RAPID: Fast Reconstruction of Flood Hydrographs in the Houston Metropolitan Area during Hurricane Harvey Based on Image Processing and In-situ Measurements

由于水位测量的空间密度低，以及已建成的基础设施、地面地形和自然景观与流动的水之间复杂的相互作用，在城市地区，在山洪、飓风和其他极端天气事件期间实时构建洪水水文曲线的能力是困难的。RAPID项目的目标是利用来自交通路口和州际公路摄像头、主要新闻媒体和社交媒体的易腐烂图像和视频片段以及参考对象/点。随后的照片图像处理，按比例缩放到参考对象，将使休斯顿大都会地区的水文曲线更加连续，准确。通过在被淹没的高速公路、街道和住宅小区的大量地点重建洪水水文曲线，高分辨率、基于飓风产生的暴潮和降雨的城市淹没模型将变得更加准确。例如，它将有助于更好地了解飓风哈维期间进出休斯顿的沉积物和污染物的运输情况。这种经重建的水文曲线验证的模型还将帮助州和地方政府及时做出低洼地区的疏散决策，以减轻类似飓风引发的危害的影响。这个基于休斯顿洪水水文重建的RAPID项目使用图像处理和原位测量，具有显著的智力优势：(1)所提出的方法是创新的和创造性的，因为它没有使用任何传统的流量测量。相反，它依赖于用于新应用程序的现有数据的独特形式。(2)重建的洪水线将显著提高对这次由飓风哈维极端降雨引起的前所未有的洪水事件的水文过程的认识。(3)这些数据将有利于休斯顿新的洪水模型的开发。(4)开发的处理交通图像数据的算法和软件将在NHERI DesignSafe-CI平台上提供，可以很容易地应用于许多其他洪水易发的城市中心，如纽约市、新奥尔良和迈阿密。

The ability to construct flood hydrographs in urban areas in real-time during flash floods, hurricanes, and other extreme weather events is difficult because of the low spatial density of water level measurements and the complex interactions of built infrastructure, ground topography, and natural landscape with flowing water. The goal of this RAPID project is to leverage perishable images and video footage from traffic intersection and interstate highway cameras, major news media outlets, and social media along with reference objects/points. Subsequent photo image processing, scaled to the reference objects, will enable development of a more continuous, accurate hydrograph in the Houston metropolitan area. By reconstructing the flood hydrographs at a large number of locations in flooded highways, streets and residential subdivisions, high-resolution, process-based urban inundation modeling from hurricane-generated surge and rainfall will become significantly more accurate. For example, it will facilitate a better understanding of transport of sediments and pollutants in and out of Houston during Hurricane Harvey. Such a model validated by the reconstructed hydrographs will also aid state and local governments in making timely evacuation decisions for low-lying areas to mitigate the impact of similar hurricane-induced hazards.This RAPID project based on reconstruction of flood hydrographs in Houston using image processing and in-situ measurements has significant intellectual merit: (1) The proposed methodology is innovative and creative because it does not employ any traditional stream gages. Instead, it relies on a unique form of existing data employed for a new application. (2) The reconstructed flood hydrographs will significantly improve the understanding of the hydrological processes of this unprecedented flood event caused by the extreme rainfall of Hurricane Harvey. (3) The data will benefit the development of a new flood model for Houston. (4) The developed algorithms and software for processing the traffic image data, which will be available on the NHERI DesignSafe-CI platform, can be readily applied to many other flood-prone urban centers, such as New York City, New Orleans, and Miami.