Introduction
The World Wide Web provides a useful way to provide information to the general public and organization staff. However, in an emergency, web sites can be overloaded by demand. Ideally web sites should be designed in advance to cope with emergency situations and techniques such as accessible design, can help with everyday web use. However, some simple techniques can be used to quickly modify existing sites to work better when the need arises. These notes were prepared in response to the ACT bush fire emergency of January 2003 and recommendations made for the Sentinel Fire Mapping System, but should have general applicability.
Limitations of the Web
Before modifying or creating a web site for emergency use, keep in mind the limitations of the web. To view a web site the user requires a working computer, with electrical power and an Internet connection. Also the user needs to know that there is useful information on the web, where and when to find it. Other information services, such as telephone, e-mail, facsimile and radio may be more effective for immediate communication. However, you can provide a web address, for example in a radio broadcast or a mail message to a predefined list, to provide more detailed information.
Challenges
-
Overloaded system: The major challenge in an emergency is the overloading of web servers from too many requests. Generally the Internet itself copes well, it is just that specific servers have too many requests on them.
-
Don't know where the information is: Users may not know where to look on the web for the information they require.
Solutions
-
Reduce graphics: Reduce the use of graphics on emergency web pages to reduce the load on web servers. Replace graphic buttons with text, remove decorative graphics which do not convey useful information. Reduce the size of remaining graphics by reducing their resolution, color range and increasing the image compression. However, as far as possible retain the usual overall look of your web site to reassure the reader that the information is authoritative.
-
Allow caching: Web browsers have caching build in to allow previously used web text and images to be recalled from a local disk. The reduces the need to recall the information from the server, greatly reducing the load. However, some web pages have parameters set to disallow caching. Reset these to allow caching, unless there is a good reason not to. Where web information is updated frequently, include the date and time of the iformation on the page and when it is next likely to be updated.
-
Use Static Pages: While customising web information for each user can provide an engaging experience, it limits capacity in an emergency. Use static web pages for emergency information as far as possible, so no additional processing is required and it can be cached. Don't have the user's name or the current date on the page as a parameter, unless needed (use a generic name and the date the information was issued instead).
-
Provide Prepared Reports from Dynamic systems: Where a dynamic system is provided, such as querying a database, provide static web pages with preprepared results of most likely queries. This reduces demand on the dynamic system. Provide queries specific to the current emergency with options likely to be used and which minimise the load on the database.
-
Put emergency information up front: As well as providing information at it usual location on the web site, provide an emergency announcement on the top of the home page. Provide links to where most needed information is located. Preferably have the emergency page in a format which can be easily printed and e-mailed.
-
Tell people what to use: If there are services on the web site, such as database queries, which are needed but slow down the system, then ask for responsible use. Provide an announcement explaining the emergency, ask for essential use only, provide alternatives, such as prepared pages and simplified queries.
-
Tell Staff What is Happening: During an emergency staff who do not normally deal with the public may be called on. Advise these staff what information is being issued on the web so that they can provide consistent information and also know what is happening themselves. Staff may be working from emergency offices not linked to internal organisation systems, so consider providing non-sensitive information for staff via the public web site.
See also:
- Dealing with Disaster - Using new Networking Technology for Emergency Coordination, For Industry Outlook Conference 2003, Canberra November 2003
Tom Worthington © 2003