Crowdsourced Satellite Image Analysis

There are many circumstances where the amount of data vastly exceeds the ability to process and analyze it—and computers can only do so much. Enter crowdsourcing. Steve Coast points to Digital Globe’s Tomnod project, which basically crowdsources satellite image analysis. In the case of the current project to  map the presence of Weddell seals on the Antarctic Peninsula and the ice floes of the Weddell Sea, users are given an image tile and asked to indicate whether there are seals in the image. It’s harder than it looks, but it’s the kind of routine task that most people can do—many hands, light work and all that—and it helps researchers focus their attention where it needs focusing. (A similar campaign for the Ross Sea took place in 2016.)

Another ongoing campaign asks users to identify flooded and damaged infrastructure and trash heaps in post-Hurricane Maria Puerto Rico.

Mapping Glacial Retreat

Elevation change of Mount Rainier glaciers, 1970-2016. David Shean/University of Washington.

Using elevation data from stereo satellite observations, David Shean is mapping the retreat of some 1,200 mountain glaciers in the continental United States. “Until recently, glaciers in the United States have been measured in two ways: placing stakes in the snow, as federal scientists have done each year since 1957 at South Cascade Glacier in Washington state; or tracking glacier area using photographs from airplanes and satellites.” Shean’s method, which measures each glacier twice a year and uses automated software to track changes, seems to cover a lot more territory. [GIS and Science]

A Look at GOES-16’s Imagery

This NOAA article looks at three kinds of imagery provided by the GOES-16 geostationary weather satellite: GeoColor, the Geostationary Lightning Mapper (!), and full disk infrared imagery from the Advanced Baseline Imager. GOES-16 launched last November and is currently in the checkout phase before it replaces GOES-13 at 75° west latitude.

California Wildfires: Mapping Sonoma County

Sonoma County’s wildfire information page points to a number of useful maps: fire perimeter boundary maps, current evacuation areas, road closures, rapid evaluation safety assessment (RESA) maps. The City of Santa Rosa’s emergency information page also has maps specific to that city; Heavy also has a roundup. See also Cal Fire’s structural status information map. [The Mercury News]

Previously: Mapping the Northern California Wildfires.

Mapping the Northern California Wildfires

NASA Earth Observatory
NASA Earth Observatory

Maps and satellite imagery of the wildfires in Northern California include the San Francisco Chronicle’s interactive map; Robin Kraft’s interactive map  showing satellite imagery from before and after the fire; this New York Times page mapping building damage in Santa Rosa; the Washington Post’s coverage of the devastation; and NASA Earth Observatory’s images of the smoke plumes here and here.

Volunteers Mapping Post-Hurricane Puerto Rico

When disaster strikes, crowdmapping kicks into high gear. Last Friday, six universities hosted mapathons where volunteers, using satellite imagery, contributed to the map of Puerto Rico and other hurricane-damaged areas on OpenStreetMap. More from one of the universities involved. Here’s the relevant project page on the OSM Wiki.

Mapping the Damage in Puerto Rico


At NASA’s Earth Observatory, before and after images of Puerto Rico’s nighttime lights illustrate the extent of power outages and infrastructure damage on the island. NASA has also produced a map of likely damaged areas of eastern Puerto Rico, based on before and after radar satellite interferometry and similar to the map they produced for the Mexican earthquake. At ground level, the CrowdRescue Puerto Rico Infrastructure Map displays crowdsourced reports of damage—downed power lines, bridge collapses, floods, mudslides and other incidents.

Looking Back at Hurricane Harvey’s Impact

Here’s a CBS News gallery of before-and-after images showing the impact of flooding in the wake of Hurricane Harvey. The page is undated but was published on 1 September. [Dave Smith]

And, via CityLab, here are a set of maps from the Urban Institute that show the impact of Hurricane Harvey on Houston’s neighbourhoods, based on income levels, home ownership rates, accumulated-equity rates, all of which looking at the economic impact of the storm. “Harvey’s aftermath puts an enormous hurdle in front of all homeowners and renters but will be a particular setback for low-income, minority families recovering from the 2008 housing bust.”

Previously: Mapping Hurricane Harvey’s Impact.

Maria’s Deluge

Some of the most striking maps of the recent bout of hurricanes have involved the sheer amount of water dropped by these storms. (See previous posts on Harvey and Irma.) Above, a is a short NASA video showing Maria’s track through the Caribbean, dumping water in its wake.

Relatedly, the Washington Post produced maps of precipitation and river gauge levels on Puerto Rico that show just how much water Maria threw at that island.

Washington Post

Tracking Hurricane Irma

Washington Post

As they did with Hurricane Harvey, both the New York Times and the Washington Post graphics departments have frequently updated map pages showing the projected path and impact of Hurricane Irma. The Times’ page looks at the hurricane’s current and projected path, threat of coastal flooding, and areas under evacuation, plus some context; the Post maps Irma’s forecasted path on this page and the potential storm surge and evacuation zones on this page, while this page compares Irma’s size to past hurricanes.

Debunking a Fake Hurricane Map

Also from last week: someone on Facebook circulated a map showing the path of Hurricane Irma hitting Houston, prompting the National Weather Service to issue a warning on Twitter about fake forecasts (real forecasts only go out five days). Media factchecking service PolitiFact has the details. Fun fact: making a counterfeit or false weather forecast is an offense in the United States.

Mapping Hurricane Harvey’s Impact

Washington Post

The Washington Post maps rainfall and flooding levels in the Houston area.

The New York Times is collecting several maps on two web pages. The first page deals with subjects like rainfall, river level, current and historical hurricane tracks, damage reports, and cities and counties under evacuation orders. Maps on the second page look at Harvey’s impact on the Houston area.

Esri’s U.S. Flooding Public Information Map includes precipitation and flood warnings.

Kenneth Field critiques the National Weather Service’s decision to add more colours to their precipitation maps (see above). “Simply adding colours to the end of an already poor colour scheme and then making the class representing the largest magnitude the very lightest colour is weak symbology. But then, they’ve already used all the colours of the rainbow so they’re out of options!”