You are here

Sierra Ancha Experimental Forest Vegetation Mapping Project

Status: 
Action
Dates: 
June, 2017

Sierra Ancha Vegetation Mapping Project - preparing to launch
Sierra Ancha Vegetation Mapping Project - preparing to launch
The Sierra Ancha Experimental Forest Vegetation Mapping Project is a collaborative study between the Rocky Mountain Research Station and the Northern Arizona University School of Informatics, Computing, and Cyber Systems. It employs ​unmanned aerial vehicle​ (UAV) technology to create highly detailed, landscape-scale vegetation maps of the Sierra Ancha Experimental Forest that can be compared among many different parameters to historical vegetation datasets dating back to the 1920s. In the past, data collection focused on three main areas of study: vegetation, water yield, and climatology. These datasets formed the foundation in which many pioneering studies were based upon over the last century. Using this new technology to update and expand upon these datasets ensures the continuation of innovative scientific inquiry into the future.

Approach

The developing field of drone technology, or unmanned aerial vehicles (UAVs), provides an alternative data source at a lower cost and higher temporal and spatial resolution compared to manned

Sierra Ancha Plot 3 - 1935
Sierra Ancha Plot 3 - 1935
 airborne and satellite images. Here we test and demonstrate the accuracies of UAV multispectral images and Structure-from-Motion(SfM) -derived 3D data in rangeland monitoring and long-term species composition change detection. For this study, we flew a light-weight, fixed-wing UAV (SenseFly, Switzerland) at 90 m altitude aboveground resulting in image spatial resolution of 12 cm and four spectral bands: green (520-580 µm), red (630-690 µm), red edge (720-750 µm), and near-infrared (760-820 µm). The UAV images were also photogrammetrically analyzed via SfM (Pix4D software, Pix4D SA, Lausanne, Switzerland) to create 3D models of topography (10 cm resolution) and vegetation height (12 cm resolution). 

 

 

Key Findings

M.W. Tallbot, a pioneer in rangeland ecology and an early scientist working at the Sierra Ancha Experimental Forest, inspects Plot 3 which was one of the first range exclusion plots established in approximately1920.
M.W. Tallbot, a pioneer in rangeland ecology and an early scientist working at the Sierra Ancha Experimental Forest, inspects Plot 3 which was one of the first range exclusion plots established in approximately 1920.
Our results indicate that long-term plot-based monitoring can be achieved using UAV-based assessments. The positional accuracies of the UAV-derived map ranged 8-15 cm in the X and Y coordinates. While the ability to accurately identify multiple species is limited by the number of spectral bands available, the very detailed, species-level UAV images over small to mid-sized areas can easily be used in conjunction with freely available, coarse-resolution satellite images to scale-up rangeland monitoring over larger areas. Thus, the unbiased, observational data records from UAV images can act as an invaluable tool for land managers informing targeted land use strategies.

 

 

 

 

 

 

Deliverables

UAV-based rangeland monitoring: Examining a century of vegetation changes (in process)

Other

For more information about the Sierra Ancha Experimental Forest and the research conducted there, please visit the Sierra Ancha Experimental Forest webpage.

For more information about the Remote Sensing and Geoinformatics lab, see the NAU lab page. https://sites.google.com/a/nau.edu/remote-sensing-lab/home

 



Project Contact: 

Principal Investigators:
Dr. Temuulen “Teki” Sankey - Associate Professor - School of Informatics, Computing, and Cyber Systems, Northern Arizona University

Research Staff:
Patrick Shin - Northern Arizona University
Joseph Bogart - Northern Arizona University Affiliate

Funding Contributors:
Northern Arizona University