area

We strongly recommend that the <area> entity defines the geographic area to be notified, not the incident area.

In the case of a tropical storm, we recommend that the <area> entity contains <polygon> or <geocode> elements that denote the places where you expect impacts from strong winds, heavy rain, or other threats from the storm. If a storm is still offshore, then don't set the <area> entity of your CAP alert to the storm's current location.

Similarly, in the case of a forest fire, we recommend that the <area> entity data also includes towns or places where you expect impacts from smoke or other threats from the fire.

Important: For noncontinuous areas under the same alert level and type, create separate <alert> messages rather than a single <alert> message that includes disjointed areas.

Important: Make sure that you only include areas to alert that are within your jurisdiction. If the alerting area in your <alert> message includes locations outside of the jurisdiction of your organization, Google reserves the right to not publish your alert.

Important: In all <area> blocks, you must include at least one of <polygon>, <circle>, or <geocode> sub-element.

area entity sub-elements

Element name	Optionality	Type	CAP and Google notes and requirements
<areaDesc>	REQUIRED	string	To generate the location text string used in the alert title or headline, Google might use an <areaDesc> element. Keep the <areaDesc> value short (less than 50 characters).
<polygon>	OPTIONAL	string	The paired value points in a <polygon> element define a polygon that delineates the area to alert in an alert message. We recommend that you represent the <polygon> element by a whitespace-delimited list of WGS84 coordinate pairs. Polygons must meet the following requirements: They must be closed. They can't overlap. Holes (like in donut-shaped polygons) and intersections aren't supported. A minimum of four coordinate pairs are required. The first and last pairs of coordinates must be the same.
<circle>	OPTIONAL	string	The <circle> element consists of paired point-and-radius values that delineate the area to alert in the form of an alert message. We recommend that you represent the <circle> element by a central point: a WGS84 coordinate pair followed by a space character and a radius value in kilometers. Note: If you specify a circle with zero or a very small radius, Google can't show the alert to our users.
<geocode>	OPTIONAL	string	Define the <geocode> element with values from a accessible and open dataset of polygons. As an example, in the US, these values come from the following data sources: FIPS6 UGC code SAME US Zip Code If you use geocodes, provide Google with a fixed list of geocode-to-polygon and shapefile maps. To post notices of updates to this list, use a separate channel, preferably as RSS or email alerts. For example, US NOAA publicly publishes their geocode updates.
<altitude>	OPTIONAL	float	The value of the <altitude> element is the specific or minimum altitude of the affected area of the alert message. Provide this measurement in feet above mean sea level according to WGS84 datum.
<ceiling>	CONDITIONAL	float	Use the <ceiling> element only if the <alert> entity contains an <altitude> element. The value of the <ceiling> element is the maximum altitude of the affected area of the alert message. Provide this measurement in feet above mean sea level according to WGS84 datum.

Example

<area>
    <areaDesc>Cavite</areaDesc>
    <polygon>14.473860833486,120.9718174024 14.347454023196,121.01386683476
     14.142014336735,121.03024107602 14.063075455227,120.85558468426
     14.221664765773,120.59001887699 14.473860833486,
     120.9718174024</polygon>
    <geocode>
        <valueName>SAME</valueName>
        <value>042100000</value>
    </geocode>
</area>

<area>
    <areaDesc>107 km SouthWest DENPASAR-BALI</areaDesc>
    <circle>-9.63,115.12 300.0</circle>
</area>