This layer displays information about the location and characteristics of the nation’s operating farmers markets.
STD Incidence / HIV Prevalence by County
Layers display information about new incidence of sexually transmitted infections, and the prevalence of HIV / AIDS.
SNAP Recipients by County, 2013
This layer displays the percentage of population receiving SNAP benefits by county. Data are from the US Census Bureau 2014 Small Area Income and Poverty Estimates (SAIPE) dataset, released December 2015.
Hypertension (High Blood Pressure) Among Medicare Beneficiaries by County, 2014
This layer shows the percentage of Medicare Beneficiaries with hypertension (high blood pressure). The prevalence of chronic conditions among Medicare beneficiaries based on Medicare insurance claims data in 2014.
Physical Inactivity by County, 2013
Layer displays the estimated percentage of adults who do not participate in any leisure-time physical activity. These figures are multi-year modeled estimates based on survey data from the CDC Behavioral Risk Factor Surveillance System.
Adult Obesity by County, 2013
Layer displays the estimated percentage of adults who are in obese across all counties in the United States. These figures are multi-year modeled estimates based on survey data from the CDC Behavioral Risk Factor Surveillance System.
Farm to School Participation by School District
This layer displays Farm to School participation based on responses to the 2013 Farm to School Census. Participation data refer primarily to activities occurring during the 2011-12 school year.
Hydrography – Waterbodies
Hydrography depicts surface water, including rivers and streams, lakes and ponds, canals, coastlines, and many other water features. The Hydrography layer combines two data sets: the 2014 National Map Hydrographic Geodatabase (1:1,000,000 scale) for small to medium scales, and the 2016 National Hydrography Datataset (NHD) (1:24,000 scale) for large scale mapping. Hydrography is depicted in two layers. Rivers & Streams depicts linear hydrography, including rivers, streams, canals, pipes, and artificial paths (line networks through larger water bodies). Waterbodies depicts area hydrography, including larger rivers, lakes, ponds, seas, bays, estuaries, etc.
National Hydrography Dataset (Flowline)
The National Hydrography Dataset (NHD) is used to portray surface water. The NHD represents the drainage network with features such as rivers, streams, canals, lakes, ponds, coastline, etc. The principal components of the NHD are:
- NHDFlowline: This is the fundamental flow network consisting predominantly of stream/river and artificial path vector features. It represents the spatial geometry, carries the attributes, models the water flow, and contains linear referencing measures for locating events on the network. Additional NHDFlowline features are canal/ditch, pipeline, connector, underground conduit, and coastline.
- NHDArea: This feature class contains many additional features of water polygons. One of the more important is the stream/river feature. It represents the aerial extent of the water in a wide stream/river with a basic set of attributes. They typically contain NHDFlowline artificial paths that are used to model the stream/river. Artificial path carries the critical attributes of the stream/river, whereas NHDArea represents the geometric extent.
- NHDWaterbody: Basic waterbodies such as lake/pond features are represented here. They portray the spatial geometry and the attributes of the feature. These water polygons may contain NHDFlowline artificial paths to allow the representation of water flow. Other NHDWaterbody features are swamp/marsh, reservoir, playa, estuary, and ice mass.
National Hydrography Dataset (Area)
The National Hydrography Dataset (NHD) is used to portray surface water. The NHD represents the drainage network with features such as rivers, streams, canals, lakes, ponds, coastline, etc. The principal components of the NHD are:
- NHDFlowline: This is the fundamental flow network consisting predominantly of stream/river and artificial path vector features. It represents the spatial geometry, carries the attributes, models the water flow, and contains linear referencing measures for locating events on the network. Additional NHDFlowline features are canal/ditch, pipeline, connector, underground conduit, and coastline.
- NHDArea: This feature class contains many additional features of water polygons. One of the more important is the stream/river feature. It represents the aerial extent of the water in a wide stream/river with a basic set of attributes. They typically contain NHDFlowline artificial paths that are used to model the stream/river. Artificial path carries the critical attributes of the stream/river, whereas NHDArea represents the geometric extent.
- NHDWaterbody: Basic waterbodies such as lake/pond features are represented here. They portray the spatial geometry and the attributes of the feature. These water polygons may contain NHDFlowline artificial paths to allow the representation of water flow. Other NHDWaterbody features are swamp/marsh, reservoir, playa, estuary, and ice mass.