Strategic thinking on major issues in China flood control

Research efforts were made to study several major issues in formulating the flood prevention plan of China's seven large river basins.The planning activity was organized by the Ministry of Water Resources.Our research recommendations were adopted during the course of the plan formulation.For example,we propose using the severe floods submerge areas of the 20th century as benchmarks for the identification of future flood prevention areas. Our viewpoint is that the most important consideration in the flood risk management is to actively circumvent risks and respond to risks.The core of circumvention risk is to restrict those unreasonable social economic activities of humankind,and thus reducing the flood risk.The design standard of a flood prevention area needs to be verified using a two-dimensional probability distribution method when the area is potentially threatened by two kinds of flood risks.Rationally upgrading the flood prevention standard is the priority in urban flood control.It is essential to better coordinate urban flood control and development,and to make full use of the urban damping effect on rainwater including retention of necessary water areas and utilization of rainwater.We should have well-balanced consideration to both options of storing and draining rainwater,rather than overemphasizing on the drainage option alone.We recommend that comparison and selection of safe development scheme for a flood retention area should comprehensively consider the risk zone that is divided using the integrated flood risk factor based upon the duration,frequency and depth of inundation, as well as the area natural and geographic conditions.