Collaborative research: Space-based detection of sinkhole activities in Central Florida

在过去的一年里，佛罗里达州中部发生了两起天坑事件，引起了媒体的广泛关注。2013年3月，塞夫纳（Seffner）一所房子下面的一个天坑坍塌，吞噬了50万英镑。一个人从他的卧室出来。2013年8月，一场天坑坍塌摧毁了迪士尼世界附近的一个度假村。然而，这些戏剧性的事件只是从持续不断的财产损失中脱颖而出的极端例子，这些财产损失在人为抽取地下水的时候会达到峰值。探测早期的天坑活动，特别是可能导致突然塌陷的活动，是一项具有挑战性的任务。然而，近年来合成孔径雷达（SAR）卫星探测和分辨率能力的提高，使目前的天基探测地球的微小运动成为可能。在毫米/年的水平上。在这个项目中，我们将使用德国和意大利SAR卫星在佛罗里达州中部获得的SAR观测数据。使用先进的时间序列技术对数据进行干涉测量处理，将提供地表运动的详细地图，并使我们能够探测到可能指示天坑活动的局部下沉区域。将使用探地雷达测量来验证天基天坑探测。成功地探测塌陷前的天坑活动将是减少佛罗里达州中部和世界上其他天坑易发地区的生命和财产危害的重要工具。佛罗里达州中部的天坑活动是一种主要的自然灾害，造成严重的财产损失，偶尔也会造成生命损失。我们建议使用计量合成孔径雷达（InSAR）来监测佛罗里达州中部的塌陷区活动，以便在塌陷区塌陷之前检测塌陷区并解决可能的前兆塌陷区。我们将委托德国TerraSAR-X卫星和意大利cosmos - skymed卫星星座在选定区域获取高分辨率观测（亚米像素分辨率），重复采集间隔为10-20天。使用InSAR时间序列技术对数据进行干涉处理，将为我们提供地表运动的高空间分辨率地图，精度为1-2毫米/年，这将使我们能够检测局部沉降，并更好地了解可能是天坑塌陷前兆的活动。我们将利用天基数据选择亚米尺度探地雷达调查的研究地点。这个有限规模项目的目的是提供一个概念验证，即InSAR观测可用于在佛罗里达中部具有挑战性的亚热带植被丰富的环境中探测天坑活动的前兆。天基对天坑活动的成功探测将导致进一步利用InSAR观测来减轻佛罗里达州中部和世界上其他天坑易发地区的天坑危害。

Over the past year two sinkhole events in central Florida attracted significant media attention. In March 2013, a sinkhole collapsed beneath a house in Seffner and ?swallowed? a person from his bedroom. In August 2013 a sinkhole collapse destroyed a resort complex near Disney World. These dramatic events, however, are just extreme examples that stand out from a steady stream of property damage, which spikes at times of anthropogenic groundwater withdrawals. Detecting incipient sinkhole activity, particularly that which may result in sudden collapse, is a challenging task. However, recent improvements in the detection and resolution capabilities of Synthetic Aperture Radar (SAR) satellites enable nowadays space-base detection of small movements of the Earth?s surface at the millimeter/year level. In this project we will use SAR observations acquired over central Florida by German and Italian SAR satellites. Interferometric processing of the data using advanced time series techniques, will provide detailed maps of surface movements and will allow us to detect localized subsiding areas that may be indicative of sinkhole activity. Verification of the space-base sinkhole detection will be conducted using Ground Penetrating Radar surveys. Successful detection of pre-collapse sinkhole activities will serve as very important tool to minimize life and property hazard in central Florida and other sinkhole-prone areas worldwide.Sinkhole activity in central Florida is a major natural hazard, resulting in severe property damage and occasionally in life loss. We propose to use Inferometric Synthetic Aperture Radar (InSAR) to monitor sinkhole activities in central Florida, in order to detect subsiding sites and resolve possible precursory subsidence prior to sinkhole collapse. We will task the German satellite TerraSAR-X and the Italian satellite constellation Cosmo-SkyMed to acquire high-resolution observations (sub-meter pixel resolution) over selected areas, with repeat acquisition intervals of 10-20 days. Interferometric processing of the data using InSAR time series techniques will provide us high spatial resolution maps of surface movements with 1-2 mm/yr accuracy, which will enable us to detect localized subsidence and better understand activity that may be precursory to sinkhole collapse. We will use the space-based data to select sites for study with sub-meter scale ground-penetrating radar surveys. The purpose of this limited scale project is to provide a proof-of-concept that InSAR observations can be used to detect precursory sinkhole activity in the challenging sub-tropical vegetation-rich environment of central Florida. Successful space-based detection of sinkhole activity will lead to further utilization of InSAR observations for sinkhole hazard mitigation in central Florida and other sinkhole-prone areas worldwide.