How Build Customised Legends/Style Files For Your Data Layers In ArcGIS 10
GIS in Ecology
How Build Customised Legends/Style Files For Your Data Layers In ArcGIS 10.
In ecology, you will frequently use a specific set of standard symbols and colours to display your data. For example, you might choose to always use a blue circle to represent records of one species and red circles for records of another. Similarly, you might always use symbols of the same sizes for different group sizes encountered. If you do, you will, at some point, get fed up with having to type your legend into the symbology tab for the umpteenth time and start thinking that there must be a better way. And there is.
There are two basic solutions to this problem. One is to use the IMPORT button in the SYMBOLOGY tab of the LAYER PROPERTIES window and import the symbology from another data layer. However, this will only work if you already have a data layer with a suitable legend in your GIS project and this is often not the case.
The second (and probably better) solution is to create what is called a Style File. A Style File is simply a small file that stores information about what symbols should be used for specific categories or values found in a specific field of a data layer. While they can be time-consuming to create, they have the potential to save you a lot of time in the long run. Your GIS work and the quality of your maps and figures will also improve if you get into the habitat of using a consistent set of symbols to show the same thing (there’s nothing worse than realising that you’ve used red symbols for a species in one map and blue for the same species in another and that this is confusing anyone who looks at them).
You can also share Style Files with others you work with to ensure that everyone in your organisation/research group is using the same symbols. This should mean that when you share maps with your colleagues, they will be easier to interpret since others will already be familiar with what the symbols mean.
You can create your own Style File in ArcGIS 10 following the instructions below
1. In ArcMap click on CUSTOMIZE menu and select STYLE MANAGER. In the STYLE MANAGER window, click on the STYLE button to open the STYLE REFERENCES window before clicking on the CREATE NEW STYLE button. This allows you to create a new empty style file. Once you have given it a name and selected the location where you want to store it, click SAVE. Now click OK to close the STYLE REFERENCES window and then CLOSE to close the STYLE manager window.
2. You now need to fill your custom style file with the symbols that you want to be able to use. To do this, right click on the name of a feature data layer (you can choose pretty much any feature data layer to do this) in your project and select PROPERTIES. In the LAYER PROPERTIES window select the SYMBOLOGY tab. Now click SINGLE SYMBOL and then click on the button in the SYMBOL section of the window (it will have a picture of the current symbol on it). This will open the SYMBOL SELECTOR tab. Select the first symbol you want to add to your custom style file from the left hand portion of the window and then customise its size and colour in the right hand section. Now click the SAVE AS button. This will allow you to save that specific symbol along with information to tell the software when it us it. Along side NAME type the name of the feature that the symbol will be applied to (e.g. COMMON DOLPHIN if you were creating a symbol you wanted to use for sightings of common dolphin). Next beside CATEGORY type in the field name where this information will be stored (in the case of creating a symbol for common dolphin, this would be SPECIES). Now select the style file you want to add it to in the STYLE section. In this case, it will be your custom style file. Now click FINISH. Add any more styles you wish to create and then click OK to close the symbol selector and OK to close the LAYER PROPERTIES window.
3. To apply a style to a data layer, right-click on the name of the data layer in the TABLE OF CONTENTS window and select PROPERTIES. Once the LAYER PROPERTIES window is open, click on the SYMBOLOGY tab and select CATEGORIES> MATCH SYMBOLS IN A STYLE. You can now browse to the locaiton where you saved the style file using the BROWSE button. Once you have selected it, you can select the field that has the designations for the style in it under FIELD VALUE before clicking on the MATCH SYMBOLS button.
NOTE: Your Style File will only work if you use exactly the same name for each feature type and for the field name. If you don’t, your style file won’t work. For example if you us the name WHITE-BEAKED DOLPHIN for the name of a feature and SPECIES for the category, it will only work if you have a field in the attribute table of your data layer called SPECIES (and not cetacean species) and you need to have used the name WHITE-BEAKED DOLPHIN for all sightings of this species (and not White beaked dolphin or White-beak Dolphin). Therefore, you need to take the time to get these right when you create your Style File and you need to be consistent when entering your data.
If you want to get into the nitty-gritty of creating and using Style Files, you will find that you can also select your symbols individually through the SYMBOL SELECTOR window. To do this, click on the STYLE REFERENCES button in the SYMBOL SELECTOR window. Next click on the ADD STYLE TO LIST button. Navigate to where you stored your Style File, select it and click OPEN. Once you’ve done it, click OK to close the STYLE REFERENCES window and you will see that your customise symbols will now be available to select on the left hand side of the SYMBOL SELECTOR window.