Browsing by Subject "roads"
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Item Methods for Monitoring and Mitigating the Use of Chloride Deicers(2020-01) Klimbal, DouglasThe winter roadway operations and maintenance community generates a breadth of data detailing the activity and performance of snowplows, deicing practices, and road conditions. While roadway ice clearing is a practical need for communities in temperate climates, one outcome of operations is the distribution of unnaturally high levels of dissolved solids, especially chloride, into environments which are hydraulically connected to maintained roadways and surfaces. The long-term buildup of chloride poses a threat to ecological integrity of freshwater systems. Salt also hastens the oxidation of metals used in the built environment, especially high-iron alloys. A 2007 study of the Twin Cities Metropolitan Area estimated that over a 5-year study period, 70% of road salt applied annually was retained in the landscape or infiltrated to deep groundwater. This research examines the road salt mass balance on a finer scale both spatially and temporally. Continuous monitoring of surface runoff was conducted in a small residential watershed using a novel approach. The results are paired with an analysis of snowplow asset tracking data to estimate what proportion of the total salt added to the catchment in the two-year study enters directly into the stormwater conveyance. Results are followed by a critical discussion of current research and considerations for future research.Item Twin Cities Metro Area Road Surface Area, 2022(2023-01-09) Marek-Spartz, Mary; patt0335@umn.edu; Marek-Spartz, Mary; Minneapolis-St. Paul Long-Term Ecological Research; University of MinnesotaThis high-resolution (1 meter) raster represents road surface area for streets (including alleys) in the seven-county Minneapolis-St. Paul Metropolitan area. Minnesota roads data contributing to this layer is compiled from several state and county agencies and accessed through the Minnesota Geospatial Commons. The Minnesota Transportation Department (MNDOT) Lane Information dataset was spatially joined with MNDOT centerlines from 2012 in order to link the Transportation Information System (TIS) ID codes for road segments with the lane information on number of through transit lanes and width of lanes. The resulting layer was then joined on the TIS code attribute with the Geospatial Advisory Council Schema road centerlines shapefile from MetroGIS. To avoid a many-to-one join, MNDOT road segments were grouped by their TIS code and the average lane width and number were summarized to make the layer compatible with the MetroGIS centerlines shapefile. Once the centerline route segment IDs were linked to the MNDOT transit lane information, the centerlines were buffered based on their average width attribute, multiplied by the number of lanes. Alleys were identified and assigned a width of 5 meters based on typical alley width measurements using satellite imagery. Due to transportation identification system scope, confidence in accuracy of private road surface area is diminished. The resulting buffered road segment vectors were rasterized and cropped to the seven-county metro area (Hennepin, Ramsey, Anoka, Washington, Dakota, Scott, and Carver County).