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Want to see how your local coastline will change if sea levels rise? See which streets will be submerged and which ones will have waterfront views?

A visit to this web site shows the impact of sea level rises from one to 14 metres in one metre intervals. The site uses Google's mapping API and 50 Gbyte of raw data from NASA.

Using Google maps, one can view the extent of potential flooding for almost anywhere, in some cases to very high levels of resolution and detail.

The inundation estimates are just that, given that there are a number of significant areas of inaccuracy. However, the estimations in most of these cases are optimistic -- correcting the inaccuracy would make the consequences of any rise look worse. The model takes no account of tides. Since some areas experience tidal variations of 10 metres or more, this is a major deficiency.

The NASA data itself is not very accurate, with buildings and trees causing a systematic overestimation of the elevation of built up and forested areas.

Further, the NASA data does not extend beyond 60 degrees of latitude. Its accuracy becomes degraded at the extremes of its range, especially in the Southern hemisphere.

The simulation takes no account of the effects of coastal erosion. Anywhere within a metre or so of daily maximum sea level would be swiftly eroded, meaning that areas which the model shows as future 'coastline' would almost certainly be quickly eroded away.

Conversely, coastal defences that protect habitable land far below sea level are not taken into account.

Finally, some places are a long way from the ocean, yet far below sea level. They are shown as flooded on the map, where clearly they are not in danger.

Nonetheless, it's a fascinating summary of the potential impact of sea level increase and a great example of maps on the internet.

ASM Newsletter is distributed by e-mail every two weeks. It reports on events in the spatial industry in Asia and events outside the region which will impact on Asia.