Remote Sensing and GIS

Soils are the foundation of terrestrial ecosystems. They provide critical services including supplying a substrate and the nutrients necessary for plant growth, retaining moisture from precipitation, filtering contaminants from percolating waters, and acting as a sink of carbon. Healthy soils are key to sustaining both human and ecosystem health. However, global- and regional-scale disturbances...

The Grand Canyon Monitoring and Research Center currently functions under a Triennial Work Plan (TWP) which is thoroughly reviewed and vetted both internally within the Center and through the GCDAMP Technical Work Group (TWG) and the Adaptive Management Work Group (AMWG). These advisory panels have been a part of the Glen Canyon Dam adaptive management process since the inception of the GCDAMP...

A high-resolution image collection in 2021 will be the most recent in a rich archive of aerial imagery that is used to track changes of the Colorado River in the Grand Canyon. Imagery will be acquired from an airplane in Grand Canyon National Park along the Colorado River corridor and the Little Colorado River starting Memorial Day weekend and continuing through the first week of June 2021. This...

Sandbars have been used as campsites by river runners and hikers since the first expeditions to the region more than 100 years ago. Sandbar campsites continue to be an important part of the recreational experience for the more than 25,000 hikers and river runners that visit the Colorado River corridor each year. Because the Colorado River is dominated by bedrock cliffs and steep talus slopes...

The field of digital soil mapping has bridged the classic theories of soil science into the modern computing age to produce high resolution predictive soil maps. This body of work utilizes classic soil factorial theory (soil = f[climate, organisms, relief (topography), parent material, time] + ɛ, or ‘clorpt’). The clorpt framework has been approximated using various environmental spatial data...

The presence of top predators is considered an indication of ecosystem health and can play a vital role in ecosystem functioning by promoting biodiversity, and can contribute to regulating prey species abundance, and herbivory. In the intermountain west, the largest mammalian predator and obligate carnivore is the mountain lion, Puma concolor. This elusive and wide-ranging predator occupies a...

Concerns about energy security and rising greenhouse gas emissions have stimulated an unprecedented increase in the push for alternative energy use, including the use of plant biomass as a source of renewable energy (bioenergy). However, meeting alternative energy goals, while also meeting food demands and mitigating potential detrimental effects of industrialized agriculture, has emerged as a...

We study the links among different geomorphic processes that affect river valley landscapes in the Colorado River downstream from Glen Canyon Dam, Arizona. Dam-released flows affect the deposition and retention of sandbars that serve as sources for other sand resources, such as windblown sand dunes, throughout the Colorado River ecosystem. The degree to which the landscapes are differentially...

Riparian vegetation has increased dramatically along the Colorado River downstream of Glen Canyon Dam since the closure of the dam in 1963. The spatial patterns and temporal rates of vegetation increase occur due to changes in river hydrology, dam operations, and climate. The increase in vegetation, particularly onto otherwise bare sandbars, has impacted recreational, geomorphological, biological...

Floodplain red gum forests are sites of high biodiversity in arid regions of south Australia. They depend on periodic floods from rivers, but dams and diversions have reduced flood frequencies, leading to deterioration of the trees. We determined the water requirements of red gum trees so environmental flows can be used to restore and maintain the forests. We used measurements of transpiration of...

The Upper San Pedro River is one of the few remaining undammed rivers that maintain a vibrant riparian ecosystem in the southwest. However, its riparian forest is threatened by diminishing groundwater and surface water inputs, due to either changes in watershed characteristics such as changes in riparian and upland vegetation, or human activities such as regional groundwater pumping. We used...

Desert bighorn sheep populations in the southwestern United States are subject to non-native disease outbreaks, habitat loss, and genetic isolation that can threaten their long-term sustainability. In some regions of the southwest, mountain lion predation on desert bighorn sheep has been found to be the primary source of mortality. Grand Canyon National Park is home to one of the largest desert...