A Standardized Procedure to Build a Spectral Library for Hazardous Chemicals Mixed in River Flow Using Hyperspectral Image

Abstract

The occurrence of natural disasters as a consequence of accidental hazardous chemical spills remains a concern. The inadequate, or delayed, initial response may fail to mitigate their impact; hence, imminent monitoring of responses in the initial stage is critical. Classical contact-type measurement methods, however, sometimes miss solvent chemicals and invoke risks for operators during field operation. Remote sensing methods are an alternative method as non-contact, spatially distributable, efficient and continuously operatable features. Herein, we tackle challenges posed by the increasingly available UAV-based hyperspect ral images in riverine environments to identify the presence of hazardous chemical solvents in rivers, which are less investigated in the absence of direct measurement strategies. We propose a referable standard procedure for a unique spectral library based on pre-scanning hyperspectral sensors with respect to representative hazardous chemicals registered on the national hazardous chemical list. We utilized the hyperspectral images to identify 18 types of hazardous chemicals injected into the river in an outdoor environment, where a dedicated hyperspectral ground imaging system mounted with a hyperspectral camera was designed and applied. Finally, we tested the efficiency of the library to recognize unknown chemicals, which showed >70% success rate.

Hyperspectral Imaging Algorithms and Applications: A Review

“…The outcomes affirm the viability of this technology for dynamic chemical reaction tracking and the identification of hazardous materials across different distances, underscoring its potential utility in diverse spectroscopic applications. In [141], the authors introduce a technique to establish a standardized spectral library for the identification of dangerous chemical solvents in riverine settings through the use of UAV-based hyperspectral imagery. The process entails defining hazardous substances using hyperspectral sensors, extracting their spectral signatures, and constructing a dedicated library.…”

“…This has implications for the early detection and warning of hazardous chemicals using HSI. In [143], the authors discuss the problem of water pollution from chemical leaks and spills, particularly the challenges of detecting colorless and water-soluble chemicals in water bodies. It points out the limitations of traditional contact-based detection methods and proposes the use of HSI for remote chemical detection in aquatic environments.…”

Remote Sensing for Water Quality Monitoring—A Case Study for the Marateca Reservoir, Portugal

“…The use of spectral information for automated pollution recognition is increasing in the literature [13][14][15]. In recent years, advances in remote sensing technology and data analysis have paved the way for innovative approaches to identify and track pollution sources.…”

“…Different materials and substances have unique spectral signatures, which can be detected and analyzed using specialized sensors, such as spectrometers and hyperspectral imagers. These devices capture data in multiple narrow and contiguous bands, providing a comprehensive view of the reflected or emitted light from a target area [13][14][15]. The benefits of using spectral information for automated pollution recognition are numerous.…”

“…However, challenges do exist. Proper calibration, atmospheric correction, and data interpretation are essential to ensure the accuracy and reliability of spectral information [13][14][15]. Additionally, integrating spectral data into existing pollution monitoring systems and decision-making processes requires collaboration between environmental scientists, engineers, and policymakers.…”