Do you know what is that shrub branch carried by a child used for? For firewood? Or, just to play with?
We have more illustrations of Fenxi's silt-trapping system and what has the program accomplished.
The picture below shows a well-built drainage ditch alongside a warping dam. My comment to this feature is that it is over elaborate, as construction projects in the 60's tended to be. I feel that once the flood flow is put under control, the rock lining along the ditch may be spared, and thus reducing the cost of construction.
