River Health and Hydrological Alteration 河流健康和水文因素Dr Chris Gippel

Training Workshop Beijing

2010 November 19

Contents

• Role of hydrology as a river health indicator

• Introduce the Taizi River basin

• Apply a hydrological index

• Develop a new method based on flow needs

• Test the method in the Taizi River basin

Water quality

Climate

Geology

Land use

Ecological processes

Hydraulic habitat

Hydrology GeomorphologyHydrology

Physical

Chemical Biological

Economy

Education

Trade, etc

Ecological river health Social river health

Catchment

management

policy

River

management

policy

Hydrology

Main Issues 主要问题

• Hydrology RESPONDS to catchment and disturbance

• Hydrology DRIVES the ecology

• Is it OK to mix response and driver variables?

• YES

• Hydrology is open to management action to improve health

Choices 选择

• Indicators of 指标 :

– Hydrological alteration

– Hydrological stress

– Hydrological disturbance

– Hydrological deviation

– …….

• Ostensibly 表面上 :

– “ecologically meaningful” “生态意义”

• Warning 警告

– From a different area 从一个不同的区域

– Not linked to ecological assets of interest 没有联系到当地的生态环境

Objectives 目标

• Assess hydrological health of Taizi River

• Try an index of hydrological stress

• Develop a new method sensitive to:

– Local ecological assets

– Local hydrology

– Local flow-ecology knowledge

– Closely linked to flow management options

Taizi River Basin

Finished 1995

Finished 1995

21.68 × 108m3

Finished 1969

7.07 × 108m3

Finished 1972

7.91 × 108m3

Yingkou

Guanyinge

Reservoir

观音阁水库

Tanghe Reservoir

汤河水库

Shenwo Reservoir

参窝水库

Flow data from 1950s

0

500

1,000

1,500

2,000

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Daily d

isch

arg

e (

m3/s

)

Flow exceeded 5 percent of the timeBenxi

0

50

100

150

200

250

300

350

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Daily d

isch

arg

e (

m3/s

)

Median and Interquartile range [exceeded 75 - 25 percent of time]

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Rela

tive IQ

ran

ge

Relative interquartile range [IQ range/median]

0

500

1,000

1,500

2,000

2,500

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Daily d

isch

arg

e (

m3/s

)

Flow exceeded 5 percent of the timeTangmazai

0

200

400

600

800

1,000

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Daily d

isch

arg

e (

m3/s

)

Median and Interquartile range [exceeded 75 - 25 percent of time]

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Rela

tive IQ

ran

ge

Relative interquartile range [IQ range/median]

Flow Stress Indicator

• Mean annual flow

• Seasonal difference

• Seasonal timing

• Low flow magnitude

• High flow magnitude

• Days of river drying up

• Flow duration

• Flow variability

0.59

0.10

0.35

0.18

0.47

0.99

0.85

0.683 0.67

0.75

0.53

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

Hyd

rolo

gic

al c

han

ge In

dex v

alu

eBenxi (pre-Guanyinge V. post-Guanyinge)

0.23

0.13

0.60

0.00

0.77

0.60

0.87

0.980

0.73

0.550.59

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

Hyd

rolo

gic

al ch

an

ge In

dex v

alu

e

Liaoyang (pre-Tanghe/Shenwo V. post-Tanghe/Shenwo)

0.06 0.09

0.32

0.00

0.68

0.770.84

0.912

0.54

0.44

0.54

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

Hyd

rolo

gic

al c

han

ge In

dex v

alu

e

Liaoyang (pre-Tanghe/Shenwo V. post-Guanyinge)

0.34

0.13

0.67

0.03

0.740.79

0.920.991

0.78

0.62 0.64

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

Hyd

rolo

gic

al ch

an

ge In

dex v

alu

e

Xiaolinzi (pre-Tanghe/Shenwo V. post-Tanghe/Shenwo)

0.10 0.03

0.46

0.34

0.66

0.860.90

0.937

0.58

0.48

0.65

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

Hyd

rolo

gic

al ch

an

ge In

dex v

alu

e

Xiaolinzi (pre-Tanghe/Shenwo V. post-Guanyinge)

Can measure differences in periods

Does not work on a single year

Rapid eco-hydraulic environmental flows

assessment

• We need to know about the eco-hydraulics

• What specific flows will satisfy the needs of the identified

ecological assets?

• Ecology responds to

– Velocity

– Depth

– Width

– Shear stress

hydraulics

Flow components

King et al (2008) Building Block Method

Baseflows

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Pre-Guanyinge Dam 3.7 3.8 4.0 8.7 20.8 17.3 23.5 38.6 26.0 15.1 11.1 5.6

Post-Guanyinge Dam 14.2 15.1 16.1 19.1 23.0 27.5 28.4 16.6 12.1 18.7 16.9 13.9

0

5

10

15

20

25

30

35

40

45

Med

ian

basefl

ow

daily d

isch

arg

e (

m3/s

) Benxi

Baseflows

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Pre-Tang/Shenwo 9.3 8.6 10.8 19.4 20.0 18.6 17.1 65.3 45.3 33.2 31.0 16.1

Post-Tang/Shenwo 10.3 10.0 13.1 11.3 16.1 59.3 35.1 32.7 25.6 18.0 17.1 11.6

Post-Guanyinge 12.6 13.3 12.8 13.6 42.8 18.8 25.8 26.6 23.5 17.7 16.4 13.6

0

10

20

30

40

50

60

70M

ed

ian

basefl

ow

daily d

isch

arg

e (

m3/s

) Tangmazai

Cease to flow

0

50

100

150

200

250

300

350

Days o

f cease t

o f

low

LiaoyangCumulative annual days of cease to f low

Annual peak cease to f low spell duration

Tangehe Shenwo Guanyinge

Flow events

DurationFrequency

Hydraulic information

• No surveys

• Need to find whatever is available

• Gauging stations have useful information

• Can derive as a function of discharge:

– Velocity

– Depth

– Width

– Shear stress

• These variables are used to determine the discharge that will

satisfy the hydraulically defined ecological and geomorphological

objectives

0 500

metresBenxi

100

105

110

115

120

0 50 100 150 200 250 300 350E

levati

on

(m

AS

L)

Chainage (m)

Benxi

18/06/2001 24/05/1978

Weir

0 2

km

Liaoyang

15

20

25

30

35

-500 0 500 1000 1500 2000 2500 3000 3500 4000E

levati

on

(m

AS

L)

Chainage (m)

Liaoyang

8/11/2001 19/07/1978

15

20

25

30

35

-500 0 500 1000 1500 2000 2500 3000 3500 4000E

levati

on

(m

AS

L)

Chainage (m)

Liaoyang

8/11/2001 19/07/1978

Weir

0 500

metres Xiaolinzi

5

7

9

11

13

15

17

19

-20002004006008001000

Ele

vati

on

(m

AS

L)

Chainage (m)

Xiaolinzi

13/09/2001 2/05/1978

0

2

4

6

8

10

12

14

16

0 200 400 600 800 1000 1200

Ele

vati

on

(m

AS

L)

Chainage (m)

Tangmazai

2/09/2001 3/06/1978

Geomorphological objectives

ID Objective Flow

component

Hydraulic

criteria

Frequency/

Duration

Timing Reach

1a Maintain

channel form

Bankfull/overba

nk

Morphologically

defined levels

Every 2 years Anytime All

1b Flush fine

sediment from

surface of bed

Low flow pulse Critical shear

stress to

mobilize silts

and >30% of

bed materiala

1 – 2/year,

0.5 – 1 day

Mar-May All

1c Mobilize coarse

bed sediments

High flow

pulse/bankfull

Critical shear

stress to

mobilize >70%

of bed material

Annual Anytime All

1d Maintain key in-

channel

physical habitat

forms

High flow

pulse/bankfull

Morphologically

defined level

Annual Anytime All

Fish objectives

ID Objective

3a Maintain sufficient water depth in pools for large bodied fish

3b Maintain sufficient depth in riffles and in depositional habitats out of the main

flow

3c Localised movement of resident fish

3d Maintenance of benthic habitats and hyporheic flushing

3e Provide habitat during the high flow period, to induce spawning and to maintain

transport of semi-buoyant eggs within the water column

3f Stimulate spawning migration and maintain longitudinal connectivity

3g Provide access to floodplain habitat

Invertebrate objectives

ID Objective

4a Maintain sufficient depth in riffles

4b Maintenance of benthic habitats and hyporheic flushing

4c Maintenance of half of the width of the bed wet for habitat

4d Provide habitat during the high flow period, make some pool along the

river full of water

4e Provide access to floodplain habitat

Waterbird objectives

ID Objective

5a Maintenance of half of the width of the bed wet for habitat

5b Provide habitat during the high flow period, make some pool along the

river full of water, provide the habitat for the bird to nest

1953

1954

1955

1956

1957

1958

1959

1960

1961

1962

1963

1964

1965

1966

1967

1968

Overbank

Bankfull

High flow pulse

Low flow pulse

High flow

Low flow 1

Low flow 2

1969

1970

1971

1972

1973

1974

1975

1976

1977

1978

1979

1980

1981

1982

1983

1984

1985

1986

1987

1988

1989

1990

1991

1992

1993

1994

Overbank

Bankfull

High flow pulse

Low flow pulse

High flow

Low flow 1

Low flow 2

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

Overbank

Bankfull

High flow pulse

Low flow pulse

High flow

Low flow 1

Low flow 2

Before Tangehe and Shenwo

After Guanyinge

After Tangehe and Shenwo

Preliminary result only

Conclusion

• It is possible to develop indicators sensitive to the local hydrology

and ecology

• Most of the data and knowledge are already there