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Umaha, et al.

                CNNs, has dramatically improved the performance of   and synthetic  data generation have been proposed as
                image classification tasks, including oil spill detection.    solutions, these techniques still have limitations. 28
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                CNNs are  a  class of deep  learning  models  designed   Another  challenge  is the  high  computational  cost
                to  process grid-like  data,  such as images.  They  are   associated  with  training  CNNs.  Advanced  models
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                composed of multiple  layers, including convolutional   require  significant  computational  resources,  which
                layers, pooling layers, and fully connected  layers.   may  not  be  readily  available  in  all  research  settings.
                CNNs automatically  learn  hierarchical  features  from   In addition, while CNNs  excel  at detecting  oil spills
                input images, making them highly effective for complex   in homogeneous environments, their performance can
                pattern  recognition.  Typically, ML models identify   degrade in heterogeneous or noisy conditions.
                and classify dark spots or regions in SAR  images
                that indicate areas covered by oil on the sea surface,   2.5. Identified research gaps
                due to the scattering of the SAR signal from the oil.   Existing research has demonstrated  some automated
                These dark spots or regions could either be oil spills or   techniques for oil spill detection. For instance, Daniyan
                look-alikes. 13-16  The accuracy of the developed model   et al.  developed a test rig comprising four flow lines,
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                in  differentiating  oil  spills  from  look-alikes  depends   each equipped with pressure sensors and gauges. The
                on how well the model is trained for identification and   system relies on a microcontroller as the main controller,
                classification  tasks. The  three  main  steps  involved  in   with pressure transducers for monitoring and detecting
                oil spill detection and classification include: (i) training   pressure drops below a threshold. However, the potential
                the dataset and identifying the dark spots, (ii) extracting   of ML approaches and their data computational abilities
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                features from these dark spots,  and (iii) training a   were not  explored.  Daniyan  et  al.  also  reported  the
                classifier using the extracted features.            development of an inline inspection robot for detecting
                  Once trained,  the  model  can be used to classify   issues such as cracks and corrosion in pipelines  to
                selected dark spots.                                prevent oil spills. Despite the reported advances, several
                                                                    gaps in research remain, particularly in utilizing CNNs
                2.3. Applications of CNNs in oil spill detection    for oil spill detection. One limitation of the study is the
                Several studies have demonstrated the efficacy of CNNs   reliance on prototype development without validation
                in detecting oil spills from satellite imagery. Fingas and   against real datasets and empirical results. In addition,
                Brown  provided a comprehensive review of oil spill   the integration of CNNs with other ML approaches,
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                remote sensing techniques, emphasizing the potential of   such as recurrent neural networks for temporal analysis,
                CNNs.                                               could enhance detection accuracy over time. Moreover,
                  More recent  work by Mahmoudi Ghara  et al.       the development of lightweight CNN models capable
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                introduced  a  novel  CNN  architecture  specifically   of running on less powerful hardware would make this
                designed for oil spill detection, incorporating attention   technology more accessible.
                mechanisms to focus on relevant parts of the image.    The  novelty  of this  study lies  in  the  development
                Their  approach  significantly  reduced  false  positives,   and implementation of a unique CNN-based algorithm
                particularly  in complex environments  with numerous   termed  “SpillNet,”  specifically  designed  for  oil  spill
                look-alikes.  Similarly, Zhan et al.  applied transfer   detection  in  SAR images.  The  proposed algorithm
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                learning to leverage pre-trained CNNs, achieving state-  leverages  the  unique  characteristics  of SAR data  and
                of-the-art results with limited labeled data.       the robust feature  extraction capabilities  of CNNs  to
                  Table  1  presents  some  of  the  ML  approaches  that   improve detection accuracy. The architecture integrates
                have been implemented for detecting and classifying oil   multiple  DSCL,  BN, and RC to enhance  feature
                spills with high accuracy.                          extraction and learning capabilities. The DSCL enables
                                                                    the model to learn the relationships between complex
                2.4. Challenges and limitations of CNNs in oil spill   patterns, such as distinguishing oil spills from their look-
                detection                                           alikes, with lower computational complexity compared
                Despite the success of CNNs, several challenges remain.   to standard convolutions. This reduces time and costs,
                One major issue in oil spill detection is the scarcity of   making the process more efficient. Moreover, the model
                labeled training data, which is essential for training deep   breaks down the convolution operations into individual
                learning models. Annotating large datasets is expensive   channel and spatial (pointwise) information, reducing
                and time-consuming.  Although data  augmentation    the parameters  needed  to train  the  datasets.  This




                Volume 22 Issue 3 (2025)                        34                                 doi: 10.36922/ajwep.8282
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