Analysis of the complex vegetation index considering greenness and shortwave infrared to determine anomalies in the vegetation spectral characteristics caused by hydrocarbon deposits

Abstract

Summary In this study, the authors analyzed the possibilities of using the standard Normalized Difference Vegetation Index (NDVI) and the finer Vegetation Index considering Greenness and Shortwave infrared (VIGS). Above hydrocarbon deposits, the vegetation state is affected by metal oxides and dioxides formed during the oxidation of soil trace elements. This fact allowed the authors to suggest the possibility of using the VIGS-to determine the anomalies of the vegetation spectral characteristics caused by hydrocarbon deposits. In the course of the work, the Landsat ETM + satellite data were sequentially processed in order to statistically calculate the probability of detecting anomalies in the vegetation spectral characteristics. Anomalies were identified based on the calculation of the values of the vegetation spectral indices (NDVI and VIGS) for 26 pairs of polygons built within the known deposits and beyond them for areas with homogeneous vegetation. The probability of recognizing anomalies for the NDVI is 66%, for the VIGS - 75%. There is a significant (85%) correlation between the NDVI and VIGS values for gas and oil and gas and 90% for oil fields. This approach can be used as a means of additional exploration of hydrocarbon deposits in areas with known explored deposits and as an auxiliary one when performing geological prospecting works in order to identify new deposits.