A false-color raster GIS dataset derived from Landsat TM satellite imagery is availbale from the Intermountain Region Digital Image Archive Center (IRDIAC) hosted by Utah State University (USU). This dataset makes for a great background / base map for digital mapping. A statewide Mr.SID mosaic and Imagine format (.IMG) files for individual counties are available through IRDIAC: http://earth.gis.usu.edu/statemosiac.html .
Raster GIS data depicting vegetation / land cover distribution can be accessed from the Intermountain Region Digital Image Archive Center (IRDIAC) hosted by Utah State University (USU). Datasets that include Utah include the 1995 Utah GAP Land Cover dataset, and the 2004 Southwest Region GAP land cover dataset.
The State Geographic Information Database (SGID) contains files and links to several different categories of data sets. Data presented for download on this site is considered to be in the public domain.
There are two main categories: vector GIS data sets [more info] wherein geographic features are represented by discrete points, lines, and polygons; and, raster data sets [more info], which represent geographic phenomena using a grid of raster cells or pixels.
Generally speaking, vector data is usually used to describe features such as roads, municipal boundaries (such as cities or counties), springs, streams, airports, etc.
Raster GIS data sets usually consist of data obtained from satellite or other remotely sensed data, and includes aerial photos, digital elevation models, scanned images of paper maps, etc.
Depending on the type of data, different data storage formats are used. Index web pages are maintained for vector and raster data on this portal that assist with the download process for specific geographic extents. These indexes also provide a link to metadata describing the datasets in detail.
Note: Most data contained within the SGID uses the Universal Transverse Mercator projected coordinate system (UTM Zone 12 North) using the 1983 North American Datum (NAD83). UTM Zone 12N, NAD 83 is the current state standard for projection, coordinate system, and datum.
A new polyline-based feature class, U024.LakesNHDHighRes, representing lakes, ponds, reservoirs, evaporation ponds, swamps, tailings ponds, and other water bodies is now available on the SGID 9.2 ArcSDE Database Server in the U024.Hydrology feature dataset. This feature class was derived from the National Hydrology Dataset (NHD) flow lines layer and offers the GNIS name (where available), reach code, and feature type/code among other attributes (see description of added cartographic attributes below). The NHD polygon work has been photo revised to the latest edition of the black and white DOQ aerial photography. Shapefiles and File-Based Geodatabase files for this layer are available on AGRC’s ftp site at: ftp://ftp.agrc.utah.gov/SGID_Vector/Hydrology/SGID_U024_LakesNHDHighRes
The state of Utah contains many hydrologic units and the relevant units have been aggregated into this new composite layer that includes some features that cross the state boundary (these have been split at the boundary into 2 features) and, also some features outside the state boundary. In order to allow for cartographic projects that are bounded by the state boundaries, an attribute field called InUtah has been added and can be used to query just those features within Utah (InUtah = 1).
In addition, an attribute field called IsMajor has been added to facilitate the display of major water bodies. This attribute was coded by AGRC staff (IsMajor = 1). Water bodies greater than 0.9 sq kilometers in area were used as a starting point for assigning this attribute value.
AGRC plans to host the full NHD hydrologic modelling datasets in the future, at present this data is available by NHD subregion from the USGS website: http://nhd.usgs.gov/data.html
