Immediately after the disaster, the UN Office for the Coordination of Humanitarian Affairs (OCHA) asked the International Charter on 'Space and Major Disasters', referred to as 'the Charter', for support by providing immediate crisis mapping of the affected areas.

Following the request, rapid mapping products were created with Earth observation (EO) satellite acquisitions taken in the wake of the event to derive an estimation of the flood surge impact and other damage information to help plan emergency response operations.

Damage maps were able to be created quickly because the RESPOND project, which delivers satellite EO-derived topographic maps of Myanmar a month before the disaster.

This activity was part of a project to help local communities reduce exposure to disaster risks.

This enabled the RESPOND team to compare up-to-date basic maps before the disaster with satellite images acquired during or after the cyclone impact.

Thanks to the Charter more than 10 different sensors - radar and optical - from several EO missions provided more than 60 satellite images, which were used to derive 29 damage maps.

These maps were provided to the UN community in Myanmar and Bangkok for the emergency response phase, which lasted more than 40 days because of the scale of devastation caused by Nargis and the difficulties encountered by the international humanitarian community to access the country.

"It is important to differentiate map products according to the needs and, in a case like this, to firstly get an overview and then move into more detailed assessments as the relief operation progresses," explained Dr Einar Bjorgo, head of UNOSAT.

After the acute phase of the disaster had passed, the range of mapping products was extended to provide further details on the condition of roads, bridges and buildings.

For instance, UNOSAT teamed with GISCorps, a US-based non-profit association, to digitise every building pre-disaster from the available data. These maps were highly accurate, showing features of less than one metre in size.

To date, the map products have been used by over 40 organisations, including non-governmental aid organisations based in Myanmar, such as the Red Cross, and governmental organisations, such as the German Federal Agency for Technical Relief (THW) and the Myanmar Department of Forestry.

"It was important to continually produce damage assessment maps for aid workers because very severe rain events occurred in the days following Nargis," said SERTIT Director Paul de Fraipont. "Based on feedback from specialists in the field, this made the products even more useful," he added. - ANI