A new method for estimating flood hazard is developed in this study for flat and low lying areas wherein floods have low flow velocity, large depth and long duration. The hazard was computed as a function of flood depth and duration, not only depth as in the past. The study area of 624 km2 in Bangkok suburban is divided into small grids, each of 200 m by 200 m. Because flood depth and duration have different dimensions, this new method categorized the depth and duration into four groups for small, medium, large and largest magnitudes represented by integers 1, 2, 3 and 4 respectively. The depth integer and duration integer of each grid were weighted by factors μ and (1-μ) respectively and summed up to obtain the flood hazard indicator. The factor µ was assumed between 0 and 1 and adjusted by trial and error until the computed hazard satisfactorily satisfied the hazard estimated from field and questionnaire surveys. For flood damage vulnerability, an established methodology was applied considering the vuln...

中文翻译：

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曼谷东部平原洪水灾害，脆弱性和洪水风险评估方法

在这项研究中，针对洪水流速低，深度大，持续时间长的平坦和低洼地区，开发了一种估算洪水灾害的新方法。危害的计算是洪水深度和持续时间的函数，而不仅仅是过去的深度。曼谷郊区的研究面积为624 km2，分为小网格，每个网格200 m x 200 m。由于洪水的深度和持续时间具有不同的维度，因此该新方法将深度和持续时间分为四组，分别针对分别由整数1、2、3和4表示的小，中，大和最大震级。每个网格的深度整数和持续时间整数分别通过因子μ和（1-μ）进行加权，并求和以获得水灾危害指标。假定因子µ在0到1之间，并通过反复试验进行调整，直到计算出的危害令人满意地满足了根据实地调查和问卷调查得出的危害为止。对于洪水灾害的脆弱性，考虑到脆弱性，采用了既定的方法。