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Site content related to keyword: "Indian River"

Scott Andres participated in the 2011 NGWA Summit in Baltimore, MD

Scott Andres of the Delaware Geological Survey and Holly Michael, assistant professor of geological sciences, participated in 2011 National Ground Water Association (NGWA) Groundwater Summit and were co-organizers of the session titled "Submarine Discharge of Groundwater and Nutrients into Estuaries and Oceans," May 3, Baltimore.

DGS Geologic Map No. 16 (Fairmont Rehoboth Beach Quadrangles) Dataset

DGS Geologic Map No. 16 (Fairmont Rehoboth Beach Quadrangles) Dataset

This vector data set contains the rock unit polygons for the surficial geology in the Delaware Coastal Plain covered by DGS Geologic Map No. 16 (Fairmount and Rehoboth Beach quadrangles). The geologic history of the surficial units of the Fairmount and Rehoboth Beach quadrangles is that of deposition of the Beaverdam Formation and its subsequent modification by erosion and deposition related to sea-level fluctuations during the Pleistocene. The geology reflects this complex history both onshore, in Rehoboth Bay, and offshore. Erosion during the late Pleistocene sea-level low stand and ongoing deposition offshore and in Rehoboth Bay during the Holocene rise in sea level represent the last of several cycles of erosion and deposition.

To facilitate the GIS community of Delaware and to release the geologic map of the Fairmount and Rehoboth Beach quadrangles with all cartographic elements (including geologic symbology, text, etc.) in a form usable in a GIS, we have released this digital coverage of DGS Geological Map 16. The update of earlier work and mapping of new units is important not only to geologists, but also to hydrologists who wish to understand the distribution of water resources, to engineers who need bedrock information during construction of roads and buildings, to government officials and agencies who are planning for residential and commercial growth, and to citizens who are curious about the bedrock under their homes. Formal names are assigned to all rock units according to the guidelines of the 1983 North American Stratigraphic Code (NACSN, 1983).

Wastewater Reuse: Benefits and Risk Assessment in Inland Bays Indian River Basin

Study domain
Project Contact(s):

The goal of this project is to develop a three-dimensional (3D) numerical groundwater flow model to evaluate the potential impacts to surface- and groundwater resulting from the disposal of treated wastewater in a portion of the Inland Bays drainage basin.

By developing a sub-regional, fresh, groundwater flow model and analyzing results, several issues will be addressed that are related to state policy, regulation revision, and proposed projects associated with land-based wastewater disposal (LBWD) in Sussex County.

RI74 Locating Ground-Water Discharge Areas in Rehoboth and Indian River Bays and Indian River, Delaware Using Landsat 7 Imagery

RI74 Locating Ground-Water Discharge Areas in Rehoboth and Indian River Bays and Indian River, Delaware Using Landsat 7 Imagery

Delaware’s Inland Bays in southeastern Sussex County are valuable natural resources that have been experiencing environmental degradation since the late 1960s. Stresses on the water resource include land use practices, modifications of surface drainage, ground-water pumping, and wastewater disposal. One of the primary environmental problems in the Inland Bays is nutrient over-enrichment. Nitrogen and phosphorous loads are delivered to the bays by ground water, surface water, and air. Nitrogen loading from ground-water discharge is one of the most difficult to quantify; therefore, locating these discharge areas is a critical step toward mitigating this load to the bays. Landsat 7 imagery was used to identify ground-water discharge areas in Indian River and Rehoboth and Indian River bays in Sussex County, Delaware. Panchromatic, near-infrared, and thermal bands were used to identify ice patterns and temperature differences in the surface water, which are indicative of ground-water discharge. Defining a shoreline specific to each image was critical in order to eliminate areas of the bays that were not representative of open water. Atmospheric correction was not necessary due to low humidity conditions during image acquisition. Ground-water discharge locations were identified on the north shore of Rehoboth Bay (west of the Lewes and Rehoboth Canal), Herring and Guinea creeks, the north shore of Indian River, and the north shore of Indian River Bay near Oak Orchard.

Number of Pages: 
17

OFR47 Digital Watershed and Bay Boundaries for Rehoboth Bay, Indian River Bay, and Indian River

OFR47 Digital Watershed and Bay Boundaries for Rehoboth Bay, Indian River Bay, and Indian River

Digital watershed and bay polygons for use in geographic information systems were created for Rehoboth Bay, Indian River, and Indian River Bay in southeastern Delaware. Polygons were created using a hierarchical classification scheme and a consistent, documented methodology that enables unambiguous calculations of watershed and bay surface areas within a geographic information system. The watershed boundaries were delineated on 1:24,000-scale topographic maps. The resultant polygons represent the entire watersheds for these water bodies, with four hierarchical levels based on surface area. Bay boundaries were delineated by adding attributes to existing polygons representing water and marsh in U.S. Geological Survey Digital Line Graphs of 1:24,000-scale topographic maps and by dissolving the boundaries between polygons with similar attributes. The hierarchy of bays incorporates three different definitions of the coastline: the boundary between open water and land, a simplified version of that boundary, and the upland-lowland boundary. The polygon layers are supplied in a geodatabase format.

Number of Pages: 
11

OFR35 Estimate of Nitrate Flux to Rehoboth and Indian River Bays, Delaware, through Direct Discharge of Ground Water

OFR35 Estimate of Nitrate Flux to Rehoboth and Indian River Bays, Delaware, through Direct Discharge of Ground Water

Agricultural fertilizer application, animal (poultry) waste, and wastewater disposal practices of the past 40 years have resulted in widespread nitrate contamination of ground water in coastal Sussex County, Delaware. Discharge of contaminated ground water to Rehoboth and Indian River bays is suspected of being a significant contributor to elevated nutrient concentrations in these surface water bodies, resulting in excessive phytoplankton growth and other related problems.

Digital Watershed and Bay Boundaries for Rehoboth Bay, Indian River Bay, and Indian River (OFR 47)

Digital Watershed and Bay Boundaries for Rehoboth Bay, Indian River Bay, and Indian River (OFR 47)

Digital watershed and bay polygons for use in geographic information systems were created for Rehoboth Bay, Indian River, and Indian River Bay in southeastern Delaware. Polygons were created using a hierarchical classification scheme and a consistent, documented methodology that enables unambiguous calculations of watershed and bay surface areas within a geographic information system. The watershed boundaries were delineated on 1:24,000-scale topographic maps. The resultant polygons represent the entire watersheds for these water bodies, with four hierarchical levels based on surface area. Bay boundaries were delineated by adding attributes to existing polygons representing water and marsh in U.S. Geological Survey Digital Line Graphs of 1:24,000-scale topographic maps and by dissolving the boundaries between polygons with similar attributes. The hierarchy of bays incorporates three different definitions of the coastline: the boundary between open water and land, a simplified version of that boundary, and the upland-lowland boundary. The polygon layers are supplied in a geodatabase format.