Monitoring land subsidence in Yangon, Myanmar using Sentinel-1 persistent scatterer interferometry and assessment of driving mechanisms

Abstract

Inhabitants and ecosystems in delta areas are becoming increasingly vulnerable to the effects of subsidence, caused by anthropogenic activities. Yangon is a city on the periphery of the Irrawaddy delta in Myanmar where little is known about the true extent of this hazard, while its effects can potentially harm millions of its inhabitants. This research presents the magnitude and extent of the subsidence hazard in Yangon through a Persistent Scatterer Interferometry (PSI) time-series analysis on the Sentinel-1 data archives in the period of December 2015 through April 2017. The PSI analysis revealed four distinct zones of varying sizes where vertical velocity differences over 20 mm/yr were found, locally exceeding 110 mm/yr. The significant subsidence zones are exclusively located in young Alluvium deposits and 95% of velocity differences over 10 mm/yr are found at Quaternary age deposits. The addition of loads, such as buildings, predominantly affect subsidence rates in the first decade after placement. Estimates of groundwater extraction for domestic supply, used by more than 2 million inhabitants, correlate with the township average subsidence rates which shows that most subsidence in Yangon can be explained by groundwater extraction. Current operation of groundwater extraction wells induces an aquifer volume loss of 5.5 million cubic meter per year in the aquifer system of Yangon city. Unless groundwater extractions are mitigated, Yangon will be increasingly vulnerable to infrastructural damages, flooding events, and degrading aquifer quality.

Understanding Land Subsidence Along the Coastal Areas of Guangdong, China, by Analyzing Multi-Track MTInSAR Data

“…However, we cannot analyze the explicit relationship between subsidence and groundwater exploitation volumes due to the vast illegal exploitation. Fortunately, deformation time series analysis is commonly adopted to analyze the subsidence caused by groundwater exploitation [26,28,29,58,59]. From the results in the aquaculture area (see Figure 8b,c and Figure 9b,c), the linear trend of the deformation time series is identified.…”

Countrywide Monitoring of Ground Deformation Using InSAR Time Series: A Case Study from Qatar

“…Recent advances in Interferometric Synthetic Aperture Radar (InSAR) time series methodologies (e.g., Persistent Scatter Interferometry [PSI] [1,2], Small Baseline Subset [SBAS] [3,4] and the combination of persistent and distributed scatterers [DS] [5,6]) enabled the cost-effective detection and monitoring of ground deformation caused by anthropogenic and natural factors over large areas worldwide. Example applications include monitoring ground deformation in urban areas where large-scale infrastructure projects were conducted [7,8], subsidence in deltas [9,10], sinkhole-related deformation and collapse [11][12][13], and subsidence due to excessive groundwater extraction from fossil aquifers in semiarid and arid environments [14][15][16][17].…”

Spatial Analysis of Land Subsidence in the San Luis Potosi Valley Induced by Aquifer Overexploitation Using the Coherent Pixels Technique (CPT) and Sentinel-1 InSAR Observation

“…Amighpey et al [40] mapped the land subsidence of Yazd province (Iran) using ENVISAT images identifying areas exhibiting maximum rates of 120 mm/yr. Subsiding deformation rates of 120 mm/yr were identified on highly compressible deposits from Yangon (Myanmar) using Sentinel-1 images [41]. Tehran was also monitored using ENVISAT-ASAR, Sentinel 1, and GPS observations, showing accumulated settlements of 39.6 cm during the 2014-2017 period [20].…”