Spatiotemporal deformation patterns of the Lake Urmia Causeway as characterized by multisensor InSAR analysis

Area of Science:

• Geodesy
• Remote Sensing
• Environmental Monitoring

Background:

• The Lake Urmia Causeway (LUC) in NW Iran is a critical infrastructure. Lake Urmia has experienced significant water level decline.
• Understanding deformation is crucial for infrastructure maintenance and environmental management.

Purpose of the Study:

• To present deformation patterns in the Lake Urmia Causeway (LUC).
• To investigate the dynamics of consolidation settlement along the LUC.
• To establish a geodetic network for detailed deformation monitoring.

Main Methods:

• Utilized Interferometric Synthetic Aperture Radar (InSAR) time series data from four SAR sensors (Envisat, ALOS-1, TerraSAR-X, Sentinel-1).
• Processed 68 images and generated 227 interferograms using the small baseline subset (SBAS) technique.
• Applied Principal Component Analysis (PCA) and a hydro-thermal model to analyze deformation dynamics.

Main Results:

• Observed a peak line-of-sight (LOS) subsidence rate of 90 mm/year between 2012-2013.
• Subsidence is primarily attributed to the substantial loss of water in Lake Urmia.
• Identified major deformation components and their correlation with water level and temperature data.

Conclusions:

• InSAR time series analysis effectively reveals deformation patterns in the LUC.
• The study highlights the impact of water level changes on the structural integrity of the causeway.
• Findings support the establishment of a geodetic network for enhanced monitoring and damage mitigation planning.