InSAR Spatial Analysis for Inspection Subsidence of Nakhon Sawan

Abstract

Land subsidence is a significant problem that continues to occur, resulting in damage to homes, infrastructure, transport routes, and groundwater systems. This research project focuses on measuring the land subsidence rate in Nakhon Sawan Province by analyzing satellite images using Time-Series Interferometric Synthetic Aperture Radar (TSInSAR), a photographic data analysis technique. This technique uses satellite data to measure distances and track elevation changes on the Earth's surface, making it useful for tracking land subsidence, and inspection of various building structures. Additionally, satellite images allow for analysis of data, reducing surveying costs and saving budget and labor. The study used time-series data consisting of 34 images taken between January 1, 2017 and February 1, 2023, from the Sentinel-1 satellite. Interferograms were created using the SNAP and MATLAB programs to obtain the results of the land subsidence rate. Checkpoints were processed in order to analyze and evaluate risk areas that may cause subsidence and to continue in the next operating step. The results showed a displacement of -5.2 to 4.4 millimeters per year, indicating significant subsidence in some areas of Nakhon Sawan Province, particularly in land use areas and areas with high use of groundwater, such as Krok Phra District, Mueang Nakhon Sawan District, Chum Saeng District, and Kao Liao District. The research demonstrates the effectiveness of InSAR time series technology in tracking land subsidence.