General US Geological Survey (maps, imagery, national data) www.usgs.gov USGS National Center for Earth Resources Observation and Science http://edcsns17.cr.usgs.gov/EarthExplorer/ USGS Digital Elevation Models http://data.geocomm.com/ http://www.mapmart.com/ http://www.atdi-us.com/ NOAA Digital Coast http://www.csc.noaa.gov/digitalcoast/data/index.html GIS Data Depot http://data.geocomm.com/ Federal Geographic Data Committee http://registry.fgdc.gov/ The Geography Network (ESRI) http://www.geographynetwork.com/data/index.html Geospatial One Stop http://gos2.geodata.gov/wps/portal/gos National Historical Geographic Information System http://www.nhgis.org/ National […]
GIS Files When you look at a folder containing GIS data in a normal window, notice that there are multiple files with similar names, in sets of around 5-9. The similar names signify that all of these files are associated with a layer you can use in GIS software. The file types signify different types […]
Shortcuts common to all editing tools Shortcut key Editing function Z key Zoom in X key Zoom out C key Pan B key Continuous Zoom/Pan V key Show vertices Esc Cancel Ctrl + Z Undo Ctrl + Y Redo Spacebar Suspend Snapping Sketch tool Shortcut key Editing function Ctrl + A Direction Ctrl + F […]
ArcMap 9.3 QuickStart Requirements: ArcGIS Spatial Data Loading Data Start Menu > Programs Folder > ArcGIS > ArcMap Select “A new empty map” > OK (or choose “An existing map”) File > Add data or click the Add Data Button Navigate to where data is stored > select file > Add Ordering Layers Column to […]
Treatment wetlands are either constructed or naturally occurring wetlands that are used in the process of treating stormwater runoff and/or effluent. The representation of a treatment wetland requires elucidating the infrastructural system and active systems from the evolving and dynamic biological systems. The two systems (infrastructural and biological) can be categorized as static and dynamic […]
Since construction of the MRGO and other canals that are intended to increase access and improve navigation in the area, average salinity levels have risen in coastal Louisiana. The MRGO, or Mississippi River Gulf Outlet, breaches the barrier islands, which serve to shelter coastal wetlands thus exposing once protected areas to the full effects […]
Salt domes begin as salt deposits in the sea that after a period of time, are cut off from the main body of water. The surrounding water evaporates and allows sediments to cover the salt pans. Because the salt was less dense than the surrounding sediments, it pushed its way toward the surface, creating roughly […]
Overuse and improper filtration of fertilizer in agricultural areas within the Mississippi River basin is causing hypoxia in Gulf of Mexico south of the Mississippi River delta. Excess levels of nitrogen and phosphorus cause heavy algal blooms. When these microorganisms decompose, oxygen is depleted from the water negatively impacts sea life off the coast of […]
The Mississippi River Delta Basin comprises approximately 521,000 acres of land and shallow estuarine water area in the active Mississippi River delta. Approximately 83 percent of this area, or 420,000 acres, is open water. The 101,100 acres of land in the basin are characterized by low relief, with the most prominent features being natural channel […]
The word “algae” refers to a large group of organisms, but typically account for plant-like aquatic organisms that generate energy through photosynthesis, but lack roots, stems, leaves and vascular tissue. It is an organism that exists worldwide, occurring in both fresh and salt waters; and is an essential part of many oceanic animal’s diet. Unicellular […]