Exploring the potential of optical remote sensing for oil spill detection in shallow coastal waters-a case study in the Arabian Gulf

Abstract

Remote sensing provides an effective tool for timely oil pollution response. In this paper, the spectral signature in the optical and infrared domains of oil slicks observed in shallow coastal waters of the Arabian Gulf was investigated with MODIS, MERIS, and Landsat data. Images of the Floating Algae Index (FAI) and estimates of sea currents from hydrodynamic models supported the multi-sensor oil tracking technique. Scenes with and without sunglint were studied as the spectral signature of oil slicks in the optical domain depends upon the viewing geometry and the solar angle in addition to the type of oil and its thickness. Depending on the combination of those factors, oil slicks may exhibit dark or bright contrasts with respect to oil-free waters. Three oil spills events were thoroughly analyzed, namely, those detected on May 26 2000 by Landsat 7 ETM + and MODIS/Terra, on October 21 2007 by MERIS and MODIS, and on August 17 2013 by Landsat 8 and MODIS/Aqua. The oil slick with bright contrast observed by Landsat 7 ETM + on May 26 2000 showed lower temperature than oil-free areas. The spectral Rayleigh-corrected reflectance (R(rc)) signature of oil-covered areas indicated higher variability due to differences in oil fractions while the R(rc) spectra of the oil-free area were persistent. Combined with RGB composites, FAI images showed potentials in differentiating oil slicks from algal blooms. Ocean circulation and wind data were used to track oil slicks and forecast their potential landfall. The developed oil spill maps were in agreement with official records. The synergistic use of satellite observations and hydrodynamic modeling is recommended for establishing an early warning and decision support system for oil pollution response.

A MODIS-Based Robust Satellite Technique (RST) for Timely Detection of Oil Spilled Areas

“…Several techniques have already been proposed for oil spill detection and monitoring using satellite data acquired in the optical band [21][22][23][24][25][26][27][28][29][30][31][32][33][34]. Most of them are based on the analysis of satellite radiances acquired in the middle (MIR) and thermal (TIR) infrared spectral regions where the contrast between the emittance of the oil-polluted area and the surrounding clean seawater is more appreciable.…”

Oil Spill Detection in Glint-Contaminated Near-Infrared MODIS Imagery

“…These limitations call for a multi-platform SAR slick detection effort, as well as for the additional use of satellites with optical sensors. The latter, with their daily global coverage, wider swaths (greater than 1000 km) and, in many cases, free-of-charge data, can complement and optimize SAR detection, also in discriminating between oil spills and look-alikes via the retrieval of their optical properties [6]. Furthermore, a multi-platform observation increases oil spill detection effectiveness, since more observational data can be fed to slick displacement and transformation forecast models, which are the object of recent research efforts [7][8][9] that seek to integrate observation and forecasting in detection systems.…”

“…Indeed, the 250-m spatial resolution of some MODIS optical bands is now sufficient to resolve typical illegal discharge slicks of 1-10 km with sufficient detail, while the typical 1-km resolution of past sensors, such as the Advanced Very High Resolution Radiometer (AVHRR) sensor, was practically useless in slick detection. Several studies exploiting oil spill optical properties in MODIS data have been carried out by Hu et al [11], Bulgarelli and Djavidnia [12] and Zhao et al [6]. However, in contrast to SAR detection, the effectiveness of which is well documented, the literature on optical oil spill retrieval is still sparse, since there is a lack of oil spill detection methodologies, if we exclude first attempts, such as those proposed by Adamo et al [13] and [6].…”

“…Several studies exploiting oil spill optical properties in MODIS data have been carried out by Hu et al [11], Bulgarelli and Djavidnia [12] and Zhao et al [6]. However, in contrast to SAR detection, the effectiveness of which is well documented, the literature on optical oil spill retrieval is still sparse, since there is a lack of oil spill detection methodologies, if we exclude first attempts, such as those proposed by Adamo et al [13] and [6]. In particular, the work of [6] is of greater interest and provides a comprehensive analysis of oil spill spectral properties for a set of oil spill cases observed in the Arabian Gulf, both under glint and glint-free conditions.…”

“…However, in contrast to SAR detection, the effectiveness of which is well documented, the literature on optical oil spill retrieval is still sparse, since there is a lack of oil spill detection methodologies, if we exclude first attempts, such as those proposed by Adamo et al [13] and [6]. In particular, the work of [6] is of greater interest and provides a comprehensive analysis of oil spill spectral properties for a set of oil spill cases observed in the Arabian Gulf, both under glint and glint-free conditions. In particular, [6] devises a methodology to distinguish between oil spills and algal blooms, based on the use of the FAI (Floating Algae Index) technique.…”