Invited Speaker

Abstract: The study presents a method to quantify the uncertainty associated with inundation damage data for an urban catchment when undertaking stormwater drainage design and management. Usually flood damage is estimated by multiplying the inundated asset value by the damage rate corresponding to the inundation depth. Figure 1 shows an example of inundation depth – damage rate relation for the household articles of a private house as a logistic curve on the basis of a national government survey. The scatter of the data around the estimated curve that means the uncertainty of the damage rate can be represented by using a suitable probability distribution. The uncertainty of the damage rates and the asset values are described by probability distributions estimated from an analysis of actual flood damage data from the national government survey. With the presence of uncertainty in damage rate and asset value, the damage potential curve defining the damage-frequency relationship is no longer a deterministic single-valued curve. Through Monte Carlo simulation which incorporates the uncertainty of the inundation damage from the damage rate and asset value, a probabilistic damage potential relation can be established which can be expressed in terms of a series of curves with different percentile levels. The method is demonstrated through the establishment of probabilistic damage potential curves for a typical urban catchment, the Zenpukuji river basin in the Tokyo Metropolis, under two cases, namely, with and without a planned flood control reservoir.

Biography: Dr. Masaru Morita is a Professor of Urban Environmental Engineering, Department of Civil Engineering, Shibaura Institute of Technology, Tokyo, Japan. He holds holds a B.E. in Civil Engineering, a M.Sc. in Civil Engineering, a Ph.D degree from Tokyo University, Japan in 1976, 1978 and 1986, respectively. He stayed as a visiting scholar at the University of Illinois at Urbana-Champaign for almost one year from 1994 to 1995. He has been working for Shibaura Institute of Technology and investigating urban environment, especially urban hydrologic system up the present and he is a specialist on urban hydrology and groundwater hydrology