• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 208
  • 135
  • 36
  • 9
  • 6
  • 4
  • 4
  • 3
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 461
  • 461
  • 180
  • 174
  • 116
  • 115
  • 97
  • 91
  • 81
  • 55
  • 55
  • 43
  • 39
  • 38
  • 37
  • 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.
1

Eco-Politics of Dams on the Gambia River

Degeorges, A, Reilly, BK 30 January 2010 (has links)
In the 1980s, USAID (US Agency for International Development) funded an environmental assessment of dams on the Gambia River, which determined that construction of the Balingho anti-salinity barrage would result in adverse unmitigative environmental and social consequences. Attempts by host country politicians, USAID and UNDP (United Nations Development Programme) to discredit this process made it necessary to take the matter to the Natural Resource Defense Council. A case study of the events surrounding these dams and their potential construction illustrates the ‘big dam’ paradigm and its potential harm to people, their livelihoods and the environment in Sub-Saharan Africa.
2

Monthly and weekly evapo-climatonomy model for the Allegheny River Basin of northwestern Pennsylvania with a sub-study of Hurricane Agnes-type effects /

Chaston, Peter Richard, January 1976 (has links)
Thesis--Wisconsin. / Includes bibliographical references (leaves 89-90).
3

FACTORS AFFECTING STAKEHOLDER PERCEPTIONS AND INFLUENCE ON MANAGEMENT AGENDAS WITHIN THE TISZA (CENTRAL EUROPE) AND MISSISSIPPI RIVER BASINS (U.S.A.)

Marshall, Amanda Christine 01 May 2017 (has links)
Stakeholder engagement and collaborative governance have become increasingly important in the field of river basin management. Modern basin management strategies tend to take an adaptive or integrative management approach, which call for broad stakeholder inclusion to account for the increasing uncertainty and competing demands placed on water resources. This dissertation examines several key aspects of stakeholder participation: public awareness and value of participation in management, opportunities and barriers to participation, and the effect of public participation on watershed management outcomes. A major goal of this project is to identify factors that enhance managers’ ability to include effective stakeholder participation in the water governance process. While opportunities for participation are increasingly mandated as part of environmental management practices, the quality of that participation is often called into question. In the first of three papers comprising this dissertation, I conducted an interdisciplinary study assessing risk perception and actual health risks from exposure to metals in fish from the Tisza River Basin of central Europe. Mining in the region has chronically introduced metals; however, two major mine-tailings spill in 2000 contributed an estimated 240,000 m3 of wastewater and tailings contaminated with cyanide and metals to the system. In 2013 and 2014, water and fish (N=99) collected from the lower Tisza River Basin were analyzed for cadmium, copper, lead, nickel, and zinc. Concurrently, surveys (N=45) collected near sampling sites assessed fish consumption patterns and risk perception. Metals in water exceeded regulatory criteria at multiple sites, however metals are not bioaccumulating to a concerning degree in fish as bioaccumulation factors were below 1. Fillets were within European Food Safety Authority recommendations; however, the Target Hazard Quotient for lead was elevated at 1.5 for average consumers and 3.5 for people who consume fish twice weekly. The majority of survey participants were unconcerned with local fish consumption (87%), citing the “clean” appearance of fishing locations. Participants also reported relatively low fish consumption, with most (76%) eating basin fish once a week or less. While our study indicates fish are generally safe for human consumption, waters are polluted, suggesting that local fishing populations may be at risk from unseen pollutants and highlighting the need for monitoring and notification systems. Broadening the analysis of local stakeholders and stakeholder perception to the basin level, the second paper for this dissertation examined public perception and public participation in Tisza River Basin management. The complexity associated with achieving sustainable river basin management plans for international, transboundary river basins, such as the Tisza River Basin in central Europe, make them an ideal study area for examining the influence of education and experience on stakeholder perception of basin management. This study presents findings from analysis of in-person surveys to examine differences in local stakeholder perceptions of the Tisza River Basin across employment and education sectors through analysis of participants’ levels of knowledge, experience, and involvement in basin management. The survey was conducted among members of the public in locations across the basin, in which participants were asked to identify and rank their opinions of factors affecting the health of the river basin, to identify observed changes in flood patterns, and to rank their level of interest and participation in basin management activities. To evaluate whether experience affected responses, participants were grouped according to whether they worked in the public or private sector, and by their level of education (no college, undergraduate, or graduate school). Significant differences in stakeholder responses were found between education levels attained among participants in the public versus the private sector, and between the reported levels of environmental concern among participants of different education levels. Participants also reported low levels of participation and monitoring of management activities. These differences and lack of participation highlight the need for public education in participatory governance structures to support sustainable river basin management efforts. The Upper Mississippi River Basin is similar to the Tisza River Basin in its transboundary nature and the predominance of agriculture in the region. The Upper Mississippi River Basin (UMRB) is a largely rural watershed (Minnesota, Wisconsin, Iowa, Illinois, and Missouri) that is heavily managed for agriculture and agricultural exports. This has led to water quality impairments both within the Upper Mississippi River Basin and contributed significantly to the large hypoxic zone of the Gulf of Mexico. Management responses have led to the formation of collaborative responses across stakeholder groups, including states, agencies, industry, non-government organizations, and the public. In the third paper of this dissertation, I shifted my focus from the public to another set of local stakeholders, environmental non-government organizations (ENGOs), and their influence on river basin management. ENGOs are recognized as serving as implementers, catalysts, and partners with government agencies in the management process. To assess the participatory role of ENGOs in watershed management in the Upper Mississippi River Basin, expert interviews were conducted with members actively engaged in watershed-related activities. Participants were asked to identify their key areas of
4

Precipitation of the Fraser River basin : a descriptive study.

Wallis, John Hubert January 1963 (has links)
This study of precipitation is based on data in the 1955 Climate of British Columbia concerning the network of 106 stations which have been operated in the Fraser River Basin, Emphasis is on the description of precipitation characteristics, with cartographic representation of the data forming the basis of the explanations and discussion in the The first portion of the study concerns the concentration of annual and seasonal precipitation throughout the Basin, followed by a similar examination of mean annual and seasonal snowfall with observations concerning the proportion of annual snowfall in each season and the proportion of seasonal precipitation which occurs as snow. A parallel discussion of proportions for total precipitation, with emphasis on seasons and months of maximum and minimum, is concluded by an analysis of precipitation regimes in various parts of the Basin. The effect of the gaps in the Coast Mountains resulting in continental or coastal characteristics of precipitation, dependent on station location, is noted repeatedly throughout the thesis. Considerations of variability as well as the value and methods of checking homogeneity of station records are included with observations concerning years in which heavy or light precipitation was general in large parts of the Basin. An examination of all topics as they affect the thirteen sub-basins of the Fraser concludes the study. / Arts, Faculty of / Geography, Department of / Graduate
5

Crop production, soil erosion, and the environment in the Maumee River Basin : a modelling approach /

Abraham, Girmai, January 1981 (has links)
No description available.
6

Optimal well field design for reducing phreatophyte uptake losses

Nelson, Gregory A. January 1989 (has links)
A two-dimensional, finite difference model was used to simulate the lowering of the water table below a floodplain in order to affect water conservation by reducing phreatophyte transpiration. Evapotranspiration capture percentages and unit water costs associated with alternative well network designs were calculated in order to determine those factors which are most important in designing an evapotranspiration capture project.
7

Ecohydrology of a riparian woodland along the Oldman River, Alberta

Phelan, Colleen Amy, University of Lethbridge. Faculty of Arts and Science January 2007 (has links)
Growth of riparian cottonwoods along regulated rivers can be limited by water availability. In this study we associate seasonal variation of environmental conditions and stream flows with water relations of a natural cottonwood grove located along a regulated river in southern Alberta. To link elements in the river-soil-plant-atmosphere continuum, river and groundwater levels and precipitation were monitored; sap flow was continuously measured with thermal dissipation probes in eight trees and stomatal conductance and leaf water potential were measured monthly; and weather conditions were monitored. From June through August, stomatal conductances at both leaf and canopy levels were increasingly limited by decreasing water availability. Artificially increasing the soil moisture in August resulted in an increase in sap flow and stomatal conductance at leaf and canopy levels. These responses can be attributed to seasonal changes in the water potential difference between soil and leaves or an alteration in hydraulic conductance, or a combination of both. / xiv, 135 leaves : ill. ; 29 cm
8

Sedimentology and stratigraphy of the southern Sustut basin, north central British Columbia

McKenzie, Kathleen Jane January 1985 (has links)
The Sustut Group within the study area is a nonmarine succession of fine to coarse grained elastics, deposited in an alluvial fan environment. Regionally, the Sustut Group is divisible into the Tango Creek and Brothers Peak Formations. In the study area, the two formations are entirely Late Cretaceous (Campanian to Maastrichtian) in age, based on palynological evidence. In the southern Sustut Basin, only the uppermost 400 m of the Tatlatui Member of the Tango Creek Formation is exposed. Sediments of the Tatlatui Member are divided into fine and coarse grained lithofacies. The fine grained lithofacies is composed of interbedded mudstone, siltstone and fine grained sandstone, which is interpreted as an alluvial plain deposit. Pebble conglomerate interbedded with coarse to medium grained sandstone comprise the coarse grained lithofacies which is considered to be a braided river deposit. The Brothers Peak Formation comprises 1 000 m of diverse elastics and tuffs, which are divisible into the lower and upper Laslui Member, and the overlying Spatsizi Member. The lower Laslui Member conformably overlies the Tatlatui Member of the Tango Creek Formation, and is characterized by several fining upwards sequences of cobble conglomerate to medium grained sandstone, attributed to deposition by high energy braided streams in the mid-fan region of an alluvial fan complex. Sediments of the upper Laslui Member are divided into a fine grained lithofacies consisting of mudstone, interbedded with lesser amounts of siltstone, fine grained sandstone and tuff beds, and a coarse grained lithofacies composed of orthoconglomerate, paracong1omerate and coarse grained sandstone. The fine grained lithofacies comprises the majority of the sequence and is interpreted as an alluvial plain deposit. Coarse grained sediments of the upper Laslui Member were likely deposited during stages of high water discharge, by major distributaries, sheetfloods and debris flows. The Spatsizi Member is gradational from the upper Laslui Member and is composed of sandstone/mudstone sequences interpreted as sandy braided stream deposits of an alluvial plain. Detrital components of the Tango Creek and Brothers Peak sandstones are mainly chert, quartz, plagioclase and volcanic rock fragments. Paleocurrent measurements and provenance considerations suggest source terranes were located to the east during Tango Creek deposition, and to the west during Brothers Peak deposition. In the southern Sustut Basin, the Tango Creek Formation documents uplift and erosion in the Omineca Belt and Paleozoic rock units, following accretion of the first composite terrane (terrane I) to the North American Margin. The Brothers Peak Formation is considered a result of local uplift and volcanic activity, accompanying the accretion of a second composite terrane (terrane II). / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate
9

Evaluation of the SWAT model in simulating catchment hydrology : case study of the Modder River Basin

Tetsoane, S.T., Woyessa, Y.E., Welderufael, W.A. January 2013 (has links)
Published Article / This paper presents the set-up and the performance of the SWAT model in the Modder River Basin. Two techniques widely used, namely quantitative statistics and graphical techniques, in evaluating hydrological models were used to evaluate the performance of SWAT model. Three quantitative statistics used were, Nash-Sutcliffe efficiency (NSE), present bias (PBIAS), and ratio of the mean square error to the standard deviation of measured data (RSR). The performance of the model was compared with the recommended statistical performance ratings for monthly time step data. The model performed well when compared against monthly model performance ratings during calibration and validation stage.
10

Optimal expansion of a water resource system and issues of water allocation and utilization : Umatilla River Basin, Oregon

Lin, Biing-Hwan 05 September 1980 (has links)
In the past decade considerable research in several disciplines has been oriented toward the design of optimal capacity expansion plans for water resource systems. The emphasis of most of these efforts has been directed toward minimization total cost outlays in project planning. This focus somewhat limits the full applicability of the optimal capacity expansion solutions since it is believed that the criteria of economic efficiency is not well addressed in this mode. This study explores the merits of scheduling water resource project facilities on the basis of anticipated economic benefits provided, an approach needed only infrequently in the systems engineering literature. Using the Umatilla River Basin in Northeast Oregon as a case study example, the facilities (and their alternatives) of a previously planned federal water resource development project in that area were carefully analyzed with respect to the magnitude and timing of anticipated benefits and costs. Irrigated agriculture and fishery development/enhancement benefits were the two principal purposes of the project considered. In addition, benefits arising from flood prevention, municipal and industrial water supply, and erosion control were also integral to the original overall evaluation. The design of the research was to first implement a basic scheduling model in the context of the case study area and then to explore the ramifications of exchange-theoretic and distribution-theoretic criteria on the timing of facilities and the ultimate allocation of water among purposes. The model implemented was aimed at maximizing the present value of net benefits inherent in an optimally timed set of facilities subject to an annual budget constraint. Having designed the model along integer programming lines, three different solution techniques were explored in order to realize a desirable level of efficiency in basic model solution. It was found that reasonably efficient solutions could be obtained. By optimally timing the facilities it was found that the total present value of net benefits of the project could be significantly enhanced when compared to the original schedule proposed in the project planning documents. Of even greater interest is the issue of incorporating into the planning process (and specifically into the capacity expansion mode of planning) considerations of tradeoffs or exchanges between project beneficiaries. Such exchanges and other distributional criteria can affect and be affected by the selection and timing of project facilities within an overall project design. These interrelationships are explored paying particular attention to the way in which exchanges of water (via water rights transfers) could establish higher levels of benefits in future years. Noneconomic exchange processes such as the enforcement of extant property rights relating to water resources are another issue which complicated the process of water planning. Such distributional criteria are difficult to incorporate into the capacity expansion mode of planning analysis. However, ways are explored by which the basic model may be modified and used by decision makers in order to take account of more realistic problems in water resource planning for individual river basins. / Graduation date: 1981 / Partially funded by the U.S. Dept. of the Interior as authorized under the Water Research and Development Act of 1978. / Final technical completion report for project no. A-046-ORE to U.S. Dept. of the Interior.

Page generated in 0.0693 seconds