Ground Deformation Analysis Using InSAR and Backpropagation Prediction with Influencing Factors in Erhai Region, China

Yuyi Wang,Xuesong Liu,Yahui Guo,Jingzhe Wang,Shunqiang Hu,Yong Li,Le Wang

doi:10.3390/su11102853

Abstract

The long continuity of Interferometric Synthetic Aperture Radar (InSAR) can provide high space and resolution data for ground deformation investigations. The ground deformation in this paper appeared in the city’s development, although it is close to the Erhai region, which is different from a water-deficient city. Therefore, the analysis and prediction of ground deformation using a new method is required. In this study, Sentinel-1 Synthetic Aperture Radar (SAR) images from 2015 to 2018 were used to study the characteristics of ground deformation in the Erhai region using the Small Baseline Subset Interferometric SAR (SBAS-InSAR) technique. The results were cross-validated using ascending and descending direction images to ensure the accuracy. In addition, the results showed that there was little ground deformation in the northern part of the Erhai region, while there was obvious ground deformation in the southern part. Four influencing factors—including the building area, water level, cumulative precipitation, and cumulative temperature of the southern Erhai region—were used together to predict the cumulative ground deformation using back-propagation (BP). The R of all the involved data was 0.966, and the root mean square errors (RMSEs) between the simulated values using BP and the true measured values were 3.063, 1.003, and 1.119, respectively. The results showed that BP has great potential in predicting the change tendency of ground deformation with high precision. The main reason for ground deformation is the continuous increase of building area; the water level followed. The cumulative precipitation and cumulative temperature are the reasons for the seasonal ground deformation. Some countermeasures and suggestions are given to face the challenge of serious ground deformation.

Highlights

Ground deformation is defined as the Earth’s surface movement due to the subsurface movement of Earth materials, which has become a common geological hazard that has caused potential threats to public safety, bringing about a series of harmful impacts [1,2,3,4]
Bing et al [30] applied the Point Target (PT) SBAS-Interferometric Synthetic Aperture Radar (InSAR) strategy to investigate coastal vertical land movements related to land reclamation in Shenzhen using the ENVISAT Advanced Synthetic Aperture Radar (ASAR), which is acquired through the ascending and descending orbit method
Iin Fthigeunroer4t;htehrenapnanrutaolfatvheeraEgrehadierfoegrmioant,iothnerasutersfaincethdeidErnhoati srhegoiwonobravnioguesddfreofomrm−3a3tioton;9hmowme/vyeera,rg.rIonutnhde dneofrotrhmerantiponarwt oafs tmheaiEnrlyhaciornecgeinotnr,atehde isnurthfaecseoduitdhenront Eshrhoawi roebgvioionu, swditehfothrme amtioosnt;sheoriwouesveorb,sgerrovuantidondpefooirnmtsarteioanchwinags amnaainvelyracgoenocefn−t3ra3tmedmin/ytehaer.southern Erhai region, with the most serious observation points reaching an average of −33 mm/year. 4.1.2

Summary

Introduction

Ground deformation is defined as the Earth’s surface movement (gradual settling, sudden sinking, or uplift) due to the subsurface movement of Earth materials, which has become a common geological hazard that has caused potential threats to public safety, bringing about a series of harmful impacts [1,2,3,4]. The SBAS-InSAR technology reduces the spatial and temporal decorrelation, and phase unwrapping and atmospheric delay errors It could provide precise features for a time series of deformation [23,24,25,26]. Zeni et al [28] applied full-resolution SBAS technology to a wide range of ground deformation calculations, covering the 1992–2010 time interval in Rome, Italy, and detected possible deformations affecting historic buildings Their results show the effectiveness of the two-scale multi-sensor SBAS-InSAR method in detecting and monitoring the displacements that affect historical and artistic monuments. Bing et al [30] applied the Point Target (PT) SBAS-InSAR strategy to investigate coastal vertical land movements related to land reclamation in Shenzhen using the ENVISAT Advanced Synthetic Aperture Radar (ASAR), which is acquired through the ascending and descending orbit method They found that the reclaimed land is experiencing significant coastal subsidence (up to 25 mm/year). The result has shown that the surface subsidence time series presented nonlinear subsidence with pronounced seasonal variations, which determined the spatial–temporal characteristics of wide-area surface subsidence and the relationship between surface subsidence and influencing factors

Methods

Results

Conclusion