Sussex County

SP28 Digital Elevation Model of Delaware

The Delaware Geological Survey led a multi-agency, state and federal effort (including DelDOT, DNREC, USGS, and NOAA) to secure funds from the Hurricane Sandy Relief appropriation to collect new, high-quality LiDAR for the entire state of Delaware. LiDAR, which stands for Light Detection and Ranging, is a remote sensing method that uses light in the form of a pulsed laser to measure distances from a source to a target object. Typically, a LiDAR device is attached to the bottom of a plane and is pointed at the ground.

RI80 Investigation of Submarine Groundwater Discharge at Holts Landing State Park, Delaware: Hydrogeologic Framework, Groundwater Level and Salinity Observations

Monitoring wells and groundwater sensors were installed and monitored in and around Holts Landing State Park on the Indian River Bay, eastern Sussex County, Delaware, between October 2009 and August 2012. Data from test drilling, geophysical logging, geophysical surveys, and well testing characterized the hydrogeological framework and spatial and temporal patterns of water pressure, temperature, and salinity in the shallow, unconfined Columbia aquifer. The work revealed a plume of freshened groundwater extending more than 650 ft into the bay from the shoreline.

Strategic Plan for Geologic Mapping of Delaware 2016-2030

Geologic maps at the DGS are created as primary deliverables of a project and as derivatives of other projects. Primary deliverables are mainly those that are the result of outside funding sources such as the AASG-USGS cooperative StateMap. Derivative maps are those that have primary data collected for reasons other than geologic mapping can be used to create geologic maps or that geologic maps are derivative products of a project rather than the primary goal of a project.

Groundwater response to extreme rainfall event – eastern Sussex County

Date

During an extreme rainfall event that occurred September 29-30, 2016, more than 12 inches in one day, caused the water table to rise over 5 feet near Harbeson, Delaware. A subsequent 3.6 inch storm on October 8 - 9 caused the water table to rise above land surface and flood the area for nearly 8 hours.

Mapping the evapotranspiration (ET) in Sussex County using satellite remote sensing data

Project Contact(s)

DGS is continuing a collaboration with climate scientist Kevin Brinson (DEOS) to develop and test methods to estimate and map annual and seasonal distribution of ET for Sussex County, Delaware. Remotely sensed data from Landsat 7 ETM+ and MODIS platforms will be used to estimate regional energy balance and water flux. These estimates are calibrated by comparison to ET estimates determined by direct point measurements (Eddy Covariance and atmometer) and models driven by meteorological data such as temperature, relative humidity, wind speed, and soil moisture. The results have the potential to improve accuracy and precision of ET models and will be valuable for efforts that use water budgets for resource management, agriculture, wetland assessment, and research.

Delaware Geological Survey Issues Report on Groundwater Monitoring and Water-Quality Impacts of Rapid Infiltration Basin Systems

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The Delaware Geological Survey released a new technical report entitled “Groundwater Quality and Monitoring of Rapid Infiltration Basin Systems, Theory and Field Experiments at Cape Henlopen State Park, Delaware” which was prepared by A. Scott Andres and Changming He of the Delaware Geological Survey, Edward Walther of the South Water Management District, Florida, Müserref Türkmen of the Izmir Water and Sewerage Administration, Turkey, and Anastasia Chirnside and William Ritter of the University of Delaware. DGS Bulletin 21C documents the results of a detailed study of groundwater quality at a rapid infiltration basin system.

B21C Groundwater Quality and Monitoring of Rapid Infiltration Basin Systems (RIBS), Theory and Field Experiments at Cape Henlopen State Park, Delaware

A rapid infiltration basin system (RIBS) consists of several simple and relatively standard technologies; collection and conveyance of wastewater, treatment, and discharge to an unlined excavated or constructed basin. By design, the effluent quickly infiltrates through the unsaturated or vadose zone to the water table. During infiltration, some contaminants may be treated by biological and/or geochemical processes and diluted by dispersion and diffusion.