Map Viewer

Map Viewer

What do you see when you launch a map service?

When you launch a map service you will see something similar to the image on the right. Notice the image is made up of 5 key sections; 1. the Map Legend (top), 2. Map Tools (left), 3. Map Frame (middle), 4. Layer Menu (right), and 5. Data Frame (bottom). Each of these elements are important as together they allow you to understand the map symbology, interact with the map, change the map display, and access the databases behind the map. For more information on each of the map elements take a look below at more detailed descriptions.

Map Legend
The Map Legend will be located above your map and will help you understand the map symbology you will see. You will sometimes see different symbols for a single feature (the circles and squares below) because map symbology will change when you zoom in beyond a certain extent. The color of the symbol represents the data source, and the symbol type tells you what is mapped.

Station Legend					CBP = Chesapeake Bay Program
Creekwatchers	TRPA	TMDL	CISNET	CBP	TRPA = Talbot River Protection Association TMDL = Total Maximum Daily Load CISNET = Coastal Intensive Site Network
Treatment Plant Discharge	Map Tool Help	Layer Help	About the database

Map Frame
This is where you see the map of the water quality parameter you have chosen (DO, NO3, etc.) from the Map Viewer page. The important thing will be utilizing the Map Legend, Map Tools, and Layers Menu so that you understand what you are seeing and are able to take advantage of the map's interactivity. There will be an overview map in the top left corner of the map frame. The red box within this overview map represents the current area you are zoomed to on the map. There is a scale bar on the bottom of the map to help you determine distance. Most importantly, you can change what displays on your map by utilizing the Layers Menu and you can interact with your map by utilizing the Map Tools.

Layers Menu
The layers menu will appear on the right side of the map and will show the different data layers available. By checking or unchecking the visible box and then clicking the Refresh button you change which layers show on your map (Note: You may have to scroll down to reach the refresh button). By changing the "active" layer you change the layer which you can access the database by using the select rectangle

from your set of Map Tools. For example, if you wanted to access data for a particular CISNet Station you would first make the CISNet layer active (by clicking in the active circle) and then click the Select Rectangle tool from your Map Tools and drag a rectangle around the desired station in the Map Window. The data will then appear in the Data Frame located below the map.

Metadata - Layer names are hotlinked to metadata. Click on a layer name to bring up information about that layer. (Note: We are still in the process of compiling metadata so this feature may not yet be available for all layers.

Map Tools
You will find a set of map tools to the left of the map. These tools perform various operations that will allow you to navigate and interact with the map. To learn more about each tool click on the Map Tool Help link which appears in the Station Legend frame above your map. Doing so will open a new window with descriptions of each tool you see on the toolbar.

Data Frame
This is where the data records show when you perform a query or make a selection. You can use the scroll bars to scroll to the left and right or up and down to insure that you see all of the fields and records. If you click on the blue hyperlink in the far left "Rec" column your map will redisplay with the selected record in the center of your map frame.