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Transdisciplinarity as a means for capacity development in water resources managementLeidel, Marco 12 June 2018 (has links)
Water resources management has to deal with complex real life problems under uncertain framework conditions. One possibility for encountering such challenges is integrated water resources management (IWRM). However, IWRM is often understood as prescriptive manual, not acknowledging the need for adaptive solutions and capacity development (CD). These challenges demonstrate that sustainable water resources management requires transdisciplinarity, i.e. the integration of several scientific disciplines, as well as the collaboration between science and local actors. Transdisciplinarity is inherently related to CD since it facilitates collaboration and provides mutual learning and knowledge on complex interrelationships. This correlates with the evidence that CD can be seen as a key factor for water resources management (Alaerts et al. 1991, Alaerts 2009).
Consequently, the objective of this thesis is to strengthen water resources management by connecting processes of IWRM and CD in a transdisciplinary sense, i.e. (i) interrelating disciplinary research within an interdisciplinary research team that collaborates with local actors, and (ii) conducting a political process for knowledge and capacity development. Based on general insights, an embedded case study in the Western Bug River Basin, Ukraine, was conducted to evaluate the concept. It is shown that CD is essential for shifting from IWRM theories towards implementation and accordingly advantages of harmonizing CD into the IWRM process are presented (Leidel et al. 2012). Next to capacity issues, also other coordination gaps were assessed. River Basin Organisations are frequently proposed as a response to the administrative gap; however, coordination efforts cannot be simply reduced by transferring tasks from jurisdictional institutions to a river basin authority, because they will always need to coordinate with organizations from within or outside the water sector (von Keitz and Kessler 2008). Thus, coordination mechanisms across the boundaries of relevant policy fields are essential.
Therefore, a management framework is established linking technical development and capacity development that describes interrelations between environmental pressures and capacity and information gaps for different levels of water management (Leidel et al. 2014). The developed model-based and capacity-based IWRM framework combines model-based systems analysis and capacity analysis for developing management options that support water management actors. This is aligned with a political process for capacity development. It constitutes a boundary object for approaching cross-scale challenges that converges analyses, assessments and participation into one strategy. As concluded by Mollinga (2008), this can improve the performance of sustainable resources management by approaching transdisciplinarity. Within the model and capacity-based IWRM framework, the results of the integrated analysis are made explicit and transparent by introducing a matrix approach. Technical issues, institutional challenges, organizational and human resources development, and information needs are jointly assessed and interrelated by confronting pressures and coordination gaps on a subsystem basis. Accordingly, the concept supports a transparent decision making process by identifying knowledge and capacities required for the implementation of technical intervention options and vice versa.
The method is applied in the International Water Research Alliance Saxony (IWAS) model region ‘Ukraine’. It could be shown that the approach delivers management options that are scientifically credible and also accepted by and relevant for the actors. The case study revealed that technical intervention measures for the urban and rural water management have to be jointly implemented with appropriate CD measures and an accompanying political process on (i) strengthening the institutional framework and interministerial collaboration, (ii) fitting RBM into the existing institutional framework, (iii) setting up prerequisites for realistic RBM (Monitoring, information management, legal enforcement), (iv) a revision of effluent standards and a differentiated levy system, (v) cost covering tariffs, (vi) association work. For the Western Bug River Basin (WBRB), the strengthening of the collaboration between actors on all levels has to be continued. For increasing the usability, the approach needs to be institutionalized and become more practice relevant, e.g. by extending it to a water knowledge management system. Developing a roadmap for establishing transboundary water management is a subsequent step.
For strengthening future water management actors, IWRM curricula development at uni-versities in Ukraine was supported. And we developed the e-learning module IWRM-education that links interactively different aspects of water management to comprehend the complexity of IWRM (Leidel et al. 2013). The evaluation showed that participants under-stand the content, appreciate this way of learning, and will use this module for further activities.
The case study showed that technical cooperation can be a facilitator for political processes and that it can support decision making in a transparent way. Yet, it also showed that IWRM is highly political process and that the developed approach cannot cover all obstacles. In summary, exploring and reducing simultaneously environmental pressures and capacity and information gaps is essential for water sector evolution worldwide. Accordingly, transdisciplinarity as a means for capacity development can support the implementation of real integrated water resources management.
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Adaptive Water Management Concepts: Principles and Applications for Sustainable DevelopmentEdalat, F.D., Abdi, M. Reza January 2017 (has links)
No / his book explores a new framework of Adaptive Water Management (AWM) for evaluating existing approaches in urban water management. It highlights the need to adopt multidisciplinary strategies in water management while providing an in-depth understanding of institutional interactions amongst different water related sectors.
The key characteristics of AWM i.e. polycentric governance, organisational flexibility and public participation are investigated and described through a critical review of the relevant literature. The book presents an empirical case study undertaken in a selected developing-country city to investigate the potential gaps between the current water management approaches and possible implementation of AWM. Feasibility of AWM operations is examined in an environment surrounded by established water management structure with centralised governance and an institutional process based on technical flexibility.
The key elements of AWM performance are (re)structured and transformed into decision support systems. Multi criteria decision models are developed to facilitate quantification and visualization of the elements derived from the case study, which is involved with water companies and water consumers.
The book describes how the concept of AWM, along with structuring suitable decision support systems, can be developed and applied to developing-country cities. The book highlights the barriers for applying the AWM strategies that include established centralised decision making, bureaucratic interactions with external organisations, lack of organisational flexibility within the institutions, and lack of recognition of public role in water management. The findings outline that despite the lack of adaptability in the current water management in the case study, as an example of developing countries, there are positive attitudes among water professionals and the public towards adaptability through public-institutional participation.
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The management of potable water supply in Mogwase Township, Moses Kotane Local Municipality / Daniel Kagiso MosimeMosime, Daniel Kagiso January 2014 (has links)
The continuous population growth and the notable development of the mining industry have resulted in challenges for potable water supply in South Africa. The ever-increasing number of people migrating to urban areas has resulted in the demand of potable water supply in South Africa. Water is regarded as a human basic right which is promulgated by the recent amendment of the potable water service provisioning Water Services Act 108 of 1997 and the National Water Act 36 of 1998. The afore-mentioned Acts started a process to address the imbalance that existed during the apartheid regime. (The apartheid regime essentially had one objective initially, namely the control of (black, coloured and Indian) people in order to protect white privilege). It was meant to separate people of different races).The Acts were formulated to address the equal distribution of national resource for all South Africans.
Mogwase Township in Moses Kotane Local Municipality is undergoing continuous growth with several mining areas being developed. Consequently, the supply of potable water has been a challenge in the area. It is, therefore, in the interest of the researcher to investigate the management of potable water supply in Mogwase Township with the aim of suggesting improved service delivery by the Moses Kotane Local Municipality.
Water is now recognised as a scarce resource that belongs to all South Africans. The provision of potable water by the water services authorities (WSAs) is an important basic service that faces a number of challenges, such as the use of outdated infrastructure, namely: pipelines from the Vaalkop Dam, the lack of skilled and knowledgeable people, improper planning, and the booming population that place overt pressure on the demand for effective and efficient service delivery.
This research was undertaken to investigate how Moses Kotane Local Municipality which obtains its potable water supply from Vaalkop Dam can improve the supply of water in a more effective, efficient, equitable, economic and sustainable manner through improved co-operative governance and integrated water resource management (IWRM).
The qualitative and quantitative research designs were used to conduct the research, which included a literature review, semi-structured interviews, data sampling and scientific analysis of the responses.
The researcher arrived at logical conclusions and S.M.A.R.T. (Simple, Measureable, and Achievable Realistic Timebound) recommendations with regard to all aspects related to the future management of potable water supply in Mogwase Township. / MA (Development and Management), North-West University, Potchefstroom Campus, 2015
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The management of potable water supply in Mogwase Township, Moses Kotane Local Municipality / Daniel Kagiso MosimeMosime, Daniel Kagiso January 2014 (has links)
The continuous population growth and the notable development of the mining industry have resulted in challenges for potable water supply in South Africa. The ever-increasing number of people migrating to urban areas has resulted in the demand of potable water supply in South Africa. Water is regarded as a human basic right which is promulgated by the recent amendment of the potable water service provisioning Water Services Act 108 of 1997 and the National Water Act 36 of 1998. The afore-mentioned Acts started a process to address the imbalance that existed during the apartheid regime. (The apartheid regime essentially had one objective initially, namely the control of (black, coloured and Indian) people in order to protect white privilege). It was meant to separate people of different races).The Acts were formulated to address the equal distribution of national resource for all South Africans.
Mogwase Township in Moses Kotane Local Municipality is undergoing continuous growth with several mining areas being developed. Consequently, the supply of potable water has been a challenge in the area. It is, therefore, in the interest of the researcher to investigate the management of potable water supply in Mogwase Township with the aim of suggesting improved service delivery by the Moses Kotane Local Municipality.
Water is now recognised as a scarce resource that belongs to all South Africans. The provision of potable water by the water services authorities (WSAs) is an important basic service that faces a number of challenges, such as the use of outdated infrastructure, namely: pipelines from the Vaalkop Dam, the lack of skilled and knowledgeable people, improper planning, and the booming population that place overt pressure on the demand for effective and efficient service delivery.
This research was undertaken to investigate how Moses Kotane Local Municipality which obtains its potable water supply from Vaalkop Dam can improve the supply of water in a more effective, efficient, equitable, economic and sustainable manner through improved co-operative governance and integrated water resource management (IWRM).
The qualitative and quantitative research designs were used to conduct the research, which included a literature review, semi-structured interviews, data sampling and scientific analysis of the responses.
The researcher arrived at logical conclusions and S.M.A.R.T. (Simple, Measureable, and Achievable Realistic Timebound) recommendations with regard to all aspects related to the future management of potable water supply in Mogwase Township. / MA (Development and Management), North-West University, Potchefstroom Campus, 2015
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Land Use, Freshwater Flows and Ecosystem Services in an Era of Global ChangeGordon, Line January 2003 (has links)
<p>The purpose of this thesis is to analyse interactions between freshwater flows, terrestrial ecosystems and human well-being. Freshwater management and policy has mainly focused on the liquid water part (surface and ground water run off) of the hydrological cycle including aquatic ecosystems. Although of great significance, this thesis shows that such a focus will not be sufficient for coping with freshwater related social-ecological vulnerability. The thesis illustrates that the terrestrial component of the hydrological cycle, reflected in vapour flows (or evapotranspiration), serves multiple functions in the human life-support system. A broader understanding of the interactions between terrestrial systems and freshwater flows is particularly important in light of present widespread land cover change in terrestrial ecosystems. </p><p>The water vapour flows from continental ecosystems were quantified at a global scale in Paper I of the thesis. It was estimated that in order to sustain the majority of global terrestrial ecosystem services on which humanity depends, an annual water vapour flow of 63 000 km3/yr is needed, including 6800 km3/yr for crop production. In comparison, the annual human withdrawal of liquid water amounts to roughly 4000 km3/yr. A potential conflict between freshwater for future food production and for terrestrial ecosystem services was identified. </p><p>Human redistribution of water vapour flows as a consequence of long-term land cover change was addressed at both continental (Australia) (Paper II) and global scales (Paper III). It was estimated that the annual vapour flow had decreased by 10% in Australia during the last 200 years. This is due to a decrease in woody vegetation for agricultural production. The reduction in vapour flows has caused severe problems with salinity of soils and rivers. The human-induced alteration of vapour flows was estimated at more than 15 times the volume of human-induced change in liquid water (Paper II). </p>
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La gestion de l'eau au coeur de l'aménagement du territoire à SingapourDrolet, Julie January 2009 (has links)
Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.
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Application of integrated water resources management in computer simulation of River Basin's status - case study of River RwiziAtim, Janet 06 1900 (has links)
Thesis (M. Tech. - (Civil Engineering, Faculty of Engineering and Technology))--Vaal University of Technology, 2010. / During the last few years, concern has been growing among many stakeholders all over the world about declining levels of surface water bodies accompanied by reduced water availability predominantly due to ever increasing demand and misuse. Furthermore, overexploitation of environmental resources and haphazard dumping of waste has made the little water remaining to be so contaminated that a dedicated rehabilitation/remediation of the environment is the only proactive way forward. River Rwizi Catchment is an environment in the focus of this statement.
The overall objective of this research was to plan, restore and rationally allocate the water resources in any river basin with similar attributes to the study area. In this research, Integrated Water Resources Management (IWRM) methodology was applied through Watershed/Basin Simulation Models for general river basins. The model chosen and used after subjection to several criteria was DHI Model, MIKE BASIN 2009 Version. It was then appropriately developed through calibration on data from the study catchment, input data formatting and its adaptation to the catchment characteristics. The methodology involved using spatio-temporal demographic and hydrometeorological data.
It was established that the model can be used to predict the impact of projects on the already existing enviro-hydrological system while assigning priority to water users and usage as would be deemed necessary, which is a significant procedure in IWRM-based environmental rehabilitation/remediation. The setback was that the available records from the various offices visited had a lot of data gaps that would affect the degree of accuracy of the output. These gaps were appropriately infilled and gave an overall output that was adequate for inferences made therefrom.
Several scenarios tested included; use and abstraction for the present river situation, the effect of wet/dry seasons on the resultant water available for use, and proposed projects being constructed on and along the river. Results indicated that the river had insufficient flow to sustain both the current and proposed water users. It was concluded that irrespective of over exploitation, lack of adequate rainfall was not a reason for the low discharge but rather the loss of rainwater as evaporation, storage in swamps/wetlands, and a considerable amount of water recharging groundwater aquifers.
Thus, the proposed remedy is to increase the exploitation of the groundwater resource in the area and reduce the number of direct river water users, improve farming methods and conjunctive use of groundwater and surface water - the latter as a dam on River Rwizi. The advantage of the dam is that the water usage can be controlled as necessary in contrast to unregulated direct abstraction, thus reducing the risk of subsequent over-exploitation. / Vaal University of Technology
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A Comparative Study of Rural Water Governance in the Limpopo BasinSithole, Pinimidzai January 2011 (has links)
In this thesis I examine and explore whether and if Integrated Water Resources Management (IWRM) inspired water reforms respond to- and address the diverse realities of women and men in informal (and formal) rural economies of Sekororo, South Africa and Ward 17 in Gwanda, Zimbabwe which are both in the Limpopo basin. South Africa and Zimbabwe, like other southern African countries, embarked on IWRMinspired water reforms, culminating in the promulgation of the National Water Acts in 1998, four years after the attainment of South Africaâs democracy in 1994 and 18 years after Zimbabwe attained independence in 1980. I argue that the adoption of IWRM, which emphasises second generation water issues such as demand management, water quality, environmental flow requirements etc, and not the development of water infrastructure, begs the question whether such reforms can make a meaningful contribution to the development agenda in countries where, during apartheid and colonialism, the water rights (among other rights) of millions of blacks were compromised because of unjust legislation and skewed underinvestment in water infrastructure
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Land Use, Freshwater Flows and Ecosystem Services in an Era of Global ChangeGordon, Line January 2003 (has links)
The purpose of this thesis is to analyse interactions between freshwater flows, terrestrial ecosystems and human well-being. Freshwater management and policy has mainly focused on the liquid water part (surface and ground water run off) of the hydrological cycle including aquatic ecosystems. Although of great significance, this thesis shows that such a focus will not be sufficient for coping with freshwater related social-ecological vulnerability. The thesis illustrates that the terrestrial component of the hydrological cycle, reflected in vapour flows (or evapotranspiration), serves multiple functions in the human life-support system. A broader understanding of the interactions between terrestrial systems and freshwater flows is particularly important in light of present widespread land cover change in terrestrial ecosystems. The water vapour flows from continental ecosystems were quantified at a global scale in Paper I of the thesis. It was estimated that in order to sustain the majority of global terrestrial ecosystem services on which humanity depends, an annual water vapour flow of 63 000 km3/yr is needed, including 6800 km3/yr for crop production. In comparison, the annual human withdrawal of liquid water amounts to roughly 4000 km3/yr. A potential conflict between freshwater for future food production and for terrestrial ecosystem services was identified. Human redistribution of water vapour flows as a consequence of long-term land cover change was addressed at both continental (Australia) (Paper II) and global scales (Paper III). It was estimated that the annual vapour flow had decreased by 10% in Australia during the last 200 years. This is due to a decrease in woody vegetation for agricultural production. The reduction in vapour flows has caused severe problems with salinity of soils and rivers. The human-induced alteration of vapour flows was estimated at more than 15 times the volume of human-induced change in liquid water (Paper II).
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Development of regional climate change projections for hydrological impact assessments in distrito federal, BrazilBorges de Amorim, Pablo 24 June 2015 (has links) (PDF)
Facing the urgency of taking actions to guarantee the water supply to Brazil's Capital, the project called IWAS/ÁguaDF aims to provide scientific knowledge for the development of an Integrated Water Resources Management (IWRM) concept. The project is organized in multiple working groups wherein climate is considered as one of the main drivers. The water supply system of Distrito Federal (DF) is mainly dependent on three major complexes: river basins, waste water and drinking water. Anthropogenic climate change has the potential to affect these water complexes in a number of ways such as by losing storage capacity due to erosion and sedimentation, through altered persistency of dry events and due to increasing water demand. As a contribution to the IWAS/ÁguaDF project, this study focuses on the development of climate change projections for hydrological impact assessments at local/regional scale. The development of proper climate information is a challenging task. The level of complexity corresponds directly to the issues that concern impact modellers as well as technical aspects such as available observational data, human and computational resources. The identification of the needs for water-related issues gives the foundation for deriving proper climate projections.
Before making projections, it is necessary to assess the current climate conditions, or baseline climate. Despite a better understanding of the regional aspects of the climate and the ongoing changes, the baseline climate provides the foundation for calibrating and validating climate models and downscaling methods. The General Circulation Models (GCMs) are the most preferred tools in simulating the response of the climate system to anthropogenic activities, like increasing greenhouse gases and aerosol emissions. However, the climate information required for regional impact studies, such as water resources management in DF, is of a spatial scale much finer than that provided by GCMs and therefore often demands a downscaling procedure. Hydrological models are usually sensitive to the temporal variability of precipitation at scales that are not well represented by GCMs. Statistical downscaling methods have the potential to bridge the mismatch between GCMs and impact models by adding local variability that is consistent with both the large-scale signal and local observations. The tool used (i.e., Statistical DownScaling Model - SDSM) is described as a hybrid of regression-based and stochastic weather generator. The systematic calibration adopted provides the appropriated predictors and model parameterization. The validation procedure takes into account the metrics relevant to the requirements of hydrological studies.
Moreover, the downscaling approach considers several climate models (i.e., 18 GCMs) and emission scenarios (i.e., SRES A1B, A2, B1) in order to sample the widest sources of uncertainties available. In spite of the elevated level of uncertainties in the magnitude of change, most of the downscaled projections agree with positive changes in temperature and precipitation for the period of 2046-2065 when compared to the reference period (i.e., 1980-1999). Large ensembles are preferable but are often associated with massive amount of data which have limited application in hydrological impact studies. An alternative is to identify subsets of projections that are most likely and projections that have lower likelihood but higher impact. A set of representative climate projections is suggested for hydrological impact assessments. Although high resolution information is preferable, it relies on limited assumptions inherent to observations and coarse-resolution projections and, therefore, its use alone is not recommended. The combination of the baseline climate with large- and local-scale projections achieved in this study provides a wide envelope of climate information for assessing the sensitivity of hydrological systems in DF. A better understanding of the vulnerability of hydrological systems through the application of multiple sources of climate information and appropriate sampling of known uncertainties is perhaps the best way to contribute to the development of robust adaptation strategies. / Starkes Bevölkerungswachstum sowie Landnutzungs- und Klimawandel gefährden die Wasserversorgung der Metropolregion Brasília. Vor diesem Hintergrund soll das Projekt IWAS/ÁguaDF die wissenschaftlichen Grundlagen für ein Integriertes Wasserressourcen-Management (IWRM) im Distrito Federal (DF) erarbeiten. Das Projekt gliedert sich in drei klimasensitive Bereiche: Einzugsgebietsmanagement, Abwasseraufbereitung und Trinkwasserversorgung. Klimaänderungen können die Wasserversorgung im DF vielfältig beeinflussen, durch Veränderung der speicherbaren Wassermenge (Wasserdargebot, Speicherkapazität von Talsperren durch Sedimentation), der Dauer von Dürreperioden und des Wasserbedarfs (z.B. für Bewässerung). Klimaprojektionen für regionale hydrologische Impaktstudien stellen jedoch eine große Heraus-forderung dar. Ihre Komplexität richtet sich nach dem Bedarf des Impaktmodellierers und hängt zudem von technischen Voraussetzungen ab, wie der Verfügbarkeit von Beobachtungsdaten sowie von Personal- und Rechenressourcen. Die Ableitung geeigneter Maßnahmen für ein nachhaltiges Wasserressourcenmanagement im DF stellt hohe Ansprüche an die Qualität der zu entwickelnden Klimaprojektionen.
Noch vor der Projektion müssen die gegenwärtigen klimatischen Bedingungen (Referenzklima) analysiert und bewertet werden. Die Analyse des Referenzklimas ermöglicht ein besseres Verständnis regionaler Unterschiede und aktueller Tendenzen und bildet die Grundlage für die Kalibrierung und Validierung von Klimamodellen und Downscaling-Methoden. Globale Klimamodelle (GCM) simulieren die Reaktion des Klimasystems auf anthropogene Treibhausgas- und Aerosolemissionen. Ihre räumliche Auflösung ist jedoch meist zu grob für regionale Klimaimpaktstudien. Zudem reagieren hydrologische Modelle meist sehr sensitiv auf zeitlich variable Niederschläge, welche in hoher zeitlicher Auflösung (Tagesschritte) ebenfalls nur unzureichend in GCM abgebildet werden. Statistische Downscaling-Verfahren können diese Inkohärenz zwischen GCM und Impaktmodellen reduzieren, indem sie das projizierte Klimasignal um lokale Variabilität (konsistent gegenüber den Beobachtungen) erweitern.
Das in der vorliegenden Arbeit verwendete Tool, Statistical DownScaling Model - SDSM, vereint regressionsbasierte und stochastische Methoden der Wettergenerierung. Geeignete Prädiktoren und Modelparameter wurden durch systematische Kalibrierung bestimmt und anschließend validiert, wobei unter anderem auch hydrologisch relevante Gütekriterien verwendet wurden. Der gewählte Downscaling-Ansatz berücksichtigt zudem eine Vielzahl verschiedener Globalmodelle (18 GCM) und Emissionsszenarien (SRES A1B, A2 und B1) um die mit Klimaprojektionen verbundene hohe Unsicherheit möglichst breit abzudecken. Die Mehrheit der regionalen Projektionen weist auf eine Zunahme von Temperatur und Niederschlag hin (Zeitraum 2046 bis 2065 gegenüber Referenz-zeitraum, 1980 bis 1999), wenngleich die Stärke des Änderungssignals stark über das Ensemble variiert. Große Modellensemble sind zwar von Vorteil, sie sind jedoch auch mit einer erheblichen Datenmenge verbunden, welche für hydrologische Impaktstudien nur begrenzt nutzbar ist.
Alternativ können einzelne „wahrscheinliche“ Projektionen verwendet werden sowie Projektionen, die weniger wahrscheinlich, aber mit einem starken Impakt verbunden sind. Ein solcher Satz repräsentativer Klimaprojektionen wurde für weitergehende Impaktstudien ausgewählt. Auch wenn in der Regel hochaufgelöste Klimaprojektionen angestrebt werden, ihr alleiniger Einsatz in Impaktstudien ist nicht zu empfehlen, aufgrund der vereinfachten Annahmen über die statistische Beziehung zwischen Beobachtungsdaten und den Modellergebnissen grob aufgelöster Globalmodelle. Der Vergleich des Referenzklimas mit großräumigen und lokalen Projektionen, wie er in dieser Arbeit durchgeführt wurde, liefert ein breites Spektrum an Klimainformationen zur Bewertung der Vulnerabilität hydrologischer Systeme im DF. Die Einbeziehung einer Vielzahl vorhandener Klimamodelle und die gezielte, den ermittelten Unsicherheitsbereich vollständig abdeckende Auswahl an Projektionen sollte die Entwicklung robuster Anpassungsstrategien bestmöglich unterstützen. / Diante do desafio de garantir o abastecimento de água potável da capital federal do Brasil, o projeto denominado IWAS/ÁguaDF tem como objetivo prover conhecimento científico para o desenvolvimento de um conceito de Gestão Integrada dos Recursos Hídricos (PGIRH). Afim de atingir esta proposta, o projeto é organizado em multiplos grupos de trabalho entre os quais o clima é considerado um dos principais fatores de influência. O sistema de abastecimento de água do Distrito Federal (DF) depende praticamente de três complexos: bacias hidrográficas, águas residuais e água potável. Mudanças climáticas causadas por ações antropogênicas apresentam um enorme potencial de impacto a estes complexos, por exemplo através de alterações no regime de chuvas, perda de volume dos reservatórios por assoriamento e aumento na demanda de água. Como contribuição ao projeto IWAS/ÁguaDF, este estudo tem como foco o desenvolvimento de projeções de mudanças climáticas para estudo de impacto nos recursos hídricos na escala local/regional.
O nível de complexidade corresponde diretamente às questões levantadas pelos modeladores de impacto, bem como aspecto técnicos como a disponibilidade de dados observados e recursos humanos e computacionais. A identificação das necessidades de questões relacionadas à água no DF dão a base para derivar projeções climáticas adequadas. Antes de qualquer projeção futura, é indispensável avaliar as condições atuais do clima, também chamado de linha de base do clima. Além de fornecer a compreenção dos aspectos regionais do clima e mudaças em curso, a linha de base provê dados para a calibração e validação de modelos globais de clima e técnicas de regionalização (downscaling). Os Modelos de Circulação Geral (GCM) são as ferramentas mais adotadas na simulação da resposta do sistema climático às atividades antropogênicas, tais como aumento de emissões de gases do efeito estufa e aerosóis. No entanto, a informação necessária para estudos regionais de impacto, tais como gestão de recursos hídricos, é de escala espacial mais refinada do que a resolução espacial fornecida pelos GCMs e, dessa forma, técnicas de regionalização são frequentemente demandadas. Modelos hidrológicos são geralmente sensitivos à variabilidade temporal de precipitação em escalas não representadas pelos modelos globais. Métodos estatísticos de ‘downscaling’ apresentam um potencial para auxiliar no descompasso entre GCMs e modelos de impacto através da adição de variabilidade local consistente com o sinal de larga escala e as observações locais.
A ferramenta utilizada (Statistical DownScaling Model - SDSM) é descrita como um híbrido entre regressão linear e gerador de tempo estocástico. A calibração sistemática adotada fornece apropriados preditores e uma parameterização consistente. O procedimento de validação do modelo leva em conta as métricas relevantes aos requerimentos dos estudos hidrológicos. Ainda, a abordagem aqui utilizada considera diversos modelos globais (isto é, 18 GCMs) e cenários de emissões (isto é, SRES A1B, A2 e B1) afim de contemplar as mais abrangentes fontes de incertezas disponíveis. Embora o elevado nível de incertezas na magnitude das mudançãs de clima, a grande maioria das projeções regionalizadas concordam com o aumento de temperatura e precipiatação para o período de 2046-2065 quando comparado com o período de referência (isto é, 1980-1999). Grandes conjuntos de projeções são preferíveis, mas são frequentement associados com uma quantidade exorbitante de dados os quais são de aplicação limiatada nos estudos de impacto. Uma alternativa é identificar sub-conjuntos de projeções que são as mais prováveis e projeções que são menos prováveis, porém apresentam maior impacto. Embora altas resoluções são preferíveis, estas baseiam-se em hipóteses inerentes às observações e projeções de larga escala e, dessa forma, não é recomendável o seu uso sozinho.
A combinação do clima de base com projeções de resoluções baixas e altas fornece um amplo envelope de imformações climáticas para avaliar a sensitividade dos sistemas hidrológicos no DF. Um compreendimento mais apurado da vunerabilidade dos sistemas hidrológicos através da aplicação de multiplas fontes de informação e apropriada abordagem das incertezas conhecidas é talvez a melhor maneira para contribuir para o desenvolvimento de estratégias robustas de adaptação.
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