Twenty-year advanced DInSAR analysis of severe land subsidence: The Alto Guadalentin Basin (Spain) case study
Twenty-year advanced DInSAR analysis of severe land subsidence: The Alto Guadalentin Basin (Spain) case study
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DOI：
10.1016/j.enggeo.2015.08.014
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发表时间：
2015-11-23
影响因子：
7.4
通讯作者：
Mora, Oscar
中科院分区：
文献类型：
--
作者：
Boni, Roberta;Herrera, Gerardo;Mora, Oscar
利用先进差分干涉合成孔径雷达（DInSAR）技术处理的多传感器SAR图像监测了西班牙东南部Alto Guadalentin盆地20年的严重地面沉降演变。本研究使用的SAR图像由ERS-1/2、ENVISAT、ALOS和cosmos - skymed卫星在1992 - 2012年间获取的4个数据集组成。通过整合不同时间段的地表位移图，我们可以量化1992年至2012年在Alto Guadalentin盆地发生的累计位移达2.50 m。将DInSAR结果与全球定位系统（GPS）数据进行了局部比较，结果表明，两种不同测量技术之间的局部垂直运动测量结果高度一致。ALOS数据的平均绝对误差为4.6 +/- 4 mm， cosmos - skymed数据的平均绝对误差为4.8 +/- 3.5 mm，证实了分析的可靠性。DInSAR地表位移的空间分析表明，地表位移与可压缩冲积层厚度有直接关系。过去20年探测到的地面沉降很可能是由于上世纪70年代以来由于对上瓜达伦丁含水层系统的过度开采导致地下水位持续下降100-200米的结果。孔隙压力的负梯度是造成极厚（bbb100 m）细粒粉土和粘土层极缓慢固结的原因，这些层具有较低的垂直水力渗透率（约50 mm/h），其中最大沉降仍未达到。(C) 2015年Elsevier B.V.出版
A twenty-year period of severe land subsidence evolution in the Alto Guadalentin Basin (southeast Spain) is monitored using multi-sensor SAR images, processed by advanced differential interferometric synthetic aperture radar (DInSAR) techniques. The SAR images used in this study consist of four datasets acquired by ERS-1/2, ENVISAT, ALOS and COSMO-SkyMed satellites between 1992 and 2012. The integration of ground surface displacement maps retrieved for different time periods allows us to quantify up to 2.50 m of cumulated displacements that occurred between 1992 and 2012 in the Alto Guadalentin Basin. DInSAR results were locally compared with global positioning system (GPS) data available for two continuous stations located in the study area, demonstrating the high consistency of local vertical motion measurements between the two different surveying techniques. An average absolute error of 4.6 +/- 4 mm for the ALOS data and of 4.8 +/- 3.5 mm for the COSMO-SkyMed data confirmed the reliability of the analysis. The spatial analysis of DInSAR ground surface displacement reveals a direct correlation with the thickness of the compressible alluvial deposits. Detected ground subsidence in the past 20 years is most likely a consequence of a 100-200 m groundwater level drop that has persisted since the 1970s due to the overexploitation of the Alto Guadalentin aquifer system. The negative gradient of the pore pressure is responsible for the extremely slow consolidation of a very thick (> 100 m) layer of fine-grained silt and clay layers with low vertical hydraulic permeability (approximately 50 mm/h) wherein the maximum settlement has still not been reached. (C) 2015 Published by Elsevier B.V.