Download or read book Simulating the Effects of Climate related Changes to Air Temperature and Precipitation on Streamflow and Water Temperature in the Meduxnekeag River Watershed Maine written by David M. Bjerklie and published by . This book was released on 2021 with total page 35 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modeling the Effects of Climate Change Forecasts on Streamflow in the Nooksack River Basin written by Susan E. Dickerson and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Nooksack River has its headwaters in the North Cascade Mountains and drains an approximately 2300 km2 watershed in northwestern Washington State. The timing and magnitude of streamflow in a high relief, snow-dominated drainage basin such as the Nooksack River basin is strongly influenced by temperature and precipitation. Forecasts of future climate made by general circulation models (GCMs) predict increases in temperature and variable changes to precipitation in western Washington, which will affect streamflow, snowpack, and glaciers in the Nooksack River basin. Anticipating the response of the river to climate change is crucial for water resources planning because municipalities, tribes, and industry depend on the river for water use and for fish habitat. I combined modeled climate forecasts and the Distributed-Hydrology-Soil-Vegetation Model (DHSVM) to simulate future changes to timing and magnitude of streamflow in the higher elevations of the Nooksack River, east of the confluence near Deming, Washington. The DHSVM is a physically based, spatially distributed hydrology model that simulates a water and energy balance at the pixel scale of a digital elevation model. I used recent meteorological and landcover data to calibrate and validate the DHSVM. Coarse-resolution GCM forecasts were downscaled to the Nooksack basin following the methods of previous regional studies (e.g., Palmer, 2007) for use as local-scale meteorological input to the calibrated DHSVM. Simulations of future streamflow and snowpack in the Nooksack River basin predict a range of magnitudes, which reflects the variable predictions of the climate change forecasts and local natural variability. Simulation results forecast increased winter flows, decreased summer flows, decreased snowpack, and a shift in timing of the spring melt peak and maximum snow water equivalent. Modeling results for future peak flow events indicate an increase in both the frequency and magnitudes of floods, but uncertainties are high for modeling the absolute magnitudes of peak flows. These results are consistent with previous regional studies which document that temperature-related effects on precipitation and melting are driving changes to snow-melt dominated basins (e.g., Hamlet et al., 2005; Mote et al., 2005; Mote et al., 2008; Adam et al., 2009).
Download or read book Simulation of Climate Change Effects on the Streamflow and Water Quality of Rural Watersheds written by Michael Peter Hanratty and published by . This book was released on 1997 with total page 846 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Estimation of Climate Change Effects on Streamflows Stream Temperatures and Fish Thermal Habitat written by Omid Mohseni and published by . This book was released on 1999 with total page 594 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modeling the Effects of Climate Change on Streamflow and Stream Temperature in the South Fork of the Stillaguamish River written by Katherine Mary Clarke and published by . This book was released on 2020 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Stillaguamish River in northwest Washington State is an important regional water resource for local agriculture, industry, and First Nations tribes and a critical habitat for several threatened and endangered salmonid species, including the Chinook salmon. The river is currently subject to a temperature total maximum daily load, so it is important to understand how projected climate change will affect future stream temperatures and thus salmon populations. Snowpack is the main contributor to spring and summer streamflow and helps to mitigate stream temperatures as air temperatures rise through the summer in the South Fork of the Stillaguamish River. I used gridded historical meteorological data to calibrate the physically-based Distributed Hydrology Soil Vegetation Model and River Basin Model and then applied downscaled, gridded projected climate data to predict how a changing climate will influence hydrology and stream temperature in the South Fork basin through the end of the 21st century.
Download or read book Simulation of Climate change Effects on Streamflow Lake Water Budgets and Stream Temperature Using GSFLOW and SNTEMP Trout Lake Watershed Wisconsin written by R. J. Hunt and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modeling the Effects of Climate Change on Stream Temperature in the Nooksack River Basin written by Stephanie E. Truitt and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stream temperatures in mountain streams in the western Cascade Mountains are heavily influenced by factors such as discharge, air temperature, and as in the case of the Nooksack River Basin in northwest Washington State; snow and glacial melt. The Nooksack basin is sensitive to warming climates due to the regions moderate Pacific maritime climate. Previous modeling studies in the upper Nooksack basins indicate a reduction in snowpack and spring runoff, and a recession of glaciers into the 21st century due to global climate change. How stream temperatures will respond to these changes is unknown. We use the Distributed Hydrology Soil Vegetation Model (DHSVM) coupled with a glacier dynamics model to simulate hydrology and the River Basin Model (RBM) to model stream temperature from present to the year 2090 in the North, Middle, and South forks of the Nooksack River basin. We simulate forecasted climate change effects on hydrology and stream temperature using gridded daily statically downscaled data from 10 global climate models (GCMs) of the Coupled Model Intercomparison Project Phase Five (CMIP5) with two different representative concentration pathways (RCP) RCP4.5 and RCP8.5. Simulation results project a trending increase in stream temperature into the 21st century in all three forks of the Nooksack. There is a strong correlation between rising stream temperatures and warming air temperatures, decreasing stream discharge; and snow and glacial meltwater. We find that the highest stream temperatures and the greatest monthly mean 7-day average of the daily maximum stream temperature (7-DADMax) values are predicted in the lower relief, unglaciated South Fork basin. For the 30 years surrounding the 2075 time period, the mouth of the South Fork is forecasted to have a mean of 115 days above the 16 °C 7-day average of the daily maximum stream temperature threshold. Streams in the Middle and North fork basins with higher elevations that sustain more snow and glacier ice are slower to respond to warming climates due to meltwater contributions, especially in the next 50 years. Towards the end of this century, when snowpack and glacial volume is greatly decreased, the buffering effect of meltwater declines, and the North and Middle forks experience larger increases in mean daily stream temperature. For the 30 years surrounding the 2075 time period, the mouths of the Middle and North forks are forecasted to have means of 35 and 23 days, respectively, above the 16 °C 7-DADMax threshold.
Download or read book Development of a Hydrologic Model to Explore Impacts of Climate Change on Water Resources in the Big Wood Basin Idaho written by Allison Marshall Inouye and published by . This book was released on 2014 with total page 73 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the Western United States where 50-70% of annual precipitation comes in the form of winter snowfall, water supplies may be particularly sensitive to a warming climate. We worked with a network of stakeholders in the Big Wood Basin, Idaho, to explore how climate change may affect water resources and identify strategies that may help mitigate the impacts. The 8,300 square kilometer region in central Idaho contains a mixture of public and private land ownership, a diversity of landcover ranging from steep forested headwaters to expansive desert shrublands to a concentrated area of urban development that has experienced a quadrupling of population since the 1970s. With nearly 60% of precipitation falling as winter snow, stakeholders expressed concern regarding the vulnerability of the quantity and timing of seasonal snowpack as well as surface water supplies used primarily for agricultural irrigation under projected climate change. Here, we achieve two objectives. The first is the development of a hydrologic model to represent the dynamics of the surface water system in the Big Wood Basin. We use the semi-distributed model Envision-Flow to represent surface water hydrology, reservoir operations, and agricultural irrigation. We calibrated the model using a multi-criteria objective function that considered three metrics related to streamflow and one metric related to snow water equivalent. The model achieved higher an efficiency of 0.74 for the main stem of the Big Wood River and 0.50 for the Camas Creek tributary during the validation period. The second objective is an analysis of the Big Wood Basin hydrology under alternative future climate scenarios. We forced the calibrated model with three downscaled CMIP5 climate model inputs representing a range of possible future conditions over the period 2010-2070. The climate models simulate an increase in basin average annual air temperature ranging from 1.6-5.7oC in the 2060s compared to the 1980-2009 average. The climate models show less of a clear trend regarding precipitation but in general, one model simulates precipitation patterns similar to historic, one is slightly wetter than historic, and one is slightly drier than historic by the mid-21st century. Under these future climate scenarios, the depth of April 1 SWE may decline by as much as 92% in the 2060s compared to the historic average. Mid to high elevations exhibit the largest reductions in SWE. Simulated streamflows show a shift in timing, with peak flows occurring up to three weeks earlier and center of timing from two to seven weeks earlier in the 2050-2069 period compared to the historic period. Reduced peak flows of 14-70% were simulated by mid-century. The simulated total annual streamflow, though, fell within the historic interquartile range for most years in the future period. These and other metrics considered suggest that the surface water hydrology of the Big Wood Basin is likely to be impacted by climate change. If the natural water storage provided by the annual snowpack is reduced and timing of streamflows shifts, water resource use and management may need to change in the future. This work provides a foundation from which to explore alternative management scenarios. The approach used here can be transferred to other watersheds to further assess how water resources may be affected by climate change.
Download or read book Modeling the Effects of Projected Climate Warming on Stream Temperatures in the Stillaguamish River Basin written by Emily Esther Gebheim Smoot and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Stillaguamish River is a snow-and-rain mixed basin and the fifth largest river in the Puget Sound basin. Elevations in the 1700 km2 Stillaguamish River basin reach roughly 2000 m and historically a snowpack is sustained above 1000 m. Snowmelt in the basin is important for sustaining spring and summer streamflow and buffering stream temperatures. Stream temperature increases are of significant concern because of the threatened Chinook salmon (Oncorhynchus tshawytscha) population. I reexamined projected stream temperatures in the Stillaguamish River by forcing the coupled Distributed Hydrology Soil Vegetation Model and River Basin Model with dynamically downscaled meteorological forcings from the Weather Research and Forecasting model and projected changes in the entire basin, including the Pilchuck subbasin and mainstem through 2099 by applying 12 dynamically downscaled Global Climate Models with high emission scenarios of RCP 8.5. Using an updated version of the River Basin Model, I applied tributary specific calibration parameters and calibrated modeled streamflow and temperature using historical gauges and field measurements. My model calibrations and projections are consistent with other modeling studies in the Stillaguamish and other western Cascade watersheds. Snow covered area in the basin is projected to decrease by 74%, and summer streamflow decreases for the primary locations and at-risk tributaries are projected to be 48% and 53%, respectively for July and August at the end of the century. With the decreases in snowpack and streamflow, stream temperatures reach their peak earlier in the year, in July instead of August which was historically the warmest month. Stream temperatures are projected to increase by 14% on average for the larger primary reaches and 21% for the smaller at-risk tributaries by the 2080s for July and August. The greatest stream temperature increases are in mountainous reaches due to a reduced snowpack. The warmest stream temperatures are projected to occur in late summer along the mainstem of the Stillaguamish River. By the end of the century, six of nine locations examined will exceed the seven-day average daily maximum adult Chinook salmon lethality threshold (22.0 °C). These results indicate that continued work on climate adaptation actions and research will be required to improve Chinook salmon resiliency in the Stillaguamish River as the climate warms.
Download or read book Climate Change Impacts on Snowmelt Driven Streamflow in the Grand River Watershed written by Amy Dietrich and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Climate change is one of the most significant global environmental drivers threatening the quality and quantity of future water resources. Global temperature increases will have significant effects on the hydrologic regime of northern regions due to changes in snowfall and snowmelt. Considerable research has been conducted in western Canada to rigorously quantify snowmelt-driven streamflow processes, however, less focus has been directed towards understanding these processes in eastern Canada and Ontario. In the southern Ontario Grand River Watershed (GRW), snowmelt contributions to streamflow (freshet) make up a significant portion of the annual water yield, and the period of snowmelt is also of key concern for flood mitigation. This thesis aims to quantify historical and projected changes to timing and streamflow during freshet in the Nith River, an unregulated tributary of the Grand River. Climate data (temperature, rainfall, snowfall, and snow proportion) from observations and future scenarios were analyzed to quantify the contributions of climate conditions surrounding the timing and volume of the freshet. The annual timing of snowmelt-driven streamflow was quantified using centre time (CT), and streamflow volumes were quantified by various percentiles of streamflow (Qn) during four periods of the water year (October-December, January-February, March-April, and May-September). Historical trends in streamflow and climate data were examined using hydrometric data (1914-2016) of a stream gauge from the Water Survey of Canada, and climate data (1950-2016) from Environment and Climate Change Canada at two stations. Projected climate data were from an ensemble of models used in the Intergovernmental Panel on Climate Change's Fourth Assessment Report (AR4). A total of nine distinct models ran two scenarios from AR4 for the 2050s; moderate (B1) and high (A1B). These time-slice projections were then used to force the hydrologic model GAWSER to simulate future streamflow data. The results show that CT in the Nith River has advanced by 17 days, on average, from 1914 to 2016 (P=0.036), and the advance is projected to continue as a function of future emissions scenario (approximately 12 days for scenario B1, and 17 days for A1B). Historical CT was weakly negatively correlated with temperature (-0.51, P
Download or read book Modeling the Effects of Forecasted Climate Change and Glacier Recession on Late Summer Streamflow in the Upper Nooksack River Basin written by Ryan D. Murphy and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Like many watersheds in the North Cascades range of Washington State, USA, streamflow in the Nooksack River is strongly influenced by precipitation and snowmelt in the spring and glacial ice melt in the warmer summer months. With a maritime climate and high relief containing approximately 34km2 of glacial ice, the streamflow response in the Nooksack River basin is sensitive to increases in temperature. Climate projections from global climate models (GCMs) for the 21st Century indicate increases in temperature with variable changes to precipitation. The watershed is a valuable freshwater resource for regional municipalities, industry, and agriculture, and provides critical habitat for endangered salmon species. Thus, understanding the impacts of forecasted climate change is critical for water resources planning purposes. I apply publically available statistically derived 1/16 degree gridded surface climate data along with the Distributed Hydrology Soil Vegetation Model (DHSVM) with newly developed coupled dynamic glacier model to simulate hydrologic and glacial processes through the end of the 21st Century. Simulation results project median winter streamflows to more than double by 2075 due to more precipitation falling as rain rather than snow, and median summer flows to decrease by more than half with a general shift in peak snowmelt derived spring flows toward earlier in the spring. Glaciers are projected to retreat significantly with smaller glaciers disappearing entirely. Ice melt contribution to streamflow is likely to play an important role in sustaining summer baseflows in the Nooksack River. Glacier melt derived streamflow is projected to increase throughout the first half of the 21st century and decrease in the latter half after glacier ice volume decreases substantially.
Download or read book Assessing the Impacts of Climate Change on Fluvial Processes written by Robert Baidoc and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Watershed models are an important tool in regional planning and conservation efforts. They can provide valuable insight into the potential impacts of different land use changes and future climate change scenarios on water resources, which can lead to better, more informed decision making. Climate impacts, in particular, add a new level of uncertainty with regard to freshwater supplies as the hydrological cycle is intimately linked with changes in atmospheric temperatures. The main objective of this study is to investigate the extent of long-term climate change on streamflow and stream temperature within an agriculturally defined watershed in Northern Ontario. For this purpose, the Soil and Water Assessment Tool (SWAT) model was utilized to provide a better understanding of how hydrological processes in the Slate River Watershed will alter in response to long-term climate change scenarios. The SWAT model is a distributed/semi-distributed physically-based continuous model, developed by the USDA for the management of agricultural watersheds, and is currently one of the most popular watershed-based models used in climate change analysis of snowmelt dominated watersheds. Historic flow data was compared to a discharge model that reflected four climate models driven by SRES A1B and A2 through the middle and end of the century. Hydrology modelling was enhanced with stream temperature analysis to gain a comprehensive understanding of the extent of changing climate regimes on the Slate River. A linear regression approach representing a positive relationship between stream temperature and air temperature was used to determine the thermal classification of the Slate River. Our results indicated that the Slate River was well within the warm-water character regime. Unusual high stream temperatures were recorded at mid- August; these were accompanied by low water levels and a lack of riparian vegetative cover at the recording site, providing a possible explanation for such temperature anomalies. The results of the flow discharge modelling supported our hypothesis that tributaries within our ecosystem would experience increasing water stress in a warming climate as the average total discharge from the Slate River decreased in both climate scenarios at the middle and end of the century. Although the lack of accurate subsurface soil data within the study region prevented our discharge model from quantifying the changes in stream discharge, the strong correlation between the observed and simulated flow data as reflected by a 0.92 r2 statistic gave us confidence that discharge from the Slate River will continue to follow a decreasing trend as climate change persists into the future. This study aims to support the future endeavours of hydrologic modelling of watersheds in Northern Ontario by illustrating the current capabilities and limits of climate change analysis studies within this region.
Download or read book Quantifying Vegetation Transpirational Controls on Streamflow in the Lehman Creek Watershed to Estimate Potential Effects of Anthropogenic Climate Change written by Christine Louise Hedge and published by . This book was released on 2014 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: While a number of studies have documented the occurrence of climate change in the Western U.S., no studies have used modern instrumental climate data to quantify the potential effect of climate change-induced increases in transpiration on streamflow (Q) in the Great Basin. We hypothesized that an increase in plant transpiration in the Lehman Creek watershed in Great Basin National Park, as a result of anthropogenic climate warming, may result in a measurable reduction in Q. We sought to quantify: (1) evapotranspiration (ET) controls on Q in the Lehman Creek watershed and how variations in ET would affect Q, and (2) how projected climate changes would impact transpiration and thus Q. Using data from the Parameter-Elevation Regressions on Independent Slopes Model, USGS, and nearby SNOTEL and weather stations, we calculated seasonal and annual ET using a general watershed balance equation. Linear regression analysis of time series data were used to evaluate short and long term patterns in climate, and to quantify relationships among precipitation, ET, Q, and air temperature. We also calculated the effects of simulated climate-induced increases in ET of 10-50% on Q. Snow water equivalent was the strongest determinant of annual ET and Q on an annual scale; however, early season air temperature was also a strong modulator of ET and Q. Years of warmer, faster, and earlier starts to early season air temperature resulted in earlier and higher early season ET, and thus lower Q. Small to moderate increases in simulated ET of 10-20% resulted in significant reductions (mean 5-10%) in Q with a 1.5-3 week extension of the growing season for drier years. Results demonstrate the risks to surface water flows in watersheds of the Great Basin and western U.S. that may result from earlier starts to the growing season, longer growing seasons, or growing seasons with higher amounts of transpiration that may result if the climate of the Great Basin continues to warm.
Download or read book Modeling the Impacts of Climate Change on Streamflow of the Nicolet River as Affected by Snowmelt Using ArcSWAT written by Fei Tang and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: " In the Nicolet River watershed of Southern Quebec, Canada, runoff resulting from snowmelt is responsible for the spring peak flow, which may result in flooding when temperature rises rapidly in a short time. In this study, streamflow modeling for the Nicolet River watershed was conducted, then the impacts of climate change on the hydrology of this basin were studied by comparing the streamflow characteristics of historical and projected future climate data under a wide range of climate change scenarios. The Soil and Water Assessment Tool (SWAT), was calibrated and validated against the observed streamflow for the period of 1986-1990 and 1991-2000, respectively. The ArcSWAT model was shown to be a reliable tool for simulating the stream flow (PBIAS within 15%, Nash-Sutcliffe efficiency (NSE) > 0.50 and RMSE-observations standard deviation ratio (RSR)
Download or read book Modeling 21st Century Peak Flows in the Nooksack River Basin in Northwestern Washington State Using Dynamically downscaled Global Climate Model Projections written by Evan A. Paul and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Nooksack River in northwest Washington State provides freshwater for agriculture, municipal, and industrial use and serves as a vital habitat for endangered salmon, a resource that is of cultural and economic importance to the Nooksack Indian Tribe and the surrounding region. Due to the complex topography in the basin and the mild maritime climate of the Puget Sound region, streamflow in the Nooksack River is highly sensitive to fluctuations in air temperature. Global climate models (GCMs) project an increase in air temperatures for the Puget Sound region, and previous modeling within the Nooksack basin projects a reduction in snowpack extent through the 21st century and an increase in winter streamflow magnitude. As more landscape becomes exposed to rain rather than snow and heavy winter precipitation events intensify, peak flows and sediment delivery to streams will likely increase due to rapid runoff, resulting in salmon habitat degradation and increased flood risk. Thus, anticipating the effect of climate change on peak flows is crucial for salmon habitat restoration efforts and flood mitigation planning. To quantify the timing and magnitude of future peak flows, I use a calibrated Distributed Hydrology Soil Vegetation Model (DHSVM) and meteorological forcings from an ensemble of high-emission GCMs dynamically-downscaled using the Weather Research and Forecasting (WRF) model. Due to the variability of climate scenarios depicted by GCMs, a range of streamflow and snowpack magnitude changes in the Nooksack River basin are projected by the hydrology simulations. By the end of the 21st century, results indicate a decrease in annual peak snow-water equivalent (-72% to -82%), a shift in the timing of peak snow-water equivalent to approximately one month earlier, an increase in winter flows (+31% to +56%), a decrease in summer flows (-37% to -72%), and the disappearance of the snowmelt derived spring peak in the hydrograph as the basin transitions from transient to rain-dominant. These results are consistent with previous modeling in the Nooksack River basin and other regional climate change studies in the Pacific Northwest and Puget Sound region. Due to more precipitation falling as rain rather than snow and heavy rain events becoming more frequent and intense, future peak flows are projected to increase in magnitude by 34-60% across all flow durations and return periods that were analyzed, with the largest changes occurring in the high relief subbasins. The frequency of high magnitude, flood-inducing peak flows will also increase into the future, lengthening the flood season by approximately three months.
Download or read book Simulation of Vegetation and Hydrology for Climate Change Analysis of a Mountain Watershed written by Scott R. Waichler and published by . This book was released on 2000 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: Climate change is expected to have both direct and indirect effects on water resources. Hydrologic impacts of two indirect effects, vegetation density and stomata! conductance, are evaluated for the American River, a 200 km2 watershed in the Cascade Range of Washington state. First, a set of distributed hydrology-biogeochemistry model structures are created by coupling DHSVM (Distributed Hydrology-Soil-Vegetation Model) and Biome-BGC (BioGeochemistry Cycles). The model structures are applied to idealized hillslopes and current and future climate scenarios for the watershed. Eleven model structures, differing in vertical 1-D hydrology parameterization, lateral water routing, timestep, slope and aspect, are tested. Sensitivity of hydrology and vegetation density (as measured by leaf area index, LAI) is evaluated with respect to model structure, lapsed climate (elevation), climate change, and soil thickness and nitrogen input rate. Lapsed climate accounts for the largest range in LAI, but choice of model structure is also significant, highlighting opportunities and problems in model development. LAI is water-limited at low elevations, temperature-limited at high elevations, and solar-limited at all elevations. All model structures predict increased LAI under the future scenario that includes reduced stomatal conductancethe conifer forest grows denser. Next, climate scenarios and LAI results from the idealized hillslope simulations are input to the hydrology model DHSVM for hydrologic analysis of the full American River watershed. Basin-average annual precipitation, streamflow, and evapotranspiration all increase under the future climate scenario. The direct effect of increased temperature causes the major hydrologic impact, reduced snowpack and altered seasonal timing of streamflow and ET. Indirect effects of altered LAI and stomatal conductance on hydrology are minor in comparison to the direct effects. Future streamflow and ET are essentially the same between the simplest treatment of climate change, involving fixed LAI and physical climate change only, and the most detailed treatment, involving variable LAI and reduced stomatal conductance in addition to physical climate change.
Download or read book Developing Methods to Assess the Potential Effects of Global Climate Change on Deer Creek Reservoir Using Water Quality Modeling written by Reed Chilton and published by . This book was released on 2011 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt: To evaluate the potential impacts of future climate change on a temperate reservoir, I used a calibrated water quality and hydrodynamic model validated using three years of data (2007-2009) from Deer Creek Reservoir (Utah). I evaluated the changes due to altered air temperatures, inflow rates, and nutrient loads that might occur under Global Climate Change (GCC). I developed methods to study GCC on reservoirs. I produced Average Water Temperature Plots, Stratification Plots, and Total Concentration Plots. Average Water Temperature Plots show the sensitivity of the water temperature to various parameters. Stratification Plots quantify stratification length and strength as well as ice-cover periods. Total Concentration Plots analyze the reservoir as a whole concerning water quality parameters. Increasing air temperature increased the water temperature, lengthened stratification time, increased stratification strength, decreased the ice-cover period, decreased the total algae concentration, decreased the flows, and caused peak nutrient concentrations to occur earlier. Decreasing flows caused increased water temperature, shorter stratification periods, weaker stratification, and increased nutrient concentrations. Increasing phosphate concentrations caused increases in total algae, dissolved oxygen, and phosphate concentrations. Variations in Nitrate-Nitrite concentrations did not influence the tested parameters. I found that the reservoir is only sensitive to these changes during the spring and summer. The tools which I developed were used to run the model scenarios, organize the data, and plot the results. They can be used on other reservoirs and for other water quality parameters.
