APPLICATIONS OF LIDAR IN THE STUDY OF LANDSCAPE GEOMORPHOLOGY, SANDWICH RANGE, WHITE MOUNTAIN NATIONAL FOREST

This study evaluated and classified landscape geomorphology through the remote analysis of 2014, 1-meter resolution LiDAR imagery. The study area is located in the southern portion of the White Mountain National Forest, in central-eastern NH, between the Kancamagus Highway to the north and the Mts. Whiteface, Tripyramid, and Chocorua to the south and east. The study area contains the following geology. Bedrock: two members of the White Mountain Magma Series (WMMS), the Jurassic Conway and Mt. Osceola Granites, that intrude Silurian and Ordovician metasedimentary rocks. Glacial: Quaternary depositional and erosional features from the Wisconsinan glaciation. Fluvial: Modern and Holocene fluvial landforms.

The bedrock, glacial and fluvial regimes which influenced and shaped the region are evident in processed LiDAR imagery through the following signatures: exposed bedrock regions are characterized through rough, densely-spaced jagged texture intersected by lineaments ranging from 3 to 23 m in length, generally striking NE-SW. Bedrock overlain by thin surficial deposits still displays lineaments, but exhibits a smoother, more uniform surface. Bedrock controlled regions in the study region are found at the highest elevations (2000-4000 ft). Glacial features include but are not limited to: hummocky till which shows a rounded topography, organized in a grid-like pattern with individual features measuring less than 200 ft across. Till which appears as homogeneous and defined by smooth sloping topography, is either dissected by fluvial channels of 1-2 meters, 3-4 meters apart or not. Meltwater channels appear as deep features, around 110 meters across, parallel to contours on the SW side of mountains. Linear eskers and moraine glacial features, and post glacial boulder deposits are also found. Glacial regions are present at lower elevations (1000 to 2000 feet). Fluvial features in the region include inactive, raised and active terraced floodplains, and active river channels, and alluvial fans (present between 1600 and 1400 feet). Fluvial features are found at the lowest elevations in the study region.

Through the delineation boundaries between the various landscape units, this study generated a series of landscape geomorphologic maps of the entire region using LiDAR supported by ground truthing.