i16 Census County DisadvantagedCommunities 2023
공공데이터포털
,The IRWM web based DAC mapping tool uses this GIS layer. Created by joining ACS 2019-2023 5 year estimates to the 2020 Census Counties feature class. The TIGER/Line Files are shapefiles and related database files (.dbf) that are an extract of selected geographic and cartographic information from the U.S. Census Bureau's Master Address File / Topologically Integrated Geographic Encoding and Referencing (MAF/TIGER) Database (MTDB). The MTDB represents a seamless national file with no overlaps or gaps between parts, however, each TIGER/Line File is designed to stand alone as an independent data set, or they can be combined to cover the entire nation. The primary legal divisions of most States are termed counties. In Louisiana, these divisions are known as parishes. In Alaska, which has no counties, the equivalent entities are the organized boroughs, city and boroughs, and municipalities, and for the unorganized area, census areas. The latter are delineated cooperatively for statistical purposes by the State of Alaska and the Census Bureau. In four States (Maryland, Missouri, Nevada, and Virginia), there are one or more incorporated places that are independent of any county organization and thus constitute primary divisions of their States. These incorporated places are known as independent cities and are treated as equivalent entities for purposes of data presentation. The District of Columbia and Guam have no primary divisions, and each area is considered an equivalent entity for purposes of data presentation. The Census Bureau treats the following entities as equivalents of counties for purposes of data presentation: Municipios in Puerto Rico, Districts and Islands in American Samoa, Municipalities in the Commonwealth of the Northern Mariana Islands, and Islands in the U.S. Virgin Islands. The entire area of the United States, Puerto Rico, and the Island Areas is covered by counties or equivalent entities. The 2020 Census boundaries for counties and equivalent entities are as of April 1, 2020, primarily as reported through the Census Bureau's Boundary and Annexation Survey (BAS).,
i17 Delta Levees Anatomy 2007
공공데이터포털
In the Delta Anatomy Mapping Project all levee anatomies were delineated using slope grids built from available LIDAR data points. LIDAR data points were converted to digital elevation models and subsequently into slope grids. Thresholds were identified that capture the levee crown, levee landside, levee waterside, ramps and toe ditches. Visual interpretations of slope thresholds were used in conjunction with heads-up digitizing to maintain smooth boundaries at a scale of 1:550. The delineation thresholds were derived from a combination of mapping scale, slope grid resolution and slope thresholds used for each anatomy classification. All anatomy has gone through an internal quality control process to ensure a minimum locational quality of +/- 3 feet. Anatomy was further reviewed and tested by DWR for compliance with an interpretive mapping standard of 80% accuracy. This data depicts the levee anatomy at the time of the LiDAR survey (2007) and are only accurate for that time. Users should be aware that temporal changes may have occurred since this data set was created and some parts of this data may no longer represent actual surface conditions.