i swat qual2k c r v · integration of swat and qual2k for water quality modeling in a datascarce...

INTEGRATION OF SWAT AND QUAL2K FORWATER QUALITY MODELING IN A DATA SCARCEBASIN: A CASE STUDY OF CAU RIVER BASIN OFVIETNAM

by Ha Ngoc HienInstitute of Environmental Technology (IET)Vietnam Academy of Science and Technology (VAST)

2017 International SWAT Conference Warsaw, 28-30 June, 2017

STUDY AREAWATERSHED DATA PROBLEMWQ MODEL CONSTRUCTION

(SWAT & QUAL2K)RESULTSRECOMENDATIONS

OUTLINE

2017 International SWAT Conference in Warsaw, 28-30 June, 2017

Cau river watershed

STUDY AREA

China

Vietnam

Lao

The Cau River is in North-East part of Vietnam. CauRiver mainstream is 288 km long. The river network in the Cau River basin is relatively dense with tributaries evenly distributed along the mainstream. The catchment’s area is 6030km2


STUDY AREA


Water quality problem

0.00

2.00

4.00

6.00

8.00

10.00

12.00

Cầu

Phà

Thác

Giề

ngN

à Bả

nCh

ợ M

ớiVă

n Lă

ngH

òa B

ình

Sơn

Cẩm

Hoà

ng V

ăn T

hụCầ

u G

ia B

ảyC

ầu T

rà V

ườn

Cầu

Mây

Tân

Phú

Cầu

Vát

Hươ

ng L

âmPh

úc L

ộc P

hươn

gVạ

n Ph

úcH

òa Lo

ngCầ

u Th

ị Cầu

Thốn

g H

ạH

iền

Lươn

gYê

n Dũ

ngPh

ả Lạ

i

BOD

(mg/

L)

Dry

Rainy


2010-2015

STUDY AREA

VN standard A2

A1

Water quality problem

00.10.20.30.40.50.60.70.80.9

1

Cầu

Phà

Thác

Giề

ngNà

Bản

Chợ

Mới

Văn

Lăng

Hòa B

ình

Sơn

Cẩm

Hoàn

g Vă

n Th

ụCầ

u Gi

a Bảy

Cầu

Trà

Vườn

Cầu

Mây

Tân

Phú

Cầu

Vát

Hươn

g Lâ

mPh

úc L

ộc …

Vạn

Phúc

Hòa L

ong

Cầu

Thị C

ầuTh

ống H

ạHi

ền L

ương

Yên

Dũng

Phả L

ại

NH4+

(mg/

L)

Dry

Rainy 2010-2015

0

0.05

0.1

0.15

0.2

0.25

Cầu

Phà

Thác

Giề

ngN

à Bả

nCh

ợ M

ớiVă

n Lă

ngH

òa B

ình

Sơn

Cẩm

Hoà

ng V

ăn T

hụCầ

u G

ia B

ảyC

ầu T

rà V

ườn

Cầu

Mây

Tân

Phú

Cầu

Vát

Hươ

ng L

âmPh

úc L

ộc P

hươn

gVạ

n Ph

úcH

òa Lo

ngCầ

u Th

ị Cầu

Thốn

g H

ạH

iền

Lươn

gYê

n Dũ

ngPh

ả Lạ

i

PO4

(mg/

L)

Dry

Rainy 2010-2015

STUDY AREA


VN standard A2

A1

Hydro-meteorology stations+ 01 Discharge station, 05

water level stations+ 06 Meteo stations + 42 Rain stations

WATERSHED DATA


Pollution source information + Point sources: about 500, spatial locations about 200 (Industry, Hospital, Trade, …)+ Non-point sources: domestic, livestock, agriculture, forest,...) calculated based Provincial Statistical Books for districts

WATERSHED DATA


Pollution load of sub-watershed (based on monitoring data and rapid estimation method)


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10000.00

15000.00

20000.00

25000.00

30000.00

11121314151617181920212223242526272829303132333435363738394041424344464748495051525455565758

BOD

(kg/

day)

Sub-watershed

Industry

Landuse

Service

Livestock

Domestic

WATERSHED DATA


River Water qualityRegular monitoring data from 2010: 42 stations, 5 times/year (BOD5, COD, EC, NO3, NH4, T, pH, PO4, TKN, T-P, TSS) in March, May, July, Sept, Nov)

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350.00

t1 t2 t3 t4 t5 t6 t7 t8 t9 t10 t11 t12

Mon

thly

ave

rage

Q (m

3/s)

Month

Discharge at Gia Bay station

2015

2014

2013

2012

2011

2010

2009

2008

2007

WATERSHED DATA


Data gaps:+ River discharge: only one station, not measured during WQ monitoring campaign+ Poor spatial data for pollution sources (houses, livestock, manufacture factories, service establishments, …)+ Poor GIS data for landuse, soil type …

WATERSHED DATA


Purpose: Construction of WQ for Cau river watershed for TDML implementation of BOD, N and P

SWAT: Poor (modest) spatial data QUAL2K: Missing discharge data in mainstream and

tributaries Proposed solution: Using calibrated SWAT for hydrology

(with observed data at Gia Bay station) for river (headwater) discharge inputs for QUAL2K; using WQ monitoring data (at mainstream and tributaries) for boundary conditions of QUAL2K.

WQ MODEL CONSTRUCTION


Target area: 3 provinces (Thai Nguyen, Bac Ninh, Bac Giang), mainstream of Cau river (yelowarea)

SWAT: constructed for whole watershed to provide river discharges, lateral flows,…

QUAL2K: river network consist of mainstream and 7 tributaries

Headwater 0

Trib. 1

Trib. 2Trib. 3

Trib. 4Trib. 5

Trib. 6

Trib. 7



SWAT model- DEM 1-arc (USGS)- Landuse: 2007 (by IET)- Soil type (FAO)- 5 Meteo stations- 42 Rain stations- Calibration period 2000-2005- Validation period 2006-2014



SWAT hydrological results

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300.00

350.00

Jan-

13

Mar

-13

May

-13

Jul-1

3

Sep-

13

Nov

-13

Jan-

14

Mar

-14

May

-14

Jul-1

4

Sep-

14

Nov

-14

Jan-

15

Mar

-15

May

-15

Jul-1

5

Sep-

15

Nov

-15

Q (m

3/s)

Observation

Simulation



QUAL2K modelSimulation period:

- 11/03/2014 to 19/03/2014 (dry season)- 03/11/2014 to 09/11/2014 (end of rainy season)- Input data: daily average (discharge, concentration, …) of the period.

Headwater 0

Trib. 1

Trib. 2Trib. 3

Trib. 4Trib. 5

Trib. 6

Trib. 7



QUAL2K model Special treatments:

- Non-point pollution load of sub-watershed bordering to the mainstream discharge uniformly to the river- Pollution load of others sub-watershed discharges to the outlet of river tributaries - Reaching ratio coefficient varies 0.1 -0.5 depending on watershed(Discharge load=reaching ratio coeff. x generated load)

Headwater 0

Trib. 1

Trib. 2Trib. 3

Trib. 4Trib. 5

Trib. 6

Trib. 7



RESULTS Dry season: 11/03/2014 to 19/03/2014

0.00

5.00

10.00

15.00

20.00

25.00

0.0050.00100.00150.00200.00250.00

T (o

C)

Distance (km)

Water temperature

Simulation

Observed

0.001.002.003.004.005.006.007.008.009.00

0.0050.00100.00150.00200.00250.00

DO

(mg/

L)

Distance (km)

DO concentration

Simulation

Observed

Month Average 2010-2015



0.00

2.00

4.00

6.00

8.00

10.00

12.00

0.0050.00100.00150.00200.00250.00

BOD

(mg/

L)

Distance (km)

BOD concentration

Simulation

Observed


0.00

5.00

10.00

15.00

20.00

25.00

0.0050.00100.00150.00200.00250.00

COD

(mg/

L)

Distance (km)

COD concentration

Simulation

Observed



Polluted channel with pump station


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1000.00

2000.00

3000.00

4000.00

5000.00

6000.00

0.0050.00100.00150.00200.00250.00

TN (m

g/L)

Distance (km)

TN concentration

Simulation

Observed


0.0050.00

100.00150.00200.00250.00300.00350.00400.00

0.0050.00100.00150.00200.00250.00

TP (m

g/L)

Distance (km)

TP concentration

Simulation

Observed



RESULTS End of Rainy season: 03/11/2014 to 09/11/2014

0.00

5.00

10.00

15.00

20.00

25.00

30.00

0.0050.00100.00150.00200.00250.00

T (o

C)

Distance (km)

Water temperature

Simulation

Observed

0.001.002.003.004.005.006.007.008.009.00

0.0050.00100.00150.00200.00250.00

DO

(mg/

L)

Distance (km)

DO concentration

Simulation

Observed


0.00

2.00

4.00

6.00

8.00

10.00

12.00

0.0050.00100.00150.00200.00250.00

BOD

(mg/

L)

Distance (km)

BOD concentration

Simulation

Observed


0.00

5.00

10.00

15.00

20.00

25.00

30.00

0.0050.00100.00150.00200.00250.00

COD

(mg/

L)

Distance (km)

COD concentration

Simulation

Observed



RESULTS End of Rainy season: 03/11/2014 to 09/11/2014

0.00

500.00

1000.00

1500.00

2000.00

2500.00

3000.00

3500.00

0.0050.00100.00150.00200.00250.00

TN (m

g/L)

Distance (km)

TN concentration

Simulation

Observed


0.00

100.00

200.00

300.00

400.00

500.00

600.00

0.0050.00100.00150.00200.00250.00

TP (m

g/L)

Distance (km)

TP concentration

Simulation

Observed



Integration of SWAT and QUAL2K is helpful when spatial data (for landuse, economic activities,…) are limited.

Combination of WQ monitoring data and pollution load estimation based on rapid estimation method can improve WQ inputs for QUAL2K.

The obtained calibration and validation results are satisfactory.

Some inputs data may require some revisit, especially the reaching ratio coefficients for sub-watersheds and time operation of pumping station.

CONCLUSIONS


The model can be used for TMDL implementation of the watershed.

The model can be used for assessing pollution contribution ratio of each sub-watershed of the basin in order to partition the TMDL for sub-watersheds for future environmental planning.


CONCLUSIONS

THANK YOU FOR YOUR ATTENTION

ANY QUESTIONS?

2017 International SWAT Conference Warsaw, 28-30 June, 2017

i swat qual2k c r v · integration of swat and qual2k for water quality modeling in a datascarce...

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