Locating water pollution and shore discharges in coastal zone and inland waters by FLS lidar

Sergey Babichenko, Jüri Lapimaa, Alexei Lisin, Larisa Poryvkina
AS Laser Diagnostic Instruments, 113A Kadaka str. 12915 Tallinn, ESTONIA
sergeyb@ldi.ee

Alexander Vorobiev
Laser Diagnostic Instruments International Inc., 146 Colonnade Road South, Unit 1
Ottawa, Ontario, Canada K2E 7Y1
vorobiev@ldi3.com

ABSTRACT

The paper reviews results of filed studies and pilot projects with airborne Fluorescent Laser Spectrometers FLS-series carried out in 2003-2004 in sea-, lake waters and watersheds aimed at the location of areas with water quality deviations from normal state due to municipal, agriculture discharges and chemical pollution. In December 2003, LDI in cooperation with the Ontario Ministry of Environment (MoE), Environment Canada, and several Ontario Conservation Authorities, conducted an airborne survey on board a single-engine aircraft in the Great Lakes region (Ontario, Canada), corroborated by simultaneous collection and laboratory analysis of flight-path ground samples. The goal of this project was to provide a comparative study - using a combination of traditional sampling and following laboratory analysis and LIF and SFS techniques. The territories covered with 30-meters spatial resolution in the 12-hour air survey included: Lake Simcoe, Lake Ontario, the entire span of the Welland canal, Lake Erie, the entire length of the Grand River, Maitland River; the lower Saugeen River; and Lake Huron. Spatial changes in the structure of dissolved organic matter, indicating possible agricultural run-off or sewage-related discharge, were clearly tracked, and oil pollution in water was detected and quantified. The combination of LIF and SFS technologies was validated as a valuable tool for near-real time environmental assessment.

Further developments of FLS-lidar resulted in an increase of sensing distance, spatial resolution and implementation of laser beam scanning system capable to provide a swath on the underlying surface. The advanced model FLS-AM based on new XeCl excimer laser (150 mJ / 150 Hz), the hyper-spectral detector (Intensified CCD) and self-adjusted telescope coupled with scanner operates up to altitudes of 500 m and provides sensing the scanned strip with the width equal to 20% of the flight altitude. The FLS-AM lidar has been successfully tested in 2004 on board a helicopter. A series of flights aimed at the monitoring of seawater quality in Estonian coastal zone was carried out in cooperation with the Estonian Rescue department, Estonian Air forces and Tallinn-Helsinki Euregio project. The results of field studies confirmed considerable improvement of operational characteristics of FLS lidar in traditional water applications: analysis of water transparency, mapping DOM distribution, oil pollution detection. Planned enhancements of airborne LIF technology, as well as its incremental value in multi-tiered environmental monitoring applications are discussed.

Last Update: 2005-03-15