How GIS and GNSS Helped Create a Digital Twin for a Jewel of the Desert

The Arizona-based Desert Botanical Garden (DBG) attracts nearly half a million visitors yearly. This nonprofit garden's collection encompasses over 50,000 specimens of 4,500 native and nonnative species—including nearly 500 endangered species. Since its founding in 1939 when Swedish botanist Gustaf Strarck posted a sign, "Save the Desert," local volunteers and boosters have grown the collection into one of the premier botanical gardens in the world, becoming one of 24 accredited by the American Alliance of Museums. DBG's extensive variety of plants originate from desert regions around the world, including the American Southwest, South America, Africa, and Australia. DBG's collection has also made the garden a center for botanical research and conservation programs.

Knowing what plants are where is essential to the garden's operations. Since its inception, DBG staff has maintained maps of its facilities and collections—initially, richly detailed, beautifully drawn paper maps. Today, DBG staff are creating a more accurate representation of the garden using digital maps powered by geographic information system (GIS) technology. DBG staff recently added the centimeter-precision Global Navigation Satellite System (GNSS) constellation to their field-mapping process, paving the road for essential collaboration and digital twin capabilities. 

Long before the term digital twin became popular, DBG staff were already creating theirs. In 2013, DBG's then GIS manager began a digitization process, converting the operations of five DBG departments to ArcGIS Pro, a single desktop GIS application that supports data visualization, advanced analysis, and authoritative data maintenance in 2D, 3D, and 4D.

"[The GIS manager] basically digitized the entire basemap with almost every rock, bench, trail—everything in the garden," said DBG's current GIS manager, Aryn Musgrave.

Musgrave explains that the initial digitization process employed handheld, resource-grade GPS devices and ArcGIS Collector to create the geodatabase. DBG was honored with a Special Achievement in GIS (SAG) Award at the 2015 Esri International User Conference for this work.

As the garden grew in plant variety and density, DBG staff needed higher-precision tools for their work. Musgrave, who began her journey at DBG while in high school as one of the estimated 600 yearly volunteers, remained fond of the garden while earning degrees from Arizona State University. It was through her studies that she was first introduced to high-precision GNSS, like Bad Elf Flex, for field asset mapping. Musgrave recognized what the survey-grade positioning could bring to asset and resource management applications at the garden.

"Our main goal here at the garden is to help conserve and protect the species that are at risk, and to do that we have to use the best tools available," said Musgrave. "Having GPS makes that much more accurate and takes us to another level."

The garden has been able to do this work by combining technologies and running apps on tablets. Staff use a high-precision GNSS system, like the Bad Elf Flex solution, for multiple applications, including asset mapping and surveying with ArcGIS Field Maps. By using the Field Maps app, staff can easily integrate survey data collected with the Bad Elf Flex solution to create data-driven maps and edit on the go. Users simply connect their mobile or tablet device's Bluetooth with the Bad Elf receiver and enable the integration with the Field Maps app.

"It does not take much time to get someone up to speed on the system," said Musgrave. "You can check that everything is connected and what your precision is. We can edit, update, and add to our GIS database easily. It is our go-to for editing anything on the ground."

Adding a new plant at DBG typically begins with a horticulturalist assessing a plant's health and registering the plant with a unique identification tag. From there, Musgrave's team uses the Bad Elf Flex solution and Field Maps to collect the plant's exact location in the garden for the geodatabase and basemap. The data is also synced with the Living Collections Management System (LCMS), where it can be utilized by staff and the international research community to locate specific plants in the garden.

By having their plant data accurate up to one centimeter, DBG staff can easily locate plants in large groupings, run reports on their health, assign tasks related to the plants, and add pins to note damages or layers for future tasks. Staff drop a pin in the Field Maps app, and a task is opened and assigned to the specialist to help. The specialist can then mark off each pin as it is completed or update the status on them. This data-driven digital twin is essential for managing the health of the collection.

"We're just able to find the plants more accurately and know which one we're looking at," said Musgrave. "Without this, when walking the grounds, it's hard to tell which one is which."

Most importantly, because the garden underwent this digital transformation, DBG staff are better positioned to be collaborators on initiatives like the National Seed Strategy (NSS). That effort, born in 2021, is benefitting from some of the $200 million in dedicated federal funding to create and manage a national revegetation plan for both federal and nonfederal land.

Crucial to this process is ensuring that seeds and plants are genetically adapted to the regions where they will be used for revegetation. Recording locations and genetic identification of wild-gathered species is key, and that's where GIS and GNSS field mapping play a central role. DBG has worked with the Bureau of Land Management on propagating the milkweed population, specifically.

"This is seed amplification, where you take wild collected seed, and essentially produce more of it by growing out those plants," said Kim Pegram, DBG's program director for pollinator conservation and research. As part of the National Seed Strategy, the garden now has an agreement with the US Fish and Wildlife Service to collect seeds from areas that are prone to burn.

Using mapped data of burn-prone areas, DBG collects a bank of seeds of various types from all areas—those ecologically adapted to natural fires and those that aren't—that can be key to restoration. Field collection teams from DBG and other partners use GIS to select areas for seed collection, log locations of collected seeds with GNSS, and then correlate it with other GIS thematic data.

This high quality from high-precision mapping has inspired staff to use the Bad Elf Flex technology in their field research. In a recent instance, when a wildfire broke out in the Sonoran Desert and endangered a species of cacti, DBG staff needed survey-grade GNSS to map where the cacti originated and relocate the species back to the garden for rehabilitation. Using both the Bad Elf Flex and Field Maps, researchers then investigated sites unaffected by the wildfire to replant the cacti. The sites had to fit specific parameters like elevation sensitivity and meet specific terrain features including slope steepness—information collected through GNSS.

High-precision mapping has enhanced management, conservation, and research efforts at DBG. According to Musgrave, the garden's future goals include continuing to refine how it uses the technology and focusing on accuracy in everything it does.

Additionally, DBG staff have used ArcGIS Pro for facilities management and leveraged geodesign for planning infrastructure, terrain, and drainage elements for construction at the garden. Musgrave also hopes the technology could be used for enhancing the visitor experience as well with potential augmented reality applications. Imagine a visitor being able to look at a precisely geospatially positioned plant through a phone or augmented reality glasses and access a wealth of attributes and linked information with it. That, says Musgrave, would be awesome.