What does this mean?
Land use within a watershed has a major effect on the water quality, hydrology and ecology present in the waterbodies within it. Runoff from agriculture and the built (urban, suburban) environment may adversely affect water quality due to non-point source pollution, such as sediments and nutrients, while wetlands have a positive impact by serving to control flooding and to filter pollutants. When vegetation is removed from the landscape during development, the watershed's ability to absorb nutrients and trap sediments is diminished, while more fertilizers, car emissions, industrial and sanitary wastes, and debris are washed into surface and groundwater by stormwater runoff.
How are the data collected? (Methods)
Land Use/Land Cover GIS data is photointerpreted from current digital orthophotos, primarily by local Water Management Districts. The methods used differ by agency, but generally older land use/land cover layers are brought into GIS and compared to the current imagery. Changes are noted and reviewed, and ultimately updated within the GIS data. Land use classifications should adhere to the statewide classifications set forth with the Florida Land Use, Land Cover Classification System (FLUCCS).
To learn more about individual methods used by each Water Management District for their most recent data, review the GIS metadata below:
SJRWMD Land Use and Land Cover (2009)
SWFWMD 2009 Land Use/Cover Classifications
SFWMD 2008 Land Cover Land Use Geodatabase
The major land use classifications are:
- Urban and built-up: This land consists of areas of intensive use with much of the land occupied by man-made structures. Included in this category are cities, towns, villages, strip developments along highways such areas as those occupied by malls, shopping centers, industrial and commercial complexes and institutions that may, in some instances, be isolated from urban areas.
- Agriculture: In a broad sense, agricultural lands may be defined as those lands which are cultivated to produce food crops and livestock.
- Rangeland: Historically, rangeland has been defined as land where the potential natural vegetation is predominantly grasses, grasslike plants, forbs or shrubs and is capable of being grazed. Management practices may include brush control, regulation of grazing intensity and season of use. If revegetated to improve the forage cover, it is managed like native vegetation. Generally, this land is not fertilized, cultivated or irrigated.
- Upland Forest: The upland forest category of land cover is reserved for those upland areas which support a tree canopy closure of ten percent or more. The Upland Forests include both the xeric (drysite) and mesic (moderately moist site) forest communities.
- Water: The delineation of water areas depends upon the scale and resolution characteristics of the remote sensor imagery used for interpretation. One definition of water bodies, provided by the Bureau of Census, includes all areas within the land mass of the United States that are predominantly or persistently water covered provided that, if linear, they are at least 1/8 mile (660 feet or 200 meters) wide or, if extended, cover at least 40 acres (16 hectares). However, in other instances, water bodies of one acre will be identified and plotted.
- Wetlands are frequently associated with topographic low lying areas. Examples of Wetlands include marshes, mudflats, emergent vegetation areas and swamps. Shallow water areas with submerged aquatic vegetation are usually, but not always, classed as water and not included in the Wetlands category.
- Barren Land has very little or no vegetation and limited potential to support vegetative communities. In general, it is an area of bare soil or rock. Vegetation, when present, is very sparse and scrubby. However, caution should be exercised since barren land may temporarily exist due to human activity. Barren Land categories include beaches exhibiting little or no evidence of human encroachment, sand other than beaches, exposed rock and disturbed lands.
- Transportation, Communication & Utilities: Transportation facilities are used for the movement of people and goods; therefore, they are major influences on land and many land use boundaries are outlined by them. Airwave communications, radar and television antennas with associated structures are typical major types of communication facilities that will be identified in this category. Utilities usually include power generating facilities and water treatment plants including their related facilities such as transmission lines for electric generation plants and aeration fields for sewage treatment sites.
For more detailed information about these classifications (and their associated sub-classes) refer to the Florida Land Use, Cover and Forms Classification System, a document prepared by the Florida Department of Transportation.
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