Download or read book Sensitivity of Large basin Hydrology Forecasts and Management to Historical Climatic Forcing written by Mary G. Mullusky and published by . This book was released on 1993 with total page 148 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 Assessing Hydrologic Impacts of Climate Change Over Semi arid Region Using Bias adjusted Dynamically Downscaled Meteorological Forcing written by Tsou Chun Jaw and published by . This book was released on 2011 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: Twentieth century climate change induced by anthropogenic forcings has been recognized as one of the most serious issues affecting the development of mankind. Impacts of climate change on hydrologic processes are highly relevant to human activities and draw a great deal of scientific attention. In particular, semi-arid hydrology and water resources, which are encountering significant challenges in present climate, are projected to be more vulnerable to the future climate. While relevant studies emphasize large-scale impacts on hydrological processes due to climate changes, investigations of the impacts of climate changes on regional, even basin-scale hydrology are relatively limited. The main objective of this dissertation is to assess the potential hydrologic impacts of climate change over a semi-arid region by means of hydrologic modeling driven by high-resolution meteorological forcings. While GCMs are considered as powerful tools to simulate large-scale climate changes in the Earth system, climate information derived from GCMs needs to be further downscaled to meet the requirements of assessing the impact of regional climate and hydrology on global climate change. In this study, dynamical downscaling implementing a Regional Climate Model (RCM) to derive finer-resolution climate data is conducted, and three GCMs (BCCR, CCSM3, and ECHAM5) are adopted as the forcing data sets of the dynamical downscaling to evaluate regional climate and its hydrologic impacts over the semi-arid Morocco under the present-day and future climate scenarios. Downscaled precipitation analyses indicate that, systematically, biases are present. Directly using biased RCM output for hydrologic assessments would lead to unrealistic results. Therefore, effective bias correction approaches for the meteorological forcings required in the hydrologic modeling are adopted. While dynamically-downscaled GCMs show varying biases, downscaled ECHAM5 runs are more realistic in reproducing the historical climate patterns. Furthermore, proposed bias corrections (QM, EDCDF, and MovingCDF) significantly reduce the biases both in the meteorological forcings and their hydrologic responses. Among the correction approaches, MovingCDF accounts for the nonstationarity within the projection period and displays the best performance in forcing correction. Hydrologic simulation runs forced by the corrected forcings are significantly improved in the historical period in comparison with the results directly forced by RCM output. For future hydrologic assessments, hydrologic simulations driven by bias-corrected climate forcings exhibit a more consistent agreement. A drier hydrologic condition in the study region is expected in the near future (2036-2065). However, the degrees of the hydrologic impact, are highly dependent on the behaviors of large-scale GCM forcings.

Download or read book Impact of Climate Change on Hydrological Regimes and Water Resources Management in the Rhine Basin written by W. Grabs and published by . This book was released on 1997 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Forecasting Seasonal Hydrologic Response in Major River Basins written by A. M. Tanvir Hossain Bhuiyan and published by . This book was released on 2014 with total page 381 pages. Available in PDF, EPUB and Kindle. Book excerpt: Seasonal precipitation variation due to natural climate variation influences stream flow and the apparent frequency and severity of extreme hydrological conditions such as flood and drought. To study hydrologic response and understand the occurrence of extreme hydrological events, the relevant forcing variables must be identified. This study attempts to assess and quantify the historical occurrence and context of extreme hydrologic flow events and quantify the relation between relevant climate variables. Once identified, the flow data and climate variables are evaluated to identify the primary relationship indicators of hydrologic extreme event occurrence. Existing studies focus on developing basin-scale forecasting techniques based on climate anomalies in El Nino/La Nina episodes linked to global climate. Building on earlier work, the goal of this research is to quantify variations in historical river flows at seasonal temporal-scale, and regional to continental spatial-scale. The work identifies and quantifies runoff variability of major river basins and correlates flow with environmental forcing variables such as El Nino, La Nina, sunspot cycle. These variables are expected to be the primary external natural indicators of inter-annual and inter-seasonal patterns of regional precipitation and river flow. Relations between continental-scale hydrologic flows and external climate variables are evaluated through direct correlations in a seasonal context with environmental phenomenon such as sun spot numbers (SSN), Southern Oscillation Index (SOI), and Pacific Decadal Oscillation (PDO). Methods including stochastic time series analysis and artificial neural networks are developed to represent the seasonal variability evident in the historical records of river flows. River flows are categorized into low, average and high flow levels to evaluate and simulate flow variations under associated climate variable variations. Results demonstrated not any particular method is suited to represent scenarios leading to extreme flow conditions. For selected flow scenarios, the persistence model performance may be comparable to more complex multivariate approaches, and complex methods did not always improve flow estimation. Overall model performance indicates inclusion of river flows and forcing variables on average improve model extreme event forecasting skills. As a means to further refine the flow estimation, an ensemble forecast method is implemented to provide a likelihood-based indication of expected river flow magnitude and variability. Results indicate seasonal flow variations are well-captured in the ensemble range, therefore the ensemble approach can often prove efficient in estimating extreme river flow conditions. The discriminant prediction approach, a probabilistic measure to forecast streamflow, is also adopted to derive model performance. Results show the efficiency of the method in terms of representing uncertainties in the forecasts.

Download or read book Hydrologic Sensitivities of Western U S Rivers to Climate Change written by Julie A. Vano and published by . This book was released on 2013 with total page 127 pages. Available in PDF, EPUB and Kindle. Book excerpt: As the climate continues to change, increasing temperatures and changes in precipitation will lead to fundamental changes in the seasonal distribution of streamflow, especially in the western United States where snowmelt plays a key role. These changes will inevitably lead to challenges for water resource managers. There is, however, considerable uncertainty as to the character of these hydrologic changes, especially at local and regional scales (102 - 105 km2). My research aims to better understand how climate influences hydrologic processes, with a particular focus on variations in runoff sensitivities to changes in precipitation and temperature, and the use of this information in water management. Using land surface model simulations, I explore the sensitivity of runoff to changes in precipitation (defined as precipitation elasticities, E, the fractional change in runoff divided by the fractional change in precipitation), changes in temperature (defined as temperature sensitivities, S, percent change in runoff per degree change in temperature) and to the combined effect of temperature and precipitation changes. The character of these sensitivities varies considerably depending on how the land surface is simulated (e.g., type of land surface model), the particulars of the location (e.g., elevation, vegetation, soil types), and the season in which changes in temperature and precipitation occur. I explore these variations through hydrologic model experiments in the Colorado and Columbia River basins - two basins which can be considered end points of hydroclimatic variability in the West, and which also have diverse management concerns as existing reservoir storage in these systems varies strongly. The total storage relative to annual inflow ratio of over four in the Colorado River, results in a management focus on total (annual) magnitudes in streamflow, whereas this ratio is about 0.3 in the Columbia River and hence changes in the seasonal distribution of streamflow is the primary driver there. Within this body of work, I use the nature of these hydrologic sensitivities (e.g., spatial and temporal variability, superposition, and the linearity of their underlying functions) to develop two complementary methodologies that can be applied to generate viable first-order estimates of future change for long-term (e.g., 30-year) annual change (applied in the Colorado River basin) and seasonal change (applied in the Pacific Northwest). My results show that these sensitivity-based estimation approaches to future change compare well with the more common, computationally intensive full-simulation approaches that force a hydrologic model with downscaled future climate scenarios. These methods can be applied to newly released climate information to easily assess underlying drivers of change and to bound, at least approximately, the range of future streamflow uncertainties for water resource planners.

Download or read book Livres modernes tableaux modernes written by and published by . This book was released on 1969 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Impact of Historical and Future Climate Change on the Source Region of the Tigris River Basin written by Aslihan Kol and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Tigris River basin is a transboundary basin shared among Iraq, Turkey, Iran and Syria. The river basin contains extensive water management infrastructure and is the main source for the economic activities in the region. While the Tigris River is a vital resource for this area, scientifically sound studies are limited due to the data scarcity. This study aimed to close this research gap and was conducted to estimate the historical climate conditions and future climate change on the source region of the Tigris River basin for the 21st century. To reconstruct atmospheric and hydrologic data, dynamically downscaled regional climate modeling was utilized over the Upper Tigris, Khbour, Greater Zab, Lesser Zab, Diyala, and Adhaim sub-basins which feed into the Tigris River. A fine resolution (9 km by 9km) hydro-climate study was used for both historical (1960-2010) and future time periods (2020-2100). For the dynamical downscaling, the non-hydrostatic Weather Forecasting (WRF) Model was implemented in this study with a sensitivity evaluation of the cumulus and planetary boundary layer parameterizations. The physically based, spatially distributed hydrological model, WEHY-HCM, was utilized for eight stations at a monthly time scale to investigate the hydrology of the sub-basins. For the historical period, the ERA 20th century data was utilized for atmospheric data reconstruction followed by calibration and validation processes of the WEHY-HCM model for each station. The validated model parameters were further used for future streamflow simulations by means of the dynamically downscaled CMIP5 products for the RCP 4.5 and RCP 8.5 scenarios. The CCSM4, GFDLESM2M, and MIROC5 GCM projections under these scenarios were dynamically downscaled over the study area. Finally, trend analysis of the results was conducted to investigate the changes in precipitation, temperature, and streamflow under both historical and future climate conditions. This research presents a comprehensive hydro-climate study in the data-scarce Tigris River region with a focus on the response of the precipitation, temperature, and streamflow changes to historical and future climate conditions. The outcomes generated throughout this study can contribute to the transboundary management plans of the region to reduce any negative impacts of climate change on the society and environment. Furthermore, this study describes the challenges and provides recommendations for future research.

Download or read book Assessment of Hydrological Climate Change Impacts on the Upper Green River Basin WY written by TaeJung Song and published by . This book was released on 2013 with total page 199 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Upper Green River Basin (UGRB) is a complex terrain and a snow-dominated area. The water resource in the UGRB is sensitive to changes of the hydrological variables by the global warming. Moreover, the UGRB is the important headwater area to secure the water resources in the UGRB. Thus, it is important to understand and assess the spatial and temporal climate changes of the hydrological variables and extreme weather events in the UGRB. Therefore, this study will investigate and discuss the regional climate change impacts on the hydrological variables and the extreme weather events over the UGRB. For the assessment of regional climate change impacts over the UGRB, this study uses the monthly 1/8th degree Bias-Corrected Spatially Downscaled (BCSD) precipitation and temperature projections from World Climate Research Programme (WCRP) Coupled Model Intercomparison Project phase 3 (CMIP3) datasets. However, the climate projections need to be temporally downscaled before being applied to the Variable Infiltration Capacity (VIC) model for streamflow simulations. For downscaling the climate projections, this study proposes the Bias Adjusted Gamma - Gamma Transformation (BAGGT) to preserve statistical properties such as mean, frequency, distribution, and the range, and to overcome the limitation of the coarse - resolution climate projection. For grid cells where historical monthly precipitation is zero, but the monthly climate projection expects precipitation, this study applies the Nearest Neighbor Resampling method to assign temporal precipitation patterns. The proposed downscaling method (BAGGT) preserves statistical properties better than other methods for precipitation data and it serves better for assessing the climate change impact on a regional scale. After statistical downscaling, this study investigates the climate change impacts on the downscaled precipitation and temperature, and evapotranspiration and streamflow simulated by the VIC model. The projected temperature shows the increasing trend with respect to the three periods (2010 - 2039, 2040 - 2069, and 2070 - 2099) and the spatial change of temperature is sensitive to the latitude and elevation. The uncertainty of temperature increases in time; however, the spatial uncertainty of temperature doesn't much change. The projected precipitation temporally increases. Particularly, winter precipitation increases and summer precipitation decreases based on all climate scenarios. The uncertainty of precipitation is high, which means that the timing of precipitation couldn't capture. The increasing pattern of evapotranspiration is associated with temperature. Both the increasing temperature and precipitation have a strong influence on the increasing evapotranspiration. The spatial and temporal uncertainty in evapotranspiration increases as the period increases. The projected streamflow during the 21st century shows the increasing trend as a result of combination of precipitation and evapotranspiration. The timing of projected maximum streamflow shifts from June to May because of influence of snowmelting. Furthermore, this study assesses the climate-change impacts on flood and drought in the UGRB. In contrast to the traditional flood frequency analysis (FFA) which we use historical streamflow under the stationarity assumption, this study uses the 50-years projected streamflow to estimate the non-stationary design flows for 2, 5, 10, 20, 25, 40, 50, 100, and 200 year return periods. Discharges for the return periods show the increasing trend in the future. Frequency of high flow significantly increases and frequency of low flow decreases in the 21st century. Moreover, to understand the temporal and spatial patterns of drought in the 21st century in the UGRB, this study proposes the modified Palmer Drought Severity Index (PDSI) from 1950 to 2099, which overcomes the several shortcomings of the traditional PDSI. Drought occurs more frequent, becomes severer, and intensifies across the basin in the 21st century. This study has broadened our understanding on the regional climate change impacts over the Upper Green River Basin. Furthermore, it would serve as a foundation for the long-term water resources management and planning. (Abstract shortened by UMI.)

Download or read book Using Hydrologic Model Ensembles to Better Understand the Impact of Climate Change on the Hydrology of Large River Basins written by Oriana Shackell Chegwidden and published by . This book was released on 2020 with total page 103 pages. Available in PDF, EPUB and Kindle. Book excerpt: Whether at the scale of a small watershed or a large multinational basin, it has become common practice for water managers to use ensembles of projections to plan for hydrologic change. Better understanding these ensembles can help improve the design of future hydrologic modeling studies. In this dissertation I will describe three uses of hydroclimate ensembles to support water resource planning efforts. In Chapter 2 I present a large ensemble of hydrologic climate change projections for the Columbia River basin within the hydroclimatically diverse Pacific Northwestern United States and Canada (PNW). I show how methodological decisions in the modeling process variously affect the projections of change depending on hydroclimatic regime and metric of interest. In Chapter 3 I delve deeper into the PNW to examine the impactful metric of changes in floods, determining how dominant flood generating processes will evolve under climate change. I also calculate first-order sensitivities of high flows to changes in climate. In Chapter 4, I apply the lessons learned from the first two studies, conducted within the transboundary Columbia River basin, to transboundary rivers around the world. I present a study identifying hot spots of changes in water availability and hydropolitical risk for over 80 rivers (esp. transboundary rivers) around the world as projected by results from the Coupled Model Intercomparison Project Phase 6. Finally, I present how the findings from this dissertation can contribute to improved hydroclimate impacts assessments.

Download or read book Modelling the Effects of Climate Change on the Surface and Subsurface Hydrology of the Grand River Watershed written by Dennis Colautti and published by . This book was released on 2010 with total page 117 pages. Available in PDF, EPUB and Kindle. Book excerpt: A numerical modelling analysis of climate change's precipitation effects on the long-term, averaged surface and subsurface hydrology of the Grand River Watershed (GRW) was undertaken in order to assess possible areas of concern for decision makers in the water management sector. The physically-based, fully-integrated and variably-saturated 3-D surface-subsurface numerical simulator, HydroGeoSphere, was used to drive five mid-21st century climate change scenarios, developed from multiple general circulation models. Calibration involved altering measured and literature-derived hydraulic conductivity and precipitation distribution estimates, resulting in very good matching between observed and simulated long-term average surface flow at all gauge stations. Subsurface head results, too, matched observed heads quite well, though groundwater linkage to neighbouring watersheds was not included. When groundwater linkage to neighbouring watersheds was allowed, via regional Dirichlet boundary conditions used in a parent study, groundwater throughput was deemed to be unrealistic. All but one of the climate change scenarios caused an increase in both river discharge and water table elevation, with the greatest climate perturbations causing the greatest increases. For Scenario 1 (5% less precipitation than the 1960-to-1999 average), percentage discharge changes averaged -15% over all gauge stations. For the other scenarios (more precipitation than average), the inter-scenario discharge response ranged from approximately +12% to +59%. In general the range of inter-subcatchment response was greater than was the range for intra-subcatchment response; the greatest percentage response was consistently in the Speed River subcatchment, while the least was consistently in the Nith and Conestogo subcatchments. The exception was the application of less-than-average precipitation to the Grand River, whose gauge stations reported percentage changes in discharge that varied more substantially from one another. Subsurface hydrology reacted to the climate change scenarios in much the same manner as did the surface hydrology, with all climate change scenarios associated with a precipitation increase unsurprisingly resulting in higher total hydraulic heads throughout the entire domain. Specifically, the minimum and maximum mean head increases among the climate change scenarios were 0.41 m and 1.25 m respectively, while the only decrease was an average of 0.55 m. Similarly, the depth from the ground surface to the water table decreased in most scenarios, the maximum water table rise being 1.08 m and the minimum 0.36 m. When precipitation was allowed to decrease by 5% relative to the long-term average, the average water table elevation decreased by 0.48 m. However the water table's pattern of high and low points remained very much the same among all climate change scenarios, suggesting that basin-wide groundwater flow patterns may not be among the hydrological measures most sensitive to climate change. Groundwater recharge, like almost all other components of the water budget, changed in linear proportion to the climate forcing and in agreement with GRW recharge estimates developed by others. Evapotranspiration, which met potential evapotranspiration in all scenarios due to the constant application of precipitation, was the only element of the water budget that did not increase, even though the water table was elevated closer to the rooting zone by most of the climate scenarios. On a smaller scale, changes in flow patterns may well be expected, given that zones of infiltration were observed to intensify with most of the climate forcing.

Download or read book Extreme Hydrology and Climate Variability written by Assefa M. Melesse and published by Elsevier. This book was released on 2019-07-03 with total page 580 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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

Download or read book Masters Theses in the Pure and Applied Sciences written by Wade H. Shafer and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 426 pages. Available in PDF, EPUB and Kindle. Book excerpt: Masters Theses in the Pure and Applied Sciences was first conceived, published, and disseminated by the Center for Information and Numerical Data Analysis and Synthesis (CINDAS)* at Purdue University in 1957, starting its coverage of theses with the academic year 1955. Beginning with Volume 13, the printing and dis semination phases of the activity were transferred to University Microfilms/Xerox of Ann Arbor, Michigan, with the thought that such an arrangement would be more beneficial to the academic and general scientific and technical community. After five years of this joint undertaking we had concluded that it was in the interest of all concerned if the printing and distribution of the volumes were handled by an international publishing house to assure improved service and broader dissemination. Hence, starting with Volume 18, Masters Theses in the Pure and Applied Sciences has been disseminated on a worldwide basis by Plenum Publishing Corporation of New York, and in the same year the coverage was broadened to include Canadian universities. All back issues can also be ordered from Plenum. We have reported in Volume 38 (thesis year 1993) a total of 13,787 thesis titles from 22 Canadian and 164 United States universities. We are sure that this broader base for these titles reported will greatly enhance the value of this impor tant annual reference work. While Volume 38 reports theses submitted in 1993, on occasion, certain uni versities do report theses submitted in previous years but not reported at the time.

Download or read book Modeling the Hydroclimatology of the San Francisco Bay Delta Estuary and Watershed written by Noah Knowles and published by . This book was released on 2000 with total page 614 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Government Reports Announcements Index written by and published by . This book was released on 1994 with total page 1496 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Geotitles written by and published by . This book was released on 1993 with total page 524 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Masters Theses in the Pure and Applied Sciences written by Sade H Shafer and published by Springer Science & Business Media. This book was released on 1995 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cited in Sheehy, Chen, and Hurt . Volume 38 (thesis year 1993) reports a total of 13,787 thesis titles from 22 Canadian and 164 US universities. As in previous volumes, thesis titles are arranged by discipline and by university within each discipline. Any accredited university or college with a grad