Comparing Different Spatial and Temporal Scales of Erosion Measurements on Santa Cruz Islands, CA

Human-induced soil erosion contributes to a host of global problems, including loss of agricultural productivity and desertification. Quantifying this erosion and understanding its impact over timescales ranging from days to centuries is not only important for a better understanding of earth surface processes but also for a variety of economic, social, and planning purposes. Recent technological advances in high resolution Light Detection and Ranging (LiDAR) instruments allow researchers to examine the earth's surface at a level of detail previously unattainable. Topographic data from a variety of instruments at different spatial scales [SPOT satellite-derived DEM (with a pixel size of 5m), Carnegie Airborne Observatory LiDAR DEM (1.5m), RIEGL Model LMS-Z420i terrestrial LiDAR scanner DEM (< 10 cm), and total station survey measurements] were used to produce and compare erosion estimates for a formerly grazed and heavily degraded watershed on Santa Cruz Island, CA. In addition to the topographic data, exploratory depth profile measurements of the short-lived isotopes 210Pb and 137Cs were collected for (24) samples from four sites along a 600m long hillslope transect within the watershed and used to produce an independent erosion rate estimate for a subsection of the study area.