Data Repositories

Below are a handful of online geospatial data repositories where users can access data for their projects at no cost. Federal and state agencies, as well as conservation groups, are often sources of secondary data. The datasets are often highly variable in terms of their geographic scope, level of detail, and currentness, which often necessitates data preparation tasks such as conversion, standardization, and subset creation. In an effort to simplify commonly used datasets for immediate use, many of these tasks have already been performed.

Basemaps

In the Carr Hall GIS lab, students may access the following "ready-to-use" datasets stored in the M:\Basemaps directory. Users can either open the project file containing all the layers for a particular theme or add layers individually. Click this link for more detailed information about each dataset.

Agriculture (📸) - Cropland Data Layer (CDL), 2008 to 2023
Boundaries (📸) - State, county, municipalities, and populated places
Cadastral (📸) - Land boundaries, owners, acreages, landuse, etc.
Elevation (📸) - Digital elevation models (DEM) at various resolutions
Geology (📸) - Soil zones, along with chemical and physical properties
Hydrography (📸) - Surface water such as streams, lakes, and wetlands
Imagery (📸) - Aerial photography captured at various times and resolutions
Indexes (📸) - Latitude and longitude gridlines
Landcover (📸) - National Land Cover Datasets (NLCD) from 1985 to 2024
Public (📸) - National forests, state park and game lands, wildlife refuges, etc.
Topography (📸) - U.S. Geological Survey topographic map sheets at various scales
Transportation (📸) - Highways, rural roads, city streets, railroads, airports, etc.

Online Repositories

Here is a list of online sources of data that are freely available to the public.

ArcGIS Living Atlas of the World - collection of maps, apps, and data layers
CropScape - Access to the Cropland Data Layer (CDL) for the conterminous U.S.
EarthExplorer - Recent and historical aerial and satellite imagery for the U.S.
MRLC Viewer - Landcover, impervious surfaces, and tree canopy from the National Land Cover Dataset (NLCD)
National Map Download - A little bit of everything, but primarily where DEM's and hydrography can be acquired
Open Data Site - Datasets related to Crawford County, Pennsylvania
PASDA - A little bit of everything, but all data sources are specific to the state of Pennsylvania
Web Soil Survey - County soil surveys including horizon boundaries and chemical and physical properties

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