California State University, Long Beach
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The Mapping Of Port Noise

Published: October 1, 2014


While early explorers mapped the California coast for bays and inlets, Electrical Engineering’s I-Hung Khoo has mapped the Port of Long Beach for noise.

In 2011, the Center for Commercial Deployment of Transportation Technologies at CSULB awarded $250,000 to support 14 interdisciplinary faculty projects focused on promoting an interest in and expansion of campus research capabilities while emphasizing the unique maritime research environment inherent to the San Pedro Bay ports. Khoo, a member of the university since 2006, received $15,000 of that funding as an innovation grant to work with Civil Engineering and Construction Engineering’s Tang-Hung Nguyen to create an automated port noise and activity monitoring system. This work is an extension of the research Khoo and Nguyen have been working on to create noise maps for the Port of Long Beach and Los Angeles. They have received a total of $180,000 in funding from METRANS for the research.

“All kinds of places are measured for noise such as airports and freeways but no one measured noise levels at the Port of Long Beach extensively, let alone map them, until we did,” said Khoo. “Our goal was to understand the impact of noise on the Port of Long Beach. Up to now, pollution concerns at the port have focused on exhaust, but noise is as much a pollutant as truck emissions. Since the campus is so close to the Port of Long Beach, it seemed urgent to begin.”

The key to noise mapping is its visual display of noise levels. “In this way, it is possible to see the exact location of noise pollution,” said Khoo. To generate the noise map, a computer noise model of the port was created that included the terrain and all pertinent sources of noise. “We wanted data about trucks, trains and cargo-handling equipment activity. The result was not only a noise map of the Port of Long Beach but a map of specific sources of noise and an analysis of noise variations.”

Noise from various transportation modes including sea ports has become a major concern for environmental and government agencies in recent years. “The LA-Long Beach port complex is the gateway to the Pacific Rim which makes them the nation’s largest ocean freight hub and its busiest container port complex. As the container sector of the Port of Long Beach has the highest potential for growth, the levels of noise generated by cargo transportation and handling activities are especially of interest,” explained Khoo. “The objective of our research, therefore, was to determine, using noise mapping, the level of noise generated by the cargo-handling and transport activities at the container terminals of the Port of Long Beach. The benefits of noise mapping include the evaluation of noise impacts, the identification of noise hot spots, the development of noise reduction measures and the prediction of what noise impact there will be on new and future development.”

The study, conducted in 2009 and 2010, concluded that the highest contributions of noise came from trucks followed by cargo-handling activities. The contribution of railroads was not considered to be significant. The noise of container trucks traffic on the roads was deemed to be within the Caltrans/FHWA limit of 71 dB for developed land 500 feet from the roads and not counting the freeways. Noise from cargo-handling activities was well below the accepted level of 75 dB at a distance of 50 feet as stipulated by the Los Angeles Municipal Code for industrial equipment.

Sensitive areas included the non-industrial area east of the Los Angeles River and the Queen Mary, both of which were found to be within the Community Noise Exposure guidelines of the L.A. Municipal Code. The noise variation was at its highest at 8 a.m. and 1 p.m. but lowest at noon. The noise was higher on the weekdays than on the weekends. As far as monthly noise, it peaked in January and dropped to a minimum in March before rising steadily again.

At the conclusion of their research, Khoo and Nguyen presented “A Preliminary Study of Noise at the Port of Long Beach” and “Developing Noise Maps for Container Terminals at the Port of Los Angeles” for the METRANS National Urban Freight Conference held in Long Beach in October 2011 and 2013. They also presented “Developing a Noise Model for Container Terminals at the Port of Long Beach” before the 2011 Transportation Research Forum held in Long Beach and published their data in the International Journal of Environmental Pollution and Remediation in 2014.

When it came to rounding up the usual suspects in noise pollution, the noise map pointed to trucks.

“One look and the user sees the major noise contribution comes from the trucks,” said Khoo. “They have so many going in and out. The trains may be noisy but they don’t operate all the time. If they want to reduce noise, they should focus on the trucks.”

The future is bright for noise mapping, Khoo believes.

“It can be used to predict changes in the future,” he said. “Say you want to pave a new road or build a new container terminal. They can be drawn into the noise model with a description of the amount of traffic to see the effect it would have. How will these changes affect the overall noise? Say noise screening is planned. A noise wall can be drawn on the map and the effect is seen. That is the most powerful part of noise modeling. You can see noise distribution clearly on a noise map. It is both prediction and prevention.”