Downloads
Data download includes three shapefiles, one tiff image, and 4 ArcGIS layer files (.lyr).
Overview
The Hydrogeologic Atlas of Massachusetts provides data on the hydraulic properties of the statewide surficial aquifers. The datasets were developed using surficial geology, bedrock altitude, a statewide groundwater flow model, and a compilation of hydraulic property data from U.S. Geological Survey groundwater reports, Massachusetts Department of Environmental Protection Zone II reports, and other Massachusetts-specific journal articles (a total of 23 sources).
The Hydrogeologic Atlas includes:
- Hydraulic Conductivity (SURFGEO24K_K_POLY) - This feature class uses the same polygons as the MassGIS USGS 1:24,000 Surficial Geology data layer (SURFGEO24K_MAPUNIT_POLY) and includes minimum, maximum, and average hydraulic conductivity in feet per day for each surficial unit. Hydraulic conductivity values were extracted from U.S. Geological Survey groundwater reports, Massachusetts Department of Environmental Protection Zone II reports, and other Massachusetts-specific journal articles (a total of 165 aquifer tests or aggregates of aquifer tests depending on the available data in each report).
- Specific Yield (SURFGEO250K_SY_POLY) - This feature class uses the same polygons as the MassGIS 1:250,000 Surficial Geology data layer (SURFGEO250K_POLY) and includes minimum, maximum, and average specific yield for each surficial unit. Specific yield values were extracted from U.S. Geological Survey groundwater reports and Morris & Johnson (1967) (a total of 60 aquifer tests).
- Transmissivity and Aquifer Yield (SURFGEO24K_T_AY_POLY) – This polygon feature class (converted from a 100-meter resolution raster dataset) uses the hydraulic conductivity fields from SURFGEO24K_K_POLY, water table elevation from the statewide groundwater flow model, and bedrock altitude to calculate aquifer yield and minimum, maximum, and average transmissivity in square feet per day. Transmissivity was calculated as hydraulic conductivity multiplied by aquifer thickness. Aquifer thickness was determined by the water table elevation minus bedrock altitude. Transmissivity cutoff values to characterize aquifer yield were from the MassGIS Aquifers layer (AQUIFERS_POLY).
- Water Table Ratio (SURFGEO24K_WTR_IMG) - This raster (100-meter resolution) uses average transmissivity from SURFGEO24K_T_AY, topographic relief, and groundwater recharge to calculate the water table ratio. Positive values indicate that the region has a topography-controlled water table, and negative numbers indicate a recharge-controlled water table. For further methods see Gleeson et al. (2011).
- Bedrock Altitude and Overburden Thickness - This dataset was developed by the Massachusetts Geological Survey and the University of Massachusetts Amherst Department of Earth, Geographic, and Climate Science. This product provides data on statewide bedrock altitude and overburden thickness. For further information and to download see the Bedrock Altitude and Overburden Thickness MassGIS page.
- USGS 1:24,000 Surficial Geology - This data layer was developed by the U.S. Geological Survey and provides surficial geology data. For further information and to download the original map see the USGS 1:24,000 Surficial Geology MassGIS page.
Production
The map products were developed by the University of Massachusetts Amherst Hydrogeology Group with support from the Massachusetts Department of Conservation & Recreation, Massachusetts Department of Environmental Protection, and Massachusetts Geological Survey. The project was funded by the Massachusetts Executive Office of Energy and Environmental Affairs.
One of the goals of this project was to understand current and projected future groundwater flooding risks across the state. To understand groundwater flooding risks, we developed a statewide three-dimensional groundwater flow model to simulate the water table elevation. The Hydrogeologic Atlas of Massachusetts compiles new datasets developed as input into the groundwater model, groundwater model simulation results, and other statewide map products created through this project. For further information regarding the methods of this study see Corkran et al. (2024), a report submitted to the Massachusetts Executive Office of Energy and Environmental Affairs.
Suggested Citation:
Corkran, D., Kirshen, A., Moran, B.J., Blin, N., King, R., Bresee, M., & Boutt, D. (2024). Massachusetts State-wide Groundwater Model and Flooding Risk Assessment 1.0. Report funded by the Massachusetts Executive Office of Energy and Environmental Affairs and published on the ResilientMass website, https://resilient.mass.gov/home.html.
Attributes
Fields in the SURFGEO24K_K_POLY attribute table:
| NAME | DESCRIPTION |
|---|---|
| MAPUNIT | Short plain-text identifier of the map unit (from MassGIS USGS 1:24,000 Surficial Geology) |
| IDECONF | Identity Confidence. Identity of a feature can be determined using relevant observations and scientific judgment; therefore, one can be reasonably confident in the credibility of this interpretation (from MassGIS USGS 1:24,000 Surficial Geology) |
| DATSRCID | Data Source ID (from MassGIS USGS 1:24,000 Surficial Geology) |
| MUPS_ID | Unique polygon ID (from MassGIS USGS 1:24,000 Surficial Geology) |
| MINK_FTDAY | Minimum hydraulic conductivity in feet per day |
| MAXK_FTDAY | Maximum hydraulic conductivity in feet per day |
| AVGK_FTDAY | Average hydraulic conductivity in feet per day |
| LITHOLOGY | Lithology description |
Fields in the SURFGEO250K_SY_POLY attribute table:
| NAME | DESCRIPTION |
|---|---|
| CODE | (From MassGIS USGS 1:250,000 Surficial Geology) 1 - sand and gravel deposits 2 - till or bedrock 3 - sandy till over sand 4 - end moraines 5 - large sand deposits where distinguished from sand and gravel deposits 6 - fine-grained deposits 7 - floodplain alluvium |
| RANGE | Range of depth of deposit in feet for code = 1 or 5 in Massachusetts (from MassGIS USGS 1:250,000 Surficial Geology). |
| MINSY | Minimum specific yield. |
| MAXSY | Maximum specific yield. |
| AVGSY | Average specific yield. |
| LITHOLOGY | Lithology description. |
Fields in the SURFGEO24K_T_AY_POLY attribute table:
| NAME | DESCRIPTION |
|---|---|
| ID | Unique ID |
| MINT_FT2_DA | Minimum transmissivity in square feet per day. |
| MAXT_FT2_DA | Maximum transmissivity in square feet per day. |
| AVGT_FT2_DA | Average transmissivity in square feet per day. |
| AQFRYLD | Aquifer yield determined by average transmissivity cutoffs (from MassGIS Aquifers) HIGH (>4,000 square feet per day) MEDIUM (1,400 - 4,000 square feet per day) LOW (<1,400 square feet per day) NONE (No aquifer present or zero transmissivity) |
Maintenance
These data layers are maintained by the University of Massachusetts Amherst Hydrogeology Group. The products may be updated as new data become available.