Human Instability in Flood Flows¹

Abstract

Loss of human stability in flood flows and consequent drowning are a high personal hazard. In this paper, we review past experimental work on human instability. The results of new experiments by the Flood Hazard Research Centre (FHRC) are also reported. These new results show that low depth/high velocity flood waters are more dangerous than suggested based on previous experimental work. It is discussed how human instability can be related to two physical mechanisms: moment instability (toppling) and friction instability (sliding). Comparison of the test results with these physical mechanisms suggests that the occurrence of instability in the tests by FHRC is related to friction instability. This mechanism appears to occur earlier than moment instability for the combination of shallow depth and high flow velocity. Those concerned to identify locations where high flood flows could be a threat to human life need to modify their hazard assessments accordingly.

Development of a spatial decision support system for flood risk management in Brazil that combines volunteered geographic information with wireless sensor networks

“…This index represents vulnerability loss related to human stability in flood flows. It was defined based on the works proposed by Jonkman and Penning-Rowsell (2008) and HRWallingford (2006) that show how flood depth and flood velocity waters are combined for dynamical body equilibrium. This index is then related to human instability due to two physical mechanisms: moment instability (toppling) and friction instability (sliding).…”

A method for tsunami risk assessment: a case study for Kamakura, Japan

“…If the result of the damage function is 1, mortality is assumed to be 100% for that given location (Jonkman and Penning-Rowsell 2008). The estimated mortality function is combined with the exposed population at a given location in time to approximate the number of casualties resulting from each of the flood scenarios.…”

“…The loss of life was determined following a methodology similar to that proposed in Jonkman and Penning-Rowsell (2008). Here, the method to estimate the loss of life has two main steps: estimating the exposed population and then estimating the mortality of that population.…”

“…Second, to estimate the number of casualties among the exposed population, a mortality function that takes into account the dv criteria was also used, based on previous research on stability of people in flood flows (Jonkman and Penning-Rowsell 2008).…”

Developing an index model for flood risk assessment in the western coastal region of Mazandaran, Iran

“…The latest investigations about the functions and tables of depth-damage have been carried out by the U.S. Army Corps of Engineers (USACE, 2003) which damage percentage is calculated based on the building content and has distributed the damage (in the form of percentage out of the building content value) in relation to water depth. Studies on the assessment method of people safety based on formulae derived from the mechanical analysis linked with experiments (Abt et al, 1989;Foster and Cox, 1973;Jonkman and Penning-Rowsell, 2008;Karvonen et al, 2000;Mitsch, 1992, 1993;Lind et al, 2004;Takahashi et al, 1992) result instability curves in floodwaters (Xia et al, 2011). The curves were presented between the product The assessing zone is not under compulsory plan (property purchase and evacuation) 10 The assessing zone is under compulsory plan and the compulsory plan: -has been completed 9 is in progress 6 has been stopped 3 has not started yet 0 of the flow velocity and the incoming depth at the point of human instability.…”