CHARACTERISTIC OF LAND SURFACE TEMPERATURE ANOMALIES BASED ON VEGETATION CORRECTED ASTER IMAGE IN GEOTHERMAL AREA (Case Study at Patuha Geothermal Field)

• Main Author: Aulian Chalik, Citra
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/36526
• Institution: Institut Teknologi Bandung

Thermal remote sensing can help geothermal exploration in measuring, mapping and identifying geothermal activity in very large areas. Land Surface Temperature (LST) is a key parameter to determine the land surface anomaly associated with geothermal fluid on the surface, but the estimation of LST from thermal image is affected by emissivity which influences of detected temperature and vegetation cover that covers the predicted area as surface temperatur anomaly. This study proposes a vegetation cover correction model to correct LST ASTER (Advanced Spaceborne Thermal Emissiion and Reflection Radiometer) image, so that the estimation of LST can represent the actual condition. The data used in this study is ASTER L1T thermal infrared (TIR) band acquisition time on Augustus, 2018 and band visible band on July 20, 2018 and field measurement data in the Patuha geothermal field such as soil temperature (T-kin), manifestation temperature, and arial photographs. This study proposes the vegetation cover correction model based on the linear equation ????????????????????=????????????????? ????????, where Tcveg is the corrected vegetation for LST ASTER image, Tem is the corrected emissivity for LST ASTER image, and Tv is vegetation temperature obtained based on EVI (Enhanced Vegetation Index) vegetation fraction. The results of Tcveg showed a good correlation with T-kin R2 = 0.79 and maximum Tcveg was 74.5°C. Based on linear regression between Tcveg and T-kin, Valid Temperature (Tval) is obtained (????????????????=????.?????????????????????????????????????.????????), the maximum Tval is 115.7°C. Anomalous characteristics of LST from Tval show two types of anomalies, anomaly 1 (17.5 - 29.4°C) and anomaly 2 (>29.4°C). Anomaly 1 is associated with the presence of hot springs in Cibuni Crater and Ciwidey Crater and warm springs in Rancawalini, while anomaly 2 is associated with hot springs and steaming ground in Cibuni Crater, and crater lakes in Kawah Putih. The not detected areas as anomaly 1 and 2 are warm springs in Rancaupas and Barutunggul, and cold springs in Kawah Tiis.