LAND SUBSIDENCE ANALYSIS USING PLT D-INSAR METHOD AND ONE-DIMENSIONAL CONSOLIDATION IN SIDOARJO MUD VOLCANO AREA

• Main Author: Bayuaji, Giri
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/86045
• Institution: Institut Teknologi Bandung

The land subsidence in Mud Volcano Sidoarjo, called LUSI, was caused by the release of fluids and clay consolidation in the area. The volume of material released was 4,301.42 m3 /year, with the highest intensity reaching 4,814.32 m3 /year. The amount of material extracted affects land subsidence, flooding, and infrastructure damage in the LUSI area. Land subsidence in the LUSI area can be caused by two main factors, namely clay consolidation and other material influences. Therefore, monitoring using differential interferometric synthetic aperture radar (D-InSAR) and one-dimensional (1D) consolidation calculations is needed to determine the rate of land subsidence, predict the time of land subsidence, know the most influential factors for land subsidence, and determine the rate of land subsidence that occurs. Pairwise Logic Technique (PLT) analysis of PLT D-InSAR was used with Sentinel- 1A imagery to determine the rate of land subsidence (cm/year). Existing GPS data then validated the processing results. The land subsidy rate results from the GPS- validated PLT D-InSAR treatment were compared with the 1-dimensional (1D) consolidated drill data analysis. From the results of PLT D-InSAR analysis, 1D consolidation, and other material influences, an analysis of the rate of land subversion in LUSI can be carried out. The results of the analysis of the PLT D-InSAR PLT method and 1D consolidation showed that the areas affected by the decline with an average rate of decline are high land subversion areas (1.47 – 1.83 cm/year), medium land subsidy areas (1.36 – 1.47 cm/year), and low land subsidence areas (1.01 – 1.36 cm/year). Land subversion due to the influence of clay consolidation is 0.343 cm/year with a maximum time of 1000 – 3753 years. The contribution due to the influence of clay consolidation was 21.37%. Land subversion due to the influence of other materials is 1,011 cm/year with a maximum time of 1000 – 6862 years. The contribution due to different material influences is 62.99%.