View from Above – Aerial Monitoring Using Satellite Imagery
To supplement our on-the-ground stewardship efforts, SAHC is developing an aerial monitoring program. SAHC stewards land spread across approximately 4,000 square miles — and as of 2020, our Stew Crew is responsible for monitoring over 50,000 acres of conservation easements and SAHC-owned land.
Individual tracts range from 0.5 acres to over 8,000 acres, with the majority of protected properties being between 100 and 200 acres – much of which is steep and rugged terrain. Annual monitoring site visits require substantial time and resources, and SAHC performs rigorously in fulfilling these monitoring responsibilities. However, as our portfolio of protected land continues to grow (yay, land protection!), the physical challenge of visiting every protected acre each year looms at the horizon of impossible — even for the Stew Crew at SAHC.
Over the years, we have used new technological tools and methods to pragmatically boost efficiency and accomplish our commitment to perpetual stewardship of protected lands. This year we are excited about integrating aerial monitoring into our stewardship program.
What is Aerial Imagery Data and How Do We Use It?
In recent years, we have augmented our monitoring procedure by using satellite imagery that is freely available through Google Earth software to prepare for field visits. However, the intermittent publication of such publicly available imagery often makes it useless for detecting changes that occur on a protected property within the current year — the fundamental objective of annual monitoring.
To address issues of satellite data availability and resolution, we have researched companies who compile satellite data captured by multiple entities and make it available via a web service. Specifically, we’ve been looking at companies that focus on providing high resolution satellite imagery (that’s 0.5 meters or less) for environmental and conservation organizations. This service is a repository for historical and current imagery, and they contract with commercial satellite companies to request current images where they are unavailable.
Aerial Monitoring in Keeping with LTA Standards and Practices
SAHC has decided to proceed with developing an aerial monitoring program in keeping with the Land Trust Alliance’s Standards and Practices.
We are currently identifying properties that SAHC stewards that are best candidates for aerial monitoring and plan to begin implementation in early spring of 2020. This program has the potential to help SAHC more completely survey properties to detect changes – especially encroachments in remote locations. It does not, however, replace on-the-ground monitoring. While monitoring using current, high resolution satellite imagery will enable us to increase efficiency and be in better touch with the condition and activity on the lands that we steward, we still very much look forward to seeing you all in the field!