RAPID: Analysis of the May 2015 Texas Flood with a Connectivity Framework and High Resolution Topography Data

在经历了四年的严重干旱之后，德克萨斯州中部在2015年5月25日至26日经历了大规模洪水。现在很明显，这种规模的地震以前从未有过记录，在几个地点，月总降雨量达到了20英寸。仅5月25日至26日的活动就带来了10英寸的降雨量。洪水中的河流数量巨大，受影响地区的空间范围也是如此，从奥斯汀和休斯顿等主要城市中心到温伯利和巴斯特罗普等较小城镇，整个德克萨斯州中部都有受影响的地区。这项提议寻求利用航空遥感技术立即获取高分辨率地形数据，以评估阵亡将士纪念日洪水的影响。这些数据将由休斯顿大学的国家机载激光测绘中心获取。数据分析将在德克萨斯大学奥斯汀分校进行。拟议研究的目的是量化这一极端事件期间河道和滩地之间的水文和沉积学连通性及其对下游泥沙输送的影响。这些知识对于通过更好地了解在重大风暴期间将在哪里发生侵蚀和沉积，从而为可持续的集水区管理提供信息至关重要。为该项目收集的数据将立即公之于众，并与工程界共享，以帮助评估受洪水影响的桥梁和大坝的结构破坏。这些数据还将被用于2015年夏季研究所的46名研究生的案例研究，该研究所是国家洪水互操作性实验的一部分。该团队将测试一个假设，即河道-滩地连通性影响下游泥沙输送，特别是高河道-滩地连通性导致下游泥沙输送减少，因为泥沙在滩地上扩散和储存。为了验证这一假设，这项研究瞄准了两个截然不同的地区：下三一河--德克萨斯州的一条主要曲折河流，泥沙运输是正在进行的研究的主题；另一个是奥斯汀市中心的城市环境。在2015年5月的事件中，这两个地区都经历了严重的洪涝灾害，但它们的洪泛区截然不同。分析工作将利用地形分析工具GeoNet与洪灾后的实地工作相结合，并加强国家洪灾互操作性试验中使用的模拟和预报模型。这些数据将被存储在美国国家科学基金会资助的开放地形库中，供广大社区访问。研究成果将通过开放获取的出版物和会议发言进行传播，作为分析一部分的工具将以开放源码格式提供给社区。

After four years of severe drought, central Texas experienced massive flooding on 25-26 May 2015. It is now clear that an event of this magnitude had never been recorded before, with monthly precipitation totals reaching 20 inches at several locations. The 25-26 May event alone contributed 10 inches of rain. The number of rivers in flood was enormous as was the spatial extent of the affected areas spanning the entire central portion of Texas from major city centers such as Austin and Houston to smaller towns such as Wimberley and Bastrop. This proposal seeks immediate acquisition of high-resolution topography data using airborne remote-sensing technology to assess the impact of the Memorial Day Floods. The data will be acquired by the National Center for Airborne Laser Mapping at the University of Houston. Data analysis will be conducted at the University of Texas at Austin. The objective of the proposed research is to quantify the hydrological and sedimentological connectivity between river channel and floodplain during this extreme event and its impact on downstream sediment transport. Such knowledge is fundamental for informing sustainable catchment management through better understanding of where erosion and sedimentation will occur during major storm events. The data collected for this project will immediately be made publically available and shared with the engineering community to aid in assessing the structural damage to bridges and dams impacted by the floods. The data will also be used in a case study to train 46 graduate students at a 2015 Summer Institute that is part of the National Flood Interoperability Experiment.The team will test a hypothesis that channel-floodplain connectivity influences downstream sediment transport, and in particular that high channel-floodplain connectivity resulted in reduced downstream sediment transport due to sediment dispersal and storage on the floodplain. To test this hypothesis, the study targets two contrasting areas: the Lower Trinity River--a major meandering river in Texas where sediment transport is the subject of ongoing research, and an urban setting in downtown Austin. Both experienced major flooding conditions during the May 2015 event, but their floodplains are quite different. Analytical work will use the topography analysis tool GeoNet in conjunction with post-flood fieldwork and enhancement of simulation and forecasting models used in the National Flood Interoperability Experiment. The data will be stored in the NSF-funded OpenTopography repository for access by the community at large. Research results will be disseminated through open-access publications and conference presentations, and the tools used as part of the analysis are available to the community in open-source format.