The system starts in Navigation Mode. You may progressively refine the region of interest, as explained below. When you are satisfied with the boundaries of the region, use the "Change to Data Retrieval Mode" button on the ICE MAPS screen. Here is how it looks:
When you are satisfied with the boundaries of the map you made above, use the "Change ... Mode" ([help]) button below to see the data layers available for creating a table or your final map:
As an additional visual aid for keeping track of which mode you are in,
the current processing mode appears at the beginning of the ICE MAPS' HTML
<title>.
Most Web browsers display the document title somewhere on-screen;
some show it in the window's title bar,
others in a special text display box.
To activate the new coordinates you entered, or to re-use the same ones for a different choice of Navigational layers , activate the button labeled "Use the Values in the Coordinate Entry Boxes" :
The zoom factor is used only in conjunction with the selectable map. If you use the values in the coordinate entry boxes by activating the "Use the Values in the Coordinate Entry Boxes" button, the zoom factor is ignored.
Browsers known not to support this arrangement include
Should you change your mind
after picking a pre-defined region,
you can "turn off" that region
by selecting the
first item
--
labeled
(none)
--
in that same list selection box.
You may alter the boundaries of a pre-defined region by editing the values in the coordinate entry boxes (remember to activate the "Use the Values in the Coordinate Entry Boxes" button). If you make such alterations, the resulting region will no longer be "pre-defined", therefore, any Special data layers that exist for that pre-defined region will not be available in Data Retrieval Mode, as explained below.
Because of the way the list selection boxes behave in an HTML form, it is possible for you to choose (highlight) one region in each of the region lists. Even so, only a single region will be used. (If you do pick more than one pre-defined region, you will see a warning message.) The precedence is determined by the order of the lists on the screen. For example, if you select both the Eel River Basin and Alpine County, the map you get will be for the Eel River because the River Basins list occurs above the County list.
Select one or more of these layers [help]:
The small in-lined images are the legend for the map symbols.
There are descriptions of these navigational layers.
If you pick a pre-defined region, but then activate the "Use the Values in the Coordinate Entry Boxes" button, the boundaries of the new map will taken from the coordinate entry boxes. The region you selected will be ignored (and you will see a warning message). Other such combinations, such as editing the coordinate entry boxes and then using the selectable map, will be treated similarly (in this case, the coordinate boxes will be ignored and you will see an appropriate warning).
Furthermore, if you pick a pre-defined region or edited the coordinate entry boxes and activate the "Change to Data Retrieval Mode" button without first creating a new navigation map, the pre-defined region or edited coordinate values will be ignored (and you will see a warning message).
On the other hand, any choices you make from the set of Navigational layers will be used in the generated map no matter which "activation" method you use.
The second step in using ICE MAPS is retrieving data from the various categories which are available for the specified region, leading to a finished map or table of (possibly numerical) data. There are Standard data layers which are available for all regions, whether user-defined or pre-defined. For some pre-defined regions, there are also Special data layers, which are grouped separately from the Standard layers. In addition, the Navigational layers are available for your final map.
There are descriptions of these data layers.
When you have selected the set of Data layers you want, activate the button labeled "Retrieve Data" to process your request:The output of Data Retrieval Mode consists of a map (in several formats), hyper-text links to sources of information related to your query, and optional tables of information.
The first map format is a PostScript file containing your map for printing or on-screen display. There is a hyper-link below the on-screen map for downloading this file. The map prints (and displays) on two pages. The first contains the map; the second, the map legend. The map is in color, but the PostScript file may be printed on a black and white printer.
In addition, there is the on-screen map that shows what the map in the PostScript file looks like. Furthermore, the map legend is displayed as a second on-screen image. These images are GIF files, and there are hyper-links to them as well.
For some data and navigational layers, there are hyper-text links to on-line sources of information related to those layers.
An optional kind of output is tabular data contained in one or more files. If these tables are created, there will be hyper-links to them.
Notice that you cannot alter the region's boundaries while in Data Retrieval Mode. To do that, you should return to Navigational Mode
To return to navigation mode [help] with the same region boundaries and the same navigational layers which are now selected, use the "Return to Navigation Mode" button here:
by backing up through the sequence of Web browser screens by using your browser's "Back" button or menu item, or
by using the button labeled "Re-initialize System (start over from the beginning)" .
ICE MAPS is used in a series of passes to refine the boundaries of the geographical region or to produce the final map. If you have made changes on the ICE MAPS screen, such as editing a coordinate or selecting a pre-defined region, you may reset the interface to the state it was in at the start of the current pass (i.e., undo your changes) by using the button labeled "Reset to initial values for this pass", which is near the very bottom of the ICE MAPS page:
Similarly, if you wish to start the entire query process over again from the very beginning, use the button labeled "Re-initialize System ...":
Note that you loose all the current settings you have selected when you use this button.
The navigational maps are plotted in longitude-latitude coordinates. This tends to shorten the geographical projection, which explains the "squashed" look of the initial map showing the entire state of California.
The final, data retrieval maps are plotted using Albers Equal Area map projection with the standard set of projection parameters used by the GIS Technology Center of the Teale Data Center . These projection parameters are:
This is our second system for accessing the ICE GIS database through the Web. There is a paper available on our first effort:
Some numbers for ICE MAPS:
There were a number of names proposed before we settle on ICE MAPS.
Harvey Chinn wrote these instructions.
![[Caution]](/icons/warning_small_icon.gif){kind=icon}
If you made selections on the Query System page before jumping to this help page, be certain to use your browser's "Back" button or menu item to return to the Query System. Otherwise, using this link will reset the system to its initial default values.