Soil Erosion and
Sediment Transport
in the Yellow River,CHINA
Amelia Chung
CEE 590
April 8,2003Picture Source:
Chinese National Geographic Magazine,Vol,1,2001
沉积物
YELLOW RIVER
The Legend
? Cradle of Chinese
Civilization
Picture Source,
http://yellowriver.org/huanghe
? Food Basket of China
Picture Source:
O.J,Todd and S,Eliassen,"The Yellow River Problem," Transactions American Society of Civil Engineers,
Vol,105 (1940),p,346,(Article published in December,1938,Proceedings)
? China’s Sorrow
The Legend
The Geography
? Originates from the Bayankela Mountain in
Tibet Highland,West of China
? Flows through 9 provinces,transverses
5,464 km,flows down from 4,500m to 400m
? Empties into Bohai Sea in Northeast China
? Divided into three reaches,
Upper,Middle,and Lower
Upper reaches
Middle reaches
Lower reaches
The snow-clad Bayankala Mountains
Picture source,YRCC,Huanghe Feng,Yellow River Pub House,1996.
Key Features of River (I)
? Hydrology:
– 745,000 km2 drainage area;
47 x 109 m3 annual runoff rate
– 478 mm annual rainfall;
~1,200 mm evaporation rate
? Sediment:
– Total 1.6 billion tons/year
– Average sediment concentration 35 kg/m3
Key Features of River (II)
1,Low Runoff(径流 ) Rate
2,High sediment load & concentration
3,Different sources and non-uniform distributions
of runoff and sediment loads
Qs (ton/year) Mavg (kg/m3)
Ganges River 1.45 x 109 3.92
Colorado River 0.135 x 109 27.5
Runoff Sediment loads
Middle Reach 43 x 109 m3/yr 1.60 x 109 t/year
River Mouth 33 x 109 m3/yr 1.00 x 109 t/year
恒河
Burdens of the River
Soil erosion
FloodingSedimentation- Reservoir
- River
Water
resources
Water Quality
Soil Erosion
?The Loess Plateau（黄土高原）
–Middle reaches
–Silt(泥沙 ) formation
Pictures source,Land Resources in the Loess Plateau of China,edited by The Northwest Institute of Soil
and Water Conservation,Academia Sinica,pub by Shaanxi Science and Technique Press,1986.
Characteristic of
Loess Deposit(堆积 )
- Fine and uniform
- Cohesive strength
- Erodible by water
- Forms steep loess
gullies,h > 100 m
Picture source,YRCC,Huanghe Feng,
Yellow River Pub House,1996.
冲沟
Sediment Transport in the YR (I)
? Size does matter
– Characteristic grain size,0.025<d<0.05mm
– Sediment carrying capacity [Xu et al,2002]
? P = k(v3/ghw)m
– Median size and concentration [Zhou et al,1999]
? D50 (mm) = 2.7 x 10-5S + 0.0139
? Sediment transport rate [Zeng et al,1991]
? Qsed = KSaQb
Peak sediment load during flood flow,turning the river violent
Picture source,YRCC,Huanghe Feng,
Yellow River Pub House,1996.
? Hyperconcentrated Flow
– TURBULENT
– Sufficient fine particles ? LAMINAR
? Siltation vs,Resuspension [Wang et al,2000]
– ?Qs = 1.8 x 10-6Q2.26 (0.44Q0.11 – 1)
– Critical flow discharge ~1800m3/s
– Rate of Siltation = Resuspension
Sediment Transport (II)
Sediment deposition in the riverbed near Middle Reaches
Picture source,YRCC,Picture Albums of the Yellow
River,China environmental Science Press,1991.
Sediment Transport (III)
? Resistance of flow - Manning coefficient,n
– Minimum resistance at ~ critical Q
– ‘n’ can be < 0.01,roughness of smooth glass
surface due to fine sediment suspension
Manning roughness n
at Lijin (river mouth) vs,
Discharge
[Wang et al,2000]
Future Works
? Sediment Control
– Soil conservation
– Sediment as
resources
Picture source,
http://www.cis.umassd.edu/~gleung/geofo/res01.htm
? Water Quality
– Organic sediments
– Interaction of
contaminants with
inorganic sediments
Future Works
Picture source,YRCC,Huanghe Feng,
Yellow River Pub House,1996.
Questions
Picture source,YRCC,Huanghe Feng,
Yellow River Pub House,1996.