23/4/19 1

Macro-scale hydrological models and the application

Fengge Su

Department of Civil and Environmental Engineering,University of Washington

Seattle, WA 98195fgsu@hydro.washington.edu

Zhenchun Hao

Hohai University, China

23/4/19 2

Contents

1. Macro-scale hydrological model

2. Runoff improvement in the land su

rface model AVIM (Atmosphere V

egetation Interaction Model)3. Streamflow simulations for major r

iver basins in China by the use of VIC model

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the Xin’anjiang Model is used as the basic model to develop a grid-based distributed hydrological model.

The Huaihe River Basin with the area of 270,000 km2 is selected as the research area. A 30km×30km squared-grid is adopted There are totally 307 grid cells.

1. Macro-scale Hydrological Model1. Macro-scale Hydrological Model

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Huaihe River Basin with 270,000km2 of the area

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14

14 14 15 15

17 17 17 17 17 17 14 14 14 15

17 17 17 17 17 17 14 14 14 14 15 17 17

17 17 17 17 17 17 17 17 14 14 15 15 17 17

17 17 17 17 17 17 17 17 17 17 17 15 17 17

4 4 4 5 5 5 17 17 17 17 17 17 17 17 17 17 17 17 17 17 17

3 4 4 4 4 4 5 5 5 5 13 13 13 17 17 17 17 17 17 17 17 17 17 17 17

3 3 3 4 4 4 4 5 5 5 5 13 13 13 16 16 17 17 17 17 17 17 17 17 17 17

3 3 3 3 3 3 4 4 8 8 8 5 5 13 13 16 16 16 16 16 17 17 17 17 17 17 17 17

3 3 3 3 3 3 3 4 4 8 8 8 11 11 13 13 16 16 16 16 16 17 17 17 17 17 17 17

3 3 2 2 2 8 8 8 8 11 11 11 16 13 16 16 16 16 16 17 17 17 17 17 17 17

3 2 2 2 2 8 8 8 8 11 11 11 16 16 16 16 16 16 17 17 17 17 17 17 17

2 2 2 2 2 2 10 10 10 10 11 11 11 16 16 16 16 17 17 17 17 17 17 17 17 17 17

1 1 1 1 9 9 9 10 10 10 10 11 11 11 12 12 16 17 17 17 17 17 17 17 17 17 17

1 1 1 1 1 9 9 9 10 10 10 11 11 12 12 12

1 1 1 1 9 9 6 6 10 10 11 11 12

1 1 1 9 9 6 6 10 10 11

1 9 9 6 6 7 7

6 7 7 7

7 7

17 sub-areas with 307 grid cells

息县

班台

漯河

周口 亳县

蒋集

横排头

阜阳

王家坝鲁台子

蚌埠明光

固镇 +宿县

沂河沭河

洪泽湖

平原区

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Xi Xian Station (1953--1985) (area: 10,190km 2)

0

200

400

600

800

1000

1200

1400

1600

1800

1 23

45

67

89

111

133

155

177

199

221

243

265

287

309

331

353

375

time (month)

Dis

charg

e (

m3/s

)

Obe.

Cal.

Xi Xian Station (1953--1985)

0

100

200

300

400

500

600

700

800

900

1000

1 3 5 7 9 11

13

15

17

19

21

23

25

27

29

31

33

year

ru

no

ff (

mm

)

Obs.

Cal.

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Bengbu Station (1953--1985) (area: 121,330km2)

0

2000

4000

6000

8000

10000

1 29

57

85

113

141

169

197

225

253

281

309

337

365

393

time (month)

dis

charge (

m3/s

)

Obs.

Cal.

Bengbu Station (1953--1985) Area = 121,330km2

0

100

200

300

400

500

600

1 3 5 7 9 11

13

15

17

19

21

23

25

27

29

31

33

year

runoff (

mm

)

Obs.

Cal.

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Hong Ze Hu (1953--1985) (AREA: 157,420KM2)

0

500

1000

1500

2000

2500

30001 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33

TIME (YEAR)

DISC

HARG

E (M

3/S

)

Cal. Discharge (m3/s)

Obs. Discharge (m3/s)

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2. Improvement of runoff parameterization in AVIM

Brief description to the land surface scheme

AVIM(Atmosphere-Vegetation Interaction

model)

Improvement of runoff parameterization in

AVIM

Hydrological simulations over Xilinhe draina

ge basin

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• Runoff plays an important role in land surface w

ater budgets.

• The treatment of hydrological processes in AVI

M is too rough, and runoff is simply an excess of

precipitation over evapotranspiration.

• The purpose of this study is to improve the para

meterization of runoff generation in AVIM.

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Brief description to AVIM

• Canopy in AVIM is considered as a uniform layer covering the soil with a shielding factor. • The soil column is divided into three layers: upper layer(d1=0.1m); lower layer(d2=0.9m); deep layer(d3=d2).

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Evap

otransp

iration

Wet canopy evaporation

Dry canopy transpiration

Bare soil surface evaporation

baccsaccw rqTqLAIE /))((

)/()))(()1( fbaccsacctr rrqTqE

)/())(( 1 sdacsag rrqTqE

Evapotranspiration in land surface scheme AVIM

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Diffusion type multi-layer scheme

The soil model

s

u

s

SwK

z

wwD

zt

w

])(

)([

3212

1211

1212

11

1

)(

)(2

)(1

)1(1

b

s

s

trgw

ccs

wd

K

ddd

wwD

rofEEDPdt

dw

3223

2

3212

2

322

2323

212

1212

2

22

)(

)(2

)(

)(2

b

s

sb

s

s

ws

tr

wd

Kw

d

K

ddd

wwD

ddd

wwD

d

E

t

dw

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Runoff

The parameterization of runoff in AVIM is verysimple. It is assumed that the rainfall Pg infiltratesthe upper layer of soil. As soil gets saturated, the surface runoff (rof) will occur and is equal to the excess of rainfall over evaporation.

else

wEProf

gg

,0

1, 1

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Wmm

Wm P R

Wm

W0

0 1

f / F

a Distribution of soi l water b Schematic of runoff generation

storage capaci ti es

The treatment of the heterogeneity in the Xinanjiang model

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Land surfaceschemeAVIM

Runoffgeneration

model

Routingmodel

Sensibleheat

Latentheat

RofRof

PgPg

ww11, w, w22Discharge QDischarge Q

RofRof

Improvement of runoff parameterization in AVIM

Improvement of runoff parameterization in AVIM

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Wm

W

0 f/F 1

A

Pgrof

WM

W0

Runoff generation model

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The calculation of runoff may then be expressed in the form ：

Then W0 and WM can be expressed as：

WMBAPWMWP

WMBAPWAPWMWMWProf

gg

gB

mmgg

)1(,

)1(,/)(1 1

).( 21 ddWM s

22110 .... dwdwW ss

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Hydrological simulations over Xilinhe drainage basin

Hydrological simulations over Xilinhe drainage basin

• Basin description

• Data

• Experimental design

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Basin description

• The Xilinhe drainage basin is located in the east of Inner Mongolia plateau of China, and belongs to arid and semi-arid climate.

• Mean annual precipitation is about 350mm; mean annual runoff depth is only5.7mm; runoff coefficient is 0.016.

• Most of the runoff is generated in spring by snowmelt, and 66.5% of the runoff occurs in Apr. and May.

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Data

• The hydrological simulations area is upstream of Xilinha

ote station, which is located at 116°10′E , 48°49′N, with t

he drainage area of 3852 square kilometers.

• The data for calibration and validation comprises daily s

treamflow from Xilinhaote gauging station and daily atm

ospheric forcing data from the year 1991 to 1994, includi

ng observed radiation, precipitation, air temperature, hu

midity, wind, and cloud cover.

• The improved AVIM model is run at an hourly time step.

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Experimental design

Model is run in the three situations :

• Running the original version of the AVIM model;

• Running the improved AVIM model, using the energy-balance snow model;

• Running the improved AVIM model, using a degree-day snow accumulation and ablation model.

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The original AVIM model results indicate that all the calculated runoff is zero. That is because, under the assumption of neglecting horizontal heterogeneities, the runoff will not occur until the entire upper layer is saturated, but the saturation is rarely reached in Xilinhe basin with the even precipitation of 350mm/y.

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0

2

4

6

8

10

12

14

1 366 731 1096

Time（day）

Dis

char

ge（

m3/

s）

0102030405060708090100

Pre

cipi

tatio

n（

mm

）

Precipitation Observed Simulated

Daily observed and simulated streamflow at gauging station Xilinhaote for the period 1991-1994 (by the improved AVIM model with the energy-balance snow model)

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0

2

4

6

8

10

12

14

1 366 731 1096

Time（day)

Disc

harg

e（

m3/

s）

0

20

40

60

80

100

Prec

ipita

tion(

mm

)

Precipitation Observed Simulated

Daily observed and simulated streamflow at gauging station Xilinhaote for the period 1991-1994 (by the improved AVIM model with the day-degree snow model)

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• The Xilinhe drainage basin is located in arid and

semi-arid zone. Annual runoff depth is only 5.7

mm,and runoff coefficient is about 0.016. It is a

challenge to select the basin to simulate the hydr

ologic processes.

• The simulated rainfall-runoff processes are acce

ptable and encouraging. It indicates that the mo

dification of runoff generation scheme in AVIM

is reasonable and effective.

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The difference of calculated upper soil water content(mm) between the original AVIM (no runoff) and the improved AVIM model (having runoff)

- 2. 5- 2

- 1. 5- 1

- 0. 50

0. 51

1. 5Ab

solu

te d

iffer

ence

(mm)

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- 40

- 30

- 20

- 10

0

10

20

30

40Ab

solu

te d

iffer

ence

w/m

（2 ）

The difference of calculated latent heat(w/m2) between the original AVIM (no runoff) and the improved AVIM model (having runoff)

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- 20

- 15

- 10

- 5

0

5

10

15

20

25

Abs

olut

e di

ffer

ence

(w/

m2)

The difference of calculated sensible heat(w/m2) between the original AVIM (no runoff) and the improved AVIM model (having runoff)

23/4/19 30

Conclusion and discussion

• The runoff generation scheme in the original AVIM was im

proved.

• The model was used to simulate daily hydrographs for the X

ilinhe drainage basin, and there was an acceptable agreeme

nt between the observed and simulated streamflow in rainfa

ll-runoff processes at the Xilinhaote station.

• Though, streamflow simulation is not the main task in land

surface scheme, it can act as a diagnostic tool for verificatio

n of water balance model in the scheme.