Saturday, October 19, 2013

New Land Management and Fire History Layers

I've recently added two new layers to CalTopo, both built built on government datasets but with homegrown rendering.

Northern California burning
The fire history layer shows wildfire activity since 2000.  There are some regional datasets that go back much further, but this was the best I could find for national coverage.  Fires are color-coded by year along a yellow-red spectrum, with yellow fires being the oldest and red being the newest.  Exact dates are listed in the map info pane at the bottom right.

I've tried to show both the year and incident name for all fires.  Large fires are labeled as you begin to zoom in, and then all fires at the lower zoom levels.  Unfortunately, in areas with overlapping fire perimeters, it can be hard to figure out which label belongs to which fire - and some of the overlapping incidents even share the same color.

Large incidents labeled at moderate zoom

The second layer shows public land management (technically, the "surface management agency").  While data for this layer is sourced directly from the government and seems reliable if a touch dated, hunters should verify with a second source - don't blame me if something's mislabeled!

A wide mix of agencies in Southern California
As you zoom in, the polygons change from opaque-ish to translucent with borders, just like the fire layer.  I chose not to label them as national forests were the only areas with unit designations, e.g. Tahoe National Forest; most areas are simply attributed to BLM or state ownership with no further information.

National Forest boundaries - have they ever made sense?
I'm open to modifying the colors used for various agencies.  While I tried to follow existing map conventions as best I could, there are only so many options available and I can see how some might cause confusion: the Bureau of Land Management and Bureau of Reclamation are both orange, but I don't know how similar their rules on activities like hunting and camping are.

Public land management in the continental US

Tuesday, October 15, 2013

SARTopo - CalTopo for SAR

CalTopo started as a project to provide better maps for search and rescue.  As I focused more effort on, the SAR version lagged behind and it became harder to bring new features from CalTopo back to the SAR code.  This summer I put a lot of effort into reworking things, and while CalTopo hasn't seen many new features, the SAR version is finally ready for a re-launch.

So without further rambling, I give you - CalTopo for SAR.  SARTopo takes the existing CalTopo UI that you've learned to at least live with if not love, and adds additional search and rescue object types like operational periods, assignments, clues and resources.

These extra objects make it easy to do things that are cumbersome at best with traditional mapping software: editing the same dataset from several computers, printing assignment maps on multiple backgrounds, dumping segments to GPS, filtering stray tracks and waypoints, color-coding data by operational period or resource type, and a lot more.

I encourage anyone involved in search and rescue to watch this 3.5 minute video and then give it a try at

Both the software that makes this happen and the map layers I've created are available for free to search and rescue teams.  You can load them on a laptop and run a mobile version of SARTopo in the field, miles from the nearest internet connection, with statewide map data including USGS topos, USFS topos, aerial imagery, shaded relief, contour lines, slope shading, viewshed analysis and even the "view from here" feature.

For more information on offline use, please visit

Assignments, Clues, Resources: some of the added SAR features

Now that SARTopo is finally live, I look forward to returning more attention to CalTopo, and several new feature blog posts are coming shortly.