输油管道重点区段SBAS-InSAR地质灾害监测研究

Research on SBAS-InSAR geological disaster monitoring in key sections of oil pipelines

关键词:  输油管道  SBAS-InSAR  Sentinel-1A数据  地质灾害  降雨

Key words:  oil pipeline  SBAS-InSAR  Sentinel-1A data  geological disaster  rainfall

摘要:

输油管道穿跨越区域地貌类型多样,管道铺设过程不可避免地会穿越山区、丘陵等地质灾害多发区,而地质灾害的发生、发展通常具有隐蔽性和潜伏性。因此,开展输油管道大范围、空间连续的地质灾害监测迫在眉睫。基于C波段Sentinel-1A卫星影像、30 m SRTM DEM数据利用小基线集干涉叠加技术提取输油管道重点区段地表形变信息,结合可见光影像、万安县降雨数据、坡度坡向数据对SBAS-InSAR监测方法的适用性和形变结果及成因进行分析研究。研究结果发现:该方法在失相干(相干性小于0.3)区域形变结果为空值,无法获得地表形变信息；利用空间域直方图设置固定阈值对其他区域进行形变分析,发现输油管道经过的斜坡和易发生水土流失平原区域形变明显,斜坡最大形变速率达到-43 mm/a,影响管道及周边0.02 km²；结合降雨情况进行成因分析,得到时间序列形变速率与月降雨天数相关性达到0.69,即当月降雨天数增多,累积形变值增加,形变速率加剧。研究结果表明,SBAS-InSAR技术可有效地获取输油管道全范围地表形变情况,为分析地质灾害孕育发生过程提供参考。 

Abstract:

The oil pipeline crosses various geomorphological types, and the pipeline laying process inevitably passes through the mountainous, hilly and other geological disaster-prone areas. Since the occurrence and evolution of geological disasters are always invisible and latent, it is urgent to carry out large-scale and spatially continuous geological disaster monitoring of oil pipelines. Based on C-band Sentinel-1A satellite image and 30 m SRTM DEM data, small baseline set (SBAS) technology was used to extract surface deformation information of key sections of the oil pipeline and the applicability of the SBAS-InSAR as well as the the deformation results and the causes were analyzed by combing the visible light images, the rainfall data in Wanan County and the slope and aspect information. The results showed that the deformation results of this method in the decoherence (coherence less than 0.3) area were null and the surface deformation information could not be obtained; when using spatial domain histograms with fixed thresholds to analyze deformation of other regions, it was found that the slopes and erosion-prone plains through which the pipeline passes were deformed significantly, with the maximum deformation rate of the slopes reached -43 mm/a which could affect the pipleline and a area of 0.02 km² surrounded. Combined with the rainfall records for cause analysis, the correlation between time series deformation rate and monthly rainfall days was determined to be 0.69, indicating that when the number of rainfall days in a single month increased, the cumulative deformation value would increase as well as the deformation rate. Overall, this study showed that SBAS-InSAR technology could be used to obtain the full-scale surface deformation of the oil pipelines effectively, which served as a good reference for analyzing the occurrence and evolution process of the geolgocial disasters.