O presente trabalho visa caracterizar, através de experimentos numéricos, a hidrodinâmica e o transporte de sedimentos em suspensão no sistema estuarino de Caravelas e Peruípe sob diferentes condições forçantes. O sistema é formado por canais que estabelecem a conexão entre os rios Caravelas e Peruípe. Dados de nível de água e velocidade de correntes, obtidos em coletas de campo foram utilizados para aplicar e calibrar o modelo numérico MOHID. Diferentes experimentos numéricos, simulando condições de maré de sizígia e de quadratura com diferentes condições de descarga fluvial, foram realizados. A partir destas simulações foram obtidas distribuições espaciais e pontuais da concentração de sedimentos em suspensão e das correntes forçadas pela maré integradas verticalmente. Em condições de sizígia o estuário é caracterizado por correntes mais intensas e assimétricas, com dominância de vazante. As maiores concentrações médias de sedimento em suspensão ocorreram em condições de sizígia e o transporte de sedimentos resultante foi em direção ao oceano, em função do domínio das correntes de maré vazante. Os experimentos numéricos mostram que os canais que conectam os dois estuários têm papel relevante na dinâmica local. Eles possuem influência na dinâmica sedimentar do sistema estuarino. A hidrodinâmica e o balanço sedimentar do sistema são principalmente modulados pela altura da maré, com pouca contribuição do aporte de água doce. / The aim of this work is to characterize, through numerical modeling experiments, the hydrodynamics and suspended sediment transport dynamics in the Caravelas ? Peruípe estuarine system under different forcing conditions. The system comprises channels that connect the Caravelas and Peruípe rivers. Water level and current velocity data obtained through field campaigns were used to apply and calibrate the MOHID numerical model. Different numerical experiments simulating spring and neap tides with different river discharge conditions have been conducted. Based on these simulations, the hydrodynamics and spatial and temporal distributions of suspended sediment concentrations have been analyzed. During spring tide the estuary is characterized by intense and asymmetric currents (ebb dominated). The highest average suspended sediment concentration occurred during spring tide conditions, with net sediment transport being seaward. The numerical experiments show that the connecting channels play a relevant role in the local suspended sediment dynamics. The hydrodynamic and sediment balance in the system are modulated mainly by the tidal range, with little influence from the freshwater supply.

Submitted by Geyciane Santos (geyciane_thamires@hotmail.com) on 2015-06-03T14:46:59Z No. of bitstreams: 1 Dissertação - Thiago Pimentel Marinho.pdf: 3937642 bytes, checksum: f6e39a3267d5717181c24c041a1ccf76 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-06-03T18:22:19Z (GMT) No. of bitstreams: 1 Dissertação - Thiago Pimentel Marinho.pdf: 3937642 bytes, checksum: f6e39a3267d5717181c24c041a1ccf76 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-06-03T18:22:36Z (GMT) No. of bitstreams: 1 Dissertação - Thiago Pimentel Marinho.pdf: 3937642 bytes, checksum: f6e39a3267d5717181c24c041a1ccf76 (MD5) / Made available in DSpace on 2015-06-03T18:22:36Z (GMT). No. of bitstreams: 1 Dissertação - Thiago Pimentel Marinho.pdf: 3937642 bytes, checksum: f6e39a3267d5717181c24c041a1ccf76 (MD5) Previous issue date: 2014-07-23 / Outras / This research presents contributions regarding studies focused Spatial Hydrology, which is presented here as an alternative for monitoring suspended sediment concentrations in the Amazon Basin. Analyses were directed to study the confluence of the Negro (Black Water) and Solimões (White Water) rivers in the state of Amazonas, Brazil. This confluence of rivers with water color and sediment concentrations suspension different, despite being internationally and national known is little studied from the viewpoint of the hydrological functioning and hydrosedimentological. The research objective is to monitor the concentration of suspended sediment at the confluence of two rivers from remote sensing. Furthermore, to sought to analyze the dynamics of the transport and concentration of suspended sediment at the confluence of the Negro and Solimões rivers in order to contribute to a better understanding of the role of each river in the hydrological cycle of the Amazon River. / Este trabalho apresenta contribuições aos estudos voltados a Hidrologia Espacial, que se apresenta aqui como uma alternativa de monitoramento das concentrações de sedimentos em suspensão para a Bacia Amazônica. As análises foram direcionadas para o estudo da confluência dos rios Negro (Águas Negras) e Solimões (Águas Brancas) no Estado do Amazonas, Brasil. Esta confluência de rios com águas de cores e concentrações de sedimentos em suspensão distintas, apesar de conhecida nacional e internacionalmente, é pouco estudada do ponto de vista de seu funcionamento hidrológico e hidrossedimentológico. O objetivo desta pesquisa é monitorar a concentração de sedimentos em suspensão da confluência dos dois rios supracitados a partir de técnicas de sensoriamento remoto. Além disso, buscou-se analisar a dinâmica do transporte e concentração de sedimentos em suspensão na confluência dos rios Negro e Solimões a fim de contribuir para o melhor entendimento do papel de cada rio no ciclo hidrológico do Rio Amazonas.

Made available in DSpace on 2017-07-10T19:24:28Z (GMT). No. of bitstreams: 1 Caroline Iost.pdf: 1234608 bytes, checksum: d5a0ddd1cd06d5366dc84b88a138a1dc (MD5) Previous issue date: 2008-02-12 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The objective of this work was to evaluate the influence of land use in the production of sediment and water quality of the micro basin of river Mandarina micro basin, located in the city of Cascavel-PR. The liquid discharge, the suspended sediment and the physic-chemical parameters dissolved oxygen (DO), electrical conductivity, pH, temperature of the water, turbidity, color, nitrate, nitrite, total nitrogen, total phosphorus was monitoring between the months January and August 2007 at the river's main. It was determined the curve-key of the liquid discharge and discharge of suspended solid, which showed good correlation (R2 equal to 0.98 and 0.93, respectively). The results indicated a low production of sediment, average of 0,27 t dia-1 and good water quality, because the parameters have not gone beyond the limits praised by Resolution 345/05 of CONAMA for rivers, Class 2, with the exception of dissolved oxygen in some collections was below 5 mg L-1, color and total phosphorus which also exceeded the limits stipulated. Agriculture is the predominant activity in the micro basin (88%) and water courses have about 79% of the area of riparian forest required by law. It is believed that the soil management in the area of agriculture with practices such as tillage and system of terraces, as well as the presence of riparian forest in rivers, influenced for the good quality water and low production sediment on the water. / O objetivo deste trabalho foi verificar a influência do uso do solo na produção de sedimento e na qualidade da água da microbacia hidrográfica da sanga Mandarina, localizada no município de Cascavel-PR. A vazão, o sedimento em suspensão e os parâmetros físico-químicos da água, oxigênio dissolvido (OD), condutividade elétrica, pH, temperatura da água, turbidez, cor, nitrato, nitrito, nitrogênio total e fósforo total foram monitorados entre os meses de janeiro e agosto de 2007, no principal rio da microbacia. Determinou-se a curva-chave da vazão e da descarga sólida em suspensão, as quais apresentaram boa correlação (R2 igual a 0,98 e 0,93, respectivamente). Os resultados indicaram uma baixa produção, média de 0,27 t dia-1 de sedimento e uma boa qualidade da água, pois os parâmetros não ultrapassaram os limites regidos pela Resolução 345/05 do CONAMA para rios de Classe 2, com exceção do oxigênio dissolvido que em algumas coletas esteve abaixo de 5 mg L-1, cor e fósforo total que também ultrapassaram os limites estipulados. A agricultura é a atividade predominante na microbacia (88%) e os cursos d água apresentam cerca de 79% da área de mata ciliar exigida por lei. Acredita-se que o manejo do solo na área agricultável com práticas como o plantio direto e sistema de terraços, assim como a presença de mata ciliar nos rios influenciaram para o boa qualidade da água e baixa produção de sedimento no curso d água.

Made available in DSpace on 2017-05-12T14:47:46Z (GMT). No. of bitstreams: 1 Caroline Iost.pdf: 1234608 bytes, checksum: d5a0ddd1cd06d5366dc84b88a138a1dc (MD5) Previous issue date: 2008-02-12 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The objective of this work was to evaluate the influence of land use in the production of sediment and water quality of the micro basin of river Mandarina micro basin, located in the city of Cascavel-PR. The liquid discharge, the suspended sediment and the physic-chemical parameters dissolved oxygen (DO), electrical conductivity, pH, temperature of the water, turbidity, color, nitrate, nitrite, total nitrogen, total phosphorus was monitoring between the months January and August 2007 at the river's main. It was determined the curve-key of the liquid discharge and discharge of suspended solid, which showed good correlation (R2 equal to 0.98 and 0.93, respectively). The results indicated a low production of sediment, average of 0,27 t dia-1 and good water quality, because the parameters have not gone beyond the limits praised by Resolution 345/05 of CONAMA for rivers, Class 2, with the exception of dissolved oxygen in some collections was below 5 mg L-1, color and total phosphorus which also exceeded the limits stipulated. Agriculture is the predominant activity in the micro basin (88%) and water courses have about 79% of the area of riparian forest required by law. It is believed that the soil management in the area of agriculture with practices such as tillage and system of terraces, as well as the presence of riparian forest in rivers, influenced for the good quality water and low production sediment on the water. / O objetivo deste trabalho foi verificar a influência do uso do solo na produção de sedimento e na qualidade da água da microbacia hidrográfica da sanga Mandarina, localizada no município de Cascavel-PR. A vazão, o sedimento em suspensão e os parâmetros físico-químicos da água, oxigênio dissolvido (OD), condutividade elétrica, pH, temperatura da água, turbidez, cor, nitrato, nitrito, nitrogênio total e fósforo total foram monitorados entre os meses de janeiro e agosto de 2007, no principal rio da microbacia. Determinou-se a curva-chave da vazão e da descarga sólida em suspensão, as quais apresentaram boa correlação (R2 igual a 0,98 e 0,93, respectivamente). Os resultados indicaram uma baixa produção, média de 0,27 t dia-1 de sedimento e uma boa qualidade da água, pois os parâmetros não ultrapassaram os limites regidos pela Resolução 345/05 do CONAMA para rios de Classe 2, com exceção do oxigênio dissolvido que em algumas coletas esteve abaixo de 5 mg L-1, cor e fósforo total que também ultrapassaram os limites estipulados. A agricultura é a atividade predominante na microbacia (88%) e os cursos d água apresentam cerca de 79% da área de mata ciliar exigida por lei. Acredita-se que o manejo do solo na área agricultável com práticas como o plantio direto e sistema de terraços, assim como a presença de mata ciliar nos rios influenciaram para o boa qualidade da água e baixa produção de sedimento no curso d água.

Excessive erosion and fine sediment delivery to river corridors and receiving waters degrade aquatic habitat, add to nutrient loading, and impact infrastructure. Understanding the sources and movement of sediment within watersheds is critical for assessing ecosystem health and developing management plans to protect natural and human systems. As our changing climate continues to cause shifts in hydrological regimes (e.g., increased precipitation and streamflow in the northeast U.S.), the development of tools to better understand sediment dynamics takes on even greater importance. In this research, advanced geomatics and machine learning are applied to improve the (1) monitoring of streambank erosion, (2) understanding of event sediment dynamics, and (3) prediction of sediment loading using meteorological data as inputs. Streambank movement is an integral part of geomorphic changes along river corridors and also a significant source of fine sediment to receiving waters. Advances in unmanned aircraft systems (UAS) and photogrammetry provide opportunities for rapid and economical quantification of streambank erosion and deposition at variable scales. We assess the performance of UAS-based photogrammetry to capture streambank topography and quantify bank movement. UAS data were compared to terrestrial laser scanner (TLS) and GPS surveying from Vermont streambank sites that featured a variety of bank conditions and vegetation. Cross-sectional analysis of UAS and TLS data revealed that the UAS reliably captured the bank surface and was able to quantify the net change in bank area where movement occurred. Although it was necessary to consider overhanging bank profiles and vegetation, UAS-based photogrammetry showed significant promise for capturing bank topography and movement at fine resolutions in a flexible and efficient manner. This study also used a new machine-learning tool to improve the analysis of sediment dynamics using three years of high-resolution suspended sediment data collected in the Mad River watershed. A restricted Boltzmann machine (RBM), a type of artificial neural network (ANN), was used to classify individual storm events based on the visual hysteresis patterns present in the suspended sediment-discharge data. The work expanded the classification scheme typically used for hysteresis analysis. The results provided insights into the connectivity and sources of sediment within the Mad River watershed and its tributaries. A recurrent counterpropagation network (rCPN) was also developed to predict suspended sediment discharge at ungauged locations using only local meteorological data as inputs. The rCPN captured the nonlinear relationships between meteorological data and suspended sediment discharge, and outperformed the traditional sediment rating curve approach. The combination of machine-learning tools for analyzing storm-event dynamics and estimating loading at ungauged locations in a river network provides a robust method for estimating sediment production from catchments that informs watershed management.

One of the primary concerns associated with timber harvesting is the production of sediments from stream crossings. While research has shown that using improved haul road crossings can mitigate sediment production in perennial streams compared to the use of unimproved crossings little research has been undertaken on temporary skidder crossings of headwater streams, a situation common to a significant percentage of ground skidding operations. This experiment consisted of a controlled replicated testing of the effectiveness of four types of temporary skidder stream crossings (unimproved ford, corrugated culvert, wood panel skidder bridge, and PVC pipe bundle) relative to bedload and suspended sediment production. Automated samplers were used to monitor sediment and bedload production during the construction, use, removal, and post-removal phases associated with the use of these temporary crossings. Results showed that elevated crossings mitigated total sediment production compared to unimproved fords. Further, wood panel bridges yielded lower amounts of sediment than culverts but PVC pipe bundles show no difference between bridges or culverts. Sediment production varied by crossing type and use phase. While no differences were found among crossings types during construction, there was a difference between improved crossings and fords during use. Further, bridges and PVC pipe bundle crossings produced significantly less sediments than culverts during both their removal and during post-removal sampling and fords produced the largest amount of sediments during these phases.

One of the major challenges for agriculture today is to manage soil properties and their spatial distribution to optimize productivity and minimize environmental impacts, such as diffuse pollution. To identify best management practices, the effects of different agricultural management practices on pollutant sources, mobilization, transfer and delivery to water bodies need to be understood. Grasslands managed for dairy and meat production, despite being widespread, have received less research attention than other agricultural land uses. Therefore, this thesis studies the effects of different grassland management practices on soil properties and their spatial distribution and the mobilization and delivery of multiple diffuse pollutants. As a grassland case study, monitoring for this thesis was conducted across three fields (6.5 – 7.5 ha) on the North Wyke Farm Platform, a grassland experimental farm in the UK. First, the effects of permanent grassland management (permanent for at least 6 years, but different grassland management > 6 years ago) were characterized as a baseline, followed by quantifying the short-term effects of ploughing and reseeding of permanent grassland fields. Throughout those management periods, i) a range of soil physical (bulk density [BD]) and chemical (soil organic matter [SOM], total N [TN], total phosphorus [TP], total carbon [TC]) soil properties and their spatial distribution were sampled and analysed by geostatistics, and ii) hydrological characteristics and multiple pollutant fluxes (suspended sediment [SS] and the macronutrients: total oxidized nitrogen-N [TONN], total phosphorus [TP], and total carbon [TC]) were monitored at high temporal resolution (monitoring up to every 15 minutes). The permanent grassland fields (or areas within fields) can be considered to be functioning differently. Past management legacy (more than 6 years ago) has affected soil properties and their distribution with subsequent effects on sediment and macronutrient delivery from the fields to surface waters. Overall, permanent grasslands were found to contribute significantly to agricultural diffuse pollution. The estimated erosion and macronutrient losses were similar to or exceeded the losses reported for other grasslands, mixed land use and even arable sites, and sediment and TP concentrations exceeded those recommended by EU / UK water quality guidelines. Ploughing and reseeding did not homogenize spatial variation and did not override past management effects. Long-term management differences affected soil properties and altered soil processes, so that the fields subsequently responded differently to ploughing and reseeding. All nutrient concentrations were significantly reduced in the older grassland field (no ploughing for 20 years), but not in the younger grassland field (no ploughing for 6 years). Ploughing and reseeding significantly accelerated the losses of sediment and macronutrients and sediment, TP and TONN exceedance frequencies of EU / UK water quality guidelines increased. Additionally, ploughing and reseeding caused a shift in the relative importance of nutrients, by increasing the relative importance of N. Such large sediment and nutrient losses from intensively managed grasslands should be acknowledged in land management guidelines and advice for future compliance with surface water quality standards. The between-field and within-field variation highlights the importance of baseline characterization and paired catchment studies. The long-term effects of management still acting on soil properties and subsequently water quality indicates how long it may take to see soil and water quality improvements after implementing mitigation measures. Therefore, long-term management history always has to be included when interpreting soil and water quality data.

O presente trabalho visa caracterizar, através de experimentos numéricos, a hidrodinâmica e o transporte de sedimentos em suspensão no sistema estuarino de Caravelas e Peruípe sob diferentes condições forçantes. O sistema é formado por canais que estabelecem a conexão entre os rios Caravelas e Peruípe. Dados de nível de água e velocidade de correntes, obtidos em coletas de campo foram utilizados para aplicar e calibrar o modelo numérico MOHID. Diferentes experimentos numéricos, simulando condições de maré de sizígia e de quadratura com diferentes condições de descarga fluvial, foram realizados. A partir destas simulações foram obtidas distribuições espaciais e pontuais da concentração de sedimentos em suspensão e das correntes forçadas pela maré integradas verticalmente. Em condições de sizígia o estuário é caracterizado por correntes mais intensas e assimétricas, com dominância de vazante. As maiores concentrações médias de sedimento em suspensão ocorreram em condições de sizígia e o transporte de sedimentos resultante foi em direção ao oceano, em função do domínio das correntes de maré vazante. Os experimentos numéricos mostram que os canais que conectam os dois estuários têm papel relevante na dinâmica local. Eles possuem influência na dinâmica sedimentar do sistema estuarino. A hidrodinâmica e o balanço sedimentar do sistema são principalmente modulados pela altura da maré, com pouca contribuição do aporte de água doce. / The aim of this work is to characterize, through numerical modeling experiments, the hydrodynamics and suspended sediment transport dynamics in the Caravelas ? Peruípe estuarine system under different forcing conditions. The system comprises channels that connect the Caravelas and Peruípe rivers. Water level and current velocity data obtained through field campaigns were used to apply and calibrate the MOHID numerical model. Different numerical experiments simulating spring and neap tides with different river discharge conditions have been conducted. Based on these simulations, the hydrodynamics and spatial and temporal distributions of suspended sediment concentrations have been analyzed. During spring tide the estuary is characterized by intense and asymmetric currents (ebb dominated). The highest average suspended sediment concentration occurred during spring tide conditions, with net sediment transport being seaward. The numerical experiments show that the connecting channels play a relevant role in the local suspended sediment dynamics. The hydrodynamic and sediment balance in the system are modulated mainly by the tidal range, with little influence from the freshwater supply.

Large amounts of sediment transported by rivers, coming from the erosive action of water on the basin soil, causing degradation of water bodies and significant damages to the population, to socioeconomic development and to the natural environment. The processes of sediment production and deposition along a watershed are natural phenomena, but its effects can be magnified by the man influence through the disordered deforestation, construction, mining and improper management of agricultural activities. During the sediments transport and deposition in water bodies there is a color change in the water due to the concentration of dissolved or suspended materials. The water bodies color is directly linked to their inherent optical properties of absorption and spreading. These properties change according to the concentration, nature and types of dissolved and particulate materials in the water. The Normalized Difference Water Index (NDWI) is a method developed by McFeeters (1996) with the purpose of delineates features in the water, such as Active Optical Components, highlighting their presence, and found by digital images processing. The author modified the NDVI formula reversing the variables and using the green band instead of the red band in order to obtain better results attentive on water analysis. In this sense, the work is presented in order to promote by analyzes, descriptions, maps and systematic studies, the assessment of water quality NDWI method in the reservoirs of Caçu and Barra dos Coqueiros Hydropower Plants (HPPs), in Claro river, located in the southwestern portion of Goiás state - Brazil, evaluating the determination of suspended sediments method in lentic environments by multispectral images. Analyses of NDWI indices produced visually coherent data, but could not find an index for correlations between real data or even a calibration value to help in the determination of suspended sediment concentration. The NDWI method enables visual inspection of sediment yield characteristics for a given location, but must be in the same scene from the same date to become comparable. It is possible to make notes of places with higher sediment production and flow spread. Is found in the statistical analysis a low correlation between the suspended sediments concentration obtained from field sampling and from values of NDWI processing. The visual analysis of maps with the NDWI results is valid to indicate regions of interest for field sampling, analyzing patterns of sediment behavior also in rainfall seasonality periods. / As grandes quantidades de sedimentos transportadas pelos cursos de água, provenientes da ação erosiva da água sobre o solo da bacia, provocam a degradação dos corpos d água e prejuízos significativos à população, ao desenvolvimento socioeconômico e ao ambiente natural. Os processos de produção e deposição de sedimentos ao longo de uma bacia são fenômenos naturais, mas que têm seus efeitos potencializados pela influência do homem, por meio de desmatamentos desordenados, construções, mineração e manejo inadequado das atividades agrícolas. Durante a fase de transporte e deposição dos sedimentos em corpos hídricos há a mudança da coloração da água devido à concentração do material dissolvido ou em suspensão. A cor dos corpos d água está diretamente ligada às suas propriedades ópticas inerentes, de absorção e espalhamento. Estas propriedades variam conforme a concentração, natureza e tipos de materiais dissolvidos e particulados presentes na água. O Índice da Diferença Normalizada de Água (Normalized Difference Water Index NDWI) é um método desenvolvido por McFeeters (1996) com o intuito de delinear feições na água, como os Componentes Opticamente Ativos, e realçar a presença destes, sendo obtido por meio de processamentos em imagens digitais. O autor modificou a fórmula do NDVI invertendo as variáveis e usando a banda verde ao invés da banda vermelha, a fim de obter melhores resultados voltados à análise da água. Nesse sentido, o trabalho se apresenta no intuito de promover por meio de análises, descrições, mapeamentos e estudos sistematizados, a avaliação do método do NDWI da qualidade da água dos reservatórios das Usinas Hidrelétricas (UHEs) Caçu e Barra dos Coqueiros, no Rio Claro, localizadas na porção sudoeste do estado de Goiás, avaliando o método de determinação de sedimentos em suspensão em ambientes lênticos por meio de imagens multiespectrais. As análises dos índices de NDWI geraram informações visualmente coerentes, porém não foi possível encontrar um índice para correlações entre dados reais ou mesmo um valor de calibração para auxílio na determinação da concentração de sedimentos em suspensão. O método NDWI possibilita inspeções visuais das características de produção de sedimentos de um dado local, porém devem estar em uma mesma cena de uma mesma data para se tornarem comparáveis. É possível estabelecer apontamentos dos locais com maior aporte de sedimentos e avanço do fluxo. Nas análises estatísticas encontrou-se uma correlação baixa entre a concentração de sedimentos em suspensão obtidos de coletas de campo e os valores do processamento NDWI. A análise visual de mapas com os resultados do NDWI é valida para apontar áreas de interesse para coletas de campo, analisando padrões de comportamento dos sedimentos também em períodos de sazonalidade pluviométricas. / Mestre em Geografia

Longshore sediment transport rate was measured during energetic sea breeze activity, on intermediate-to-reflective sandy beaches in Southwestern Australia. Estimates of suspended load were obtained using backscatter sensors, current meters and streamer traps. Total load was determined using fluorescent tracer sand and an impoundment study. The measurementsw ere cross-compareda nd usedt o evaluates everalw idely-used longshore transport equations. The streamer trap measurement revealed an exponential distribution of the suspended sediment flux with vertical mixing decreasing in the onshore direction. A continuous time series of the longshore suspended sediment flux across the surf zone was obtained by combining the streamer trap measurements with data collected using surf zone instruments. Comparison of the suspended longshore flux with the total longshore flux derived from the dispersal of the sand tracer indicated that the relative contribution of the suspendedlo ad to the total load was at least 59 %. The movement of sandt racer on four different beaches demonstrated that nearshore sediments were transported obliquely across the surf zone, challenging our conventional view of dividing nearshore sediment transport into cross-shore and longshore components. Furthermore, tracer was found to move from the outer surf zone to the swash zone and vice versa, indicating a cross-shore sediment exchange. The contribution of the swash zone to the total longshore flux was estimated around 30-40 %. Despite large differences in the temporal and spatial scales of the measurement techniques, the littoral drift rates are comparable, suggesting a northward transport rate of 138,000-200,000 m3 year-1. Longshore sediment transport during sea breezes is mainly the result of a high longshore energy flux exerted by wind waves. This is accurately predicted by the equations of Inman and Bagnold (1963) and CERC (1984). The bimodal wave field, characteristic of Southwestern Australia, renders the Kamphuis (1991b) formula unsuitable in this instance.