Integrated River Management - River Dynamics and Integrated River Management - page 774

Fig. 11.60 A cross section of the Wenjiagou valley and the landslide deposit in June 2008

Fig. 11.61 (a) Bed profiles of the old and new Wenjiagou channels and the landslide deposit in 2008; (b) New
Wengjiagou gully developed during debris flows on the landslide deposit (See color figure at the end of this topic)

11.3.2.2 Artificial Step-Pool System in 2009
To stabilize the new Wenjiagou and mitigate debris flow hazard 33 artificial step-pools were constructed
in a 400 m long section of the new Wenjiagou channel at a construction cost of only $ 0.03 million US
dollars from May to June of 2009. Figure 11.62 shows the design of the steps with 2-4 keystones on the
bed to form a step. Boulders and cobbles were placed interlocking with the keystones for high stability.
Steel wire nets with cobbles and boulders inside were used to form two wings for protection of the two

Fig. 11.62 Artificial steps with keystones on the bed and steel wire nets with cobbles inside to form two wings for
protection of bank slopes