Creating a Canopy DEM from LiDAR

In a previous post, I described how to create a hybrid hillshade from a standard bare-earth DEM and a DEM including canopy.  Well, what if you don’t have a fancy canopy DEM? Do you have classified LiDAR data, or know where to get your hands on some? Then you are in luck! I’m here to walk you through the process of creating your very own canopy DEM in ArcGIS.

CanopyHeight.jpg

Continue reading “Creating a Canopy DEM from LiDAR”

Advertisements

ArcGIS 10.2 Released with Spatialite Support

So, ArcGIS 10.2 was released last week, with a bunch of exciting new features. Among other things, they turned on multi-core support in a few spatial analyst tools, made it easy to create Python add-ins for the GUI, and have posted code templates on GitHub. All of these features are very exciting, but what I’m most excited about is support for Spatialite databases.

by Massimo Zedda
Continue reading “ArcGIS 10.2 Released with Spatialite Support”

From a Different Angle: Averaging Upslope Aspect

In flow accumulation modeling, a common bit of data needed is the average upslope value of a parameter of interest, such as slope or curvature.  In most cases, this is simply a matter of calculating a flow accumulation weighted by the parameter in question, then dividing this by the unweighted flow accumulation.  But what if you want average upslope aspect?  Since aspect is measured in degrees, and a value of 0° and 360° are the same, a simple arithmetic mean will be useless.  So, what to do? In this post, I will walk you through the process of calculating the mean upslope aspect using ArcGIS, and leave you with a working python script that will automate the process.

Raw aspect raster, in ArcMap's default Technicolor scheme.
Raw aspect raster, in ArcMap’s default Technicolor scheme.

Continue reading “From a Different Angle: Averaging Upslope Aspect”