New tool - Hypsometric Integral Toolbox for ArcGIS

Adriano Matos and I have put together a new tool for calculating hypsometric integral for ArcMap users. The new tool is called the Hypsometric Integral Toolbox for ArcGIS and is available by clicking HERE. You can also download this tool by clicking on our lab's tools download page HERE.

The hypsometric integral (HI) is one of the most commonly used measures that geomorphologists use to describe the shape of the Earth’s surface.  A hypsometric integral is usually calculated by plotting the cumulative height and the cumulative area under that height for individual watersheds and then taking the area under that curve to get the hypsometric integral.  In a GIS hypsometric integral is calculated by slicing watersheds into elevation bands and plotting the cumulative area for each band. Due to the iterative nature that is required for calculating hypsometric integral it tends to be one of the harder to calculate watershed variables, and thus the need for an automated tool. Although there are instructions online for how to calculate HI in ArcGIS this tool automates the processes and doesn’t require users to do their own plotting or export results to spreadsheets.

This toolbox contains two models.  Hypsometric Integral (for shapefiles only) is the main model that most users will want to run.  Hypsometric Integral (submodel) is a model that is nested within the Hypsometric Integral (for shapefiles only) model and doesn’t need to be run by itself. The tool computes the hypsometric integral for a given watershed. A new shapefile will be created representing the same watershed the user inputs, but includes a new field, "HI," representing hypsometric integral percentages.

In some instances the Hypsometric Integral (for shapefiles) will show up with a red X and won’t be useable.  The workaround for this is to open the Hypsometric Integral (for shapefiles) tool in edit mode (ModelBuilder) delete the Hypsometric Integral (submodel) and drag in your version of the Hypsometric Integral (submodel). Re-connect the following parameters: input DEM, Input Watershed, TempWorkspace, and then connect the output (HI Values for all Watersheds) to the Append tool.  Click save.

In the example map above on the left we have 19 sample watersheds from central Nevada with a Digital Elevation Model. The map above on the right shows the hypsometric integral for each of the watersheds. As you can see smaller more "canyon-like" watersheds have higher values of HI compared to the more open watersheds.

New masters students in the Weisberg Lab

These past two weeks have seen the addition of two new lab members joining the Great Basin Landscape Ecology Lab.  Joe Brehm and Anna Knight are both starting master's programs in natural resources. Joe comes to us from the Great Basin Institute where he worked as a data administrator.  Anna comes to us by the way of USGS in Moab, UT. Joe's thesis will take our cheatgrass die-off mapping to the next level. In addition to extending the analysis to Skull Valley, Utah, there will be methodological improvements to the remote sensing and a more thorough assessment of the spatial pattern of die-offs.

Anna's project is aimed at understanding which watersheds in the Great Basin are susceptible to long-term degradation, like erosion and incision.  Dave Board and myself have already calculated watershed morphometrics for thousands of watersheds in the Great Basin, which will help feed into Anna's analysis.

Congratulations Anna and Joe.  I look forward to getting to work with both of you.