{"accessLevel": "public", "bureauCode": ["010:12"], "contactPoint": {"@type": "vcard:Contact", "fn": "Jeffrey Kennedy", "hasEmail": "mailto:jkennedy@usgs.gov"}, "description": "A numerical model was developed using MODFLOW-NWT and FloPy to simulate groundwater flow and \ndemonstrate a practical method for incorporating repeat microgravity observations (i.e., small changes in \nthe acceleration due to Earth\u2019s gravity) as a new type of calibration target for groundwater-flow models. \nThe single-layer, 250-m cell size model was kept relatively simple to focus on the value of repeat microgravity \ndata in the East Mesa area of the Imperial Valley, in the vicinity of the All American Canal, southeast \nCalifornia, USA. The method is demonstrated with repeat microgravity data collected over a 10-year period \nfollowing the lining of the All American Canal with concrete. This lining of the canal resulted in the removal \nof a large source of seepage (recharge) causing groundwater levels, groundwater storage, and gravity all \nto declined considerably. The study area and field data are used to demonstrate a novel forward gravity \nmodeling application linked to MODFLOW input and output files. The analysis demonstrates that including \ngravity data, compared to drawdown data alone, improves model parameter identifiability and reduces \nuncertainty in parameter estimates. This USGS data release contains all of the input and output files for the \nsimulations described in the associated journal article (https://doi.org/10.1111/gwat.13167).", "distribution": [{"@type": "dcat:Distribution", "accessURL": "https://doi.org/10.5066/P9575C61", "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.79e2e22d-b0cb-4b3b-a9a5-d9f32f679d22.xml", "format": "XML", "mediaType": "text/xml", "title": "Original Metadata"}], "identifier": "http://datainventory.doi.gov/id/dataset/USGS_79e2e22d-b0cb-4b3b-a9a5-d9f32f679d22", "keyword": ["Algodones Dunes", "Arizona Water Science Center", "California", "Colorado River", "Groundwater", "Groundwater Model", "Imperial County", "Imperial Valley", "InlandWaters", "MODFLOW-NWT", "PEST++", "Southwest Gravity Program", "USGS:79e2e22d-b0cb-4b3b-a9a5-d9f32f679d22", "environment", "geoscientificInformation", "location", "repeat microgravity", "usgsgroundwatermodel"], "modified": "2022-01-05T00:00:00Z", "publisher": {"@type": "org:Organization", "name": "U.S. Geological Survey"}, "spatial": "-115.3400, 32.5700, -114.6039, 33.0823", "theme": ["geospatial"], "title": "MODFLOW-NWT groundwater model demonstrating groundwater model calibration with repeat microgravity measurements"}