The reason that the gully floor is not fully utilized is because of the threat of severe floods which may come once in several years. Here in Weifen River watershed we see a gully which has been eroded to its rocky bottom from past floods is left undeveloped. A village is situated 10 m above the gully floor to avoid the passage of severe floods. Actually this gully has been protected from flood by constructing a 35-m high check dam upstream. Yet, the gully floor is still left abandoned. It should be a good investment to fill in the gully and turn it into high-yield farmland.

The bottom picture shows a well-developed gully floor. This site is particularly favorable for development because the gully is broad and wide. Even major flood flowing down this gully will only cause partial damage to the field. Ideal sites like this have already been utilized, but we advocate the development of even less ideal sites, like that shown in the upper picture.

Picture source: George Leung (1995)