- ItemOpen AccessAgricultural water conservation in the Colorado River basin: alternatives to permanent fallowing research synthesis and outreach workshops, part 1 of 5(Colorado State University. Libraries, 2017-12) Udall, Brad, author; Peterson, Greg, author
- ItemOpen AccessUsing remote sensing assessments to document historical and current saved consumptive use (CU) on alfalfa and grass hayfields managed under full and partial-season irrigation regimes(Colorado State University. Libraries, 2017-08) Cabot, Perry E., author; Vashisht, Aman, author; Chávez, José L., author
- ItemOpen AccessManagement of large wood in streams of Colorado's Front Range: a risk analysis based on physical, biological, and social factors(Colorado State University. Libraries, 2017-03) Wohl, Ellen, author; Bestgen, Kevin, author; Bledsoe, Brian, author; Fausch, Kurt, author; Gooseff, Mike, author; Kramer, Natalie, authorInstream and floodplain wood can provide many benefits to river ecosystems, but can also create risks to inhabitants, infrastructure, property, and recreational users in the river corridor. In this report we outline a decision process for managing large wood, and particularly for assessing the relative benefits and risks associated with individual wood pieces and with accumulations of wood. This process can be applied at varying levels of effort, from a relatively cursory visual assessment to more detailed numerical modeling. Decisions of whether to retain, remove, or modify wood in a channel or on a floodplain are highly dependent on the specific context: the same piece of wood might require removal in a highly urbanized setting, for example, but provide sufficient benefits to justify retention in a natural area. Our intent is that the decision process outlined here can be used by individuals with diverse technical backgrounds and in a range of urban to natural river reaches.
- ItemOpen AccessReconstructing a water balance for north Crestone Creek: streamflow variability and extremes in a snowmelt dominated internal drainage basin(Colorado State University. Libraries, 2013-05) Venable, Niah B. H., author; Fassnacht, Steven R., authorThe San Luis Valley in Colorado is a semi-arid region that relies on streamflow from the surrounding mountain ranges for agricultural productivity and to recharge the important aquifer systems of the basin. The (North) Crestone Creek watershed is characteristic of the many small watersheds that drain the Sangre de Cristo Mountains on the eastern side of the valley providing water for local water users, wildlife, and augmentation of Rio Grande flows through the Closed Basin Project reclamation efforts. This study investigates the range of hydrologic variability and extremes in this area over the last 426 years using readily available historic hydrologic and paleo-climatic data derived from tree-rings and other sources. Streamflow and precipitation reconstructions were generated and compared to the historic period of observation. Water balance modeling was performed using historic and paleo-derived model inputs. The results of this study show that the drought conditions experienced in the San Luis Valley over the last decade are not unusual in the context of streamflow and precipitation reconstructions spanning hundreds of years. Past droughts were at least as intense as those in 1950 and 2002 and several droughts in the paleo-record were of much longer duration than any recorded in the instrumented period. These results are similar to those demonstrated in other paleo-hydrologic research from the western part of the San Luis Valley in Colorado and throughout the western United States. The water balance modeling provided a means to examine monthly changes to runoff and other hydrologic and state variables output by the model under differing past climate conditions. Together, the climate reconstructions and water balance model provide insight into regional water use sustainability and future development issues for a highly variable natural system.
- ItemOpen AccessWater quality impacts of the mountain pine beetle infestation in the Rocky Mountain west(Colorado State University. Libraries, 2014-11) McCray, John E., author; Bearup, Lindsay A., author; Rodriquez, Nicolas, authorThe Mountain Pine Beetle (MPB) is the primary cause of insect-induced mortality in pine forests in western North America where some lodgepole forests have experienced more than 90% tree mortality. The implications of MPB infestation on water resources are particularly important in the Rocky Mountains, which serve as the source-water region for more than 60 million people. Two important potential watershed impacts are changes in the hydrologic cycle and water quality. While impacts on the hydrologic cycle have received some attention, the interconnection between these changes and the impacts of the widespread infestation on water quality are not well understood. This study uses a combination of field sample analysis and modeling based in Rocky Mountain National Park to address two potential MPB-driven effects on water quality: increased metal concentrations with ecotoxicological and human health ramifications and the changes in source water contributions to streamflow with possible implications for metal and carbon transport to downstream drinking water supplies. Previous work from the research team at Colorado School of Mines identified increased potential for disinfection byproduct formation at water treatment plants receiving water from heavily MPB-killed forests. These increases exhibited surprising seasonal trends that suggest that the transport of carbon to streams, and thus the flowpaths of water, may be different in MPB-killed forests. The first question was investigated by sequentially extracting trace metals from soils under trees with vary levels of impact, and using geochemical models to identify important process-level drivers of changes in metal mobility. Laboratory results identify redistribution of metals in soils under beetle-killed trees with greater mobilization potential for cadmium, and increases in zinc and copper, likely related to fluxes from needle leachate. Results also align with geochemical models and identify changes in organic carbon inputs as the primary driver of increased metal mobility. The second questions was addressed using a chemical hydrograph separation approach to partition streamwater into the fractions derived from groundwater, rain, and snow. Results demonstrate that fractional late-summer groundwater contributions from impacted watersheds are approximately 30 ± 15% greater after infestation and when compared with a neighboring watershed that experienced earlier and less-severe attack. Water budget analysis compared to published sap flux and remotely sensing studies reveals that this change is consistent with expected increases in groundwater from loss of transpiration across the watershed. A predictive statistical model (calibrated to observations within and around Rocky Mountain National Park) suggests that dissolved organic carbon concentrations in streams will be higher in areas where tree mortality is higher. Although, a strong statistical correlation was not found with the method used. Ultimately, this study identifies process-level hydrologic and biogeochemical changes that improve understanding of the vulnerability of Rocky Mountain water supplies to MPB outbreaks.