flood

Google Earth Imagery Updates: Floods

July 4, 2017

Google has recently updated the ‘historical imagery’ layer and today we are having a look at a couple of floods.

Black River, Arkansas.
We had a look at this flooding event last month using low resolution Sentinel-2 imagery. Now there is higher resolution DigitalGlobe imagery we can see a lot more detail. The imagery was captured on May 6th, 2017.

The road below appears to have also served as a levee to prevent flooding. However, it has clearly been breached in a number of places, causing major flooding downstream.

Multiple breaches in a levee, Black River, Arkansas (near Pocahontas).

Flooded houses downstream from the breached levee.

Pocahontas, Arkansas, showing how the height of the river during the flood compares to the normal level.

Rigaud, Quebec, Canada.
According to this article, between April 5 and May 16, more than 5,700 homes were flooded and more than 4,000 people forced from their homes in Quebec, Canada. One of the worst affected towns was Rigaud. There are some DigitalGlobe images from May 17 after the water started to subside, but we can still see some flooded areas.

Flooded houses in Rigaud, Quebec, Canada.

Retreating flood waters, Rigaud, Quebec, Canada.

For outlines of the above imagery and locations of interest, download this KML file.

Google Earth Imagery Updates: Flooding and Factory Fire

June 5, 2017

Today we are having a look at three different floods and a factory fire.

Dominican Republic
In late April and early May, the Dominican Republic and neighbouring Haiti experienced heavy rainfall. There is a DigitalGlobe image captured on April 29th showing a region around Santo Domingo, the capital of the Domincan Republic:

Flooding to the north of Santo Domingo.

Malaysia
In January this year Malaysia experienced severe flooding, forcing 23,000 people from their homes. According to Wikipedia severe flooding is a near yearly occurrence in Malaysia. Worst affected were the north-eastern provinces Kelantan and Terengganu. The image below is from Kelantan. It is often hard to tell in rice growing regions what is abnormal flooding and what is deliberately flooded rice fields. In the region pictured, the houses appear to be on higher ground and appear to be mostly dry. We have included an older image for comparison as we initially mistook the local canals for flooded roads.

San Jose, California.
In February, Coyote Creek overflowed in San Jose, California, resulting in evacuations of thousands of people. The image is black and white and we could only find one location that shows signs of flooding:

Flooding in San Jose, California.

Factory fire in the Philippines
In February, a factory caught fire near General Trias, the Philippines, injuring more than a hundred workers and resulting in at least five fatalities.

Factory fire in the Philippines.

To find the above locations in Google Earth, download this KML file. We have included outlines of relevant imagery and a couple of placemarks for other interesting sights we found while exploring the areas.

Ongoing Sri Lanka flooding visible in Sentinel-2 imagery

May 30, 2017

Sri Lanka is currently experiencing severe flooding across its south-western region, reportedly killing at least 122 people so far. We had a look at Sentinel-2 imagery and were impressed to find some very recent imagery from May 28th, 2017, already available on Amazon Web Services (AWS).

Below you can see the southern city of Matara surrounded by flood waters, as well as the muddy water streaming into the Indian Ocean.

Southern Sri Lanka as seen in Sentinel-2 imagery.

A close up of Matara.

To see the above Sentinel-2 image in Google Earth download this KML file.

The Peru Floods with Google Earth

May 22, 2017

A couple of weeks ago we had a look at three different floods around the world, including Lima, Peru. However, the flooding in Peru was very extensive, so today we are looking at some other locations around Peru.

Here is a ‘before and after’ showing how the Moche River, which passes through Trujillo, Peru, created a new delta:

Moche River delta creation.

Further north we can see how the Chancay River grew significantly wider:

Chancay River. We are seeing it after the water has subsided from it highest levels.

Zooming out and using Landsat imagery, we can see some large areas that were completely flooded. They are naturally swampy areas, but we could not find this extent of flooding in older imagery, so we believe it to be quite unusual.

Left: Google Earth imagery composed of Landsat/Sentinel-2 mosaic. Right: Landsat image from April 4th, 2017.

To find the above locations in Google Earth, download this KML file. We have included an image overlay of the Landsat image. We have also outlined all the 2017 imagery we could find for Peru. If you come across any other 2017 imagery in the region, please let us know in the comments.

The inland parts of Peru drain into the Amazon basin. There was also significant flooding there, but it is rain forest, so it is unlikely that we will see any high resolution satellite imagery (too much cloud cover). It also seems probable that as the water flows towards the ocean we will see floods along the Amazon in Brazil later in the year.

Google Earth Imagery Update – Floods around the World

May 8, 2017

As we mentioned last week Google recently did an imagery update. The fresh imagery has now been pushed to ‘historical imagery’ and we are looking at three floods around the world.

Lima, Peru
We mentioned Lima, Peru in a previous imagery update. At that time, the imagery was from just before the worst floods. 2017 has seen heavy rains in much of South America with significant flooding in Brazil, Chile, Colombia and Peru. According to Wikipedia, more than 115,000 homes were demolished, leaving approximately 178,000 people homeless. A total of 113 people were killed, 354 were injured, and a further 18 were missing.

The Rímac River flows through Lima and you can see it forming a delta in February and March.

Speed in milliseconds per image:
Rímac River delta forming in Lima, Peru.

Rímac River, Lima, Peru. In the photo, a foot bridge is partially flooded and a road is damaged. However, we believe that at the height of the floods, most of the surrounding roads were flooded.

New Zealand. Cyclone Debbie.
Cyclone Debbie caused major flooding across the eastern coast of Australia and parts of New Zealand. Last week we had a look at Rockhampton, Queensland, Australia using Sentinel-2 imagery. Below we see some flooding around Edgecumbe, North Island, New Zealand.

Flooding around Edgecumbe, New Zealand.

A closeup of Edgecumbe, New Zealand.

Madagascar – Tropical Cyclone Enawo
Tropical Cyclone Enawo passed over Madagascar in early March causing major flooding along the eastern coast. DigitalGlobe released some spectacular images which, unfortunately, haven’t made their way into Google Earth. However, there is quite a lot of fresh DigitalGlobe imagery, mostly from after the worst of the flooding along the coast. We only found one image captured during the flood:

The region around Maroantsetra, Madagascar

A close up of some houses up-river from Maroantsetra, Madagascar

To find the above locations in Google Earth, download this KML file