Improving National Land Cover Database Estimates of Road Network Impervious Cover Using Vector Road Networks in GIS

摘要

Polyline data are often adequate for qualitative representation of roadways for mapping and GIS yet they are often lacking when compared with surface coverages, such as raster data, for performing quantitative environmental simulation modeling where spatial representations are necessary. Widely used land cover raster data, such as the National Land Cover Database (NLCD), were however not collected with sufficient spatial resolution to allow adequate representation of small-scale features such as roadways. Using tools available in ArcGIS software, vector road files were obtained from the Accident Location Information System (ALIS) at the New York State Department of Transportation (NYSDOT) and converted to raster data to create spatially explicit representations of impervious area associated with roadways. Comparison of this new coverage with the NLCD results in an increase of approximately 3120 km~2 of newly identified impervious coverage for New York State (NYS) not present in the NLCD, representing a 244 percent increase from the transportation class in the NLCD. Of the land cover that would be reclassified to roadway using this methodology, approximately 40 percent would be reclassified from forest land, 31 percent from agricultural land, and 28 percent from the residential land cover classifications.