O presente estudo propôs uma nova leitura dos dados do monitoramento hidrológico de sete microbacias experimentais, considerando que as variáveis que caracterizam os sistemas aquáticos destas microbacias constituem indicadores da qualidade do manejo florestal. Os objetivos do estudo foram: a) selecionar, entre as variáveis já monitoradas, os potenciais indicadores para o monitoramento hidrológico de florestas plantadas; b) testar a viabilidade da utilização da comunidade de macroinvertebrados bentônicos como indicador biológico. O estudo foi desenvolvido nas seguintes microbacias: na região do Município de Guaíba, RS, uma com floresta plantada e uma com pastagem; em Itatinga, SP, uma com floresta plantada; em Alagoinhas, BA, uma com floresta plantada e três em Imperatriz, MA, uma com floresta nativa, uma com floresta plantada de eucalipto e uma com pastagem. O estudo consistiu na análise de dados da medição contínua da vazão, da precipitação e de variáveis físicas e químicas da água dos córregos das microbacias durante diferentes períodos e também no estudo da comunidade de macroinvertebrados bentônicos por um período de um ano. Como resultado, foram selecionadas, para o início de um programa de monitoramento de florestas plantadas na escala da microbacia hidrográfica, 12 indicadores que atendem a três critérios. São eles: 1 - manutenção dos processos hidrológicos da microbacia e da qualidade das operações florestais com os indicadores balanço hídrico, picos de vazão, sólidos em suspensão, turbidez, condutividade elétrica, fósforo, oxigênio dissolvido, potássio, temperatura da água e macroinvertebrados bentônicos; 2 - manutenção do potencial produtivo do solo com os indicadores fósforo, nitrogênio, cálcio, potássio, magnésio, e sólidos em suspensão, e 3 - manutenção do equilíbrio dinâmico do ecossistema aquático, com os indicadores oxigênio dissolvido, fósforo, nitrogênio, temperatura da água, sólidos em suspensão, pH e macroinvertebrados bentônicos / This study proposes a new analysis of data from hydrological monitoring of seven experimental catchments considering that the monitored hydrological variables can be used as indicators for forest management quality. The objectives of the study were: a) select, among the monitored variables potential indicators for the hydrological monitoring of planted forests; b) investigate weather macroinvertebrate community can be used as biological variable. The study was carried out in catchments covered by Eucalyptus forests located in the Municipalities of Guaíba, State of Rio Grande do Sul, Itatinga, State of São Paulo, Alagoinhas, State of Bahia and Imperatriz, State of Maranhão; catchment covered by native forests in the Municipality of Imperatriz State of Maranhão and catchments used as pastureland in the Municipalities of Guaíba, State of Rio Grande do Sul and Imperatriz, State of Maranhão. The study involved data analysis of precipitation, streamflow and water quality variables measured during different periods and the study of the macroinvertebrate community during one-year period. As a result, 12 variables according to 3 criteria of forest sustainable management were selected. The criteria and indicators are the following: 1 - maintenance of catchment hydrologycal processes and forest management quality, for which the indicators are water balance, peak flow, suspended solids, turbidity, conductivity, phosphorus, dissolved oxygen, potassium, water temperature and benthic macroinvertebrate community; 2 – maintenance of soil productivity, with the indicators phosphorus, nitrogen, calcium, potassium, magnesium, and suspended solids, and the third criteria, maintenance of the dynamic equilibrium of aquatic ecosystem, with the indicators dissolved oxygen, phosphorus, nitrogen, water temperature, suspended solids, pH, and benthic macroinvertebrate community

La variabilité spatio-temporelle de l’évolution morpho-sédimentaire du fond de la vallée de la Choisille (bassin versant : 288 km²), affluent de la Loire moyenne dans le sud-ouest du Bassin parisien (37), a été étudiée par 78 forages (8 transects), prospection géophysique, analyses sédimentologiques et datations 14C et OSL. Huit phases d’évolution du système fluviatile depuis le début Weichsélien ont été définies et corrélées avec les données palynologiques et archéologiques locales, afin de comprendre l’impact des facteurs forçants : climat ou/et anthropisation. Du Weichsélien jusqu’au début du Subatlantique, l'activité d'incision ou de sédimentation de la Choisille a évolué sous contrôle climatique strict. Depuis l’Allerød, cette évolution a été différente de celles observées sur d’autres rivières en Europe du Nord-Ouest, indiquant des spécificités climatiques et géologiques régionales. Dès l’Âge du Bronze, la rivière a évolué sous contrôle climatique et anthropique ; l'impact anthropique sur la sédimentation fut prépondérant, mais très variable dans le temps et l'espace au sein du bassin selon les potentialités agricoles des secteurs considérés. / The spatio-temporal variability of the Choisille valley morpho-sedimentary evolution (catchment: 288 km²), a tributary of the middle Loire River in the south-western Parisian Basin (37), was studied through 78 core-drillings (8 transects), geophysical prospecting, sedimentological analyses and 14C and OSL dating. Eight phases of fluvial system evolution were defined and correlated with palynological and archaeological dataset, in order to highlight the impact of forcing factors: climate and/or human activity. From the Weichselian up to the Subatlantic, the fluvial incision or sedimentation activity has strictly evolved under climate control. Since the Allerød, this evolution was different from what has been observed on other rivers of north-western Europe, indicating regional climatic or geological specificities. Since the Bronze Ages, the river has evolved under climatic and human control; the anthropogenic impact on sedimentation was dominant, but spatio-temporaly variable in the catchment, in relationship with the agricultural potentialities of the different areas.

Thesis (MSc. (Horticulture)) -- University of Limpopo, 2018 / Rainwater harvesting is an old age practice used in water-scarce rainfed crop production areas. It is practiced to supplement additional water for crops with insufficient amounts of rainfall for optimum production. The aim of this study was to assess yield responses of Swiss chard under In-field rainwater harvesting techniques (IRWH) and catchment areas. The trials were conducted at two sites, University of Limpopo experimental farm (Syferkuil) and on farmer’s field at Apel. The main plots were two catchment areas (2 m (1 m runoff strip plus 1 m basin)) and (3 m (2 m runoff strip plus 1 m basin)), while the subplots were five IRWH techniques namely; Control (farmers practice), Rainfed, IRHW (without mulch + irrigation), IRWH+Mulch and IRWH+Mulch+Irrigation. The results obtained showed no significant differences in yield of Swiss chard in relation to catchment areas of 3 and 2 m respectively. However, significant differences in plant height, plant vigour, number of leaves and chlorophyll contents were obtained under different IRWH techniques. Significantly, highest average plant height of 40.75 cm was obtained in IRWH+Mulch compared to Rainfed with the lowest average 28.50 cm at Syferkuil. A similar trend was obtained at Apel. There were significant differences in number of leaves under IRWH techniques; the highest mean of 16.00 was obtained in the control (farmers practice) treatment, while the lowest mean of 9.00 was obtained in IRWH treatment at Apel. At Syferkuil, significantly highest average number of leaves was obtained in the IRWH+Mulch+irrigation treatment, while the lowest average number of leaves was obtained in the rainfed treatment. Regarding the yield of Swiss chard, the significantly highest average yield was obtained under IRWH+Mulch+irrigation and 3 m catchment treatment combination which was 84.86 t ha-1 compared to 20.66 t ha-1 in rainfed and 3 m catchment treatment combination at Syferkuil. Similar trend was found at Apel with the highest average yield recorded in IRWH+Mulch+irrigation treatment combination. Hence, IRWH technique with mulch and irrigation could be adopted by growers in a water-scarce environment like the Limpopo Province of South Africa.

This study investigates provisions made within institutional and regulatory frameworks of water resources management to enhance multi-stakeholder relationships and the challenges of maintaining those relationships, and implications of water resources management for rural communities in the Densu River basin, Ghana. The primary objectives of this study were four fold, these are to: i) review the existing regulatory framework and how it promotes or hinders multi-stakeholder relationships within the catchment area; ii) examine multi-stakeholder relationships to identify challenges in promoting effective collaboration in water resources management; iii) explore the impacts of catchment management on the livelihoods of rural communities; and iv) generate a model that best or appropriately conceptualizes relationship mechanisms within the framework of water governance. The study employed a mixed methods approach which included data collected through reviewing regulatory and policy documents, key informant interviews, observation, and a household survey of 327 respondents. The results indicate that provisions are made within the existing institutional and regulatory framework to foster multi-stakeholder inter-relationships in the water resources management in the Densu River basin. The management of the Densu River basin is guided by a number of regulatory mechanisms that are scattered within different institutions. The regulatory mechanisms are seen as the instruments for building and maintaining multi-stakeholder relationships, but some have become a source of conflict among stakeholders, posing threats to water resources management in the Densu basin. The findings show that several issues hinder effective multi-stakeholder inter-relationships in water resources management in the Densu River basin. These issues include colonial legacies embedded within institutions, institutional challenges, and political processes. Despite the adoption of integrated water resources management (IWRM) some institutions still hold on to the old water resources management arrangements instituted during the colonial era, creating challenges for effective institutional collaboration. Additionally, institutional challenges such as limited financial and human resources, corruption, high attrition rate, and lack of integration of projects and programs are also threatening multi-stakeholder inter-relationships. The political processes at the district assemblies that determine representatives on the Densu Basin Board were also identified as posing significant threat to building effective multi-stakeholder inter-relationship for water resources management in the Densu River basin. The findings further indicate that a number of uncoordinated catchment management strategies such as restrictions on farming areas, bans on illegal mining and logging, and others strategies have been instituted in the upper Densu basin to prevent degradation of the river. However, these strategies are having significant socioeconomic impacts on the local communities. A majority of residents are aware and comply with the enforcement of the strategies, but some are quite reluctant to adhere to them because of increasing economic hardships. This situation threatens the successful implementation of the strategies and the overall protection of the river. Other residents, however, have adopted alternative strategies (expanding petty trading, farming improvement, multiple jobs and others) to cope with the increasing economic hardships as a result of the enforcement of the catchment management strategies by the government.

Catchment management organisations often use computer-based water quality models to support their decision-making needs. However, literature suggests that model use by catchment managers can be highly problematical. Commonly reported issues that negatively impact upon the effectiveness of modelling for decision-making are data quality and availability, miscommunication between analysts and decision-makers, inappropriate treatment of uncertainty, excessive model complexity (‘sophistication’) or simplicity and poor modelling practice. The challenges that beset catchment managers are usually framed as technical problems that can be overcome by using or communicating the science that underlies the models more effectively. As a result, many of the problems associated with the use of models by catchment managers have not been adequately elucidated from the standpoint of a manager. This thesis examines the problem of modelling for decision-making from a fresh perspective. Systemic approaches to research are commonly used where the research problem is ill-defined, as it is here. ‘Action research’ is one qualitative, systemic methodology, and was used here as the guiding methodology to explore the model related problems faced by catchment managers. Action research involves recurrent cycles of planning, action, observation and reflection. The research was undertaken with the Sydney Catchment Authority (SCA), a New South Wales government agency responsible for water quality and catchment health in the drinking water catchments of Sydney, Australia. The SCA had expressed a particular need for tools to support the assessment of development applications with respect to potential impacts on water quality, and to prioritise rural land for remedial action to improve water quality in the drinking water catchments. The research had two broad aims that were:1.to develop two models differing in sophistication, and to use them to prioritise nutrient pollution sources and calculate nutrient loads; And, through the participatory development of the models, 2.to learn methodological lessons that catchment managers can apply to choose and use models more effectively. In this research, action was in the form of five planned activities, including: i. a review of relevant literature from diverse disciplines; ii. the holding of two workshops; the first exclusively involving SCA managers to identify their modelling needs, and the second involving water quality scientists and modelers to discuss methods for meeting the modelling needs; iii. the development and use of two export coefficient nutrient models; iv. a focus group discussion involving key staff in the SCA; and v. a review of published guidelines for good modelling practice in environmental management. Note was also taken of statements or behaviour at numerous meetings and seminars, mostly with SCA staff, that were relevant to the research questions. / Doctor of Philosophy (PhD)

Glenbrook Lagoon, an 8 hectare lake receiving rainfall runoff from a residential catchment, is experiencing nutrient enrichment problems expressed as excessive aquatic plant presence. This study aims to assess the relative nutrient contribution of the total system compartments, including catchment loading, water column, aquatic plants and surface sediment. This information is utilised in the formulation of management strategies which may produce a sustainable nutrient reduction and general improvement in the system. The total nutrient content of the aquatic system was determined to be high in comparison with the present nutrient loading from the catchment. The ideal management case considers nutrient reduction of the surface sediment compartment firstly, followed by the aquatic plant community, with the water column and catchment influence as relatively low priority compartments. Various strategies for managing these are proposed. The total system benefits of the ideal management case are reductions in nutrients, aquatic plant biovolume and suspended solid loading. Unavoidable constraints placed upon the ideal management case include the excessive aquatic plant presence restricting accessability to the surface sediment for dredging. The resulting best management case requires aquatic plant eradication prior to sediment management, with the total system benefits associated with the ideal management case being retained. / Master of Science (Hons)

The most important priority for the management of Australian drinking water catchments is the control of pathogen loads delivered to raw water reservoirs and treatment plant intakes. A process-based mathematical model was developed to estimate pathogen catchment budgets (PCB) for Cryptosporidium, Giardia and E. coli loads generated within and exported from catchments. The model quantified key processes affecting the generation and transport of microorganisms from humans and animal excreta using land use and hydrologic data, and catchment specific information including point sources such as sewage treatment plants and on-site systems. The PCB model was applied in the Wingecarribee catchment, Sydney and used to predict and rank pathogen and indicator loads in dry weather, intermediate (<30 mm in 24 h) and large wet weather events (100mm in 24 h). Sensitivity analysis identified that pathogen excretion rates from animals and humans, and manure mobilisation rates were the most significant factors determining the output of the model. Comparison with water quality data indicated that predicted dry weather loads were generally within 1-2 log10 of the measured loads for Cryptosporidium and E. coli and within 1 log10 for Giardia. The model was subsequently used to predict and rank pathogen and indicator loads for the entire (16 000 km2) Sydney drinking water catchment.

Coastal wetlands are dynamic ecosystems that are highly susceptible to change due to natural and human factors. The study area, located within the Native Dog Creek sub-catchment of the Logan River - which drains into Moreton Bay, south east Queensland - holds a detailed history of environmental change spanning most of the Holocene epoch. This history is preserved in the estuarine sedimentary record and is a valuable indicator of natural environmental change. More recently, human-induced changes within the study area have been superimposed on the natural process of environmental change. In order to develop a conceptual bio-geomorphic model of the coastal wetlands of Native Dog Creek, this thesis examined - on an integrated catchment basis - the evolution and connectivity of four coastal wetland community types (Melaleuca, Casuarina, saltmarsh and mangroves). The research consisted of four discrete studies within the study area: a geomorphic investigation that provided a framework for understanding how the wetlands evolved during the Holocene epoch; an acid sulfate soil (ASS) study that surveyed the distribution and concentration of sulfides; a palynological study that examined the natural directions of ecosystem change; and an investigation of the impact of specific human activities on these ecosystems. Detailed stratigraphic modelling found that the Logan River system (and its Native Dog Creek sub-catchment) has evolved from an infilling estuary since the peak of the Holocene transgression 6500 years before present. Recognition of the major controls that influenced geomorphic coastal development during the Holocene, provided important insights into the distribution and genesis of estuarine pyritic sediments which strongly influence the soils within the study area. In general, the estuarine central basin and fluvial delta sediments posed the greatest risk to the environment from acidification if disturbed. The major focus of the ASS study was to survey the distribution of ASS and to identify other areas most vulnerable to acidification. A predictive approach that combined chemical and stratigraphic analysis was used. Results showed that these areas are intrinsically related to their environment of deposition. The study found, for example, that the alternation of excessively wet and dry conditions - combined with high organic carbon levels and variations in microtopography - provided ideal conditions for the re-formation of pyrite in the stream channel within the Melaleuca wetlands. The palaeo-environmental study reconstructed the evolution of Holocene coastal wetland vegetation during the marine transgression and subsequent shoreline progradation. Pollen records from the four representative wetland communities (previously mentioned) were examined. The results found the mid-late Holocene vegetation history was controlled by the development of geomorphic features that have affected freshwater input, drainage and salinity. In response to the progradation of the shoreline after sea level stabilised, changes in fossil pollen from mangroves and saltmarsh taxa during the early-mid Holocene, to freshwater taxa during the late Holocene, are estimated to have taken 800 years. Thus, pollen analysis when used in combination with stratigraphic modelling, provided an important point of reference for rates of natural ecological change in response to evolutionary changes to the physical environment. The wetlands within the study area have suffered varying degrees of disturbance since European settlement in the 1820s. The most significant changes occurred during early European settlement, when vast areas of coastal lowlands were cleared for timber, sheep and cattle grazing and for agricultural purposes. A second period of change occurred from 1989 to 1995, when the Melaleuca community suffered dieback in response to hydrological modifications to Native Dog Creek for the development of a golf course. Results indicate that human-induced changes over the past 170 years have occurred at a rate far beyond the ability of the natural ecosystem to adapt or move to a more ecologically sustainable state, at least in the short-term. Hence the current environment is experiencing degradation through both decline in health and loss of indigenous species. The development of a conceptual bio-geomorphic model was based on the integration of results from all four studies, in an effort to provide a holistic understanding of the coastal wetland environment and of the impact of human-induced changes upon that environment. If these vulnerable ecosystems are to be maintained, successful and sustainable coastal management strategies must rely on a sound scientific understanding of the response of a coastal ecosystem to both human and environmental changes.

The term 'Intermittently Closed and Open Lake or Lagoon (ICOLL)' has been adopted in NSW to described wave dominated barrier estuaries with an intermittent connection to the ocean. ICOLLs can also be found in south east Queensland, south-west Western Australia, and some parts of Victoria and Tasmania, although they are not the dominant estuary type as in NSW. From an international perspective, ICOLLs are also found in South Africa, New Zealand, Mexico and the Atlantic coast of Brazil and Uruguay. Within NSW, ICOLLs are mostly located south of Sydney, due to the high wave activity and close proximity of the Great Dividing Range to the coast, which results in small coastal catchments and thus small fluvial and sediment runoff. The distinguishing difference between ICOLLs and other estuary types is the variable condition of their entrances, which also makes them the most sensitive type of estuary to human interference (HRC, 2002; Boyd et al., 1992). The sensitivity of ICOLLs to external inputs has been described in this thesis based on their morphometric characteristics, which includes their size, shape and predominant entrance condition. NSW ICOLLs exhibit a wide range of physical conditions. Some ICOLLs are rarely open to the ocean, while others are rarely closed. Also, some ICOLLs have experienced extensive development within their catchments, while some are located mostly or wholly within National Parks and other protected reserves. When closed, ICOLLs behave like terminal lakes, retaining and assimilating 100% of the external inputs delivered to the system. When open, tidal flushing assists with advection and dispersion of inputs, however, significant tidal attenuation across the entrance still limits opportunities for effective removal of pollutants. The majority of NSW ICOLLs are considered to be mostly closed (i.e., have a closed entrance for more than 60% of the time), while remaining ICOLLs tend to be mostly open (i.e., have a closed entrance for less than 20% of the time). Few ICOLLs have entrances that are open and closed for roughly equal proportions of time, thus resulting in a distinctive bimodal behaviour of entrance condition (i.e., mostly open or mostly closed). NSW ICOLLs tend to be mostly closed unless (i) the catchment is larger than 100km2, and/or (ii) the exposure of the entrance to ocean swell waves is less than 60 degrees and/or (iii) the entrance channel contains geomorphic controls (e.g. shallow bedrock outcrops). Unless opened artificially, ICOLLs will generally remain closed until a sufficient volume of catchment runoff accumulates within the waterway to increase water levels to a level that overtops (breaches) the entrance sand berm. Once breached, high velocity flows over the berm cause scour and the development of a formalised entrance channel, which increases exponentially until an optimum width and depth has been reached (determined by the hydrostatic head, geomorphic controls and tidal conditions at the time). Following entrance breakout and lowering of the lagoon level, sand is reworked back into the entrance under the influence of flood tides and wave processes. The environmental condition of ICOLLs has generally been assumed as being dependent on the state of the catchment and the associated input of nutrients (form and magnitude) to the system. Biogeochemical processes also are reported to influence the condition of ICOLLs, particularly denitrification, which is controlled by the organic load on the bed and the extent of benthic algae and macrophytic productivity. In addition to this, however, it is demonstrated that the predominant and prevailing entrance conditions (i.e. open or closed) also influence the physical, chemical and biological environments. ICOLLs are particularly susceptible to the impacts of future climate change. This thesis provides a description of expected impacts on NSW ICOLLs environments associated in response to future climate changes, based on a detailed appreciation of physical processes and their follow-on consequences. Impacts on ICOLLs are expected as a result of increasing sea level, altered rainfall patterns, and modified offshore wave climate. A survey of relevant government officials has revealed that more than 50% of NSW ICOLLs are artificially opened before water levels reach the height of the natural entrance sand berm. Artificial entrance opening is mostly carried out to mitigate inundation of public and/or private assets around ICOLL foreshores, such as roads, backyards, farming lands and on-site sewage (septic) systems. Truncation of the hydraulic regime of ICOLLs can modify other physical, chemical and biological processes, and can result in deleterious impacts such as the terrestrialisation of estuarine wetlands and foreshores. Few statutory environmental planning mechanisms protect ICOLLs from future degradation. This thesis has identified the key issues that potentially compromise ICOLL integrity and sustainability, which include the expected future population growth in coastal NSW (thus increasing pressure for intensification of development within ICOLL catchments), future climate change (particularly increases in sea level), and the increased demand for amenity, particularly during summer holiday periods (i.e. 'summer impacts'). A series of management models have been developed to address key issues. The models comprise a suite of strategies that target future development and existing management practices, through a range of new or modified planning instruments. Models for the future management of ICOLL entrances aim to prevent artificial openings in the long-term. This requires, however, the systematic relocation, raising or flood-proofing of public and private assets that have been established on land that is potentially subject to inundation. Increasing sea levels in the future will compound the need for improved entrance management. Pro-active, integrated and adaptive management strategies need to be implemented today to minimise the on-going conflict and potential for continued environmental degradation in the future.

Appropriately constructed pollutant export models can help set management priorities for catchments, identify critical pollutant source areas, and are important tools for developing and evaluating economically viable ways of minimising surface water pollution.¶ This thesis presents a comparison, an evaluation and an integration of models for predicting the export of environmental pollutants, in particular sediment, through river systems. A review of the capabilities and limitations of current water quality modelling approaches is made. Several water quality and quantity modelling approaches are applied and evaluated in the catchment of the upper Murrumbidgee River.¶ The IHACRES rainfall-runoff model and a simple hydrologic routing model are applied with the aim of developing a capacity to predict streamflow at various catchment scales and to enable integration with other pollutant load estimation techniques. Methods for calculating pollutant loads from observed pollutant concentration and modelled streamflow data are also investigated. Sediment export is estimated using these methods over a 10-year period for two case study subcatchments. Approaches for water quality sampling are discussed and a novel monitoring program using rising stage siphon samplers is presented. Results from a refinement of the Sediment River Network model in the upper Murrumbidgee catchment (SedNet-UM) are presented. The model provides a capacity to quantify sediment source, transport and to simulate the effects of management change in the catchment. The investigation of the model includes rigorous examination of the behaviour of the model through sensitivity assessment and comparison with other sediment modelling studies. The major conclusion reached through sensitivity assessment was that the outputs of the model are most sensitive to perturbation of the hydrologic parameters of the model.¶ The SedNet-UM application demonstrates that it is possible to construct stream pollutant models that assist in prioritising management across catchment scales. It can be concluded that SedNet and similar variants have much potential to address common resource management issues requiring the identification of the source, propagation and fate of environmental pollutants. In addition, incorporating the strengths of a conceptual rainfall-runoff model and the semi-distributed SedNet model has been identified as very useful for the future prediction of environmental pollutant export.