A satellite-based analysis of the Val d'Agri Oil Center (southern Italy) gas flaring emissions

Abstract

Abstract. In this paper, the robust satellite techniques (RST), a multi-temporal scheme of satellite data analysis, was implemented to analyze the flaring activity of the Val d'Agri Oil Center (COVA), the largest Italian gas and oil pre-treatment plant, owned by Ente Nazionale Idrocarburi (ENI). For this site, located in an anthropized area characterized by a large environmental complexity, flaring emissions are mainly related to emergency conditions (i.e., waste flaring), as industrial processes are regulated by strict regional laws. While regarding the peculiar characteristics of COVA flaring, the main aim of this work was to assess the performances of RST in terms of sensitivity and reliability in providing independent estimations of gas flaring volumes in such conditions. In detail, RST was implemented for 13 years of Moderate Resolution Imaging Spectroradiometer (MODIS) medium and thermal infrared data in order to identify the highly radiant records associated with the COVA flare emergency discharges. Then, using data provided by ENI about gas flaring volumes in the period 2003-2009, a MODIS-based regression model was developed and tested. The results achieved indicate that the such a model is able to estimate, with a good level of accuracy (R 2 of 0.83), emitted gas flaring volumes at COVA.

The VIIRS-Based RST-FLARE Configuration: The Val d’Agri Oil Center Gas Flaring Investigation in Between 2015–2019

“…Therefore, VIIRS-based findings can be also compared with the ones achieved by means of the original RST-FLARE configuration. The latter is using the FRP as the satellite metric aimed at computing the gas flare emissive power [32]. The VIIRS-based RH and MODIS-based FRP values, aggregated at an annual scale, in the temporal period 2015-2019, are shown in Figure 14.…”

“…Future research studies will be addressed in two directions. The MODIS-based RST-FLARE scheme is able to provide GF information for COVA since 2000, which characterizes this thermal source not only in terms of FRP but also in terms of gas volumes emitted into the atmosphere [32]. The portion of the MODIS-based configuration on the VIIRS IR Imagery bands (i.e., I4 and I5, centered at 3.74 and 11.45 µm, respectively) will be tested to guarantee the continuity of the provision of this type of information in view of assessing the possible improvements coming from the finer (i.e., 375 m versus 1000 m) spatial resolution of these data.…”

“…As anticipated in the introduction, the first satellite-based analysis of the COVA has been carried out by Reference [32] using MODIS data at 1 km of spatial resolution. In this paper, VIIRS data, with an improved spatial footprint of 750 m, have been exploited.…”

“…The strategy developed to identify thermal anomalies associated with gas flaring at COVA follows the general prescriptions of the RST-FLARE algorithm, previously implemented on multi temporal series of MODIS nighttime thermal data [32,33]. In this work, taking in mind the considerations shown in the previous paragraphs, the algorithm has been exported on VIIRS nighttime bands and the procedure was slightly modified ( Figure 5).…”

A Methodology for Gas Flaring Detection and Characterisation Using SLSTR

“…With the advent of vegetation fire detection products based on mid and thermal infrared bands (MIR and TIR), flaring was highlighted as a main source of false alarms [24,25]. This feature was exploited to study flaring [26,27] and later the additional evaluation of short-wave infrared (SWIR) bands allowed for a more accurate detection [28][29][30][31][32], being at present the state-of-the-art.…”