Assessments of land subsidence along the Rizhao–Lankao high-speed railway at Heze, China, between 2015 and 2019 with Sentinel-1 data

Chuanguang Zhu,Wenhao Wu,Zongli Jiang,Liya Zhang,Mahdi Motagh,Sichun Long

doi:10.5194/nhess-20-3399-2020

Abstract

Abstract. The Heze section of Rizhao–Lankao high-speed railway (RLHR-HZ) has been under construction since 2018 and will be in operation by the end of 2021. However, there is a concern that land subsidence in the Heze region may affect the regular operation of RLHR-HZ. In this study, we investigate the contemporary ground deformation in the region between 2015 and 2019 by using more than 350 C-band interferograms constructed from two tracks of Sentinel-1 data over the region. The small baseline subset (SBAS) technique is adopted to compile the time-series displacement. We find that the RLHR-HZ runs through two main subsidence areas: one is located east of the Heze region with rates ranging from −4 to −1 cm yr−1, and another one is located in the coalfield with rates ranging from −8 to −2 cm yr−1. A total length of 35 km of RLHR-HZ is affected by the two subsidence basins. Considering the previous investigation and the monthly precipitation, we infer that the subsidence bowl east of the Heze region is due to massive extraction of deep groundwater. Close inspections of the relative locations between the second subsidence area and the underground mining reveals that the subsidence there is probably caused by the groundwater outflow and fault instability due to mining, rather than being directly caused by mining. The InSAR-derived ground subsidence implies that it is necessary to continue monitoring the ground deformation along RLHR-HZ.

Highlights

The Heze region, lying in the North China Plain, has been adversely affected for decades by ground subsidence, mainly caused by the soil compaction and consolidation due to the excessive exploitation of aquifer (Cui, 2018; Hu et al, 2004; Guo et al, 2019; Xue et al, 2005)
As no in situ data are publicly available, we assess the consistency and precision of interferometric synthetic aperture radar (InSAR) results by a crosscomparison of the displacement rates derived from the S1-40 and S1-142
This study investigates the time-series displacement over the Heze region in 2015–2019 using MT-InSAR based on two sets of Sentinel-1A datasets

Summary

Introduction

The Heze region, lying in the North China Plain, has been adversely affected for decades by ground subsidence, mainly caused by the soil compaction and consolidation due to the excessive exploitation of aquifer (Cui, 2018; Hu et al, 2004; Guo et al, 2019; Xue et al, 2005). To slow down the subsidence, the local governments have proposed new regulations on exploitation of groundwater. Groundwater extraction is still greater than recharge due to the urban sprawl and industrial development, which results in continuous ground subsidence. The resulting subsidence has already caused some environment hazards, e.g., collapse of roads, buildings and other infrastructures (Yue, 2020). The ground subsidence may menace the RLHR-HZ and currently is a matter of major safety concern. It is crucial to monitor ground deformation along the RLHR-HZ to avoid potential hazards in the future

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Conclusion