Use of Google earth for planning whitewater expeditions

I first realised how useful Google Earth could be for expeditions when I watched this great TED talk about using Google to plan a climbing expedition.   Tim Burn then used to it plan a kayaking trip to Sulawesi. 

Whilst planning a kayak expedition to Borneo, I was keen to use Google Earth and see how useful it could be.

Finding rivers with potential for Kayak Borneo before we headed out.

Accurate maps of many countries are incredibly hard to come by, especially ones with contours detailed enough to work out gradients.  This is where Google Earth came in really handy.  Its new cloud free satellite imagery of the whole world and topographical (height) data means you can gain a lot of information about rivers all over the world.

Drawing a ‘Path’ down your intended river enables you to see; the average gradient, particularly steep sections and distance.  Combined with the satellite imagery, you can see bridges, villages and roads for potential access and egress points.  With recent and detailed images, newly built dams and other potential hazards such as weirs and rivers going underground can also be seen.  It is also to see the size of individual rapids and even start to scout possible lines!

Scouting the Humla Karnali using Google Earth.

If looking at a lot of rivers, like we did for Kayak Borneo, it is really important to establish a key for them before things get too confusing.  Creating a document with all the important stats on the river before you head out means that before you even land in the country, you have a hit list of rivers to check out.

Another cool feature that is possible to make fly overs which can be used to make grant applications and also give perspective to videos after the trip.

How is it all possible

I think this is a good point to stress that I am a technophobe but with a little bit of time on Google and scrawling through help forums and youtube, it is easy to work things out.
First download Google Earth a ≥ medium power computer is needed to get then most from it
Find a river
After finding a country with loads of whitewater potential, start finding rivers to explore.  A paper map can be useful for this but not essential and it is easy to mistake roads for rivers.

Google Earth showing the Tutoh deep in the Heart Of Borneo

Adding a path
Use the 'add path' button on the tool bar.  Carefully draw a line down the intended river.  You can remove sections from each end by selecting the final point then 'right clicking'.  In the pop up box, rename the river (think carefully about a coding system) and also change its 'style and color'.

'add path' button - http://www.google.com/earth/outreach/tutorials/annotate.html

Path added in Google Earth.

Once a path is added, it is possible to get a lot of information from the satellite imagery.

Calculating gradients

The topography data contained in Google Earth is also really useful.  By right clicking on a river in the 'Places' menu and selecting 'Show Elevation Profile', a graph appears in the bottom of the image.  It is possible to quickly see river length and rough gradient variations.  The river appears to rise and fall rapidly along the length of the graph.  This is due to low resolution topography data and also not quite following the rivers course.  Not a problem.

To calculate an over all gradient, divide the height difference from get on to get off by the total length.  Keep it in meters over kilometers to get a useful number.  For low volume runs 25m/km to 50m/km is good.  for example the Nevis is 30m/km.  For higher volumes, a lower gradient is ideal.

Making a flyover
This is when it gets cool.  Select the river to make a flyover with and press the 'play tour' button.

'Play Tour' button on Google Earth

There is possibly an easier way to do this next step, however this is the way I found.  Download some 'screen capture' software then use it to film the 'Play Tour' in Google Earth.  You can adjust the screen size so it excludes all of the gubbins round the edges.  The output file can be converted from .xesc to .mp4 file for use in video editing.

Mid flyover in Google Earth

As with all technology, the future is exciting and mind boggling.  Google Street View kit is on rucksacks is traveling to some really remote areas such as the Grand Canyon making scouting rivers even more detailed.

I hope I have explained this process clearly.  If you are trying to follow this and you encounter problems, ether comment below or drop me a message or Google search.

Hurrah for Google!