Cyclone Gabrielle floods: First satellite images shows extent of ...

New satellite data has revealed just how hard Cyclone Gabrielle hit Hawke’s Bay causing widespread flooding and devastation across the region.

Flood estimates were prepared by Wellington’s Dragonfly Data Science using imagery collected by the European Space Agency’s Copernicus Sentinel-1 mission at 8.07pm on February 14, two days after the first effects of Cyclone Gabrielle were felt across the North Island.

The satellite data was analysed by data scientist Dr Sadhvi Selvaraj who - along with colleague geospatial analyst and developer Ian Reese - overlayed the flooding estimates on a standard Land Information New Zealand (LINZ) map.

Dr Selvaraj said data was used from one of the two satellites that make up the Sentinel-1 mission. The satellite provides black-and-white imagery that can be used to map flooding as well as other effects of weather events, like landslides.

“There are heaps of applications for it. You can map bigger landslides, you can map land movement and you can even use Sentinel-1 satellite data for mapping wind speed and direction and the oceans.”

The satellites provide images every six to seven days and it was just luck that they captured the estimated flooding from Cyclone Gabrielle. The satellite is able to pick up flooding that is larger than 10 by 10m or more, meaning not all flooding incidences would have been captured.

Cyclone Gabrielle – the most severe weather event to hit New Zealand this century according to the Prime Minister – unleashed severe gales and heavy rain on the North Island from Sunday.

Gabrielle’s wrath has devastated Hawke’s Bay, claiming three lives in the region including a child, and causing widespread flooding that has washed away homes and isolated communities, leaving thousands of people displaced.

In total, five people in New Zealand have been confirmed dead.

New images from Hawke’s Bay’s Esk Valley, where homes and vehicles have been destroyed, and crops ruined, have laid bare the cyclone’s horrific destruction.

A woman is still missing in Hawke’s Bay after the Eskdale property she was housesitting was suddenly inundated by floodwaters early on Tuesday morning, RNZ reported.

In Napier, desperate residents queued for petrol, cash and gas as the city faces up to two weeks without power and after the only lifeline to Hastings, State Highway 51, closed again on Thursday.

Search crews in Hawke’s Bay have been trying to get to more people stranded by floodwaters while community fears grow of multiple deaths in one of the areas hardest hit by Cyclone Gabrielle. Coastal residents of Napier’s Bay View claimed they saw several bodies washed away by raging flood waters.

Napier - cut off from the rest of Hawke’s Bay on Monday night - was briefly reconnected this morning but the road was closed again for bridge assessment.

More than 40,000 Hawke’s Bay households were without power, according to a Transpower update at 1pm. Most of these homes, 31, 700, were in Napier.

People were being evacuated from their homes in the Napier suburb of Taradale as well as central Hawkes Bay’s Drumpeel Rd. Earlier in the day, the district council ordered all residents in the area to get to the local municipal theatre.

In Puketapu, near Napier, a large group that was taking shelter in a handful of surviving homes were being flown out by private helicopter just hours after sending a message that they were running low on fresh water and food.

State Highway 2 between Napier and Wairoa has been destroyed by floodwaters while the Wairoa area has been completely cut off, according to aerial photos supplied by Hawke’s Bay Civil Defence.

Authorities worked frantically to establish communication and transportation routes with the community because there were fears that supplies would only last for one more day in the town.

About half of the town’s 8000 residents live in the 10-15 per cent of the town submerged by the river when its banks broke in Wairoa.

On Thursday, Wairoa mayor Craig Little said while they had experienced an “absolutely devastating” storm event, he believed everybody had been accounted for at this stage.

“People are suffering, their homes have been inundated with water and we just need to still get it sorted.

“So people are struggling but you can’t get hold of them because our communications are down, don’t stress that because you can’t get hold means of them there’s something wrong.”

The effects of Cyclone Gabrielle have been felt across the North Island. MetService said the tail-end of the storm was impacting the Wairarapa and Wellington region today.

A National State of Emergency was declared by the Government on Tuesday. Minister for Emergency Management Kieran McAnulty said the declaration would allow the Government to provide extra resources to the affected regions.