Stevens Researchers Help Hudson River Pilots to Navigate Severe Drought




October 15, 2012

Hudson River Pilots consult real-time technology to traverse shallower waters

This has been the hottest year ever recorded in the Northeastern United States, and 80 percent of the continental United States has endured the worst drought in half a century. The drought and heat has led to dangerous wildfires, increased prices in supermarkets, and reduced water quality. It has also damaged important elements of our nation’s infrastructure, including highways and railroad tracks. Many industries are struggling to adapt to the heat and severe drought, which experts estimate will cost more than $12 billion in total losses. The extreme dry weather has also reduced the levels of bodies of water all over the nation. Although New York City has avoided most effects of the drought, most of New York State, including many areas that drain into the Hudson River, has been hit by conditions ranging from abnormally dry to severe drought. Less water draining into the Hudson has meant shallower waters for one of the busiest waterways in the world, and consequently some concerns for large ocean-going freighters that travel up to the Port of Albany, which is located near critical rail connections and highway junctions and boasts the largest grain elevator in the Eastern United States.

Vessels that travel along the Hudson River rely on federally and state licensed river pilots of the Hudson River Pilots Association (HRPA) to safely guide them into port. The association sought the expertise of researchers at Stevens Institute of Technology to determine what precautions to take in response to the drought and reduced water levels of the Hudson.

The data from Stevens alerted the Hudson River Pilots to a seasonal drop in the water levels which, aggravated by the drought, caused the water level in the upper Hudson to be 12-18 inches below its normal levels. In response, the HRPA has placed the first-ever restrictions on vessel draft, which is a ship’s depth below the water line. The draft limit was reduced from 31 feet to 30 feet for ships loading or discharging in the Port of Albany, where water levels have dropped an average of two feet. The draft limit remains 31 feet for ships navigating other parts of the river.

Clearance Diagram

Courtesy of US Army Corps of Engineers

“A draft limit has never been needed before on the Hudson,” says Paul Capel, President of the Hudson River Pilots Association. “For their own safety, freight ships may need to decrease the amount of cargo they carry in order to float higher in the water.”

So far, the new limit has not impacted the Port of Albany negatively. Freight ships are still able to transport the amount of cargo originally intended, without making any weight concessions. However, if the drought worsens, a stricter draft limit could be established.

It is difficult to say whether conditions will improve, because droughts are complicated phenomena with a combination of causes. Less rainfall, higher rates of evaporation due to hotter air temperatures or wind shifts, and less snowfall in the previous winter are all factors that can contribute to droughts, making them difficult to model and predict.

The experts at the Stevens Institute of Technology Center for Maritime Systems and the HRPA used exhaustive data on Hudson River water levels from the New York Harbor Observation and Prediction System (NYHOPS) to inform the historic decision. An advanced oceanic monitoring system created and housed at Stevens, NYHOPS collects detailed information about conditions throughout the region’s waterways, including New York Harbor, Newark Bay, Long Island Coast, Long Island Sound, and the New Jersey Coast. NYHOPS is a versatile tool due to the wealth of data it collects, and it has helped municipal governments prepare for extreme weather, including storm surge flooding and hurricanes. Although the system is most well-known for analyzing and predicting flood conditions, the data and models can be used in various maritime conditions, including drought.

“NYHOPS combines real-time information collected from over 200 sensors and historic data with advanced models of ocean physics to forecast future oceanic conditions,” says Dr. Alan Blumberg, Director of the Center for Maritime Systems and a major contributor to the creation of NYHOPS. “The system was created to analyze and predict ocean conditions in order to protect lives and property, so we are pleased to help the HRPA ensure the safety of ships on the Hudson River.”

NYHOPS utilizes advanced three-dimensional circulation and wave models based on the Estuarine Coastal and Ocean Model (ECOMSED), a derivative of the Princeton Ocean Model (POM. The system simulates a wide variety of marine phenomena, including circulation and mixing processes in rivers, estuaries, shelf and slope, lakes, semi-enclosed seas as well as open and global oceans. The ECOMSED/POM combination has been adapted by over 3,000 research groups around the world, and over 600 papers employing the modeling engine have been published. The NYHOPS operational forecast system adheres to NOAA National Ocean Service standards and guidelines for Operational Forecast System (OFS) use and reliability, and now meets the NOAA National Ocean Service standard of keeping root-mean-square forecast errors below 0.5 feet 90% of the time.

Dr. Blumberg is an expert in maritime domain awareness. He has served on the boards and technical committees of the Environmental Protection Agency, National Oceanic and Atmospheric Administration (NOAA), American Meteorological Society, and the Integrated Ocean Observing System. He is the Director of the Center for Maritime Systems at Stevens, which works to preserve and secure our nation’s maritime resources and assets through collaborative knowledge development, innovation and invention, and education and training. The Center integrates the fields of naval architecture, coastal and ocean engineering, physical oceanography, marine hydrodynamics and maritime security to address the highly-specialized issues confronting each discipline, as well as the more complex, integrated issues facing natural and man-made maritime systems.


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