Collaborative Research: The Hydrology, Hydraulics and Hydrometeorology of Flood Response in Urbanizing Drainage Basins

0208225米勒综合水文，水力和水文气象过程，控制洪水在城市化流域将通过分析洪水响应在巴尔的摩大都市地区进行检查。 科学问题是：（1）暖季雷暴系统的尺度相关洪水响应如何依赖于降雨的时空结构？ (2)洪水响应如何随地表特性（包括不透水覆盖层和城市排水管网结构）而变化？ 以及（3）与河道漫滩形态的地质控制相比，城市化导致的河道/漫滩形态变化在确定洪水波衰减方面的相对作用是什么？ 问题1和2将通过对1996-2003年期间25-30次洪水事件的24个小于200平方公里的流域的洪水事件进行水文和水文气象分析来审查。 洪水事件的降雨和流量观测的诊断分析将与模型分析结合使用，以解决问题1和2。 水文模型分析将基于分布式水文模型，即网络模型。 将对24个流域的一个子集进行洪水波传播的水力分析，并将包括4个河段，每个河段都有上游-下游流量测量站对。 二维深度平均水力模型，TELEMAC，将用于评估城市化河道洪水响应的水力控制。 本研究中使用的关键观察结果是：（1）高分辨率（1公里，5分钟）雷达雨量估计，（2）高分辨率（0.6米等高线间隔）地形数据集，（3）高分辨率（0.6米网格，0.15米垂直分辨率）从机载雷达获得的地形数据集，（4）不透水覆盖层的高分辨率（1米）图示，（5）现场调查的河道横截面、纵剖面和卵石计数。

0208225MillerThe integrated hydrologic, hydraulic and hydrometeorological process that controls flooding in urbanizing drainage basins will be examined through analyses of flood response in the Baltimore metropolitan region. The science questions are: (1) How does the scale-dependent flood response of urban drainage basins depend on the space-time structure of rainfall for warm season systems of thunderstorms? (2) How does flood response vary with land-surface properties including impervious cover and structure of the urban drainage network? And (3) What is the relative role of changing channel/floodplain morphology due to urbanization, as compared with geologic controls of channel floodplain morphology, in determining the attenuation of flood waves? Questions 1 and 2 will be examined through hydrologic and hydrometeorological analyses of flood events in 24 drainage basins smaller than 200 km2 for 25-30 flood events during the period 1996-2003. Diagnostic analyses of rainfall and discharge observations for the flood events will be used in conjunction with model analyses to address questions 1 and 2. Hydrologic model analyses will be based on a distributed hydrologic model, the Network Model. Hydraulic analyses of flood wave propagation will be carried out for a subset of the 24 basins and will include 4 stream reaches, each with upstream-downstream pairs of stream gaging stations. The 2-d depth-averaged hydraulic model, TELEMAC, will be used for assessing hydraulic controls of flood response in urbanizing stream channels. The key observations used in this study are: (1) high-resolution (1 km, 5 minutes) radar rainfall estimates, (2) high-resolution (0.6 m contour interval) topographic data sets, (3) high-resolution (0.6 m grid, 0.15 m vertical resolution) topographic data sets derived from airborne radar, (4) high-resolution (1 m) representations of impervious cover, and (5) field-surveyed channel cross sections, longitudinal profiles and pebble counts.