 show 21-48 mm.

flow dependence on air temperature

Observed and simulated thawing depths in bare rocks, bush tundra and larch forest, 1962

Bush tundra

Bare rocks

Larch forest

Runoff modelling at slope scaleRunoff modelling at slope scaleYuzny Creek,

area 0.27 km2 , sparse forest

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Severny Creek, area 0.33 km2, bush tundra

1 – observed runoff, 2 – simulated runoff, 3 - precipitation

1978: NS = 0.86

1980: NS = 0.74

1 2 301.0901.0801.0701.06

P,

mm

50

0

F,

mm

80

60

40

20

0

14

Kontaktovy Creek, 21.2 km2, 1978, m3/s

Наблюденный Рассчитанный

10.197808.197806.197804.1978

м3/с

8

6

4

2

0

Наблюденный Рассчитанный

10.197808.197806.197804.1978

м3/с

8

6

4

2

0

Morozova Creekarea 0.63 km2,bare rocks

Landscape distribution:Bare rock – 32 %Bush tundra – 29 %Sparse forest – 21 %Larch forest – 18 %

1 – observed runoff, 2 – simulated runoff, 3 - precipitation

Runoff modelling at slope and small scaleRunoff modelling at slope and small scale

1979: NS = 0.79

1978: NS = 0.85

•Hydrograph model proved its capability to successfully describe soil thawing and freezing, water and ice dynamics in rocky stratum in diverse landscapes based on relatively simple algorithms and observable parameters.

•Good agreement between observed and simulated active layer depth and runoff is achieved for small watersheds of the KWBS

•Developed set of model parameters which are systematized according to main landscapes of the Upper Kolyma River basin might be transferred to other basins without specific observations

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Conclusions

Semenova O., Lebedeva L., Vinogradov Yu., 2013 Simulation of subsurface heat and water dynamics, and runoff generation in mountainous permafrost conditions, in the Upper Kolyma River basin, Russia. Hydrogeology Journal vol. 21, iss. 1, 107 – 119. DOI:10.1007/s10040-012-0936-1

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Thank you for attention