Publications
Below is a list of available Colorado Water Science Center publications and published products.
Filter Total Items: 762
A caveat regarding diatom-inferred nitrogen concentrations in oligotrophic lakes
Atmospheric deposition of reactive nitrogen (Nr) has enriched oligotrophic lakes with nitrogen (N) in many regions of the world and elicited dramatic changes in diatom community structure. The lakewater concentrations of nitrate that cause these community changes remain unclear, raising interest in the development of diatom-based transfer functions to infer nitrate. We developed a diatom calibrati
Authors
Heather A. Arnett, Jasmine E. Saros, Alisa Mast
Relating management practices and nutrient export in agricultural watersheds of the United States
Relations between riverine export (load) of total nitrogen (N) and total phosphorus (P) from 133 large agricultural watersheds in the United States and factors affecting nutrient transport were evaluated using empirical regression models. After controlling for anthropogenic inputs and other landscape factors affecting nutrient transport-such as runoff, precipitation, slope, number of reservoirs, i
Authors
Lori A. Sprague, Jo Ann M. Gronberg
Geologic processes influence the effects of mining on aquatic ecosystems
Geologic processes strongly influence water and sediment quality in aquatic ecosystems but rarely are geologic principles incorporated into routine biomonitoring studies. We test if elevated concentrations of metals in water and sediment are restricted to streams downstream of mines or areas that may discharge mine wastes. We surveyed 198 catchments classified as “historically mined” or “unmined,”
Authors
Travis S. Schmidt, William H. Clements, Richard B. Wanty, Philip L. Verplanck, Stan E. Church, Carma A. San Juan, David L. Fey, Barnaby W. Rockwell, Ed H. DeWitt, Terry L. Klein
Estimating risks to aquatic life using quantile regression
One of the primary goals of biological assessment is to assess whether contaminants or other stressors limit the ecological potential of running waters. It is important to interpret responses to contaminants relative to other environmental factors, but necessity or convenience limit quantification of all factors that influence ecological potential. In these situations, the concept of limiting fact
Authors
Travis S. Schmidt, William H. Clements, Brian S. Cade
Strontium isotope systematics of mixing groundwater and oil-field brine at Goose Lake in northeastern Montana, USA
Groundwater, surface water, and soil in the Goose Lake oil field in northeastern Montana have been affected by Cl−-rich oil-field brines during long-term petroleum production. Ongoing multidisciplinary geochemical and geophysical studies have identified the degree and local extent of interaction between brine and groundwater. Fourteen samples representing groundwater, surface water, and brine were
Authors
Zell E. Peterman, Joanna N. Thamke, Kiyoto Futa, Todd Preston
Mapping critical loads of nitrogen deposition for aquatic ecosystems in the Rocky Mountains, USA
Spatially explicit estimates of critical loads of nitrogen (N) deposition (CLNdep) for nutrient enrichment in aquatic ecosystems were developed for the Rocky Mountains, USA, using a geostatistical approach. The lowest CLNdep estimates (3 kg N ha−1 yr−1), resulting in CLNdep exceedances ≥1.5 ± 1 kg N ha−1 yr−1. CLNdep and CLNdep exceedances exhibit substantial spatial variability related to basin c
Authors
Leora Nanus, David W. Clow, Jasmine E. Saros, Verlin C. Stephens, Donald H. Campbell
Variance partitioning of stream diatom, fish, and invertebrate indicators of biological condition
Stream indicators used to make assessments of biological condition are influenced by many possible sources of variability. To examine this issue, we used multiple-year and multiple-reach diatom, fish, and invertebrate data collected from 20 least-disturbed and 46 developed stream segments between 1993 and 2004 as part of the US Geological Survey National Water Quality Assessment Program. We used a
Authors
Robert E. Zuellig, Daren Carlisle, Michael R. Meador, Marina Potapova
Groundwater availability of the Denver Basin aquifer system, Colorado
The Denver Basin aquifer system is a critical water resource for growing municipal, industrial, and domestic uses along the semiarid Front Range urban corridor of Colorado. The confined bedrock aquifer system is located along the eastern edge of the Rocky Mountain Front Range where the mountains meet the Great Plains physiographic province. Continued population growth and the resulting need for
Nitrate in the Mississippi River and its tributaries, 1980 to 2008: Are we making progress?
Changes in nitrate concentration and flux between 1980 and 2008 at eight sites in the Mississippi River basin were determined using a new statistical method that accommodates evolving nitrate behavior over time and produces flow-normalized estimates of nitrate concentration and flux that are independent of random variations in streamflow. The results show that little consistent progress has been m
Authors
Lori A. Sprague, Robert M. Hirsch, Brent T. Aulenbach
Evaluation of fecal contamination by human and ruminant sources in upper Fountain Creek, Colorado, 2007-2008, by using multiple lines of evidence:
Fountain Creek is a high-gradient stream on the Front Range of the Rocky Mountains in Colorado. The headwaters of Fountain Creek drain Pikes Peak, a major destination for tourism. Fountain Creek is a drinking-water source for the City of Colorado Springs, Colorado, and is used for irrigation, recreation, and other purposes between Colorado Springs and the confluence with the Arkansas River at Pueb
Authors
Donald Stoeckel
Response of lake chemistry to changes in atmospheric deposition and climate in three high-elevation wilderness areas of Colorado
Trends in precipitation chemistry and hydrologic and climatic data were examined as drivers of long-term changes in the chemical composition of high-elevation lakes in three wilderness areas in Colorado during 1985–2008. Sulfate concentrations in precipitation decreased at a rate of −0.15 to −0.55 μeq/l/year at 10 high-elevation National Atmospheric Deposition Program stations in the state during
Authors
Alisa Mast, John T. Turk, David W. Clow, Donald D. Campbell
Application of the SPARROW watershed model to describe nutrient sources and transport in the Missouri River Basin
Spatially Referenced Regression On Watershed attributes (SPARROW) models were developed to provide spatially explicit information on local and regional total nitrogen and total phosphorus sources and transport in the Missouri River Basin. Model results provide estimates of the relative contributions from various nutrient sources and delivery factors. The models also describe instream decay and res
Authors
Juliane B. Brown