Ice Atlas for the Ohio, Allegheny and Monongahela Rivers, 1984-85.
COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER NH
Pagination or Media Count:
Ice conditions on inland rivers can change rapidly and adversely affect navigation. The ice maps in this atlas were prepared to document the 1984-85 ice conditions on those reaches of the Ohio, Allegheny and Monongahela Rivers that are included in study areas for the River Ice Management RIM Program, namely river mile 0 to 437 on the Ohio River, mile 0 to 7 on the Allegheny, and mile 0 to 66 on the Monogahela. The maps were prepared from interpretation of vertical aerial video imagery taken from a low-flying aircraft. The interpreted ice conditions were classified into five units and transferred to base maps by reference to navigation charts and topographic maps. Fragmented Ice Cover and Ice Floes or Frazil Slush and Pans were the most common ice units in the lower pools of the Monongahela River and lower Allegheny. Solid Ice Cover and Fragmented Ice Cover were the most common units in the upper pools of the Monongahela. Fragmented Ice Cover and Open Water were the most extensive units in the Emsworth to New Cumberland pools of the Ohio Open Water and Ice Floes or Frazil Slush and Pans were the predominant units in the downstream pools. There were frequent cancellations of flights during the 1984-85 winter because of low cloud ceilings. To get more frequent video coverage of ice during the 1985-86 winter, a wider-angle lens on the video camera will be used. This will allow flights at a lower altitude, permitting video coverage even when the ceiling is low.
- Snow, Ice and Permafrost