Colorado River

Drylands are moisture-limited environments that cover ~40% of the global land surface. Ecosystems in drylands include the grasslands, shrublands, woodlands, riparian areas, and rivers that comprise most of the western United States and most of the land managed by the DOI, other federal agencies, and tribal Nations.

Glen Canyon Dam has altered ecological processes of the Colorado River in Grand Canyon. Before the dam was built, the Colorado River experienced seasonable variable flow rates, including springtime flooding events. These spring floods scoured the river bottom and enhanced natural processes that sustained the Colorado River ecosystem. Since the dam’s construction in 1963, springtime floods have...

The U.S. Geological Survey’s Southwest Biological Science Center, and more specifically, its River Ecosystem Science branch which includes the Grand Canyon Monitoring and Research Center (GCMRC), is a preeminent science group that has more than 20 years of experience of providing high-quality, detailed science to resource managers and stakeholders primarily concerned with the effects of dam...

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 Grand Canyon Monitoring and Research Center maintains an enterprise GIS platform built upon ESRI ArcGIS Server and Portal applications. This enterprise system allows for spatial data, maps and analytical tools to be served through online applications. The Geospatial Science and Technology project provides access to this content through different avenues. Online maps can be accessed through...

The Grand Canyon Monitoring and Research Center develops and collaborates with other science centers to create online data applications that provide access to project data as it becomes available to the public. Some of these applications provide data in near real-time, while other project data are updated at some regular interval (annually, quarterly). Content listed here include applications that...

The Grand Canyon Monitoring and Research Center offers a collection of data resources and online tools -- including web maps, applications, and other content -- that convey scientific information related to on-going monitoring of the Colorado River. Some applications are a culmination of long-term monitoring work, while others are developed around more a specific set of information usually derived...

The overall goal of this project is to advance inter- and trans-disciplinary research coordination, focusing on the transformation of social-ecological systems by hydroelectric dam construction in the Amazon and the United States. The experience gained by Southwest Biological Science Center researchers working on the Glen Canyon Dam Adaptive Management Program in the Colorado River in Grand Canyon...

Aquatic invertebrates are critical food for fish and other species that inhabit large rivers. In the Colorado River Basin, invertebrates that get transported down the river (“in the drift”) are particularly important to rainbow trout and other species of interest to recreational users. This research seeks to compare rivers downstream of large dams throughout the Colorado River Basin in order to...

Introductions of bio-control beetles (genus Diorhabda) are causing defoliation and dieback of exotic Tamarix spp. in riparian zones across the western U.S., yet the factors that determine the plant communities that follow Tamarix decline are poorly understood. In particular, Tamarix-dominated soils are often higher in nutrients, organic matter, and salts than nearby soils, and these soil...

Introduced rainbow trout and brown trout are considered a threat to the endangered humpback chub in the Colorado River in Grand Canyon. These introduced species eat native fish, but impacts are difficult to assess because predation vulnerability depends on the physical conditions under which predation takes place. We studied how predation vulnerability of juvenile humpback chub changes in response...

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...