New Web Site Features Resources for Cave Mapping and Analysis

Bern Szukalski is ArcGIS product manager and technology evangelist at ESRI.  Earlier this year, I spoke to Bern at length about visualization and ArcGIS Explorer, which resulted in a two-part blog post (see “A Conversation with Bern Szukalski about Geospatial Visualization,” Part I and Part II).   What didn’t come out in that interview is Bern’s deep-seated interest in exploring—and mapping—the world’s caves.  I recently spent a few minutes with Bern to talk about the launch of his new web site, which features mapping and GIS resources for cavers.

cave1

Matt:  What was the impetus for putting this web site together?

Bern:  The site in general combines more than a “hobby” with the other thing I love to do—make maps and use mapping software.  Digital mapping of caves is somewhat unique, involving specialized software, procedures, and techniques.  One of the driving reasons for the site is that many people have asked me for help, examples, or about how to implement things, so this is a place that I can point out examples.

Matt:  Is cave mapping difficult?

Bern:  Cave mapping, for the most part, is still done the old fashioned way – with a compass, clinometers, and tape. Nowadays the old reel tapes have been replaced by laser rangefinders, which provide not only greater accuracy and ease of use, but are also friendlier on the caves, as you don’t have to worry about the tape snagging formations as you wind it up. And it also eliminates the need to physically go to places to pull the tape; you just use the laser to beam distant walls. So you can keep on a single trail if you’re surveying a delicate cave.

The Hidden River Cave survey data has been georeferenced and exported to DXF format using Compass cave survey software. Using ArcGIS the cave passage is symbolized and is shown here in ArcScene, a component of the ArcGIS 3D Analyst.

The Hidden River Cave survey data has been georeferenced and exported to DXF format using Compass cave survey software. Using ArcGIS the cave passage is symbolized and is shown here in ArcScene, a component of the ArcGIS 3D Analyst.

Matt: So how is the data collected?

Bern: Well, you set stations as you go through the cave and measure the distance, azimuth, and inclination between each station. You also measure to the left, right, above, and below each station. That goes in your survey book, along with a detailed sketch. Some folks use handhelds to record the data.

Matt: So how does that get into a GIS?

Bern: Several cavers have developed cave survey programs that are used to manage the survey data, and create lineplots and even passage wall models and more. These are actually quite sophisticated, and can even import DRGs and so forth. The one I use is called Compass, and is authored by Larry Fish, a Denver area caver who has an excellent Web site where you can download the software. Years ago, there wasn’t a way to get the Compass data into a GIS format, at least not easily. I was doing some volunteer work in Hawai’i Volcanoes National Park, and the cave resources specialist there–Bobby Camara–was using ArcView 3. He also used Compass, and asked me if there was a way to get the Compass cave survey data into ArcView. At the time I was on the ArcView team and knew it could be done, and spent most of my volunteer time there working on writing an extension for ArcView that would import the Compass cave survey data and create shapefiles. So, while my caving buddies and wife went cave surveying, I’d be in front of the laptop writing Avenue code. That extension was called CaveTools, and was the way many cavers and cave resource specialists originally got their cave survey data into ArcView. Since then Larry has added direct support in Compass for shapefiles, as well as KML, and it’s an easy way to integrate the cave survey data into GIS.

Matt: So what can you say about people using cave survey data and GIS now?

Bern: Many of the federal cave resource managers do a lot of their own GIS work with cave data, or use their park or regional GIS staff for their GIS work. Most of the applications focus on integrating not only the locations of caves and other karst features, but integrating the cave survey data and even final maps, and managing the inventory data and other information that is collected about them. There’s not quite as much GIS analysis being used specifically for caves, but certainly a lot of analysis has been used to manage groundwater in karst areas and things like that. I think the State of Kentucky is a great example of using GIS for managing karst data, and even publishes their sinkhole database online. And there’s many more. There is some excellent work going on and great examples using GIS in this specialized application area. The ESRI cave and karst site links to a bunch of examples.

This map series was created for an article on Bermuda caves and the Bermuda Cave and Karst Information System (BeCKIS) project.

This map series was created for an article on Bermuda caves and the Bermuda Cave and Karst Information System (BeCKIS) project.

Matt: Any general trends you see, or comments about how this is working?

Bern: One interesting thing I have noticed about my experience with this over the years is that people either don’t know how easy some of this can be or they tend to over-engineer things. I’ve seen a few projects struggle over the years because they’ve gotten too complex, and when staff or interests shift it’s hard to keep things going.  My philosophy in general is: less is more, simpler and sustainable trumps an elegant technical implementation, and don’t use a jackhammer when a small tack hammer will do. And so most of my examples represent “easy” rather than “examples of technical elegance,” but they should always also fit well into an existing context, if there is one. But nowadays it’s pretty simple to get cave survey data into a GIS where you can do some really interesting things.

Matt:  Are caves in danger?  Can GIS help?

Bern:  One of the hot issues right now in the US caving community is something called White Nose Syndrome, or just WNS. It’s a fungus that’s affecting bats, stirring them out of hibernation and causing millions to die and threatening several species. It’s called “white nose” because of the distinctive fungal ring around the bats’ noses. It was first identified in the northeast United States, and has since spread and been identified in other states. Many caves are now closed by the state agencies that manage them, and some are closed voluntarily by cavers, to avoid spreading the fungus to other areas. It’s not quite fully understood, so there are lots of precautions being taken. Many of the agencies in the affected areas are using GIS in their work. One of the first maps published about White Nose was a GIS map by the Pennsylvania Game Commission. Bat Conservation International, who also got a significant grant from ESRI to support their work, has used ArcGIS in their work to support the various states, and a recent ArcWatch article was written about that.