Wednesday, October 11, 2017

NorCal Fire Response

The quick summary:

  • If you are seeking information on the Northern California wildfires, or trying to understand CalTopo's current fire activity layer, please see this blog post.
  • Edit: big thanks to the Google crisis response team for rapidly lifting the map quota.  The OpenLayers warning no longer applies.  CalTopo will be intermittently running on OpenLayers instead of Google Maps.  If the zoom controls at the top left of the map viewer are blue instead of white, Google layers (map, terrain, satellite) will be unavailable, and text based location search will not work.  You can use the search bar to locate lat/long or UTM coordinates, but not named places.
  • The current fire activity layer now includes VIIRS 375m detections as well as MODIS.
  • CalTopo now sports a new mobile UI.  If you have issues with it, please let me know.
The details: in case you've been living under a rock since Sunday night, California is on fire:

Sunday night's VIIRS capture: fires that look like cities

On Tue morning, CalTopo started seeing increased visits from people looking at the fire activity layer, and pageviews rapidly grew to well above normal.  This caused some scaling issues, but barring another order of magnitude in growth, those are temporarily solved with a combination of software fixes and throwing hardware at the problem.

The larger issue is that I ran into the 100k pageview limit for the Google Maps standard plan, and CalTopo stopped loading.  I've fixed this by switching to OpenLayers, which is the map viewer used in CalTopo Offline, but it's not a perfect substitute: in addition to missing Google's map layers, text-based location searches (like "santa rosa, ca") will no longer work.  The version of OpenLayers I'm using is also old and heavily customized, so there may be some compatibility issues with touch gestures on mobile devices.

I'm working with Google on fixing the issue, but in the meantime, I'll turn on Google Maps at some point in the morning, and leave it on until the quota runs out.  If the zoom +/- buttons at the top left of your screen are white, you're using the Google Maps viewer and everything should function normally.  If they're blue, it means you're using OpenLayers.

In order to better serve people looking for fire information, I've also held a marathon coding session to wrap up and deploy two back-burner upgrades.  The first is the addition of VIIRS 375m fire detections alongside MODIS.  At more than double MODIS's resolution, VIIRS should provide a more accurate picture of the fires' behavior.  Although VIIRS suffers from a limited number of passes (just like MODIS), adding a second source will increase the layer's all-important update frequency.  And certainly the most common question I've gotten today is "when will the layer update"?

Looks just like MODIS, but with more points

The current fire activity layer was already customizable (smoke vs no smoke); now you can choose all sources (a mix of MODIS and VIIRS on the same map) or view them one at a time for a cleaner image.

The second change is a revamped mobile UI.  Normally I'd hang on to a change like this for another month or two in order to test it thoroughly and smooth out the edges.  However, the vast majority - > 90% - of people seeking fire information are doing so on their phones.  And, the previous mobile UI was non-functional enough that I'm unlikely to make things worse.  I know it's 2017 already, but now the CalTopo mobile site supports 90% of the features the desktop site does.  More details in a later post once I get things cleaned up, but in the meantime let me know of any bugs.


  1. IN layman's terms, is this current and updated as of when?

    1. Fire perimeters are current as of each morning (as long as they can be flown with IR overnight).

      Hotspots are updated several times per day. As you zoom in the hotspots are labeled with the time at which they were observed.

  2. Nice work, Caltopo is a great resource. I was wondering if there are plans to overlay EPA AQI data/forecasts, would be a nice supplement to the recent weather data and with these fires would be helpful when planning.

    1. Last time I looked (which was a while ago), I couldn't find a viable public datasource. If you know of one I'd be happy to take a look. Definitely wouldn't happen during this fire cycle, though.

    2. EPA Airnow appears to have an API that exposes the pm2.5 and ozone data