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)

Dates

Release Date: 2021-01-01
Start Date: 2005-01-01
End Date: 2015-12-31
Publication Date: 2023-09-15

Citation

Walter, D.A., Masterson, J.P., Finkelstein, J.S., Monti, J. Jr., Misut, P.E., and Fienen, M.N., 2021, 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): U.S. Geological Survey data release, https://doi.org/10.5066/P9KWQSEJ.

Summary

In 2016, the United States Geological Survey (USGS) began development of a regional-scale numerical model of the Long Island aquifer system, as part of the National Water Quality Assessment (NAWQA) Program. The three-dimensional groundwater-flow model was developed to evaluate 1) responses of the hydrologic system to changes in natural and anthropogenic hydraulic stresses 2) the subsurface distribution of groundwater age, and 3) the regional-scale distribution of groundwater travel times and the source of water to fresh surface waters and coastal receiving waters. The model also provides the groundwater flow components used to define model boundaries for possible inset models used for local-scale analyses. Unconsolidated sediments [...]

Summary

In 2016, the United States Geological Survey (USGS) began development of a regional-scale numerical model of the Long Island aquifer system, as part of the National Water Quality Assessment (NAWQA) Program. The three-dimensional groundwater-flow model was developed to evaluate 1) responses of the hydrologic system to changes in natural and anthropogenic hydraulic stresses 2) the subsurface distribution of groundwater age, and 3) the regional-scale distribution of groundwater travel times and the source of water to fresh surface waters and coastal receiving waters. The model also provides the groundwater flow components used to define model boundaries for possible inset models used for local-scale analyses. Unconsolidated sediments underlying the Island comprise a sole source aquifer that supplies water to about 2.9 million people in Nassau and Suffolk Counties; the aquifer also contributes groundwater discharge to freshwater and marine ecosystems. Anthropogenic activities have affected both the quantity and quality of groundwater, owing to the Island's large population and the generally unconfined conditions prevalent across the aquifer system. Groundwater withdrawals, particularly in the western part of the Island, have resulted in large declines in water-table altitude and in the landward movement of the freshwater/saltwater interface encroaching on local water supplies. Subsurface contamination emanating from numerous point sources, often associated with industrial sites in developed areas in western Long Island, adversely affect downgradient water supplies. In central and eastern Long Island, nutrients emanating from non-point sources associated with residential development and agricultural activities have degraded water quality in shallow parts of the aquifer system. The model uses the numerical code MODFLOW-NWT to represent steady-state conditions for predevelopment and 2005-2015 average groundwater pumping and aquifer recharge. The particle-tracking algorithm MODPATH was used to simulate advective transport in the aquifer, to delineate the areas at the water table that contribute recharge to coastal and freshwater bodies, and to estimate total travel times of water from the water table to discharge locations. This USGS data release contains all of the input and output files for the simulations described in the associated model documentation report (https://doi.org/10.3133/sir20205091). UPDATE: In July 2021, the MODFLOW-NWT output for the steady-state 2005-2015 model were used with the particle-tracking algorithm MODPATH6 to estimate the recharge areas to 1,662 simulated public-supply wells in the aquifer system underlying Long Island, NY. An array of particles with a uniform spacing of 250 feet were specified at the water table and tracked forward to model cells containing simulated wells. The starting locations of the particles terminating in the simulated well represents the recharge area to that well. The particle starting locations were then georeferenced and used to create a polygon shapefile of individual recharge areas. This new information has been added to the ancillary directory of this data releases - December 2021.

Contacts

Point of Contact :: Donald A. Walter, U.S. Geological Survey
Originator :: Donald A. Walter, John P. Masterson, Jason S. Finkelstein, Jack Monti Jr, Paul E. Misut, Michael N. Fienen
Metadata Contact :: U.S. Geological Survey
SDC Data Owner :: New York Water Science Center
USGS Mission Area :: Water Resources

Attached Files

sorting

Metadata First

Recent First

Alphabetical

Click on title to download individual files attached to this item.

sir2020-5091.xml Original FGDC Metadata	View	20.49 KB	application/fgdc+xml
Version_History_2.0_sir2020-5091.txt		3.04 KB	text/plain
readme.txt		42.25 KB	text/plain
modelgeoref.txt		1.16 KB	text/plain
bin.zip		11.02 MB	application/zip
georef.zip		186.71 KB	application/zip
model.zip		91.54 MB	application/zip
source.zip		32.61 MB	application/zip
sir2020-5091Thumbnail.jpg		161.99 KB	image/jpeg
ancillary.zip		782.52 MB	application/zip
output.zip		622.42 MB	application/zip

Related External Resources

Type: Related Primary Publication

Related Primary Publication	https://doi.org/10.3133/sir20205091

Type: browseImage

Image of the model domain and active and inactive areas of the model.	https://www.sciencebase.gov/catalog/file/get/631405e0d34e36012efa3480?name=sir2020-5091Thumbnail.jpg

Purpose

The groundwater-flow model of the aquifer system of Long Island, New York was developed to evaluate 1) responses of the hydrologic system to changes in natural and anthropogenic hydraulic stresses 2) the subsurface distribution of groundwater age, and 3) the regional-scale distribution of groundwater travel times and the source of water to fresh surface waters and coastal receiving waters. The model also provides the groundwater flow components used to define model boundaries for possible inset models used for local-scale analyses. The development of the model input and output files included in this data release are documented in the U.S. Geological Survey Scientific Investigations Report 2020-5091 (https://doi.org/10.3133/sir20205091).

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)

Dates

Citation

Summary

Summary

Contacts

Attached Files

sorting

Metadata First

Recent First

Alphabetical

Purpose

Preview Image

Map

Communities

Tags

Provenance

Additional Information

Identifiers

Item Actions

View Item as ...

Save Item as ...

View Item...

Dates

Citation

Summary

Summary

Contacts

Attached Files sorting Metadata First Recent First Alphabetical

Related External Resources

Purpose

Preview Image

Map

Communities

Tags

Provenance

Additional Information

Identifiers

Item Actions

View Item as ...

Save Item as ...

View Item...

Attached Files

sorting

Metadata First

Recent First

Alphabetical