English

1. ACEDP Project: Environmental
Flows in The Lower Yellow River
Jiang Xiaohui
YRCC
Workshop, Beijing
2012 Feb 23

2. Contents
Background
General environmental flow assessment
methodology
Brief description of work
Experience and recommendations

3. Background
Study Area
Survey
N Site three Lijin
Lijin
Zibo
Luokou Jinan
Liaocheng
,
Tai an
Aishan
Sunkou
Dongping
Dongping Lake
Dam
Xiaolangdi Gaocun
Sanmenxia River
Qinyang Kaifeng
Huayuankou
Hydrological station
Luoyang
Sanmenxia Zhengzhou City
Lake

4. Lower Yellow River Flow Issues
• “Mother River”
– High water demand
– High degree of regulation
• Climate change and human activities
– Flows reducing over past 50 years, cease to flow sometimes
from 1970s to 1990s
• Sediemnt
– A very high sediment load to the lower river,flood
• Yellow River Delta – a dynamic estuarine Ramsar wetland
– Depends on sediment supply for growth
• Riverine wetlands
– Mostly disconnected due to flood dyke construction
• Aquatic ecosystem
– lost diversity

5. In China there is a strong awareness of the need and importance of
environmental flows. Environmental flow assessments have been undertaken in
a number of rivers,

6. General environmental flow assessment
methodology
Environmental flow methods used in China:
• Hydrological--Tennant
• Hydraulic rating-Wetted perimeter method,
R2CROSS(Focus on one or a few key species)
• Habitat simulation-IFIM (focus on one or a few key species)
• Holistic
• --Consider the entire ecosystem
• --Not constrained by the analytical tools
• --Consider other water user
• --expensive

7. General environmental flow assessment

8. Brief description of work
Select sites and reaches

9. Field trip 、 sample 、 workshop and literature search

10. Reaches River channel 4
3
Delta
2 wetlands
Dongping
Lake
1
Zhengzhou
Mengjin Kaifeng
wetlands
wetlands wetlands

11. Identify ecological assets

12. River asset
• A river asset is any attribute of the natural ecosystem of
value to society. The value could be ecological, social
and/or economic.
• River assets include species, biological communities,
habitats and ecosystems of conservation importance
(collectively referred to as “conservation assets”).

13. Assets in the low Yellow River
• Fish species, e.g. Yellow River Carp
• Wetland vegetation
• Birds
• Spawning process
• Sediment transport
• Water quality
• Geomorphology

14. Develop conceptual models linking asset health and flow components
Geomorphology, plants, fish, macroinvertebrates, water quality, birds…

15. Flow regime
Low flows Flow pulses High flows Floods
Sediments from
Maintain depth upstream and
of water in Food resources
catchments
refuge pools increase. and DO
decreases
Maintain Stimulate Maintain larval Maintain backwater refuges
adult fish spawning and and food resources for fish.
population juvenile habitat in Fish mortality increases.
river channel
Figure. The links between individual flow components and flow requirements for carp

16. Table. Flow components and hydraulic criteria relevant to Yellow River Carp requirements.
D = depth, V = velocity
Objective Flow Hydraulic criteria Timing
component
Maintain sufficient water Low flow Max D > 1.5 m Nov-Mar,
depth in pools for large V: 0.1-0.8 ms-1 April-June
bodied fish
Stimulate spawning Flow pulse D: 1-2 m at peak of flow April - June
pulse.
Inundated beach area, and
increase back water
V<0.3 ms-1
Provide new habitat and High flow Average D > 0.7 m; July-October
feeding opportunities for V: 0.3 ms-1-1ms-1
fish
Provide new habitat and Flood Average D > 0.8 m; July-October
feeding opportunities for V: 0.5 ms-1-1.2ms-1
fish, but increased
sediment and low DO may
increase mortality

17. No. Flow component Hydraulic/hydrologic criteria
F1 Cease-to-flow; Low flow Q ≥ YRCC warning standards of low flow emergency; maintain area‡
≥ critical depth* at pool crossings (specified each month)
Fish F2 Low flow Maintain area‡ ≥ critical depth* with V ≤ 2.0 m/s1,2
F3 High flow, high flow recession Maintain longitudinal connectivity and area‡ ≥ critical depth* over
barriers (shallow areas)
F4 Low flow Maintain area‡ with depth ≥ critical depth* in pools
F5 High flow pulse Achieve area‡ with depth ≥ critical depth* over barriers (shallow
areas)
F6 High flow Maintain area‡ with D = 0.5 – 1.0 m1,2 and V ≤ 1.4 m/s1,2
F7 High flow Maintain area‡ with velocity 1.0 – 2.0 m/s1
F8 High flow pulse Maintenance of appropriate† salinity gradient in estuary
F9 Low flow and high flow Maintain area‡ of D ≥ 1.5 m1,2 and V ≤ 1.0 m/s1,2
F10 Low and high flow pulses Achieve sufficient depth* to replenish/maintain water in river
associated wetlands and backwaters
F11 Low flow and high flows Maintain adequate cross-sectional area/discharge* to transport
nutrients required to sustain primary productivity
F12 Bankfull 2,600 - 4,000 m3/s - see Geomorphologic objective G1
F13 Bankfull 2,600 - 4,000 m3/s - see Geomorphologic objective G2
F14 High flow See Vegetation objective V1
F15 High flow and low flow See Vegetation objective V7
F16 Low flow Maintain mean pool velocity ≥ 0.01 m/s
F17 High flow and low flow Sufficient discharge* to maintain morphology in and around the
estuary mouth
F18 Bankfull 2,600 - 4,000 m3/s - see Geomorphologic objectives G3 and G4

18. Plants
No. Objective Flow component Hydraulic/hydrologic criteria
V1 Maintain submerged aquatic High flow Inundation to ≤ 1 m
vegetation (e.g. Vallisneria,
Potomageton and Myriophyllum
spp.)
V2 Maintain meadow vegetation High flow Inundation to ≤ 0.3 m
V3 Maintain Tamarix/Salix shrubland High flow, low flow and low 100% of time shallow groundwater; Jul – Sep
flow pulse waterlogging; inundation by summer flow
pulse events ≤ 30 days; soil salinity 10 –
30 psu
V4 Maintain Tamarix/Salix woodland High flow, low flow and low 100% of time shallow groundwater (at 1.5 –
flow pulse 3.0 m); inundation by summer flow pulse
events ≤ 30 days; soil salinity 10 – 30 psu
V5 Maintain sand flats High flow and low flow 100% of time shallow groundwater (at
≤ 1.8 m); soil salinity ≥ 30 psu
V6 Maintain Suaeda salsa High flow pulse Inundate once per year for ≤ 30 days or 30 to
180 days of varying depth from -0.1 to
+0.1 m; 100% of time shallow groundwater
(at 1.8 m); soil salinity 5 – 30 psu
V7 Maintain Phragmites australis High flow and low flow 100% of time waterlogging; varying
grassland inundation 0 – 0.5 m deep (1.5 m max.; 0.3 m
mean) in summer

19. Birds
No. Objective Flow component Hydrologic/hydraulic
criteria
B1 Foraging Low flows Expose Carex
B2 Foraging Low flows Shallow water (<0.3 m)
over submerged or
emergent aquatic plant
community with mud or
sand base
B3 Foraging Low flows Expose mudflats
B4 Wintering area Low flows Maintain ice free water
bodies*
B5 Food supply and breeding High flows Inundate areas of
submerged macrophytes
(Vallisneria, Phragmites,
Typha, Carex, Tamarisk)
B6 Foraging High flow recession Gradually receding water
levels from Bankfull peak
B7 Mudflat foraging habitat Bankfull An annual event that
creation supplies enough sediment
load to at least maintain
delta area
B8 Summer-autumn habitat Bankfull An annual event to
area inundate backwaters and
wetlands

20. Geomorphology
Geomorphologic-based objectives and flow requirements.
No. Objective Flow Hydrologic criteria Mean annual Inter-annual Timing Reach Reference
component frequency/duration frequency
G1 Scour and deposition processes Bankfull 2,600 - 4,000 m3/s ≥ 1 per year / ≥ 1 day* ≥4 in 5 years Jun – Reach 1 Richards et al.
to maintain dynamic and diverse duration Sep (2002)
habitats in the channel and
connected floodplains
3
G2 Maintain channel capacity at Bankfull 2,600 - 4,000 m /s ≥ 1 per year / ~10 – 30 ≥4 in 5 years Jun – All Liu et al. (2006)
3
4,000 m /s days duration; Sep reaches
rates of rise and fall within
natural range
8
G3 Seaward progradation of the Bankfull Sediment load >3.45 × 10 ≥ 1 per year ≥4 in 5 years Jun – Reach 4 Wang K et al.
delta tonnes at Lijin; event mean Sep (2007); Wang et
sediment concentration al. (2010)
3
≥ 35 kg/m
G4 Flow into delta wetland Bankfull >3,000 m3/s to allow ≥ 1 per year / ≥ 10 days* ≥4 in 5 years Jun – Reach 4 Jiang Xiaohui
channels to maintain channel gravity flow days duration (or as Sep (YRCC, pers.
form (and also provide required) comm., November
freshwater and nutrients to the 2010)
delta wetlands)
* Based on expert opinion; refinement of this criterion will require investigation.

21. Set objectives for each asset and important process
•Ecological management objectives (what level of river health is desired?
taking account of constraints, and other uses of the river)
•Hydraulic/hydrologic objectives to achieve the ecological objectives

22. Set objectives
• 18 Fish objectives
• 6 Water quality objective
• 8 Bird objective
• 8 Macroinvertebrate objectives
• 4 Geomomorphic objectives
• These can be rationalised to a smaller group for evaluation
– 13 objectives

23. Key Obj. met Objectives description Flow component
obj.
A F1; M1 Prevent habitat loss through drying of shallow areas Cease to flow
B B1; B2; B3 Expose Carex and mudflats; shallow water over submerged aquatics Low flow
C F2 Maintain shallow habitats with moderate-high velocity for shallow water dwelling species Low flow
and spawners during low flow periods
D WQ1, WQ2, WQ3, Dilute contaminants to Grade III standard Low flow and high flow
WQ4
E V3; V4 Maintain Tamarix/Salix shrubland and woodland Low flow and high flow
F M2; M5; F3; F4; F11; Maintain reasonable area of habitat for most of the time for longitudinal connectivity, Low flow and high flow
F16 survival of large-bodied fish, maintenance of primary productivity in the estuary; and
maintenance of DO levels in deep pools
G F6; F7; F9 Provide suitable habitats for spawning, allow access of large bodied fish to backwater High flow
and wetland habitats; maintain downstream transport of semi-buoyant eggs within the
water column; and sufficient depth in pools for large-bodied fish
H V1; B5; M3; M4; F14 Maintain submerged aquatic vegetation High flow
I V2 Maintain meadow vegetation High flow
J M6; F8 Maintain favourable salinity at estuary and mouth for rearing of Chinese shrimp; and High flow
maintain salinity gradient for anadromous fish spawning migration
K V3; V4; F10 Maintain Tamarix/Salix shrubland and woodland; and replenish/maintain water in river Low flow pulse
associated wetlands and backwaters
L F5; F10 Stimulate spawning, migration (anadromy and potadromy) and maintain habitat High flow pulse
continuity between near-shore/estuarine and freshwater habitats to allow free upstream
passage; and replenish/maintain water in river associated wetlands and backwaters
M G1, G2, G3, G4, Scour and deposition processes to maintain dynamic and diverse habitats in the Bankfull
WQ6; B6; B7; B8; M7; channel and connected floodplains; maintain channel capacity at 4,000 m /s; seaward
3
M8; F12; F13; progradation of the delta; allow flow into delta wetland channels for habitat provision and
physical maintenance; provide low velocity littoral habitats for small bodied species; and
maintain shallow pool crossings with moderate-high velocities

24. Hydrological and hydraulic modelling
Determine the characteristics of the flows (magnitude, duration,
frequency and timing) required to meet the objectives

25. Hydraulic model
Convert Hydraulic index to flow index
• 1-dimension
– Inexpensive
– Cover a long reach
– Cross-section average Mean velocity V Depth D
• 2-dimension
– Expensive
– Cover a short reach
– Depth-averaged Mean velocity V
Depth D

26. 1-D HEC-RAS model output

27. 2-D River2D model output
Mesh Depth
Velocity Flow direction

28. Lower Yellow River data
• 370 cross-sections
– Surveyed every year
• Use for 1-D model of whole river
• 3 sites surveyed in detail
– Lijin
– Huayuankou
– Yiluo junction
• Use for 2-D model

29. Establish flow rules
Integrate the information through collaboration:
•Produce a set of practical flow rules that stakeholders agree on
•Create options with different levels of risk to the health of the assets

30. Huayuankou recommendation – low risk
Objectives met Flow component Hydrologic criteria Mean annual Inter-annual Timing
frequency/duration frequency
F1; M1 Cease to flow No cease to flow Continuous 100% of the time All year
B1; B2; B3, F2; WQ1, Low flow Dec ≥ 307 Continuous ≥ 75% of the time Dec - May
WQ2, WQ3, WQ4; Jan ≥ 280
V3; M2; M5; F3; F4;
Feb ≥ 321
F11; F16
Mar ≥ 377
Apr ≥ 463
May ≥ 430
F6; F7; F9; V1; B5; High flow Jun ≥ 434 Continuous ≥ 75% of the time Jun - Nov
M3; M4; F14 Jul ≥ 783
Aug ≥ 1,137
Sep ≥ 1,124
Oct ≥ 866
Nov ≥ 543
V3; V4; F10 Low flow pulse ≥ 2,000 ≥ 1 per year / ≥4 in 5 years Nov - May
1 – 30 days;
rates of rise and fall
within natural range
G1, G2, G3, G4, Bankfull 3,000 – 4,000 ≥ 1 per year / ~10 – ≥4 in 5 years Jun – Sep
WQ6; B6; B7; B8; 30 days duration;
F12; F13; F5; F10 rates of rise and fall
within natural range

31. Huayuankou recommendation – medium risk
Objectives partly met Flow Hydrologic Mean annual Inter-annual Timing
comp criteria frequency/duratio frequenc
onen n y
t
F1; M1 Cease to No cease to flow Continuous 100% of the All year
flow time
B1; B2; B3, F2; WQ1, Low flow Dec ≥ 185 Continuous ≥ 75% of the Dec - May
WQ2, WQ3, WQ4; Jan ≥ 174 time
V3; M2; M5; F3; Feb ≥ 191
F4; F11; F16 Mar ≥ 229
Apr ≥ 284
May ≥ 263
F6; F7; F9; V1; B5; M3; High flow Jun ≥ 265 Continuous ≥ 75% of the Jun - Nov
M4; F14 Jul ≥ 466 time
Aug ≥ 754
Sep ≥ 744
Oct ≥ 534
Nov ≥ 335
G1, G2, G3, G4, WQ6; Bankfull 3,000 – 4,000 ≥ 1 per year / ~10 – 30 ≥4 in 5 years Jun – Sep
B6; B7; B8; F12; days duration;
F13; F5; F10 rates of rise and fall
within natural range
V3; V4; F10 Not
provi
ded

32. Model water resources availability
What are the impacts on river users from the flow options?

33. Experience and recommendations
Experience
--- Get new think, method from Australian expert
---The result close to the think of river manager, and can be
implement
Recommendation
---The e-flow assessment can be applied in other river in China

34. THANK YOU FOR YOUR ATTENTION