Quick Check of the Sahana Disaster Management System

by Tom Worthington

For a Seminar, 8 February 2006 and Tools for New Media and the Web (COMP1710), 13 March 2006, The Australian National University, Canberra.

See also: updated presentation at the Department of the Environment and Heritage, Canberra, 11 May 2006.


Sahana is an Open Source disaster management system for finding missing persons, coordinating relief organizations and tracking victims in relief camps. The system was developed at short notice for the December 2004 Tsunami. Version 2 of Sahana is now in the test phase:

The first release of Sahana phase II is now being tested. For the first release we have looked to cover pretty much all of the phase I functionality + enhancement that make the application a lot more complete in terms of functionality.

It is currently being hosted at http://cvs.opensource.lk/sahana2 for review. Once this this has been tested we will make a release available (with LiveCD) for anyone to download. Additionally we will look to have a stable version live, available as required to help out/propose in a new disaster situation.

Please submit any bugs (not enhancements right now please :-) you may come across on the bug tracker at http://sourceforge.net/tracker/?group_id=127855&atid=709778 r group on the web, go to: http://groups.yahoo.com/group/humanitarian-ict/

From: Sahana phase II testing available for review, humanitarian-ict, Chamindra, 9 Nov 2005, URI: http://groups.yahoo.com/group/humanitarian-ict/

Sahana uses a web browser for the user interface, allowing it to be used over the Internet on just about any desktop PC or laptop. For the new version I suggested using features built into the web to make the interface even more flexible:

This document gives an example of how the web interface of disaster management software can be redesigned to make it more effective in an emergency. ... Better web design can reduce resource needs on overloaded emergency networks, allow operation on small screen mobile devices in the field and allow emergency information to be automatically translated into local languages. ...

From: Web Disaster Management, Tom Worthington, 2005, URI: http://www.tomw.net.au/2005/wd/sahana.html

This is a brief review of the user interface for Version 2, to see if it lives up to these ideals. Overall, no problem which could prevent the use of the system as is, were found. The user interface is usable not only on conventional PCs but hand-held devices. Some recommendations are made to speed up the interface for low speed links and improve the interface on hand held devices. It is suggested that an introduction for the user be added to give the system a self briefing feature.

It should be noted that the flexible user interface of Sahana 2 can not only be used by individuals with small hand held devices, but on large projection screens as used in a crisis centre to keep a team of people up to date. This could also be used as a briefing and training tool.

Web based Interface

Sahana uses a web browser as the user interface linked via the Internet to a server running a database. It uses the newer versions of HTML (XHTML 1.0 Transitional), cascading style sheets (CSS) and Javascript.

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="en" "en">
<title>Sahana Disaster Management System </title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<link rel="stylesheet" media="screen, projection" type="text/css" href="theme/default/sahana.css" />
<!-- <script type="javascript" src="theme/default/sahana.js"/> -->

Source code from Sahana Disaster Management System, 2005 URI: <http://cvs.opensource.lk/sahana2/

The use of CSS for defining the structure of the web page, in place of fixed tables usually used, allows the page to adjust itself to fit on a wide range and size of computer screens. This can be from a credit card size device which fits in a packet to a wall sized projection screen.

/* Now to layout elements... */

#container {

#header {
border-bottom: #036 5px solid;
padding: 0 1em;
background-color: #369;
height: 100px;
position: relative;

#header h1 {
position: absolute;
top: 0;
left: 0;
height: 100px;
width: 400px;
text-indent: -9999px;

From: Sahana - Default Theme - Stylesheet, Prabhath Sirisena, 2005, URI: http://cvs.opensource.lk/sahana2/theme/default/sahana.css

Look of the Page

Sahana has a simple three panel design, with the title in the top panel, menu on the left and content on the right.

Illustration 1: Sahana on a SVGA Screen

The the menu panel is fixed, while the other two panels adjust to the width of the browser window:

Illustration 2: Sahana on a VGA screen

With the CSS disabled, the design reverts to a single column, with what were the three panels arranged vertically (title, menu and content).

Illustration 3: Sahana on a QVGA Screen with no CSS

Usable with PCs and hand-held devices

With the default three panel layout, the system is usable low cost PC and laptops with lower resolution VGA screens (640 x 480 pixels). With the alternate one column layout the system is usable on a monochrome QVGA screen of a hand held device, such as a PDA, in landscape mode (320 x 240 pixels).

The system may not be usable on some PDAs and mobile phone devices with portrait mode QVGA (240 pixels wide by 320 pixels high) or smaller screens. When tested on the Openwave SDK 6.2.2 mobile phone emulator with a portrait QVGA screen the columns of data in a Missing Person Search became too narrow to be easily read.

Illustration 4: Sahana Missing Person Search Displayed on Portrait Mobile Phone Screen

However when tested with the Opera browser set to emulate a mobile device (small screen mode) each cell of the table was displayed on a separate line, making the display just usable. A test on a real device (Sharp gx30 GSM mobile phone with QVGA portrait screen) showed a similar result. The table cells are displayed column order (Picture, Name, Appearance, Missing Details, Status), then by rows (Person 1, person 2, person 3). This is somewhat confusing as all the column headings are displayed first, then the data, but is readable.

Illustration 5: Sahana missing person report on the Opera browser in small screen mode

The table's column headings have been correctly marked <THEAD> to identify them to the browser. The column headings have been marked as data <TD>, when they should be marked as header information <TH>. This makes little difference with ordinary web browsers, but can assist accessible devices for the disabled.

<TD>Picture</TD><TD>Name</TD> <TD>Appearance</TD><TD>Missing Details</TD><TD>Status</TD>

From: Missing Person Registry Search, Sahana Disaster Management System, 2005 URL: ttp://cvs.opensource.lk/sahana2/index.php?mod=mpr&act=search

Recommendation: Mark column headings as <th> to assist accessible devices to render tables.

When used on a small screen, the menus fill the display. The user needs to scroll down to see the contents of the page. Hypertext links are provided at the top of the screen to jump to the contents or the module menu. However the layout can still be confusing as when the user selects an option from the menu, nothing seems to happen. The contents have changed, but that is not visible on the screen, just the unchanged menus. The design could be changed to move the contents up to between the two menus. However, to maintain compatibility with a conventional PC screen this would result in the layout changing to have the content in the centre of the screen with one menu on each side of it. This may not be worth changing for.

Download time

With a wireless hand held device, screen space and bandwidth are at a premium. Any unnecessary graphics should be disabled as these take up screen space and bandwidth. The HTML for the Sahana home page is only 3kbytes, making it very quick to load however, graphics will make this twenty times as large. With CSS disabled the flower motif of the top panel is disabled, but a decorative 63kbyte image on the home page remains (http://cvs.opensource.lk/sahana2/theme/default/img/home_pic1.png).

On a 14.4Kbps link, as might be expected with a hand held device, or a laptop with a satellite phone connection or slow dial up modem, the home page would take 46 seconds to download. This is unacceptable (ideally it should be under 10 seconds). A work around would be for the user to set the browser to disabled images. Images could be manually turned on where needed. However, the only part of the application which appears to need images is for photos of missing people. The operators of the system are likely to receive limited training and may not know how to disable and enable graphics. So it would be better to minimise unnecessary graphics.

A test using a GSM 2.5 generation phone displayed the home page in 14 seconds. The graphics did not display due to incompatibility with the phone web browser, speeding the display.

Recommendation: The decorative images should be disabled for non CSS and hand held devices. Or then remove them to a separate "About" page (see below).

Recommendation: An "about" page should be added to the main menu. This will provide an overview and introduction to the system. It should include a link to a presentation giving the background to the system, with similar content to a Powerpoint presentation but in web format (URI: http://www.linux.lk/~chamindra/docs/Sahana-Pakistan.pdf). This will allow briefings on the system to be given using the system.


The page has a title but no author description or keywords metadata. This will make it harder to find with a search.

Recommendation: Author, description and keywords metadata be added to the head of each page.


The images lack an ALT tag, to aid access. The images are only decorative and not essential and this needs to be conveyed to the reader who can't see them.

Recommendation: Blank ALT tag be used to indicate the images are not necessary.

Translation of Interface

It proved possible to display the Sahana interface using the Google automatic translation service. It was possible to select menu items in the translated language. The translation is not suitable for updating the database as any data downloaded is translated and will currupt the database when uploaded.

Google offers a free service that automatically translates pages published in languages other than English. Not all languages are translated and not all pages in those languages we do support are translated completely. Nor does the translation software recognize text within images, so these remain untranslated.

From: Translation of Snippets and Web Results, Google, 2005, URI: http://www.google.com/intl/en_ALL/help/faq_translation.html

Illustration 6: Sahana Machine Translated into French

Translation also worked on a small screen device (although these may be limited by available fonts for languages such as Chinese and Japanese).

Illustration 7: Sahana on a Mobile Device in Simplified Chinese

However, a problem was found with the results of a missing person search not being translated by the Google translation service. After a search the interface slipped back into English. This problem did not occur with the Babel Fish Translation Service.