River Ecology and Restoration - River Dynamics and Integrated River Management - page 650

the water flow in the Minjiang River, which is a tributary of the Yangtze River, is cut off due to water
diversion. To exploit the hydro-power at low cost many low dams have been constructed on the river and
the river water is diverted through pipelines and tunnels to the hydropower plants, which are located at
several tens of kilometers downstream. Because all water has been diverted the reaches between the
dams and the power plants became dry and all aquatic life were killed or seriously impacted. There are
many such hydro-power plants on the rivers in southwestern China, and, more hydro-power plants of
such a type are being planned or are in construction. The management of stream ecology in southwestern
China is facing a serious challenge.

Fig. 10.24 Water flow in the Minjiang River is cut off due to water diversion

Fragmentation of habitat —Some river training works result in the fragmentation and isolation of
habitats. Figure 10.25 shows the Yangtze River and numerous riparian lakes with different sizes. Naturally
these lakes connected with the Yangtze River and formed a huge habitat in the past. Humans cut the
connection for flood defense and aquatic farming, thus, fragmenting the habitat. The fragmentation of
habitat has resulted in deterioration of the ecology and extinction of some species.

Fig. 10.25 Isolation of riparian lakes along the Yangtze River results in fragmentation of habitat (Satellite image
from the web http://earth.google.com ) (See color figure at the end of this topic)