Mapping Land Subsidence Hazard through InSAR (Case study: Kashmar and Khalil Abad plain)

Document Type : Original Article

Authors

1 Ph.D. Candidate, Combating Desertification, Faculty of Desert Studies, University of Semnan, Semnan, Iran

2 Associate Professor, Faculty of Desert Studies, University of Semnan, Semnan, Iran

3 Assistant Professor, Earthquake Research Center, Ferdowsi University of Mashhad, Mashhad, Iran

Abstract

Measuring of subsidence is often challenging due to the gradual occurrence in large-scale, and advanced measuring techniques are required. The first foresighted consequence of this catastrophic phenomenon is irreversible loss of aquifer reservoir. Subsidence is downward motion of the earth's surface with negligible horizontal vector component. Subsidence is occurring with different rates in many aquifers of the country constantly, because of excessive extraction of groundwater for years which causes lowering of the water table. Increasing the intensity of this phenomenon in recent years requires modern methods of measuring subsidence. InSAR technique can be strongly powerful that can extract vertical component in large extent, especially in areas with insufficient geodetic data. In this study, new Sentinel-1A imagery from 2014 to 2018 were used to examine the subsidence rate in the Kashmar and Khalil Abad plain. According to the high correlation between pair images, basic interferograms was calculated. Then, using SBAS method unnecessary phases were removed. Thereafter, the displacement phase was calculated and converted to the vertical component. Maximum subsidence rate is observed near the southwest suburb of Kashmar city and western part of Khalilabad plain. Results indicate that the Kashmar and Khalilabad plain was encountered maximum of 17 cm downward movement annually. Due to uneven and heterogeneous subsidence, the area has susceptibility for formation of longitudinal cracks. Final map can be used to control and manage water resources and prevent natural hazards and desertification

Keywords

Desert Management
Volume 7, Issue 13 - Serial Number 13
12 Articles
September 2019
Pages 65-76

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History

  • Receive Date: 30 October 2018
  • Revise Date: 01 December 2018
  • Accept Date: 03 March 2019

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