Physically Based Modelling of the Impacts of Climate Change on Streamflow Regime PDF Download

Author: Nazmus Shams Sazib
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
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.

Author: Robert Baidoc
Publisher:
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Category :
Languages : en
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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.

Author: Tamar Zohary
Publisher: Springer
ISBN: 9401789444
Category : Science
Languages : en
Pages : 674

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This condensed volume summarizes updated knowledge on the warm-monomictic subtropical Lake Kinneret, including its geophysical setting, the dynamics of physical, chemical and biological processes and the major natural and anthropogenic factors that affect this unique aquatic ecosystem. This work expands on a previous monograph on Lake Kinneret published in 1978 and capitalizes on the outcome of more than 40 years of research and monitoring activities. These were intensively integrated with lake management aimed at sustainable use for supply of drinking water, tourism, recreation and fishery. The book chapters are aimed at the limnological community, aquatic ecologists, managers of aquatic ecosystems and other professionals. It presents the geographic and geological setting, the meteorology and hydrology of the region, continues with various aspects of the pelagic and the littoral systems. Finally, the last section of the book addresses lake management, demonstrating how the accumulated knowledge was applied in order to manage this important source of freshwater. The section on the pelagic system comprises the heart of the book, addressing the major physical processes, external and internal loading, the pelagic communities (from bacteria to fish), physiological processes and the major biogeochemical cycles in the lake.

Author: Susan E. Dickerson
Publisher:
ISBN:
Category : Climatic changes
Languages : en
Pages : 0

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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).

Author: Katherine Mary Clarke
Publisher:
ISBN:
Category : Salmonidae
Languages : en
Pages : 132

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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.

Author: Assefa M. Melesse
Publisher: Elsevier
ISBN: 0128159995
Category : Science
Languages : en
Pages : 580

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Book Description
Extreme Hydrology and Climate Variability: Monitoring, Modelling, Adaptation and Mitigation is a compilation of contributions by experts from around the world who discuss extreme hydrology topics, from monitoring, to modeling and management. With extreme climatic and hydrologic events becoming so frequent, this book is a critical source, adding knowledge to the science of extreme hydrology. Topics covered include hydrometeorology monitoring, climate variability and trends, hydrological variability and trends, landscape dynamics, droughts, flood processes, and extreme events management, adaptation and mitigation. Each of the book's chapters provide background and theoretical foundations followed by approaches used and results of the applied studies. This book will be highly used by water resource managers and extreme event researchers who are interested in understanding the processes and teleconnectivity of large-scale climate dynamics and extreme events, predictability, simulation and intervention measures. Presents datasets used and methods followed to support the findings included, allowing readers to follow these steps in their own research Provides variable methodological approaches, thus giving the reader multiple hydrological modeling information to use in their work Includes a variety of case studies, thus making the context of the book relatable to everyday working situations for those studying extreme hydrology Discusses extreme event management, including adaption and mitigation

Author: Jan C. van Dam
Publisher: Cambridge University Press
ISBN: 9780521543316
Category : Science
Languages : en
Pages : 164

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Book Description
Examines the implications of possible climate changes and variability on both global and regional water resources.

Author: Sulochan Dhungel
Publisher:
ISBN:
Category :
Languages : en
Pages :

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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.

Author: Makoto Taniguchi
Publisher: CRC Press
ISBN: 0415472792
Category : Science
Languages : en
Pages : 700

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Book Description
The vulnerability of water resources due to climate change and human activities is globally increasing. The phenomenon of hydrological change is complicated because of the combinations and interactions between natural climate fluctuation, global warming and human activities including changes in land utilization. The impact areas of hydrological changes are also not only within the basin, but reach to the ocean through coastal water exchanges. This book presents contributions focused on integrated water management from headwater to the ocean in a time of climate change and increasing population.

Author: Yifan Cheng
Publisher:
ISBN:
Category :
Languages : en
Pages : 124

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Human activities, especially dam construction, greatly modify the response of river thermal regimes to climate change. Dams impound large water bodies, decrease surface to volume ratios, and increase water residence times. All of these changes affect the interaction between surface meteorology and river systems. During warm seasons, surface energy fluxes can only warm a reservoir’s top layer (epilimnion) while the bottom layer (hypolimnion) remains cold. As a result, the cold hypolimnetic releases greatly depress downstream river temperatures. Additionally, reservoir releases during cold seasons can increase downstream river temperatures. Thus far, most large-scale stream temperature studies have ignored seasonal thermal stratification and therefore underestimated the regulation impacts on downstream fluvial thermal regimes. In the papers that constitute this dissertation, I synthesized a physically-based model framework to simulate regulated river flow and temperature, explicitly considering the impacts of reservoir thermal stratification. This model framework laid the basis of this dissertation and was applied in all subsequent analyses. In Chapter 2, I applied this model framework in the southeastern United States and investigated the impacts of reservoir regulation and climate change on mean summer river temperature and cooling potentials, a metric designed to evaluate the compound impact of river flow and temperatures. Under climate change, summer river temperatures in the regulated rivers will remain colder compared to those in the unregulated rivers but under climate change the effect does not carry as far downstream. The impact of reservoir regulation on cooling potentials remains strong for rivers heavily influenced by thermal stratification, but under climate change higher river temperatures will decrease cooling potentials for all river segments. In Chapter 3, I examined extreme fluvial thermal events, i.e., high river temperatures, so as to facilitate risk management for regional aquatic ecosystem and power sectors. We introduced a standard characterization with three attributes, i.e., duration-intensity-severity, to quantify the climate change impacts on thermal extremes in a regulated river system. Thermal extremes will be greatly exacerbated by climate change. In the baseline (unregulated) scenarios, duration, intensity, and severity are projected to increase to 85.6 day/year (+77.4 day/year), 5.2 °C (+4.4°C), and 193.4 °C day/year (+187.9 °C·day/year), respectively, by the 2080s under RCP8.5, with values in parentheses indicating the changes relative to the historical, unregulated values. Even though reservoir mitigation impacts are projected to be stronger, only 12.2%, 19.7%, and 26.0% of duration, intensity, and severity by the 2080s under RCP8.5 can be mitigated by reservoir regulations. In Chapter 4, I projected potential fish distribution due to climate change in the highly regulated Tennessee River. By coupling the model framework for regulated river systems described in Chapter 2 with a species distribution model, I simulated fish presence probability for historic and future periods considering the effects of dams on flow, thermal regime, and reach connectivity. The number of stream segments that are environmentally suitable for an exotic and lucrative rainbow trout, a coldwater species, will greatly shrink under climate change. Only 4.4% of historically suitable streams will remain, mostly located at reservoir tailwaters. For endemic coolwater species, projected higher river temperature may facilitate their expansion, but it will be constrained due to the physical blockage of dams.