Thesis (Ph. D.)--University of Hong Kong, 2006. / Title proper from title frame. Also available in printed format.

Thesis (Ph.D.) - University of Queensland, 2006. / Includes bibliography.

Thesis (MScIng)--University of Stellenbosch, 2005. / Bibliography. Also available via the Internet.

Thesis (Ph. D.)--University of Washington, 2005. / Vita. Includes bibliographical references (leaves 172-184).

Thesis (M.C.E.)--University of Delaware, 2007. / Principal faculty advisor: James T. Kirby, Dept. of Civil & Environmental Engineering. Includes bibliographical references.

Thesis (Ph. D.)--Texas State University-San Marcos, 2007. / Vita. Appendix: 1 folded map in sleeve. Includes bibliographical references (leaves 95-100).

Thesis (Ph. D.)--University of Canterbury, 2006. / Typescript (photocopy). Includes bibliographical references (p. 343-364). Also available via the World Wide Web.

Thesis (Ph. D.)--Oregon State University, 2008. / Printout. Includes bibliographical references (leaves 164-178). Also available on the World Wide Web.

Many environmental free surface flows involve water and sediment transport. The net changes to the surface level of an erodible bed by sediment entrainment and deposition processes have a feedback effect on the local ow hydrodynamics. Bed morphological change is of great socio-economic and environmental importance in that it affects navigation, flood risk management, water quality, species diversity, and overall river sustainability. This thesis describes a mathematical model of the depth-averaged shallow water-sediment equations based on mass and momentum conservation laws. A 2D numerical model is then presented of the fully coupled, variable-density governing equations, which are solved using a Godunov-type HLLC scheme. Dependent variables are specially selected in the numerical model to handle the presence of the variable-density mixture in the mathematical formulation. The model includes suspended sediment, bedload transport, and bed morphological change. The numerical model is verified against benchmark analytical and semi-analytical solutions for complicated, clear water flows, bedload transport and suspended sediment transport. The well-balanced property of the governing equations is verified for a variable-density dam break flow over a bed step. Simulations of an idealised dam-break flow over an erodible bed, in excellent agreement with previously published results, validate the ability of the model to capture complex water-sediment interactions under rapidly-varying flow conditions and a mobile bed, and validate the eigenstructure of the system of variable-density governing equations. The model is then further validated against laboratory based data for complex 2D partial dam breaks over fixed and mobile beds, respectively. The simulations of 2D dam break flows over mobile beds highlight the sensitivity of the results to the choice of closure relationships for sediment transport. To investigate this further, a parameter study is carried out using a variety of commonly used empirical formulae for suspended sediment transport. The numerical model is also used to inform a theoretical model that predicts the flow through and around a porous obstruction in a shallow channel. This problem is relevant to several practical applications, including flow through aquatic vegetation and the performance of arrays of tidal turbines in a finite-width tidal channel. The theoretical model is used to reinterpret the core flow velocities in laboratory-based data for an array of emergent cylinders in a shallow channel. Comparison with experimental data indicates the maximum obstacle resistance for which the theoretical model is valid. In a final application, the theoretical model examines the optimum arrangement of tidal turbines to generate power in a tidal channel, confirming that natural bed resistance increases the power extraction potential for a partial tidal fence.

Submitted by ANTONIO APARECIDO COUTO JUNIOR null (acjunior_2003@hotmail.com) on 2016-01-21T19:53:04Z No. of bitstreams: 1 COUTO JUNIOR, A.A..pdf: 3010240 bytes, checksum: fe4cb682bc6ec5ccb27e530d99f668e2 (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2016-01-25T13:20:03Z (GMT) No. of bitstreams: 1 coutojunior_aa_me_rcla.pdf: 3010240 bytes, checksum: fe4cb682bc6ec5ccb27e530d99f668e2 (MD5) / Made available in DSpace on 2016-01-25T13:20:03Z (GMT). No. of bitstreams: 1 coutojunior_aa_me_rcla.pdf: 3010240 bytes, checksum: fe4cb682bc6ec5ccb27e530d99f668e2 (MD5) Previous issue date: 2016-01-07 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Os processos erosivos são elementos essenciais para o conhecimento da evolução da paisagem continental. A ação desses processos resulta na degradação do solo, demandando a utilização de todas as ferramentas disponíveis para a avaliação dos mesmos. Nesse contexto, este trabalho teve por objetivo avaliar e comparar as taxas de erosão hídrica e transporte de sedimentos da bacia do Ribeirão Cachoeirinha, Rio Claro (SP). Este trabalho foi conduzido considerando as seguintes etapas: caracterização dos aspectos fisiográficos da bacia, avaliação da erosão hídrica pela EUPS e quantificação do transporte de sedimentos pelo método simplificado de Colby (1957). Os resultados obtidos indicaram perda de solo de 1,40 t.ha-1. ano-1, com a taxa de 0,9 t.ha-1.ano-1 para o ano de 2014. O transporte de sedimentos foi de 0,37 t.ha-1.ano-1 para o mesmo ano, indicando que aproximadamente 41% do total de sedimento gerado pela erosão hídrica saiu efetivamente da bacia do Ribeirão Cachoeirinha. Assim, os resultados podem servir como uma estratégia viável para estudos de perda de solo e transporte de sedimentos, visando à elaboração de material consistente como subsídio a uma abordagem de planejamento ambiental e gestão territorial. / The erosive processes are essential elements for understanding the evolution of continental landscape. The action of these processes results in soil degradation and demands the use of all the tools available for this evaluation. In this context this research aimed to evaluate and compare erosion rates and sediment transport of Cachoeirinha stream basin, Rio Claro (SP). This work was done considering the following steps: characterization of the physiographic features of the basin, assessment of water erosion by USLE and quantification of sediment transport by the simplified method of Colby (1957). The results indicated soil loss of 1,40 t.ha-1 .year-1 , with the rate of 0,9 t.ha-1 for the year 2014. Already sediment transport was 0,37 t ha-1 .year-1 for the same year, indicating that about 41% of sediment generated by water erosion effectively leaves the Cachoeirinha stream basin. Thus, the results can contribute to the understanding of hydrosedimentological dynamic in this area and serve as a viable strategy for studies of soil loss and sediment transport, aiming at developing consistent material for future researches about environmental planning and land management. / FAPESP: 2014/02189-6