{"accessLevel": "public", "bureauCode": ["010:12"], "contactPoint": {"@type": "vcard:Contact", "fn": "Donald A. Walter", "hasEmail": "mailto:dawalter@usgs.gov"}, "description": "In 2016, the United States Geological Survey (USGS) began development of a regional-scale numerical\nmodel of the Long Island aquifer system, as part of the National Water Quality Assessment (NAWQA) \nProgram. The three-dimensional groundwater-flow model was developed to evaluate 1) responses of the \nhydrologic system to changes in natural and anthropogenic hydraulic stresses 2) the subsurface \ndistribution of groundwater age, and 3) the regional-scale distribution of groundwater travel times and \nthe source of water to fresh surface waters and coastal receiving waters. The model also provides the \ngroundwater flow components used to define model boundaries for possible inset models used for \nlocal-scale analyses. Unconsolidated sediments underlying the Island comprise a sole source aquifer \nthat supplies water to about 2.9 million people in Nassau and Suffolk Counties; the aquifer also \ncontributes groundwater discharge to freshwater and marine ecosystems. Anthropogenic activities \nhave affected both the quantity and quality of groundwater, owing to the Island's large population and \nthe generally unconfined conditions prevalent across the aquifer system. Groundwater withdrawals, \nparticularly in the western part of the Island, have resulted in large declines in water-table altitude and \nin the landward movement of the freshwater/saltwater interface encroaching on local water supplies. \nSubsurface contamination emanating from numerous point sources, often associated with industrial \nsites in developed areas in western Long Island, adversely affect downgradient water supplies. In \ncentral and eastern Long Island, nutrients emanating from non-point sources associated with \nresidential development and agricultural activities have degraded water quality in shallow parts of \nthe aquifer system. The model uses the numerical code MODFLOW-NWT to represent steady-state \nconditions for predevelopment and 2005-2015 average groundwater pumping and aquifer recharge. \nThe particle-tracking algorithm MODPATH was used to simulate advective transport in the aquifer, \nto delineate the areas at the water table that contribute recharge to coastal and freshwater bodies, \nand to estimate total travel times of water from the water table to discharge locations. This USGS \ndata release contains all of the input and output files for the simulations described in the associated \nmodel documentation report (https://doi.org/10.3133/sir20205091). UPDATE: In July 2021, the \nMODFLOW-NWT output for the steady-state 2005-2015 model were used with the particle-tracking \nalgorithm MODPATH6 to estimate the recharge areas to 1,662 simulated public-supply wells in the \naquifer system underlying Long Island, NY. An array of particles with a uniform spacing of 250 feet \nwere specified at the water table and tracked forward to model cells containing simulated wells. The \nstarting locations of the particles terminating in the simulated well represents the recharge area to \nthat well. The particle starting locations were then georeferenced and used to create a polygon \nshapefile of individual recharge areas. This new information has been added to the ancillary directory \nof this data releases - December 2021.", "distribution": [{"@type": "dcat:Distribution", "accessURL": "https://doi.org/10.5066/P9KWQSEJ", "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.64bd0ee4-9afb-4086-b2ec-4d2c1aa749a1.xml", "format": "XML", "mediaType": "text/xml", "title": "Original Metadata"}], "identifier": "http://datainventory.doi.gov/id/dataset/USGS_64bd0ee4-9afb-4086-b2ec-4d2c1aa749a1", "keyword": ["Groundwater", "Groundwater Model", "InlandWaters", "Kings County", "Long Island", "MODFLOW-NWT", "MODPATH6", "Nassau County", "New York", "Queens County", "Suffolk County", "USGS:64bd0ee4-9afb-4086-b2ec-4d2c1aa749a1", "environment", "geoscientificInformation", "inlandWaters", "particle tracking", "usgsgroundwatermodel"], "modified": "2021-12-06T00:00:00Z", "publisher": {"@type": "org:Organization", "name": "U.S. Geological Survey"}, "spatial": "-74.164641, 40.351862, -71.701159, 41.383572", "theme": ["geospatial"], "title": "MODFLOW-NWT and MODPATH6 Models Used to Simulate Groundwater Flow in the Regional Aquifer System of Long Island, New York, for Pumping and Recharge Conditions in 2005-2015 (ver. 2.0, December 2021)"}