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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
141

Stochastic Simulation Methods for Precipitation and Streamflow Time Series

Li, Chao 03 October 2013 (has links)
One major acknowledged challenge in daily precipitation is the inability to model extreme events in the spectrum of events. These extreme events are rare but may cause large losses. How to realistically simulate extreme behavior of daily precipitation is necessary and important. To that end, a hybrid probability distribution is developed. The logic of this distribution is to simulate the low to moderate values by an exponential distribution and extremes by a generalized Pareto distribution. Compared with alternatives, the developed hybrid distribution is capable of simulating the entire range of precipitation amount and is much easier to use. The hybrid distribution is then used to construct a bivariate discrete-continuous mixed distribution, which is used for building a daily precipitation generator. The developed generator can successfully reproduce extreme events. Compared with other widely used generators, the most important advantage of the developed generator is that it is apt at extrapolating values significantly beyond the upper range of observed data. The major challenge in monthly streamflow simulation is referred to the underrepresentation of inter-annual variability. The inter-annual variability is often related with sustained droughts or periods of high flows. Preserving inter-annual variability is thus of particular importance for the long-term management of water resources systems. To that end, variables conveying such inter-annual signals should be used as covariates. This requires models that must be flexible at incorporating as many covariates as necessary. Keeping this point in mind, a joint conditional density estimation network is developed. Therein, the joint distribution of streamflows of two adjacent months is assumed to follow a specific parametric family. Parameters of the distribution are estimated by an artificial neural network. Due to the seasonal concentration of precipitation or the joint effect of rainfall and snowmelt, monthly streamflow distribution sometimes may exhibit a bimodal shape. To reproduce bimodality, nonparametric models are often preferred. However, the simulated sequences from existing nonparametric models represent too close a resemblance to historical record. To address this issue, while retaining typical merits of nonparametric models, a multi-model regression-sampling algorithm with a few weak assumptions is developed. Collecting hydrometric data is the first step for building hydrologic models, and for planning, design, operation, and management of water resource systems. In this dissertation, an entropy-theory-based criterion, termed maximum information minimum redundancy, is proposed for hydrometric monitoring network evaluation and design. Compared with existing similar approaches, the criterion is apt at finding stations with high information content, and locating independent stations.
142

Hydrologic, social and legal impacts of summary judgement of stockwatering ponds (stockponds) in the general stream adjudications in Arizona

Young, Don William. January 1994 (has links) (PDF)
Thesis (Ph. D.)--University of Arizona, 1994. / Includes bibliographical references (leaves 233-242).
143

River channel adjustment to hydrologic change /

Tilleard, John. January 2001 (has links)
Thesis (Ph.D.)--University of Melbourne, Dept. of Civil and Environmental Engineering, 2001. / Typescript (photocopy). Includes bibliographical references.
144

The hydrology and biology of Cypress Creek (Hays County), a subtropical karstic stream in south central Texas /

Dedden, John Eric. January 1900 (has links)
Thesis (M.S.)--Texas State University--San Marcos, 2008. / Vita. Includes bibliographical references (leaves 47-51). Also available on microfilm.
145

Local and downstream effects of contemporary forest harvesting on streamflow and sediment yield /

Zégre, Nicolas P. January 1900 (has links)
Thesis (Ph. D.)--Oregon State University, 2009. / Printout. Includes bibliographical references (leaves 154-164). Also available on the World Wide Web.
146

Spatial-temporal GIS modeling of the relationship between precipitation and streamflow a thesis presented to the Department of Geology and Geography in candidacy for the degree of Master of Science /

January 2009 (has links)
Thesis (M.S.)--Northwest Missouri State University, 2009. / The full text of the thesis is included in the pdf file. Title from title screen of full text.pdf file (viewed on June 22, 2009) Includes bibliographical references.
147

Bedrock-controlled fluvial geomorphology and the hydraulics of rapids on the Colorado River /

Magirl, Christopher Sean. January 2006 (has links) (PDF)
Thesis (Ph.D.)--University of Arizona, 2006 / Includes bibliographical references (p. 246-257). Also available via the Internet.
148

Tidal influences on bacterial and phytoplankton abundances and the resulting effects on patterns of dissolved oxygen in the Skidaway River estuary

Brazell, Casey Colleen. Vives, Stephen P. January 2009 (has links) (PDF)
"A thesis submitted to the Graduate Faculty of Georgia Southern University in partial fulfillment of the requirements for the degree Master of Science." Title from PDF of title page (Georgia Southern University, viewed on April 5, 2010). Stephen P. Vives, major professor; Sophie B. George, Risa A. Cohen, committee members. Electronic version approved: December 2009. Includes bibliographical references (p. 37-40).
149

Hydrological budgets of landfalling tropical cyclones

Lyttek, Tamara Ann. Krishnamurti, T. N. January 2004 (has links)
Thesis (M.S.)--Florida State University, 2004. / Advisor: Dr. T.N. Krishnamurti, Florida State University, College of Arts and Sciences, Dept. of Meteorology. Title and description from dissertation home page (viewed June 18, 2004). Title and description from dissertation home page (viewed <date>). Includes bibliographical references.
150

Changes in fish diversity due to hydrologic and suspended sediment variability in the Sandusky River, Ohio a genetic programming approach /

Sanderson, Louis. January 2009 (has links)
Thesis (M.S.)--Bowling Green State University, 2009. / Document formatted into pages; contains xi, 81 p. : ill., maps. Includes bibliographical references.

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