![]() ![]() The remaining parks were processed using the best available digital GIS park boundary. As of September 2018, 375 parks were processed using LRD endorsed digital GIS boundaries. An 'official' LRD endorsed digital GIS park boundary, however, is not available for all park units. This project strives to use the most up-to-date park boundaries supplied by the NPS Land Resources Division (LRD). Hydrographic statistics are also greatly influenced by the park boundary used when processing a park. Incorporating larger scale data into the NHD would typically increase the values of all hydrographic statistics. Additionally, hydrographic statistics may also change if higher-resolution/larger scale data are incorporated into NHD (e.g. Consequently, statistics generated for a park based on NHD data downloaded in 2009 may be different than the same statistics generated on NHD data downloaded in 2011 due to corrections to the geometric network, topology, and attributes made during various USGS maintenance phases and state stewardship efforts. Geological Survey (USGS) and state stewards constantly seek to improve the database. Although officially complete since August 2007, the NHD is a dynamic representation of the surface water network. The hydrographic statistics presented here are based on processing the high-resolution (1:24,000 1:63,360 in Alaska, except for Bering Land Bridge National Preserve, Cape Krusenstern National Monument, Denali National Park, and Glacier Bay National Park, which have been updated to 1:24,000 scale) National Hydrography Dataset (NHD).
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |