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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.
1

Geomorphic and hydrologic processes in Coombs Brook, Macclesfield Forest

Abu-Maila, Y. S. January 1987 (has links)
No description available.
2

Utgör omgivande lantbruk någon risk för Skottorps vattentäkt?

Sjödin, Sanna January 2015 (has links)
The intensification of agriculture through Europe has led to a lot of environmental issues. Among these are the increased use of fertilizer and pesticides which also constitutes a risk for many water resources. This is mainly due to the leakage of nitrate and pesticides to the water which makes it unsuitable for drinking. The aim of this study was to investigate whether the nearby agriculture constituted a risk in the catchment of Skottorp. If risks were found, the study was also aiming to evaluate possible measures that could be taken. An additional aim was to find out whether a co-operative agreement between the local authorities responsible for the catchment and the farmers would be a possible solution in case of future problems. For the study, water data related to agriculture was analyzed statistically and interviews were performed with the farmers. The study shows that there are no imminent risks to the water in the catchment related to agriculture, which makes measures unnecessary. If problems would arise in the future the study also shows that co-operative agreements are a suitable course of action.
3

The Greco-Roman Water Catchment Theater: Identification and Distribution

Lee, Allison Nicole 01 March 2015 (has links) (PDF)
Water has always been a necessity for human beings. How individuals and populations have reacted to, adapted, and manipulated water is apparent in the archaeological record. Ancient urban water systems often utilized a number of components, including aqueducts, siphons, underground tunneling, and cisterns. This thesis proposes that Greco-Roman theaters were utilized as components of ancient urban water systems in specific environments, and that this theater type may be identified in the archaeological and literary record as a water catchment theater. The goal of my thesis was to define, describe, identify, and plot the distribution of water catchment theaters in order to compare their distribution with the environments where they were found. Previous research on Greco-Roman theaters has not focused on theaters as components of ancient urban water systems. Because of this deficiency, it was necessary to define what water catchment theaters were, describe the architectural traits that were found in water catchment theaters, and finally, using this information, identify water catchment theaters and look at their distribution throughout the Greco-Roman world. To meet my objective I created a new typology of water theaters based on extensive research and on-site visits to 30 theaters in five countries, surveyed and classified the 927 theaters found in Frank Sear's Roman Theatres: An Architectural Study, and plotted the distribution of water catchment theaters in relation to space, time, and climate. My study gives new insight into the uses of Greco-Roman theaters but also introduces new methods to examine these ancient buildings with relation to their potential roles in urban water systems.
4

Modelling of pesticide exposure in ground and surface waters used for public water supply

Pullan, Stephanie January 2014 (has links)
Diffuse transfers of pesticides from agricultural land to ground and surface waters can lead to significant drinking water quality issues. This thesis describes the development and application of a parameter-efficient, numerical model to predict pesticide concentrations in raw water sources within an integrated hydrological framework. As such, it fills an unoccupied niche that exists in pesticide fate modelling for a computationally undemanding model that contains enough process complexity to be applicable in a wide range of catchments and hydrogeological settings in the UK and beyond. The model represents the key processes involved in pesticide fate (linear sorption and first-order degradation) and transport (surface runoff, lateral throughflow, drain flow, percolation to the unsaturated zone, calculated using a soil water balance) in the soil at a daily time step. Soil properties are derived from the national soil database for England and Wales and are used to define the boundary conditions at the interface between the subsoil and the unsaturated zone. This is the basis of the integrated hydrological framework which enables the application of the model to both surface water catchments and groundwater resources. The unsaturated zone model accounts for solute transport through two flow domains (accounting for fracture flow and intergranular matrix flow) in three hydrogeological settings (considering the presence and permeability of superficial deposits). The model was first applied to a small headwater sub-catchment in the upper Cherwell. Performance was good for drainflow predictions (Nash Sutcliffe Efficiency > 0.61) and performed better than the MACRO model and as well as the modified MACRO model. Surface water model performance was evaluated for eight pesticides in five different catchments. Performance was generally good for flow prediction (Nash Sutcliffe Efficiency > 0.59 and percentage bias below 10 %, in the validation period for all but two catchments). The 90th percentile measured concentration was captured by the model in 62 % of catchment-pesticide combinations. In theremaining cases predictions were within, at most, a factor of four of measured 90th percentile concentrations. The rank order of the frequency of pesticides detected over 0.1 μg L-1 was also predicted reasonably well (Spearman’s rank coefficient > 0.75; p < 0.05 in three catchments). Pesticide transport in the unsaturated zone model was explored at the point scale in three aquifers (chalk, limestone and sandstone). The results demonstrate that representing the unsaturated zone processes can have a major effect on the timing and magnitude of pesticide transfers to the water table. In comparison with the other catchment scale pesticide fate models that predict pesticide exposure at a daily time-step, the model developed stands out requiring only a small number of parameters for calibration and quick simulation times. The benefit of this is that the model can be used to predict pesticide exposure in multiple surface and groundwater resources relatively quickly which makes it a useful tool for water company risk assessment. The broad-scale approach to pesticide fate and transport modelling presented here can help to identify and prioritise pesticide monitoring strategies, to compare catchments in order to target catchment management and to highlight potential problems that could arise under different future scenarios.
5

The role of water quality modelling in decision-making

McNamara, Les. January 2007 (has links)
Thesis (Ph.D) -- University of Western Sydney, 2007. / A thesis submitted to the University of Western Sydney, College of Health and Science, School of Natural Sciences, in fulfilment of the requirements for the degree of Doctor of Philosophy. Includes bibliography.
6

Avaliação das tecnologias sociais como alternativa de convivência com o Semiárido Cearense: O Projeto de Cisternas / Evaluation of social technologies as an alternative to coexistence with the Semi-arid Cearense: The Cistern Projec

Albuquerque, Cícero Lima January 2012 (has links)
ALBUQUERQUE, Cícero Lima. Avaliação das tecnologias sociais como alternativa de convivência com o Semiárido Cearense: O Projeto de Cisternas . 2012. 104f. – Dissertação (Mestrado) – Universidade Federal do Ceará, Programa de Pós Graduação em Avaliação de Políticas Públicas, Fortaleza (CE), 2012. / Submitted by Gustavo Daher (gdaherufc@hotmail.com) on 2017-05-05T17:19:07Z No. of bitstreams: 1 2012_dis_clalbuquerque.pdf: 1332863 bytes, checksum: b58a5597319ac0333a642773e6cadf25 (MD5) / Approved for entry into archive by Márcia Araújo (marcia_m_bezerra@yahoo.com.br) on 2017-05-08T11:05:12Z (GMT) No. of bitstreams: 1 2012_dis_clalbuquerque.pdf: 1332863 bytes, checksum: b58a5597319ac0333a642773e6cadf25 (MD5) / Made available in DSpace on 2017-05-08T11:05:12Z (GMT). No. of bitstreams: 1 2012_dis_clalbuquerque.pdf: 1332863 bytes, checksum: b58a5597319ac0333a642773e6cadf25 (MD5) Previous issue date: 2012 / This study assesses the project selected in Proclamation 02/2008 of the BNB / ETENE - New Social Technologies (ST) Living with the Semi-Arid.These technologies are intended to promote better coexistence with the semiarid, with the increase of farming systems, income generation and community participation. Technology should be used as an example to reapply in the Brazilian semiarid. We opted for an ex post evaluation, which is held throughout the execution or after completion of the project. Through qualitative and quantitative methodologies, we seek to verify the implementation of TS cistern in three communities of the cities of Santana and Acaraú Morrinhos, Ceará. The field was developed with the use of questionnaires with representatives of the families, and interviews with the coordinator and community leaders. We observed the dependency of families on the help of government and civil society, low educational levels of most parents, the small amount of land used for cultivation and production of traditional beans, maize and cassava. We present the characterization of Brazilian Semiarid (SAB), the biome, the coexistence of man with that environment, the technologies adapted to their reality, as well as key programs developed by civil society. Farmers traditionally hold their crops during the winter, receiving little or no technical assistance from municipal and state agencies. The social technology implemented by the project requires more time for use to generate satisfactory income families. Water is a precious asset for these communities, however, it is essential that the availability of infrastructure such as better roads, schools and health posts to local development and improved coexistence with the semiarid. / Esta pesquisa faz uma avaliação do projeto selecionado no Edital 02/2008 do BNB/ETENE – Novas Tecnologias Sociais (TS) de Convivência com o Semiárido. Essas tecnologias têm como objetivo promover uma melhor convivência com o semiárido, com o aumento das explorações agropecuárias, a geração de renda e a participação comunitária. A tecnologia deveria ser utilizada como exemplo de reaplicabilidade no semiárido brasileiro. Optamos por uma avaliação ex post, que é realizada ao longo da execução ou após a conclusão do projeto. Através de metodologias qualitativas e quantitativas, procuramos verificar a implantação da TS cisterna calçadão em três comunidades dos municípios de Santana do Acaraú e Morrinhos, no Ceará. A pesquisa de campo foi desenvolvida com a aplicação de questionários com os representantes das famílias, e entrevistas com a coordenadora e os líderes comunitários. Observamos a dependência das famílias quanto à ajuda do Governo e da sociedade civil organizada, a baixa escolaridade da maioria dos pais, a pouca quantidade de terra utilizada para a produção e o cultivo tradicional do feijão, do milho e da mandioca. Apresentamos a caracterização do Semiárido Brasileiro (SAB), o bioma, a convivência do homem com esse ambiente, as tecnologias adaptadas à sua realidade, bem como os principais programas desenvolvidos pela sociedade civil. Os agricultores, tradicionalmente, realizam seus plantios durante o inverno, recebendo pouca ou nenhuma assistência técnica dos órgãos municipal e estadual. A tecnologia social implementada pelo projeto requer maior tempo de utilização para a satisfatória geração de renda às famílias. A água é um bem precioso para essas comunidades, entretanto, verificou-se que é fundamental a disponibilidade de infraestrutura, como melhores estradas, escolas e postos de saúde para o desenvolvimento local e a melhor convivência com o semiárido.
7

Avaliação da variabilidade de qualidade ambiental de bacias de mananciais de abastecimento público com a aplicação de um índice para o estado de Goiás / Evaluation of environmental quality of water supple watershed basins by appliction of variability measure index for the state of Goiás

Cruvinel, Karla Alcione da Silva 31 March 2016 (has links)
Submitted by Marlene Santos (marlene.bc.ufg@gmail.com) on 2016-09-08T16:58:41Z No. of bitstreams: 2 Tese - Karla Alcione da Silva Cruvinel - 2016.pdf: 6969385 bytes, checksum: e3b015b1a1c9a8dd5fc6ec8b43f1bb62 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-09-09T14:38:30Z (GMT) No. of bitstreams: 2 Tese - Karla Alcione da Silva Cruvinel - 2016.pdf: 6969385 bytes, checksum: e3b015b1a1c9a8dd5fc6ec8b43f1bb62 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2016-09-09T14:38:30Z (GMT). No. of bitstreams: 2 Tese - Karla Alcione da Silva Cruvinel - 2016.pdf: 6969385 bytes, checksum: e3b015b1a1c9a8dd5fc6ec8b43f1bb62 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-03-31 / Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG / The need for environmental preservation and responsible use of natural resources is something increasingly discussed between civil society and the scientific community and the need to monitor the environmental quality of areas such as river basins requires planning and choice of variables that help in understanding functionality of these systems. In addition, the index and indicators are presented as efficient tools in order to make them more easily visualized technical data. In this study, socioeconomic and environmental indicators were used in order to structure an index able to estimate the degree of environmental quality of the watershed. The Environmental basins Quality Index (EQI) was built from the variables Soil Loss (SL), Native Vegetation Index (NVI), Water Quality Index (WQI) and Municipal Development Index (MDI). The GIS was used to identify the NVI and loss of soil in the basin, and for the latter employed Universal Soil Loss Equation (USLE). It was applied still Soil and Water Assessment Tool software (SWAT) in soil loss prediction five basins studied in order to promote the direct comparison of the model front applicability of the method implemented USLE. We studied different scenarios in these same five basins in SWAT, which we sought to evaluate the influence of vegetation in sediment yield for different land cover scenarios. To obtain the WQI of each basin, we used the adaptation of the method developed by Sousa (2014). After that, the EQI was applied in 126 basins of supply water sources in Goias State, which enabled the identification of the degree of environmental quality of each. It was found that almost 85% of the studied basins are classified as very bad or bad EQI, and in almost all of these the WQI of the spring is also bad. By analyzing the EQI basins in ten different regions of Goias State Planning it was noted that average is best in the Northwest region, which also has better native state of vegetation index. Regarding the loss of soil, it is noted that most of the basins (64%) are classified in low and moderate erosive susceptibility, but with some in erosive susceptibility very high severe. Therefore, it was concluded that the methodology used in this study proved to be an effective management strategy for catchments and can be used as an environmental planning instrument in these areas. / A importância de conservação ambiental e o uso consciente de recursos naturais é algo cada vez mais discutido entre a sociedade civil e comunidade científica. Existe uma necessidade urgente do monitoramento da qualidade ambiental de áreas como bacias hidrográficas, o que requer planejamento e escolha de variáveis que auxiliem no entendimento da funcionalidade desses sistemas. Desta forma, os índices e indicadores apresentam-se como ferramentas eficazes, no sentido de tornar os dados técnicos mais facilmente visualizados. Assim, neste estudo foram utilizados indicadores socioeconômicos e ambientais, com o objetivo de estruturar um índice capaz de estimar o grau de qualidade ambiental de bacias hidrográficas. O Índice de Qualidade Ambiental de Bacias (IQAB) foi construído a partir das variáveis Perda de Solo (PS), Porcentagem de Vegetação Nativa (PVN), Índice de Qualidade da Água (IQA) e Índice de Desenvolvimento dos Municípios (IDM). Foi utilizado o Geoprocessamento na identificação do PVN e da perda de solo nas bacias, sendo que para este último empregouse a Equação Universal de Perda de Solos (EUPS). Aplicou-se ainda o software Soil and Water Assessment Tool (SWAT) na predição de perda de solo de cinco das bacias estudadas, a fim de promover a comparação da aplicabilidade direta deste modelo frente ao método implementado EUPS. Estudou-se a mudança de cenários nestas mesmas cinco bacias, no SWAT, onde se buscou avaliar a influência da vegetação na produção de sedimentos para diferentes cenários de cobertura vegetal. Para a obtenção do IQA de cada bacia, utilizou-se a adaptação do método desenvolvido por Sousa (2014). Após a sua construção, o IQAB foi aplicado em 126 bacias de mananciais de abastecimento do estado de Goiás, o qual possibilitou a identificação do grau de qualidade ambiental de cada uma. Verificou-se que quase 85% das bacias estudadas estão classificadas em IQAB péssimo ou ruim, sendo que em quase todas estas o IQA do manancial também é ruim. Ao analisar o IQAB das bacias nas dez diferentes regiões de Planejamento do estado de Goiás, observou-se que a melhor média é na região Noroeste, a qual também possui melhores PVN do estado. Com relação a perda de solo, nota-se que maior parte das bacias (64%) estão enquadradas na susceptibilidade erosiva baixa e moderadas, mas com algumas em susceptibilidade erosiva muito alta a severa. Portanto, conclui-se que a metodologia utilizada neste trabalho mostrou ser uma eficiente estratégia de gestão para bacias hidrográficas podendo ser utilizada como instrumento de planejamento ambiental dessas áreas.
8

Avaliação da qualidade de água de um sistema de captação de água pluvial. Estudo de caso: Laboratório de Ecologia Isotópica/CENA/USP / Valuation of water quality in a system of rainwater collection. Case study: Laboratory of Isotope Ecology/CENA/USP

Carvalho, Jean 23 April 2014 (has links)
Devido à intensificação das atividades industriais e agrícolas, aliada ao grande crescimento urbano e ao aumento exponencial da população no último século, a pressão sobre os recursos hídricos se intensificaram drasticamente. Sendo assim, existe a necessidade de se buscar novas fontes de abastecimento público de água. A captação de água pluvial remonta a milhares de anos, no entanto, por se tratar de uma área onde os estudos são recentes, muitas dúvidas permeiam sobre o método a ser adotado para a implantação de sistemas de captação pluvial, de forma que garanta a saúde de seus usuários. Desta forma, procurando acrescentar cientificamente e analisar novas possibilidades para sistemas de aproveitamento de água pluvial, este projeto objetivou analisar e caracterizar a qualidade da água em diversos pontos em um sistema de captação, armazenamento e utilização de água pluvial, instalado no Laboratório de Ecologia Isotópica do CENA/USP no município de Piracicaba, SP. Foi construído um sistema em escala real contendo cinco recipientes de 100 L para o descarte de primeiras águas, totalizando aproximadamente 3,3 mm de água descartada, com duas cisternas de 5 mil litros cada para armazenar a água captada. Foram coletadas amostras de água em sete pontos do sistema totalizando 36 análises por evento pluviométrico. Os parâmetros analisados foram pH, condutividade elétrica (CE), nitrogênio total (NT), carbono inorgânico dissolvido (DIC), carbono orgânico dissolvido (DOC) e oxigênio dissolvido (OD). As análises de OD foram descontinuadas após a constatação de que o OD, nas diferentes etapas do sistema, não apresentavam diferenças estatísticas devido ao esquema utilizado na montagem do sistema. O pH coletado sempre apresentou valores mais altos que os valores da precipitação, tendendo a diminuir conforme a água captada era descartada atingindo uma média de pH de 6,1 quando a água encontrava-se nas cisternas. A CE e o NT apresentaram valores mais altos que os valores encontrados na precipitação com um decaimento significativo para cada etapa de descarte, assim como apresentaram correlação com a intensidade pluviométrica e o intervalo de estiagem entre eventos pluviométricos. O desvio padrão de CE tendeu a diminuir a cada etapa de descarte, demonstrando que o sistema de descarte atuava como um homogeneizador da água coletada, independente das características pluviométricas. Os parâmetros de DIC também apresentaram valores maiores que os encontrados na água de chuva, assim como apresentaram queda significativa conforme a quantidade de água descartada. Os parâmetros de DOC não apresentaram qualquer correlação com a quantidade de água descartada ou com os parâmetros pluviométricos. Concluiu-se que o sistema de descarte de primeiras águas tem um papel fundamental na qualidade final da água captada. Assim como, que a recomendação da ABNT, de descartar os primeiros 2 mm de chuva, condiz exatamente com o ponto onde se obtêm a melhor qualidade de água com o mínimo de perda. Foi possível constatar que o intervalo de estiagem e a intensidade pluviométrica influenciaram diretamente na qualidade da água que será coletada. / Due to increasing industrial and agricultural activities, coupled with the extensive urban growth and the exponential increase in population in the last century, the pressure on water resources has intensified dramatically. Thus, there is a need to seek new sources of public water supply. The collection of rainwater goes back thousands of years, however, because it is an area where the studies are recent, many questions permeate on the method to be adopted for the implementation of rainwater harvesting systems, as well as ensure health of its users. Thus, seeking to add scientifically and analyze new possibilities for harnessing rainwater systems, this project aims to analyze and characterize water quality at various points in a system of capture, store and use rainwater, at the Laboratory of Isotope Ecology CENA / USP in Piracicaba, SP. A system has been built in real scale with five drums of 100 L for discarding of first waters, totaling approximately 3.3 mm discarted water, with two cisterns of 5000 liters each to store the collected water. Were seven sampling points totaling 36 analyzes per rainfall event. Parameters of pH, electrical conductivity (CE), total nitrogen (TN), dissolved inorganic carbon (DIC), dissolved organic carbon (DOC) and dissolved oxygen (OD) were analyzed. Analyses of OD were discontinued after the realization that the OD, in the different stages of the system, showed no statistical differences due to the layout of the system. The analyzed pH always showed a higher values than the precipitation and has tended to decrease as the collected water was discarded. Showing an average pH of 6.1 when the water reaches the cistern. The values of EC and NT were higher than the values found in precipitation and tended to decrease gradually in each stage of disposal system of the first water, as also showed a correlated pattern with the rainfall intensity and with the interval between rainfall events. The CE standard deviation tend to decrease at each step of the disposal system of the first water, demonstrating that the disposal system of the first water serves as a homogenizer of water captured, regardless of the rainfall characteristics. The parameters of DIC also showed higher values than those found in rain water, and showed a gradual decrease in each stage of disposal system of the first water. The parameters of DOC showed no correlation with the amount of discarted water or with the rainfall parameters. It was concluded that the disposal system of the first waters has a key role in the final quality of water abstracted. As well as the recommendation of ABNT, of discarding the first 2 mm of rain, matches exactly the point where you can get the best quality water with minimal loss. It was found that the drought period and the rainfall intensity directly influence the quality of water that will be collected.
9

AvaliaÃÃo das Tecnologias Sociais como Alternativa de ConvivÃncia com o SemiÃrido Cearense: O Projeto de Cisternas. / Evaluation of Social Technologies as an Alternative to Coexistence with the Semi-arid Cearense: The Cistern Project.

CÃcero Lima De Albuquerque 13 August 2010 (has links)
Universidade Federal do Cearà / Esta pesquisa faz uma avaliaÃÃo do projeto selecionado no Edital 02/2008 do BNB/ETENE â Novas Tecnologias Sociais (TS) de ConvivÃncia com o SemiÃrido. Essas tecnologias tÃm como objetivo promover uma melhor convivÃncia com o semiÃrido, com o aumento das exploraÃÃes agropecuÃrias, a geraÃÃo de renda e a participaÃÃo comunitÃria. A tecnologia deveria ser utilizada como exemplo de reaplicabilidade no semiÃrido brasileiro. Optamos por uma avaliaÃÃo ex post, que à realizada ao longo da execuÃÃo ou apÃs a conclusÃo do projeto. AtravÃs de metodologias qualitativas e quantitativas, procuramos verificar a implantaÃÃo da TS cisterna calÃadÃo em trÃs comunidades dos municÃpios de Santana do Acaraà e Morrinhos, no CearÃ. A pesquisa de campo foi desenvolvida com a aplicaÃÃo de questionÃrios com os representantes das famÃlias, e entrevistas com a coordenadora e os lÃderes comunitÃrios. Observamos a dependÃncia das famÃlias quanto à ajuda do Governo e da sociedade civil organizada, a baixa escolaridade da maioria dos pais, a pouca quantidade de terra utilizada para a produÃÃo e o cultivo tradicional do feijÃo, do milho e da mandioca. Apresentamos a caracterizaÃÃo do SemiÃrido Brasileiro (SAB), o bioma, a convivÃncia do homem com esse ambiente, as tecnologias adaptadas à sua realidade, bem como os principais programas desenvolvidos pela sociedade civil. Os agricultores, tradicionalmente, realizam seus plantios durante o inverno, recebendo pouca ou nenhuma assistÃncia tÃcnica dos ÃrgÃos municipal e estadual. A tecnologia social implementada pelo projeto requer maior tempo de utilizaÃÃo para a satisfatÃria geraÃÃo de renda Ãs famÃlias. A Ãgua à um bem precioso para essas comunidades, entretanto, verificou-se que à fundamental a disponibilidade de infraestrutura, como melhores estradas, escolas e postos de saÃde para o desenvolvimento local e a melhor convivÃncia com o semiÃrido. / This study assesses the project selected in Proclamation 02/2008 of the BNB / ETENE - New Social Technologies (ST) Living with the Semi-Arid.These technologies are intended to promote better coexistence with the semiarid, with the increase of farming systems, income generation and community participation. Technology should be used as an example to reapply in the Brazilian semiarid. We opted for an ex post evaluation, which is held throughout the execution or after completion of the project. Through qualitative and quantitative methodologies, we seek to verify the implementation of TS cistern in three communities of the cities of Santana and Acaraà Morrinhos, CearÃ. The field was developed with the use of questionnaires with representatives of the families, and interviews with the coordinator and community leaders. We observed the dependency of families on the help of government and civil society, low educational levels of most parents, the small amount of land used for cultivation and production of traditional beans, maize and cassava. We present the characterization of Brazilian Semiarid (SAB), the biome, the coexistence of man with that environment, the technologies adapted to their reality, as well as key programs developed by civil society. Farmers traditionally hold their crops during the winter, receiving little or no technical assistance from municipal and state agencies. The social technology implemented by the project requires more time for use to generate satisfactory income families. Water is a precious asset for these communities, however, it is essential that the availability of infrastructure such as better roads, schools and health posts to local development and improved coexistence with the semiarid.
10

An assessment of recent changes in catchment sediment sources and sinks, central Queensland, Australia

Hughes, Andrew Owen, Physical, Environmental & Mathematical Sciences, Australian Defence Force Academy, UNSW January 2009 (has links)
Spatial and temporal information on catchment sediment sources and sinks can provide an improved understanding of catchment response to human-induced disturbances. This is essential for the implementation of well-targeted catchment-management decisions. This thesis investigates the nature and timing of catchment response to human activities by examining changes in sediment sources and sinks in a dry-tropical subcatchment of the Great Barrier Reef (GBR) catchment area, in northeastern Australia. Changes in catchment sediment sources, both in terms of spatial provenance and erosion type, are determined using sediment tracing techniques. Results indicate that changes in sediment source contributions over the last 250 years can be linked directly to changes in catchment land use. Sheetwash and rill erosion from cultivated land (40-60%) and channel erosion from grazed areas (30-80%) currently contribute most sediment to the river system. Channel erosion, on a basin-wide scale, appears to be more important than previously considered in this region of Australia. Optically stimulated luminescence and 137Cs dating are used to determine pre-and post- European settlement (ca. 1850) alluvial sedimentation rates. The limitations of using 137Cs as a floodplain sediment dating tool in a low fallout environment, dominated by sediment derived from channel and cultivation sources, are identified. Low magnitude increases in post-disturbance floodplain sedimentation rates (3 to 4 times) are attributed to the naturally high sediment loads in the dry-tropics. These low increases suggest that previous predictions which reflect order of magnitude increases in post-disturbance sediment yields are likely to be overestimates. In-channel bench deposits, formed since European settlement, are common features that appear to be important stores of recently eroded material. The spatially distributed erosion/sediment yield model SedNet is applied, both with generic input parameters and locally-derived data. Outputs are evaluated against available empirically-derived data. The results suggest that previous model estimates using generic input parameters overestimate post-disturbance and underestimate predisturbance sediment yields, exaggerating the impact of European catchment disturbance. This is likely to have important implications for both local-scale and catchment-wide management scenarios in the GBR region. Suggestions for future study and the collection of important empirical data to enable more accurate model performance are made.

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