Radar Interferometry Time Series Analysis of Mashhad Subsidence
Radar Interferometry Time Series Analysis of Mashhad Subsidence
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DOI：
10.1007/s12524-009-0006-x
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发表时间：
2009-03-01
影响因子：
2.5
通讯作者：
Wright, Tim
中科院分区：
文献类型：
--
作者：
Dehghani, Maryam;Zoej, Mohammad Javad Valadan;Wright, Tim
伊朗东北部马什哈德市以北20公里处的大片农业区遭受地面沉降。通过1995年至2005年期间的精确水准测量和2005年至2006年期间获得的连续GPS测量获得了几个稀疏点的沉降率。为了研究高空间分辨率下变形的时间行为，使用小基线子集（SBAS）算法来生成干涉SAR时间序列分析。使用2003年至2006年间12个ENVISAT ASAR数据计算出的19个干涉图进行时间序列分析。时间序列结果表明该地区正在持续下沉，没有明显的季节性影响。从时间序列分析获得的平均LOS变形速度图显示出相当大的沉降率，高达24（厘米/年）。为了评估时间序列分析结果，采用连续 GPS 测量作为大地测量方法。比较表明干涉测量结果与大地测量技术之间非常一致。而且，1995年至2005年对应地区分布的各测压井信息显示，地下水位显着下降达20米。测压信息与井位地表变形之间的相关性表明，马什哈德发生的沉降是由于过量抽取地下水造成的。
A large agricultural area located in 20 km north of the city of Mashhad in the north-east of Iran is subject to land subsidence. The subsidence rate was achieved in a couple of sparse points by precise leveling between 1995 and 2005, and continuous GPS measurements obtained from 2005 to 2006. In order to study the temporal behavior of the deformation in high spatial resolution, the small baseline subset (SBAS) algorithm was used to generate the interferometric SAR time series analysis. Time series analysis was performed using 19 interferograms calculated from 12 ENVISAT ASAR data spanning between 2003 and 2006. The time series results exhibited that the area is subsiding continuously without a significant seasonal effect. Mean LOS deformation velocity map obtained from time series analysis demonstrated a considerable subsidence rate up to 24 (cm/yr). In order to evaluate the time series analysis results, continuous GPS measurements as a geodetic approach were applied. The comparisons showed a great agreement between interferometry results and geodetic technique. Moreover, the information of various piezometric wells distributed in the area corresponding to 1995 to 2005 showed a significant decline in water table up to 20 meters. The correlation between the piezometric information and the surface deformation at well's locations showed that the subsidence occurrence in Mashhad is due to the excess groundwater withdrawal.