Friday, February 16, 2018

Non Bare Earth Lidar

Lidar (light detecting and ranging) is a landscape reading tool that I use whenever the imagery is available. I have frequently posted lidar derived imagery. The ability to have bare earth imagery with accurate elevation has been a huge change for geologists. But the non bare earth imagery is also a powerful tool.  

Lidar image showing electric high voltage power lines, forest, pastures and homes

The image above has not gone through the computer program that removes the trees and thus does not show the underlying bare earth features very well. But in this case I wanted to see the areas of forest cover; Where are there big trees? I was able to compare this 2013 lidar image with Google Earth images to assess if the a stand of large trees was still present. At issue was the role large trees play in intercepting and partially routing debris floods and debris flows on alluvial fans. Having the imagery of where large tree stands were located versus just brush helped my analyses.   

1 comment:

Deane said...

As a life-long student of studying vegetation growth over time, the greatest days were when I had full&free access to the Aerial Photography Library at UC Santa Cruz in the early 1990's. Whereas in the past couple decades in PNW, I've never found equivalent access. The state of Washington charges outrageous prices for just one aerial photo, let alone the several dozen I need to study a specific forest. Google and County geo-databases haven't been much help either.

This is the first time I've seen Lidar before vegetation stripped from it... Gets me super excited!

Anyways, do you have any links or suggestions about how myself, or a non-profit I'm part of can get access to vegetation data / aerial photos dating back to the 1930's? It's so frustrating to not have any access!