The West Virginia DEP mapserver uses a variety of geographical data sources to produce customized map images in response to user input. A small javascript program allows rubberband box and drag-pan operations, providing an enhanced user interface without requiring the user to download a large applet or plugin. Query operations draw from a several databases, including WVDEP's primary ERIS system.
Zoom in. Zooms in to area represented by rectangle drawn on the map.
Zoom out. Zooms out based on the size of the rectangle drawn. A smaller rectangle results in a larger zoom.
Pan. Hold the left mouse button down and drag the map to recenter
Zoom in 2x. Click on the map to zoom in by a fixed amount. The display will be recentered on the location of the mouse click on the map display.
Zoom out 2x. Click on the map to zoom out by a fixed amount. The display will be recentered on the location of the mouse click on the map display.
Query. Returns features of the selected layer located within a rectangle drawn on the map. A simple mouse click will cause the query to perform a select-boy-point operation with a 3-pixel radius. Query results are displayed in the frame below the map display.
Reset to a state-wide map extent
Redraw the map at the current extent (e.g. after turning layers on/off)
Displays controls to search/zoom to features or a coordinate, in the lower frame below the map display. The feature search/zoom uses he USGS geographic names database, containing over 25,000 named features from USGS maps. Features include towns, streams, airports, mountains, churches and many others.
Show / hide the overview map. The overview map shows the current map extent as a red rectangle or crosshair.
The left-hand panel contains infotmation and controls for the various layers. The left checkbox beside each layer turns the layer on/off. Use the redraw button to refresh the map display after turning layers on or off. The right checkbox selects which layer will be queryed. Only one layer can be selected as the query layer.

The aerial photography and topographic map layers are larger datasets and may require longer to draw. It may be better to zoom to a desired area, using the other layers as a guide, before turning these layers on.

Some layers contain too much detail and will not draw until zoomed in. Viewable layers will be labeled using a dark color in the legend, while layers labeled with a lighter color will not be drawn.. Road, stream, and town layers use increasingly detailed datasets depending on the scale.

County boundaries. Digitized from 7.5' USGS DRGs. Demographic info from Census Bureau, via ERSI Data & Maps CDROM 2003.
2007 Aerial Photography. 1-meter color infrared aerial photography flown in 2007. Constructed from tiles clipped from the original source data. Layer will ony display at scales larger than 1:40,000 due to database size and server speed limitations. Querying the doqq layer will display the source quarter-quadrangle.
USGS Topographic Map. USGS 1:24,000 topographic maps, consisting of 2,742 5000x5000 meter tiles covering the entire state. Layer will ony display at scales larger than 1:50,000 due to server speed limitations.
Watersheds. 11-digit watersheds from the Natural Resource Conservation Service. Query will produce statistics for selected landcover types (based on MRLC landcover data from USEPA) and wetlands (based on NWI wetlands data). Though widely used, This dataset has been superseded and may be replaced.
Streams. At scales of 1/50,000 and larger-- 1/24,000 scale National Hydrology Dataset, including polygon waterbodies and wide streams, and wetlands. From 1/50,000-1/100,000-- 1/100,000 scale EPA Reach. At 1/100,000 and smaller-- subset of 1/100,000 scale EPA Reach. Querys always reference 1:24,000 scale layer, so stream names may be returned even though they are not displayed.
Roads. Displays primary highways at small scales, 1/100,000 scale roads (from TIGER Dataset) at scales greater than 1/75,000.
Towns/Populated Places. Displays major towns at scales smaller than 1/100,000 or populated place names from the USGS GNIS database at scales greater than 1/100,000.
LCAP Sites. Point Locations of LCAP Landfills.
LCAP Access Roads. Point Locations of access roads associated with LCAP sites, collected using GPS.
LCAP Monitoring Wells. Locations of LCAP Monitoring Wells, collected using GPS.
LCAP Structures (polygon). LCAP Structures, primarily tanks and sediment basins, collected using GPS.
LCAP Structures (points). LCAP point features, primarily getes, collected using GPS.
The West Virginia DEP Mapserver was built using open source software acquired at no cost. The core map engine is Mapserver. Map rendering and query scripts are written in PHP, and selected database queries use Postgres RDBMS. The current webserver is a dual-processor PIII running Linux and Apache. The user interface uses javascript to enable zoom/query rectangles, drag pan, and real-time coordinate update.