{"accessLevel": "public", "bureauCode": ["010:12"], "contactPoint": {"@type": "vcard:Contact", "fn": "Kalle L. Jahn", "hasEmail": "mailto:kjahn@usgs.gov"}, "description": "This groundwater model application data release documents transient and steady-state regional and inset numerical models of the Long Island aquifer system that simulate groundwater flow and nitrogen transport for the period 1900-2019 using the US Geological Survey groundwater modeling software MODFLOW 6 (Langvin and others, 2017 and 2022). The development and calibration of the regional groundwater flow model is documented in Walter and others (2024). The development of the regional groundwater nitrogen transport model and inset groundwater flow and nitrogen transport models are documented in Jahn and Walter (2025). The particle-tracking algorithm MODPATH 7 (Pollock, 2016) was used to simulate advective transport in the aquifer, to delineate the areas at the water table that contribute recharge to coastal water bodies, and to estimate total travel times of water from the water table to discharge locations. Model input and output files included in this data release are documented in the readme.txt.\nFirst posted August 2025, ver 1.0\nRevised January 2026, ver 2.0\nVersion 1.0: \nIn this version of the dataset, models MF7, MF8, and MF9 had 250x250-foot inset\nmodel arrays (such as recharge, nitrogen inputs, initial conditions) that were\nshifted north by 1 regional model rows (equivalent to 500 feet) and west by 1\nregional model column (equivalent to 500 feet) due to a geospatial processing\nerror. This resulted in the incorrect placement of those arrays relative to the\ninset coastlines. Additionally, the MF7 recharge input file\n(inset_historic_lgr/child-flow.rcha) points to a single average 2010-2019\nrecharge array for each of the 10 stress periods rather than the 10 unique\narrays representing annual average recharge rates for each year from 2010-2019.\nVersion 2.0:\nThis version of the dataset has been updated with correctly aligned inset model\narrays for MF7, MF8, and MF9. The MF7 recharge input file has been updated to\ncorrectly point to the 10 annual average recharge arrays. Corresponding model\noutput files have been updated.", "distribution": [{"@type": "dcat:Distribution", "accessURL": "https://doi.org/10.5066/P14KKUF7", "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.6825e5c9d4be02062b8d5182.xml", "format": "XML", "mediaType": "text/xml", "title": "Original Metadata"}], "identifier": "http://datainventory.doi.gov/id/dataset/USGS_6825e5c9d4be02062b8d5182", "keyword": ["Kings County", "Long Island", "MODFLOW 6", "MODPATH 7", "Nassau County", "New York", "Queens County", "Suffolk County", "USGS:6825e5c9d4be02062b8d5182", "environment", "geoscientificInformation", "groundwater", "inlandWaters", "model", "modflow6", "nitrogen", "usgsgroundwatermodel"], "modified": "2026-01-12T00:00:00Z", "publisher": {"@type": "org:Organization", "name": "U.S. Geological Survey"}, "spatial": "-74.0665, 40.3862, -71.7916, 41.2270", "theme": ["geospatial"], "title": "MODFLOW 6 Models Used to Simulate Groundwater Flow and Nitrogen Transport in the Long Island Sound Watershed on Long Island, New York (ver. 2.0, January 2026)"}