Riverine Science at the Fort Collins Science Center

Gunnison River, Black Canyon of the Gunnison National Park, Colo. Photo: Greg Auble, USGS.

As stewards of our Nation’s natural resources, land and water management agencies are responsible for balancing use and conservation of water resources. Agency managers face increasing and often competing demands for water resources that can result in alteration or loss of critical riverine, riparian, and wetland habitats. At every level of government, managers need quantitative, objective, science-based information that helps them manage, conserve, and plan for the Nation’s water resources and the species and habitats they support.

Providing objective information concerning the Nation’s water resources has long been a core mission of the U.S. Geological Survey (USGS) (e.g., see the National Water Information System) and continues to be an important element of USGS strategic plans for the future.

Similarly, developing tools and information to support water management decisions has been and continues to be an important activity at the USGS Fort Collins Science Center (FORT). In the 1970s, the Instream Flow Group began working on decision processes, field techniques, and physical habitat simulation models to help managers incorporate environmental effects into their flow management decisions. Much of the early work at FORT focused on cold-water fisheries and managed rivers in the western United States. Several aspects of that work guide current riverine work at FORT. Other ongoing studies address riparian vegetation, constructed wetlands, water quality, and aquatic species.

Research

Scientists take spectral signature measurements of tamarisk, an invasive plant prevalent in riparian areas throughout the West. Photo by Paul Evangelista, Colorado State University. Used with permission.

Effective river management depends on understanding the relations between variables—both the expected responses to alternative management actions and the management actions required to produce a desired objective. The target of riverine research is to describe and quantify these relations in order to improve the foundation on which river management decisions are made.

Riverine scientists at FORT focus their investigations on the various aspects of river and riparian ecosystems and how the goods and services these ecosystems provide are affected by changes in flow, sediment, invasive species, and climate. FORT scientists specializing in different aspects of ecosystem science work together to integrate their expertise and address complex research questions in interdisciplinary and novel ways. They also work closely with scientists in the USGS Water Resources Discipline, several of whom are collocated at FORT. Our riverine research trends along three paths: biophysical relationships, climate change, and restoration.

Understanding Biophysical Relationships

An important long-term focus of riverine science at FORT is on connections between physical and biological factors, processes, and effects. In recent work, FORT investigators have

1. incorporated higher-resolution hydraulic models (e.g., 2- and 3-D models) and expanded the range of physical variables (e.g., temperature, sediment transport, water and sediment quality).
2. examined linkages between flow and riparian vegetation.
3. expanded the range of biological response variables beyond fish physical habitat (e.g., diatoms, aquatic insects, fish populations, vegetation, birds, small mammals, herptofauna).
4. addressed more biotic-abiotic interactions, examining reciprocal influences of biota on the physical environment (e.g., competition, herbivory, hydraulic effects of riparian vegetation).
5. increased the range of anthropogenic changes and management actions considered (e.g., atmospheric deposition, introduction and control of non-native species such as saltcedar, dam removal, changes in channel form and sediment supply, riparian herbivory).
6. broadened the domain of studies from the reach and river scales to basin and regional scales.

USGS scientist Joan Daniels collects bulrush samples from a constructed wastewater-treatment wetland for biomass determination. USGS photo.

Climate Change

Climate change is rapidly becoming an important component of the river systems picture. FORT scientists increasingly have directed their attention to investigating how river ecosystems and their management might be altered by global climate change.

Restoration

“Restoration” research at FORT has embraced a number of distinct studies, including saltcedar removal and subsequent revegetation, native riparian plantings, wetland creation for wastewater treatment, flow prescriptions, and hydraulic design of channel habitat features to promote fish reproduction and recruitment. Taken together, these efforts involve designing river restoration and engineering actions to achieve desired species or ecosystem services.

Development

Effective river management depends not only on scientific understanding of the many interacting components of river systems, but also on how well that information is accessed, communicated, and used in decision processes. Therefore, one emphasis at FORT is on acquiring and conveying scientific information and analyses in forms that are relevant to legal and institutional decision processes. We develop tools and methodologies that managers can use to assess status and understand the many variables involved, the possible outcomes of different management actions, and likely ecosystem responses. Recent efforts have produced the following types of products: 

Screen capture from Smart River GIS decision tool showing changes in estimated brown trout numbers by life stage, through time, for a section of river based on depth and velocity habitat-suitability criteria.

1. decision-support systems to summarize the often voluminous data and model output supporting many water management decisions,
2. tools to synthesize and compare flow regimes that employ hydroecological indices, and
3. new monitoring protocols.

Direction

Riverine science at FORT is management-oriented and interdisciplinary. Thus, we continue to explore possibilities for working in partnership with management agencies faced with water resource decisions and in collaboration with scientists from many disciplines. We are especially interested in situations that combine informing a management decision with the possibility of advancing general scientific understanding and the capability of addressing broad classes of questions.