A Disturbance Automated Reference Toolset (DART) for Monitoring Anthropogenic Impacts.

A new disturbance automated reference toolset (DART) was developed to monitor human land surface impacts using soil-type and ecological context. DART identifies reference areas by using a newly developed 30-m map of soil particle size in the control section (as defined by US Soil Taxonomy) and local neighborhood unsupervised classifications of digital topography data and Landsat 8 band ratios. These mapping layers are used to match a disturbance location to nearby reference areas with the similar soil texture, topography, and geologic classes. Parallel work on the underlying automated reference toolset infrastructure shows that reference areas closely map the ecological potential of sites. Reference areas identified by DART are then used to compare with the disturbance using satellite vegetation index data as a proxy for vegetation cover. Vegetation recovery on abandoned oil and gas well-pads on the Colorado Plateau was assessed using DART. At those sites, DART was able to represent 52% of variation of relative differences in exposed bare ground when comparing well-pads on the Plateau with nearby ecological reference areas using the soil adjusted total vegetation index (SATVI). Half of well-pads plugged and abandoned from 1997-2005 (n=1866) on the Plateau fell below the 23^rd percentile of their paired reference areas indicating generally poor recovery by 2014, the date of the SATVI image used for comparison. Recovery was poorer in grasslands, blackbrush (Coleogyne ramosissima), arid canyon complexes, warmer areas with more summer dominated precipitation, and state administered areas. Results showcase the usefulness of DART for assessing discrete surface land disturbances, and highlight the need for more targeted rehabilitation efforts at oil and gas well-pads.