VARIATIONS IN RIVER LONGITUDINAL PROFILES ALONG THE KITTATINNY RIDGE, APPALACHIAN MOUNTAINS

The eastern-most ridge of the Appalachian Mountains, Kittatinny Ridge, extends from New York south to Tennessee and Alabama. The ridge is composed of erosion resistant quartzite conglomerate throughout (Shawangunk Formation) underlain by the Bloomsburg Formation, made up of sandstone, siltstone and shale. The consistent composition of the Kittantinny Ridge makes it ideal for analyzing how variations in climate and glacial history have impacted long-term erosion rates. Variations in climate and glacial history combine to affect erosion rates differently along the ridge, while the relatively consistent lithologic composition of the ridge minimizes changes in bedrock that potentially complicate such studies. This project measured river longitudal profiles and valley hypsometries to determine long-term erosion amounts along the ridge. This was done using geographic information system (GIS) ArcMap v. 10.0 and Arcinfo 10.0 to delineate the ridge and determine valley and river geometries. One-third arc second digital elevation models (DEMs) were downloaded from the National Map, and standard hydrologic GIS procedures (sinks filled, flow direction determined, flow accumulation calculated, and stream networks identified using a threshold of 5,000 cells) followed to determine watershed area and river networks. Trends in the data show a more convex shaped hypsometry and long profile in New Jersey and a more concave hypsometry and long profile in Tennessee. The watershed areas are higher in New Jersey (1.24 km2) than in Tennessee (0.74 km2). New Jersey (0.59) has a higher elongation ratio than Tennessee (0.53). Tennessee also shows a much smaller change in elevation when compared to New Jersey. This data suggests erosion is greater in the southern states than compared to the northern states along the ridge. In order to ground-truth the GIS data, field measurements have been taken with a Total Station and laser range finder at randomly selected streams along the ridge to determine profiles in the field.