SGER: Surveying the Southern California Flash Floods of January 2005

0520899 2005年1月初，加利福尼亚州南部出现特大降雨，引发山洪暴发和泥石流，造成十几人死亡，基础设施遭到严重破坏，全国商业活动中断，数千名居民被困。无数的城乡公路、主要高速公路、高速公路以及客运和货运铁路被关闭，包括洛杉矶和长滩的美国主要港口的货运通道。数千人被迫疏散，数百人失去家园。初步估计损失超过3亿美元。尽管历史上罕见但极端的降雨事件，南加州地区山洪暴发的生产和发展仍然是个谜。邻近沿海相对较高、陡峭的山区，使南加州在风暴从西南部(而不是更典型的西北风)逼近时，特别容易受到山洪暴发的影响。最近发生的事件为详细研究提供了机会。在大量实物流动证据和临时记录被销毁或无法获得之前，迫切需要开展实地调查和数据收集运动。它计划通过雷达、雨量计和我们自己的嵌套高分辨率模拟降水和地表径流模型运行，以及灾难性事件的地图来识别山洪地区。然后，将派遣小组调查高水位线、高海拔地区发生的山泥倾泻或泥石流，以及测量其他主要河床水文特征。小组还将负责联系各县的水务和防洪区，从雨量计、径流和其他通常不包括在标准业务预报数据流中的地面数据中收集模拟数据。拟议研究的主要目标是通过及时进行实地调查和收集该地区水利工程和防洪区的所有可用数据，协助开发一个区域事件数据库，否则这些数据将会丢失。拟议工作的最后结果将是一个数据库和相关文件，以便能够对2005年1月南加州的山洪暴发进行区域研究。

0520899GeorgakakosExtreme rainfall in Southern California in early January 2005 led to flash floods andmudslides that caused over a dozen fatalities, and extensive infrastructure damage,interrupted national commerce and stranded thousands of residents. Countless urban and rural roads, major highways, freeways, and passenger and freight railways were shut down, including freight access to major US Ports at Los Angeles and Long Beach. Thousands were forced to evacuate and hundreds lost their homes. Preliminary damage estimates topped $300 million.Regional flash flood production and development in Southern California remains enigmatic despite a history of infrequent but extreme rain events. The proximity of relatively high, steep mountain terrain along the coast makes Southern California uniquely susceptible to flash flooding when storms approach from the southwest (rather than a more typical northwesterly approach). The recent events provide an opportunity for detailed study. A field survey and data collection campaign is urgently needed before a wealth of information in the form of physical flow evidence and temporary records are destroyed or unavailable. It is planned to identify flash flood areas from radar, raingauge and our own nested high resolution simulated precipitation and surface runoff model runs, along with maps of disastrous incidents. Teams will then be deployed to survey catchments of interest targeting high water marks, occurrence of land slides or mudflows in higher elevations, and measurements of other key streambed hydrographic characteristics. Teams will also be charged with contacting Water and Flood Control Districts of various counties to gather analog data from raingauges, streamflow and other surface data not typically included in the standard operational forecast data stream.It is the main objective of the proposed research to assist in the development of a regional event database through timely field surveys and collection of all available data from Water and Flood Control Districts in the region that would otherwise be lost. The final result of the proposed effort will be a database and associated documentation that would allow the regional study of the flash floods of Southern California of January 2005.