This layer shows the vulnerability of Maryland’s aquifers and farmland to saltwater intrusion, based on the GALDIT index. The GALDIT framework evaluates coastal aquifer vulnerability using six factors: aquifer type, hydraulic conductivity, groundwater level, distance to shoreline, chloride concentration, and aquifer thickness. The index values highlight areas of moderate to high susceptibility to saltwater intrusion, particularly along Maryland’s Eastern Shore, where agriculture is most at risk.
The data is sourced from the Maryland Geological Survey well monitoring networks, the U.S. Geological Survey groundwater geochemical database, and aquifer confinement estimates. The vulnerability assessment was conducted using Esri ArcGIS with Inverse Distance Weighted (IDW) interpolation to create statewide raster layers at a 30x30m resolution.