Monitoring Land Subsidence in Bangkok Metropolis and Vicinity during 2017 – 2022 by InSAR Time Series Technique with MintPy Software

Abstract

Natural and human activities both cause land subsidence, either directly activity, groundwater pumping and indirectly activity, urbanization and economic development. When the cumulative subsidence size exceeds the limits, it can cause damage. Thus, a routine system of monitoring land subsidence should be implemented. Although there are many methods that can precisely detect land subsidence but high cost and have a low spatial resolution. On the contrary, remote sensing using the InSAR technique can detect land subsidence. This research applies the Small Baseline technique to process Sentinel-1 data in ascending orbit 2017 - 2022 and in descending orbit 2018 - 2022 through MintPy software that has a processing time to update data quickly and suitable for detect land subsidence. The study area was Bangkok metropolis and vicinity which are the economic area of Thailand. From the research, it was found that the area with high subsidence tendency is Srinakarin-Romklao road and Samut Sakhon industrial area, with the displacement in the range of less than -30 millimeters per year. The correlation of the two datasets was in the range of 0.6 – 0.9 which are related. Therefore, there should be continuous monitoring and surveillance in such areas.