Environmental Engineering Reference
In-Depth Information
the new river mouth area (about 30 × 40 km) was silted up and emerged from the sea, with the maximum
siltation of 14 m. In the meantime the old river mouths were eroded by waves and tidal currents. The
maximum erosion depth is about 6 m (Zhang et al., 1997). The Qing-shui-gou channel extended by
11 km in 1976 and 5 km in 1977. The speed of extension decreased sharply in the succeeding years. The
average speed of the river mouth moving into the sea was about 2.3 km/yr in the period from 1976-1994
and was zero in the period from 1994-1996. The rate of land creation is reduced because of the
stabilization of the river mouth.
Fig. 6.37
Contours of siltation of the Qing-shui-gou mouth (1 to 14 m) and erosion of the Diao-kou-he and Shen-
xian-gou mouths (-1 to -6m) from 1976-1988
The Yellow River delta is rich in oil and gas resources. The Shengli Oil Field, second largest in China,
is developed on the delta. No long or medium term construction of oil fields can be planned if the
channel cannot be stabilized. The Kendong Oil Field is located in the offshore area near the river mouth
(the Chahe mouth in Fig. 6.35), with oil reserves of 257 million tons and could be developed into an oil
field with an annual production of 5 million tons/year. The water depth in the area is in the range of 1-5 m.
By utilizing sediment transported by the Yellow River to silt up the field, the cost of oil extraction can be
reduced by $0.35 billion US.
The river was artificially switched to the Fork Channel in July 1996 for land creation (Zhang et al.,
1997). When the first flood flowed through the Fork Channel in 1996, erosion took place and the channel
became 3.5-4 m deep and 300-400 m wide. The new fork channel can be clearly seen from the satellite
image shown in Fig. 6.38. The stage of 2,100 m
3
/s flood on August 5,1996, was recorded at 5.8 m at
Ding-zi-kou and at only 5.81 m for a flood of 3, 860 m
3
/s on August 26, 1996, due to scouring of the
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