This research examines how water flows affect populations, communities, ecosystems, and hydroscapes. Studies elucidate the interactions among hydrologic, geomorphologic, biogeochemical, biological, and anthropogenic processes. Scientists identify and quantify the spatial and temporal attributes of water flow for ecological needs. Flow alternations by humans are a primary contributor to the degradation of aquatic ecosystems and the loss of freshwater biodiversity, and researchers provide innovative scientific methods and tools on flow-related ecological issues.
Reconstructing Flood History from Tree Rings
Shifts in river flow regimes are a major threat to water supplies and riverine ecosystems. Understanding and predicting flow changes and their effects on vegetation are critical to effective river management. Scientists analyze rings of riparian trees relating tree growth and establishment to historical flow. We then use the tree rings to reconstruct the flow in past centuries. Flow reconstructions discover the frequency and magnitude of past droughts and floods—information that is essential for management of rivers and water supplies. We also use downscaled drought projections and watershed models to predict changes in flow and tree growth. We have pioneered the use of cottonwood, a dominant riparian species, for tree ring analysis; this is a significant advance in arid regions where old trees of other species are otherwise scarce. Ongoing studies focus on rivers of the Upper Missouri Basin and the Tarim River in China.
Large-scale streamflow experiments
Because the underlying cause of riparian system alteration is often attributed to the effects of dams on flow regime, managing flow releases, particularly high flows, from dams is an often-advocated approach to river and riparian restoration. Our work has focused on understanding effects of managed high flow releases (a.k.a., pulse flows, controlled floods) from dams along rivers in the lower Colorado River basin. On the Bill Williams River in western Arizona, we have had the opportunity to help design and monitor the effects of several high flow releases since the mid 1990’s. On the main stem of the Colorado River, we helped study the effects of the 2014 “pulse flow” to the Colorado River delta (Minute 319), and are working with a range of collaborators to provide input to possible future releases to the delta (Minute 32X). Finally, we are working with collaborators from USGS, USDA Forest Service, and Northern Arizona University to understand how different groups of riparian plants (“riparian response guilds”) respond to high flow experiments on the Colorado River in Grand Canyon.
Streamflow-fluvial Geomorphology-riparian Vegetation Interactions
The foundation for applying science to river and riparian restoration contexts lies in a basic understanding of the factors that drive riparian vegetation dynamics. Much of our research is focused on clarifying relationships between streamflow, fluvial geomorphology, and riparian vegetation, including various feedbacks. In some cases this work involves studying river reaches or segments that are relatively unaltered by anthropogenic activities; in many cases it involves study of river segments that have been altered by human activities, most notably river damming. Our research often includes field studies, but also experiments (e.g., in greenhouses) to help control for specific factors hypothesized to influence riparian plants. This work is often done in collaboration with scientists whose primary emphasis lies in the physical sciences (e.g., fluvial geomorphology, hydrology).
Below are other science projects associated with this project.
Reconstructing Flow History From Riparian Tree Rings
Large-scale streamflow experiments
Streamflow-fluvial Geomorphology-riparian Vegetation Interactions
Small Unoccupied Aircraft System (sUAS) Flights
This research examines how water flows affect populations, communities, ecosystems, and hydroscapes. Studies elucidate the interactions among hydrologic, geomorphologic, biogeochemical, biological, and anthropogenic processes. Scientists identify and quantify the spatial and temporal attributes of water flow for ecological needs. Flow alternations by humans are a primary contributor to the degradation of aquatic ecosystems and the loss of freshwater biodiversity, and researchers provide innovative scientific methods and tools on flow-related ecological issues.
Reconstructing Flood History from Tree Rings
Shifts in river flow regimes are a major threat to water supplies and riverine ecosystems. Understanding and predicting flow changes and their effects on vegetation are critical to effective river management. Scientists analyze rings of riparian trees relating tree growth and establishment to historical flow. We then use the tree rings to reconstruct the flow in past centuries. Flow reconstructions discover the frequency and magnitude of past droughts and floods—information that is essential for management of rivers and water supplies. We also use downscaled drought projections and watershed models to predict changes in flow and tree growth. We have pioneered the use of cottonwood, a dominant riparian species, for tree ring analysis; this is a significant advance in arid regions where old trees of other species are otherwise scarce. Ongoing studies focus on rivers of the Upper Missouri Basin and the Tarim River in China.
Large-scale streamflow experiments
Because the underlying cause of riparian system alteration is often attributed to the effects of dams on flow regime, managing flow releases, particularly high flows, from dams is an often-advocated approach to river and riparian restoration. Our work has focused on understanding effects of managed high flow releases (a.k.a., pulse flows, controlled floods) from dams along rivers in the lower Colorado River basin. On the Bill Williams River in western Arizona, we have had the opportunity to help design and monitor the effects of several high flow releases since the mid 1990’s. On the main stem of the Colorado River, we helped study the effects of the 2014 “pulse flow” to the Colorado River delta (Minute 319), and are working with a range of collaborators to provide input to possible future releases to the delta (Minute 32X). Finally, we are working with collaborators from USGS, USDA Forest Service, and Northern Arizona University to understand how different groups of riparian plants (“riparian response guilds”) respond to high flow experiments on the Colorado River in Grand Canyon.
Streamflow-fluvial Geomorphology-riparian Vegetation Interactions
The foundation for applying science to river and riparian restoration contexts lies in a basic understanding of the factors that drive riparian vegetation dynamics. Much of our research is focused on clarifying relationships between streamflow, fluvial geomorphology, and riparian vegetation, including various feedbacks. In some cases this work involves studying river reaches or segments that are relatively unaltered by anthropogenic activities; in many cases it involves study of river segments that have been altered by human activities, most notably river damming. Our research often includes field studies, but also experiments (e.g., in greenhouses) to help control for specific factors hypothesized to influence riparian plants. This work is often done in collaboration with scientists whose primary emphasis lies in the physical sciences (e.g., fluvial geomorphology, hydrology).
Below are other science projects associated with this project.