A FIELD AND GIS-BASED ANALYSIS OF LAND-USE INDUCED SEDIMENTATION IN EASTERN CONNECTICUT

This study examines the consequences of landuse change in terms of erosion at a broad scale using GIS/RUSLE, and associated deposition at a local scale based on field measurements. The primary study site, a campus forest/wetland property (Arboretum), serves as a learning resource for students in a variety of classes at Eastern Connecticut State University (ECSU). Recent clearing of forest for a housing subdivision (4.7 ha) adjacent to the Arboretum has resulted in significant sedimentation. Detailed measurements of eroded sand thickness (n > 150), and total station survey data points (n >270) were imported into 3D modeling software to create isopach maps and estimate the total sand volume (2830 m^3). Analysis of the results, indicate substantial spatial variability in the thickness and lateral extent of these deposits, particularly in the vicinity of a stonewall. Sands are dramatically thicker, by a factor of 2 or more, on the up slope side of the wall where funneling also influences the distribution of sediments down slope. In addition to valley side deposits, two percussion core samples were recovered from a pond and wetland complex located down slope. The cores indicate substantial contributions of sand from the construction site including redistribution well after initial deposition. Ongoing GIS analysis makes use of NED 10 meter digital elevation model data, Department of Environmental Protection (DEP) soil and landuse shapefiles and other inputs derived from NRCS/RUSLE website. These results from both GIS analysis and a field based approach will be used to determine similarities between spatial characteristics of the primary study site and the larger watershed containing it.