Evaluation and Further Improvement of Existing Criteria for Human Stability in Floodwaters

Abstract:

There have been numerous urban flood disasters in recent years, causing considerable loss of life. Therefore, the current investigation can provide a scientific basis for flood risk management for people living in urban areas. This paper reviewed previous investigations into human stability in floodwaters. Most of the existing criteria are empirical; other theoretical analyses usually neglect the effects of body buoyance and nonuniform velocity profile of incoming flow, which does not agree with real situations. Although the latest research results have overcome those deficiencies, further improvement is still required because the adopted approach neglects the difference of body structure attributes between the European and Chinese people. Therefore, it is necessary to improve the criterion of human body stability in floodwaters. This paper modified the existing equation of buoyancy force with the parameters of human body structure of Americans or Europeans. Two parameters in the formulas of incipient velocity were recalibrated based on existing experimental data and an improved criterion for the stability of children and adults in floodwaters was presented. Finally, the proposed formula was validated in detail against existing field experimental data. Because the control conditions for the laboratory experiments were better than those in real floodwaters, the criterion for human stability proposed in this paper tends to be more dangerous in terms of flood risk management.