Presidential Young Investigators Award - Estimation of Exceedance Probabilities of Extreme Storms

本次总统青年研究员的研究计划分为三个部分：1)极端暴雨风险的量化；2)极端洪水风险量化；3)将开发的方法纳入基于风险的决策框架。基于已完成的风暴区划工作和风暴转换的概率方法，调查的第一部分包括对极端风暴数据库的评估和评估方法的发展，以解决记录不完整的问题；发展随机空间模型；利用极值理论研究了分布尾部解析渐近逼近的可行性；并确定替代估计程序的可靠性，量化超出概率估计的不确定性。第二部分研究了极端条件下与降雨/径流转换相关的几种流域特征的空间变异性；研究和评估土地利用变化对洪水的影响，实现暴雨数据库向洪水的同质转换；研究几种降雨/径流模型的性能，将极端降雨转换为洪水水文；并将所有发现整合到一种估计极端洪水概率的方法中，并评估这些估计的可靠性。第三部分是将开发的模型应用于实际系统，并将其纳入基于风险的决策框架。

The research plan for this Presidential Young Investigator is divided in three parts: 1) quantification of the risk of extreme rainstorms; 2) quantification of the risk of extreme floods; and 3) incorporation of the developed methodology into a risk-based decision-making framework. Based on work done on storm regionalization and a probabilistic approach to storm transposition, the first part of the investigation includes the assessment of extreme storm data base and development of estimation methods to account for record incompleteness; develop stochastic spatial models; study the feasibility of analytic asymptotic approximations to the tails of the distributions using extreme value theory; and determine the reliability of alternative estimation procedures and quantify the uncertainty of the exceedance probability estimates. The second part comprises research on the spatial variability of several basin characteristics relevant to rainfall/runoff transformations under extreme conditions; study and assess the effects of land use changes on resulting floods for the homogeneous conversion of storm data bases to floods; investigate the performance of several rainfall/runoff models for converting extreme rainfall into flood hydrographs; and integrate all findings into a method for estimating probabilities of extreme floods and assess the reliability of those estimates. The third part is to apply the developed models to real systems and to incorporate them into a risk-based decision making framework.