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 Potential Effects of a Warming Climate on Water Resources Within the Lehman and Baker Creek Drainages Great Basin National Park Nevada written by John Michael Volk and published by . This book was released on 2014 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: Warming trends in near-surface air temperature across the Southwestern U.S. have been observed over the last century and are projected to continue over the 21st century. This warming trend will result in decreased snowpack and earlier snowmelt in mountainous basins throughout the West; however, predictions of future precipitation in the Southwest are much more uncertain among global climate models (GCMs). In this study, the objective was to quantitatively evaluate the impacts of projected warming on streamflow in the Lehman and Baker Creek drainages. The drainages are located in Great Basin National Park that encompasses the highest elevations in the southern part of the Snake Range in eastern Nevada. The Precipitation-Runoff Modeling System (PRMS) was used to evaluate impacts of warming on streamflow. Calibration and validation periods had total errors between 0.6 and 12 percent in simulated streamflow. Daily maximum and minimum temperatures for a future 90-year period were used in the model to evaluate how warming temperatures may affect streamflow. Daily temperatures were statistically downscaled and bias corrected using daily projections from the National Center for Atmospheric Research Community Climate System Model 4.0 for four representative greenhouse gas concentration trajectories. A 30-year record of historical precipitation was repeated three times over the 90-year simulation. Results from the 90-year simulation were divided into three 30-year periods (water years 2009-2038, 2039-2068, and 2069-2098) and were compared among the four greenhouse gas concentration trajectories such that volumes and variations in precipitation were identical and changes could be directly related to different projected warming temperatures. The study area was sensitive to small increases in temperature; results include shifts to earlier snowmelt timing for most warming trajectories from May to April with an increase in winter streamflow. For a temperature rise of 5.5°F by the end of the century, mean annual streamflow was reduced more than 10 percent and resulted in a corresponding increase in evapotranspiration; also a significant decrease in peak snowpack and May runoff was simulated. Reduced snowpack and earlier snowmelt affected the snow-dominated watersheds by reducing soil moisture and evapotranspiration in July and August.

Download or read book Modeling the Potential Impacts of Climate Change on Streamflow Variability in the North Fork of Elk Creek Experimental Watershed West Central Montana written by Katie Marie Jorgensen and published by . This book was released on 2012 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study hypothesizes the effects of global climate change on the hydrologic regime of West-Central Montana, focusing on the North Fork of Elk Creek, a 6.6 km2 (2.6 mi.2) Experimental Watershed. This is important to understand in snowmelt-dominated watersheds, as it is already well documented by current trends and future climate projections that the natural hydrologic regime is experiencing alterations. There have been shifts in the 20th century of the timing of snowmelt trending towards an earlier spring peak flows and declines in the overall snow water equivalent (Regonda et al., 2005; Mote et al., 2005; Hamlet et al., 2005). The goals for this study are to analyze for significant changes in the timing of important hydrologic events, and determine how discharge throughout the year will be altered in the Elk Creek Experimental Watershed (ECEW). To address these issues, a semi-spatial hydrologic model is employed, and run using current meteorological data and under downscaled climate-change scenarios conditions, under three relevant time periods. Snowmelt Runoff Model (SRM) is deterministic and conceptual and is used to generate streamflow in snowmelt dominated basins by the degree-day method (Martinec, 1985). Data is gathered from two SNOTEL sites located within the watershed and streamflow collected directly on the North Fork of Elk Creek. The specific metrics that will be statistically analyzed are mean summer and winter flows, and trends in peak flow and center of mass date timing (Wenger et al., 2009; Regonda et al., 2005). These results can be useful for management purposes because changes in the way water is released from the mountains affects water storage, flooding, and overall watershed resilience such that current practices may need to be accordingly adjusted.

Download or read book Quantifying Impacts of Global Change on Hydrology and Sediment written by Travis A. Dahl and published by . This book was released on 2019 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt: The hydrologic cycle evolves over time, with landscape changes driving differences in evapotranspiration, runoff, and groundwater recharge while climate change affects the timing and magnitude of precipitation as well as temperature. These changes also affect how sediment moves across the landscape and through watersheds. In this dissertation, I examine how land use changes and climate change both affect the movement of water and sediment through watersheds in the Great Lakes Basin.Extreme cases of land use change, such as the logging and forest fires that affected large swaths of the Great Lakes in the late 19th and early 20th centuries, can greatly increase both streamflow and sediment transport. Chapter 1 utilizes the process-based Landscape Hydrologic Model (LHM) to examine the hydrologic effects of land use change from the forested pre-settlement condition to clearcut, burned, and modern land uses in the northwestern corner of Michigan's Lower Peninsula. I show that extensive fires could have increased streamflow by 160% relative to the virgin forest landscape and 96% relative to the logged scenario. Chapter 2 focuses on modeling of the Jordan River watershed, showing that logging may have increased sediment transport in the river by up to 34% compared to pre-settlement conditions and a watershed-wide fire could have increased the sediment transport capacity by as much as 166% above the pre-settlement levels. A reach-based sediment budgeting tool, the Sediment Impact Assessment Methods (SIAM), highlights the possibility of complex system responses to land use change over time.Chapter 3 explores the potential impacts of climate change on sediment yield and dredging costs in the adjacent Maumee and St. Joseph River watersheds where I project that dredging costs may change in opposite directions (−8 to −16% in the St. Joseph but +1 to +6% in the Maumee). This difference between the two watersheds is driven by differences in the proportion of farmland and assumptions about how farmers will respond to a changing climate. I also show that there is a large variation in sediment yield and sediment discharge predictions because of the differences among the various Global Climate Model (GCM) projections.Rather than downscale and run all of the GCM projections, many researchers average a subset of the projections together and use the ensembled climate data as the input to hydrologic models. In Chapter 4, I compare different climate change scenario ensembling methodologies to determine if they produce the same results. I show that a climate ensemble produces significantly (p

Download or read book Estimating the Effects of Global Climate Change on Streamflow and Wetlands in the Watershed of the Pere Marquette River Michigan written by Avram G. B. Primack and published by . This book was released on 1999 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Addressing Climate Change in Long term Water Resources Planning and Management written by Levi D. Brekke and published by DIANE Publishing. This book was released on 2011 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: Describes the water management community¿s needs for climate change info. and tools to support long-term planning. Technical specialists and program managers have worked with their planners, water operators, and environmental compliance managers to identify the information and tools most relevant to their programs. They also have engaged and consulted with other Federal, State, and local agencies and stakeholder groups that have a role in water and water-related resource management to identify complementary priorities and individual perspectives. This report will help focus research and technology efforts to address info. and tools gaps relevant to the water management user community. Charts and tables. This is a print on demand report.

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 Prediction of Climate Change Effects on Streamflow Regime Important to Stream Ecology written by Sulochan Dhungel and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A major challenge in freshwater ecosystem management is to predict future changes in streamflow regime. This thesis focused on identifying and modeling specific characteristics of streamflow that are important to stream ecosystems. The need to evaluate the potential impacts of climate change on stream ecosystems makes it important to study how streamflow regime may change. In this thesis we sought to advance understanding of the effect of climate change on streamflow regime by (1) examining the spatial variation in streamflow attributes across the continental US, (2) modeling how these streamflow attributes vary with current climate and watershed features, and (3) using this model with future climate projections of changes in precipitation and temperature to predict how streamflow attributes change with climate change. We used long-term daily flow measurements for 601 gauged streams whose watersheds were in relatively unimpaired condition to characterize streamflow regimes. Sixteen streamflow variables were identified which in our judgment sufficiently characterized aspects of the streamflow regime most relevant to stream ecosystem structure and function. These are computed for each stream. Principal component analysis with Varimax rotation reduced the dimensionality to five uncorrelated streamflow factors that quantify lowflow, magnitude, flashiness, timing and constancy. These independent factors were used to hereafter classify the streams based on distances in factor space into three broad classes which were further divided into eight classes. We used Random Forests to develop a model to predict these stream classes using watershed and climate attributes. The model had an accuracy of about 75%. Downscaled climate projections of precipitation and temperature were used to predict the changes in these stream classes by 2100 using the RF model. Thirty-three percent of selected sites were predicted to change into a different stream class by 2100. The least changes were predicted in snow-fed streams in the west while most of changes were predicted for rain-fed small perennial streams and intermittent streams in the central and eastern US. Class changes predicted, due to projected climate change provide a basis for (i) considering the extent of projected changes and (ii) formulating approaches to protect ecosystems that may be subject to change.

Download or read book Physically Based Modelling of the Impacts of Climate Change on Streamflow Regime written by Nazmus Shams Sazib and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding the implications of climate change on streamflow regime is complex as changes in climate vary over space and time. However, a better understanding of the impact of climate change is required for identifying how stream ecosystems vulnerable to these changes, and ultimately to guide the development of robust strategies for reducing risk in the face of changing climatic conditions. Here I used physically based hydrologic modeling to improve understanding of how climate change may impact streamflow regimes and advance some of the cyberinfrastructure and GIS methodologies that support physically based hydrologic modeling by: (1) using a physically based model to examine the potential effects of climate change on ecologically relevant aspects of streamflow regime, (2) developing data services in support of input data preparation for physically based distributed hydrologic models, and (3) enhancing terrain analysis algorithms to support rapid watershed delineation over large area. TOPNET, a physically based hydrologic model was applied over eight watersheds across the U.S to assess the sensitivity and changes of the streamflow regime due to climate change. Distributed hydrologic models require diverse geospatial and time series inputs, the acquisition and preparation of which are labor intensive and difficult to reproduce. I developed web services to automate the input data preparation steps for a physically based distributed hydrological model to enable water scientist to spend less time processing input data. This input includes terrain analysis and watershed delineation over a large area. However, limitations of current terrain analysis tools are (1) some support only a limited set of specific raster and vector data formats, and (2) all that we know of require data to be in a projected coordinate system. I enhanced terrain analysis algorithms to extend their generality and support rapid, web-based watershed delineation services. Climate change studies help to improve the scientific foundation for conducting climate change impacts assessments, thus building the capacity of the water management community to understand and respond to climate change. Web-based data services and enhancements to terrain analysis algorithms to support rapid watershed delineation will impact a diverse community of researchers involved terrain analysis, hydrologic and environmental modeling.

Download or read book Modeling the Impacts of Climate Change on Hydrology and Agricultural Pollutant Runoff in California s Central Valley written by Darren L. Ficklin and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Soil and Water Assessment Tool (SWAT) and HYDRUS were used to assess the impact of climate change on the hydrologic cycle (streamflow, surface runoff, groundwater recharge, evapotranspiration, and irrigation water use) and agricultural pollutant runoff (sediment, nitrate, phosphorus, chlorpyrifos, and diazinon) in the Sacramento and San Joaquin River watersheds in California's Central Valley. Five separate studies were constructed. For the first three studies, hydrological responses were modeled in the San Joaquin River watershed using variations of atmospheric CO2 (550 and 970 ppm), temperature (+1.1 and +6.4°C), and precipitation (0%, ±10%, and ±20%) based on Intergovernmental Panel on Climate Change projections. The fourth study used a calibration and an uncertainty analysis technique for the calibration of the Sacramento River watershed. This study confirmed that SWAT was able to capture the large amount of uncertainty within the Sacramento River watershed and successfully simulate streamflow, sediment, nitrate, chlorpyrifos and diazinon loads. The final study used a novel stochastic climate change analysis technique to bracket the 95% confidence interval of potential climate changes. For all studies, increases in precipitation generally changed the hydrological cycle and agricultural runoff proportionally, where increases in precipitation resulted in increases in surface runoff and thus agricultural runoff and vice-versa. Also, for all studies, increasing temperature caused a temporal shift in plant growth patterns and redistributed evapotranspiration and irrigation water demand earlier in the year. Increasing atmospheric CO2 resulted in watershed-wide decreases in evapotranspiration, therefore increasing water yield and streamflow while concurrently decreasing irrigation water use. This research improves the understanding between climate change and hydrology and agricultural pollutant runoff within the Central Valley of California. Theses climate change analyses may be used by water resource managers to evaluate the potential effects of climate change.

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 Watershed Modeling to Assess the Sensitivity of Streamflow Nutrient and Sediment Loads to Potential Climate Change and Urban D written by Epa and published by . This book was released on 2015-08-06 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: Report on watershed modeling conducted in 20 large, U.S. watersheds to characterize the sensitivity of streamflow, nutrient (nitrogen and phosphorus), and sediment loading to a range of plausible mid-21st century climate change and urban development scenarios. The study also provides an improved understanding of methodological challenges associated with integrating existing tools (e.g., climate models, downscaling approaches, and watershed models) and data sets to address these scientific questions. Results provide an improved understanding of the complex and context-dependent relationships between climate change, land-use change, and water resources in different regions of the nation. Results indicate that in many locations future conditions are likely to be different from past experience. Figures and tables. This is a print on demand report.

Download or read book Baseline for Climate Change written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Objectives of the two-year study were to (1) establish baselines for fish and macroinvertebrate community structures in two mid-Atlantic lower Piedmont watersheds (Quantico Creek, a pristine forest watershed; and Cameron Run, an urban watershed, Virginia) that can be used to monitor changes relative to the impacts related to climate change in the future; (2) create mathematical expressions to model fish species richness and diversity, and macroinvertebrate taxa and macroinvertebrate functional feeding group taxa richness and diversity that can serve as a baseline for future comparisons in these and other watersheds in the mid-Atlantic region; and (3) heighten people's awareness, knowledge and understanding of climate change and impacts on watersheds in a laboratory experience and interactive exhibits, through internship opportunities for undergraduate and graduate students, a week-long teacher workshop, and a website about climate change and watersheds. Mathematical expressions modeled fish and macroinvertebrate richness and diversity accurately well during most of the six thermal seasons where sample sizes were robust. Additionally, hydrologic models provide the basis for estimating flows under varying meteorological conditions and landscape changes. Continuations of long-term studies are requisite for accurately teasing local human influences (e.g. urbanization and watershed alteration) from global anthropogenic impacts (e.g. climate change) on watersheds. Effective and skillful translations (e.g. annual potential exposure of 750,000 people to our inquiry-based laboratory activities and interactive exhibits in Virginia) of results of scientific investigations are valuable ways of communicating information to the general public to enhance their understanding of climate change and its effects in watersheds.

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 Potential Impacts of Climate Change on Major Watersheds of Western North America written by Daniel Barandiaran and published by . This book was released on 2011 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effects of Changes to Rainfall Estimates Due to Climate Change on Runoff written by Binta Coleman and published by . This book was released on 2013 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent studies show that climate change is occurring and may lead to significant changes in the environment. These changes may directly affect weather patterns and the intensities of storms experienced in California. With the State being heavily dependent on its flood control system, climate change's effects on weather may increase risks of flooding. The State of California's Department of Water Resources (DWR) has begun to focus on the potential increase in risks of flooding due to climate change and increasing the sustainability of the State's flood control systems. The purpose of this study was to examine the effects of increased rainfall on peak runoff magnitudes on the Ulatis Creek Watershed located in California's Central Valley. Analysis was completed using estimated changes in precipitation developed by Das et al. (2011) and a rainfall-runoff model developed for the Central Valley Hydrology Study (CVHS) by the United States Army Corps of Engineers (USACE). Das et al. (2011) used downscaled general circulation models (GCMs) to develop estimates to changes in precipitation. Rainfall runoff modeling was completed using the Hydrologic Modeling System developed by the USACE's Hydrologic Engineering Center (HEC-HMS). Results of this study show that increased precipitation resulted in increased runoff peaks. Using the maximum precipitation estimates of an increase of 10.7 percent in early century epoch, and 3.0 percent in the late century, the resulting runoff increased approximately 13.5 percent and 3.7 percent respectively. Reduced precipitation estimates of -0.5 percent in the early century and -10.1 percent in late century estimates, yielded reduction in flow magnitudes of -0.64 and -12.5 percent, respectively. Further analysis would be needed in order to accurately predict the effects of climate change on peak runoff. With many uncertainties in climate change estimations and modeling assumptions, it is difficult for law makers to develop approaches to planning for future flood risks.

Download or read book Uncertainty in Climatic Change Impacts on Multiscale Watershed Systems written by Olga V. Tsvetkova and published by . This book was released on 2013 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt: Uncertainty in climate change plays a major role in watershed systems. The increase in variability and intensity in temperature and precipitation affects hydrologic cycle in spatial and temporal dimensions. Predicting uncertainty in climate change impacts on watershed systems can help to understand future climate-induced risk on watershed systems and is essential for designing policies for mitigation and adaptation. Modeling the temporal patterns of uncertainties is assessed in the New England region for temperature and precipitation patterns over a long term. The regional uncertainty is modeled using Python scripting and GIS to analyze spatial patterns of climate change uncertainties over space and time. The results show that the regional uncertainty is significant in variation for changes in location and climatic scenarios. Watershed response to climate change under future scenarios is assessed using hydrologic simulation modeling for the Connecticut River watershed. Changes in water budgets are assessed for each of the subbasins using spatial analysis and process modeling using GIS and Soil and Water Assessment tool (SWAT). The results show that climate change uncertainty in precipitation and temperature can lead to uncertainty in both quantity and quality in the watershed system. A spatiotemporal, dynamic model was applied to subbasins within the Chicopee River Watershed to estimate climate change uncertainty impacts at a micro scale. These changes were assessed relative to changes in land use and climatic change. The results show that there is a significant potential for climate change to increase evaporation, watershed runoff and soil erosion rates and this varied with climate change uncertainty. Finally, water sustainability gradient analysis was applied to the Volga River watershed in Russia to assess potential climate change impacts by combining with downscaled Global Circulation Model estimates and spatial assessment. Results show that runoff and evapotranspiration are projected to increase with potential for more localized floods and drought events effecting both water resources and food supply. Overall results show that climate change uncertainty can impact watershed systems and spatial and temporal assessments is important for developing strategies for adaptation to climatic change conditions at local and regional scales.