Turf Grass v. Mixed Open Peter Claggett, U.S. Geological Survey March 8, 2016 Urban Stormwater Workgroup Meeting U.S. Department of the Interior U.S. Geological Survey
What s the difference between turf and mixed open? Turf Grass: low vegetation and some barren areas within developed lands and adjacent to non-road impervious surfaces. Mixed Open: scrub-shrub everywhere and low vegetation and barren that is not turf grass or known to be agriculture (e.g., beaches, vacant lots, transmission line right-of-ways, junkyards, fairgrounds, etc.). FOR MXO TG (SwM) 2.1 3.0 14.9 84.4 Relative Nitrogen Export Rate (#/acre/yr) Silage with Manure FOR MXO TG 0.1 0.7 1.2 4.7 Relative Phosphorus Export Rate (#/acre/yr) CON
P6 Developed Areas- defined With local data: Land Use: residential, commercial, industrial, recreational, institutional and other urban uses. Parcels: <=10 acres with >=1% impervious, or >10 acres with >=10% impervious surfaces. With national data: Census Blocks: average housing density >= 0.2 dwelling units per acre (e.g., less than 5-acre lots). Institutional and recreational areas (NAVTEQ, 2014).
Impervious Non-Roads over Developed Land Uses (national data) Developed Areas Impervious Non-Roads over Developed Land Uses (local data) Impervious Non-Roads over Developed Parcels (local data)
Land Cover to Land Use Crosswalk Chesapeake Conservancy/ UVM Phase 6 CBP Worldview Solutions Inc. Water Water + NWI + NHD Water Impervious Roads Impervious Roads Impervious Impervious Structures Impervious Non-Roads Impervious Other Tree Canopy (TC) Forest Forest TC over Roads TC over Turf Grass Trees TC over Structures TC over Impervious Harvested/Disturbed Scrub-shrub Open Space Scrub-shrub Barren Barren Emergent Wetands Tidal Wetlands Wetlands + NWI & State data + Modeled occurrence Low vegetation (herbaceous) Turf Grass Turf Grass Pasture Pasture Cropland Cropland
Shrubbery from High-res Imagery and LiDAR: quintessential mixed open
Turf Grass and Tree Canopy over Turf are near buildings, driveways, and parking lots Urban Area Forest Tree Canopy over Turf Rural Area
Turf Grass vs Agriculture (land cover)
Turf Grass vs Agriculture (low vegetation)
Turf Grass vs Agriculture (developed land use overlay)
Definition Challenges What are the defining characteristics of turf grass? - fertilized? - mowed? - compacted? - minimal organic A soil horizon? - all of the above? What are the defining characteristics of mixed open? - maintained in early successional state (e.g., bush hogged)? - minimally compacted/disturbed? - not fertilized? - potentially barren? - outside developed areas?
Definition Challenges How do we classify low vegetation and barren land within complex land uses: - Institutional campuses - Military installations - County, State, and National Parks - Dirt and gravel roads - Highway right-of-ways - Railroad right-of-ways - Commercial/industrial barren areas - Quarries and surface mines - Landfills - Vacant lots - Sandy and rocky waterbody margins - Adjacent to rural buildings
Solution Low vegetation and barren lands = X% mixed open and X% turf grass: Institutional grounds/campuses Military installations and other Federal Facilities County, State, and National Parks Commercial/industrial areas Quarries and surface mines Low vegetation and barren lands = turf grass: Highway right-of-ways Airports Areas adjacent to buildings, driveways, and parking lots Low vegetation and barren lands = mixed open: Landfills Vacant lots Sandy/rocky outcrops and waterbody margins Beaches Railroad right-of-ways (4m width) = impervious non-roads. Dirt and gravel roads = impervious roads.
Given how turf grass and mixed open are mapped, are the current target loading rates and input assumptions accurate? FOR MXO TG (SwM) 2.1 3.0 14.9 84.4 Relative Nitrogen Export Rate (#/acre/yr) Silage with Manure FOR MXO TG 0.1 0.7 1.2 4.7 Relative Phosphorus Export Rate (#/acre/yr) CON