{"accessLevel": "public", "bureauCode": ["010:12"], "contactPoint": {"@type": "vcard:Contact", "fn": "Integrated Modeling &Prediction Division", "hasEmail": "mailto:gs-w-model-data-management@usgs.gov"}, "description": "This data set represents the average annual nitrogen input from\ncommercial fertilizer applied to agricultural lands, 1992-2001,\nin kilograms per hectare, in the conterminous United States.\nThe data set was used as an input data layer for a national\nmodel to predict nitrate concentration in shallow ground water.\nNolan and Hitt (2006) developed two national models to predict\ncontamination of ground water by nonpoint sources of\nnitrate. The nonlinear approach to national-scale Ground-WAter\nVulnerability Assessment (GWAVA) uses components representing\nnitrogen (N) sources, transport, and attenuation.\nOne model (GWAVA-S) predicts nitrate contamination of shallow\n(typically less than 5 meters deep), recently recharged ground\nwater, which may or may not be used for drinking.  The other\n(GWAVA-DW) predicts ambient nitrate concentration in deeper\nsupplies used for drinking.\nThis data set is one of 17 data sets (1 output data set and 16\ninput data sets) associated with the GWAVA-S model. Full details\nof the model development are in Nolan and Hitt (2006).\nFor inputs to the model, spatial attributes representing 16\nnitrogen loading and transport and attenuation factors were\ncompiled as raster data sets (1-km by 1-km grid cell size) for\nthe conterminous United States (see table 1).\n>Table 1.-- Parameters of nonlinear regression model for nitrate in shallow\n>           ground water (GWAVA-S) and corresponding input spatial data sets.\n>           [kg, kilograms; km2, square kilometers.]\n>\n>Nitrogen Source Factors                  Data Set Name\n>   1 farm fertilizer (kg/hectare)        gwava-s_ffer\n>   2 confined manure (kg/hectare)        gwava-s_conf\n>   3 orchards/vineyards (percent)        gwava-s_orvi\n>   4 population density  (people/km2)    gwava-s_popd\n>   5 cropland/pasture/fallow (percent)   gwava-s_crpa\n>\n>Transport to Aquifer Factors\n>   6 water input (km2/cm)                gwava-s_wtin\n>   7 carbonate rocks (yes/no)            gwava-s_crox\n>   8 basalt and volcanic rocks (yes/no)  gwava-s_vrox\n>   9 drainage ditch (km2)                gwava-s_ddit\n>  10 slope (percent x 1000)              gwava-s_slop\n>  11 glacial till (yes/no)               gwava-s_gtil\n>  12 clay sediment (percent x 1000)      gwava-s_clay\n>\n>Attenuation Factors\n>  13 fresh surface water withdrawal      gwava-s_swus\n>     for irrigation (megaliters/day)\n>  14 irrigation tailwater recovery (km2) gwava-s_twre\n>  15 histosol soil type (percent)        gwava-s_hist\n>  16 wetlands (percent)                  gwava-s_wetl\n\"Farm fertilizer\" is the average annual nitrogen input from\ncommercial fertilizer applied to agricultural lands, 1992-2001, in\nkilograms per hectare.\n\"Confined manure\" is the average annual nitrogen input from\nconfined animal manure, 1992 and 1997, in kilograms per\nhectare.\n\"Orchards/vineyards\" is the percent of orchards/vineyards land\ncover classification.\n\"Population density\" is 1990 block group population density, in\npeople per square kilometer.\n\"Cropland/pasture/fallow\" is the percent of\ncropland/pasture/fallow land cover classifications.\n\"Water input\" is the ratio of the total area of irrigated land\nto precipitation, in square kilometers per centimeter.\n\"Carbonate rocks\" is the presence or absence of Valley and Ridge\ncarbonate rocks.\n\"Basalt and volcanic rocks\" is the presence or absence of basalt\nand volcanic rocks.\n\"Drainage ditch\" is the area of National Resources Inventory surface\ndrainage, field ditch conservation practice, in square kilometers.\n\"Slope\" is the soil surface slope, in percent times 1000.\n\"Glacial till\" is the presence or absence of poorly sorted\nglacial till east of the Rocky Mountains.\n\"Clay sediment\" is the amount of clay sediment in the soil, in\npercent times 1000.\n\"Fresh surface water withdrawal for irrigation\" is the amount of\nfresh surface water withdrawal for irrigation, in megaliters per day.\n\"Irrigation tailwater recovery\" is the area of National\nResources Inventory irrigation system, tailwater recovery\nconservation practice, in square kilometers.\n\"Histosol soil type\" is the amount of histosols soil taxonomic\norder, in percent.\n\"Wetlands\" is the percent of woody wetlands and emergent\nherbaceous wetlands land cover classifications.\nReference cited:\nNolan, B.T. and Hitt, K.J., 2006, Vulnerability of shallow\nground water and drinking-water wells to nitrate in the United\nStates: Environmental Science and Technology, vol. 40, no. 24,\npages 7834-7840.", "distribution": [{"@type": "dcat:Distribution", "accessURL": "https://doi.org/10.5066/P9LJ3IF5", "description": "Landing page for access to the data", "format": "XML", "mediaType": "application/http", "title": "Digital Data"}, {"@type": "dcat:Distribution", "description": "The metadata original format", "downloadURL": "https://data.usgs.gov/datacatalog/metadata/USGS.3b6ec9ba-7493-4c75-8a74-5e595affb269.xml", "format": "XML", "mediaType": "text/xml", "title": "Original Metadata"}], "identifier": "http://datainventory.doi.gov/id/dataset/USGS_3b6ec9ba-7493-4c75-8a74-5e595affb269", "keyword": ["Farm Fertilizer", "Ground water", "Ground water contamination", "Ground water pollution", "Ground water susceptibility", "NAWQA", "National Land Cover Data", "National Water-Quality Assessment Program", "Nitrate", "Nitrate concentration", "Nonlinear model", "Nutrients", "USGS:3b6ec9ba-7493-4c75-8a74-5e595affb269", "environment", "geoscientificInformation", "inlandWaters"], "modified": "2020-11-17T00:00:00Z", "publisher": {"@type": "org:Organization", "name": "U.S. Geological Survey"}, "spatial": "-128.30785909, 22.73659812, -65.14338696, 51.857984", "theme": ["geospatial"], "title": "Vulnerability of shallow ground water and drinking-water wells to nitrate in the United States: Model of predicted nitrate concentration in shallow, recently recharged ground water -- Input data set for farm fertilizer (gwava-s_ffer)"}