Dissertations / Theses on the topic 'Catchment management'

Water resource management has become a pertinent issue of global environmental concern in response to the conditions of a growing global population, increasing development and a limited freshwater supply. It is against the backdrop of such conditions that effective water resource management has gained popularity in seeking to ensure that the needs of the growing population will be met and secured for future generations. The notion of integrated water resource management (IWRM) is a perspective on water resource management that has evolved out of the global opinion that social and ecological systems are linked and therefore cannot be managed separately. The department of water affairs (DWA) in South Africa highlights the importance of approaching management of water resources from a catchment perspective which forms the basis for a particular integrated approach to management called integrated catchment management (ICM). ICM recognizes the catchment as the correct administrative unit for management. It integrates water resources and the land that forms the catchment area in planning and management. Researchers have described the implementation of ICM as being complicated and difficult. This is no exception to South Africa. Principles of ICM have received widespread prominence in South Africa as they have been incorporated into national water policy. Actual implementation however is still in its infancy. The study is therefore a case study of ICM with respect to factors influencing implementation amongst different stakeholders. The study aims to explore the theme of implementation of ICM within the context of the Gamtoos River Catchment with a view toward identifying and addressing challenges that may be more broadly applicable. The study adopts an inductive, exploratory approach to the connection between theory and practice. A systems-based framework characterized by sequential steps similar to that employed in a case study conducted by Bellamy et al. (2001) in Queensland Australia is used to facilitate the evaluation of ICM in the Gamtoos River Catchment. The evaluation is achieved through a three step process of exploration in the current study. Triangulation is applied to the choice of methods of analysis which involves the use of a global analysis method, the use of learning scenarios and a grounded theory method. Findings reveal seven core themes which help to provide a detailed, contextual understanding relating to the status quo for ICM in the catchment. Results from a grounded theory analysis summarized the main challenges to implementation into five broad categories. Based on this analysis method and the application of the three learning scenarios for the Gamtoos River Catchment, the extent to which these challenges exist was discovered. The state of ICM in the catchment was classified as falling within a condition of a level of success being achieved with room for improvement to a condition of optimal ICM. The study concludes that based on the context of ICM being an example of a Complex Adaptive Systems (CAS), this state of ICM in the Gamtoos River Catchment is subject to change. This therefore necessitates the consideration of approaches to implementation that are adaptive to change. Findings may serve to inform decision making on how ICM can be effectively implemented elsewhere in a South African context.

Includes bibliographic references
Of all the natural resources available on earth, it could be argued that water is the most important and essential to human health and well - being. Water is a scarce and finite resource and must therefore be used in such a manner as to preserve and protect it. Statistically, South Africa is a water scarce country and water demand is on the increase due to an increase in population, economic development and living standards. The scarcity creates a need to protect the little water South Africa has and so various policies, laws, guidelines and entities exist to control the use and management of water. South Africa has recently put plans into action to establish nine catchment management agencies, as provided for in the National Water Act (Act 36 of 1998), to deal with the management of water at a catchment level. The establishment and operation of these nine institutions are behind schedule and the outcome of the process thus far is below the desired level. Management of natural resources is done by a wide range of institutions with a variety of management styles according to certain management principles and plans. These management styles can be adjusted to suit the management of most types of natural resources, and because of the interdisciplinary nature of water management, elements from all the management styles can be drawn from to suit water management. Three management and governance styles or concepts were identified for this study. The characteristics and principles of these concepts have been divided into different aspects or broad themes of water management. The National Water Act 36 of 1998, specifically the sections related to catchment management agencies, is reviewed to identify the provisions that might be preventing them from adopting the principles of successful management as suggested by the three governance and management styles.

This research report is a completed Catchment Diagnostic Framework (CDF) for the Klip River catchment (Johannesburg) for the period October 1998 to September 1999. The framework consists of a catchment description and a diagnostic index which provide a simple and representative view of the catchment and its characteristics and assist in identifying problem areas. GIS maps, graphs and tables are used to provide a background of the catchment. The Diagnostic Index is based on a set of Indicators that are calculated and then scored according to a rating system allowing for the calculation of an overall value for the catchment. The indicators and description cover resource conditions, socioeconomics, water quantity, water quality and management. Using this CDF it was found that the Klip River catchment is highly altered due to mining, urban, industrial and agricultural development. All of these have impacts on the beneficial use of the Klip River itself and on the downstream users of the Vaal Barrage.
AC 2016

This thesis examines the relationship between rural land management and downstream flood risk. The recent increase in flood frequency and magnitude has been hypothesised to have been caused by either climate change or land management. The theoretical basis for why these factors might increase flood risk is well known, but showing their impact on downstream flood risk remains a challenge. Field scale studies have found that changing land management practices does affect local runoff and streamflow. Upscaling these effects to the catchment scale continues to be problematic,both conceptually and, more importantly, methodologically. Conceptually, upscaling is critical. As land management may impact upon the relative timing as well as the magnitude of runoff, any changes in land management practice may lead to changes in the synchronisation of tributaries flows, either reducing or increasing downstream flood risk. Methodologically, understanding this effect requires capturing the spatial resolution associated with field-scale hydrological processes simultaneously with the upscaling of these processes to the downstream locations where flood risk is of concern. Most approaches to this problem aim to upscale from individual grid cells to whole catchments, something that restricts the complexity of possible process representation,produces models that may not be parsimonious with the data needed to calibrate them and, faced with data uncertainties, provides computational limitations on the extent to which model uncertainty can be fully explored. Rather than upscaling to problems of concern, this thesis seeks to downscale from locations of known flood risk, as a means of identifying where land use management changes might be beneficial and then uses numerical modelling to identify the kinds of management changes required in those downscaled locations. Thus, the aim of this thesis is to test an approach to understanding the impacts of rural land management upon flood risk based upon catchment-to-source downscaling. This thesis uses the case study of the River Eden catchment (2400 km2) as a test case. Firstly the downstream flood risk problem was assessed using both gauged data and documentary evidence to investigate the historical flood record. This found the last decade does not differ significantly from previous flood rich periods, which were defined as 1) 1873-1904; 2) 1923-1933; and 3) 1994-present. Second, the potential causes of floods within the catchment were investigated; firstly climate variability was assessed using Lamb weather types, which found that five weather types were responsible for causing 90% of the floods in the last 30 years. Third, spatial downscaling of catchment-scale flood risk was undertaken using two methods; databased statistical analysis; and hydraulic modelling. Both approaches consider the magnitudes and the timing of the flows from each major sub-catchment. The statistical approach involved a principal components analysis to simplify the complex subcatchment interactions and a stepwise regression to predict downstream flood risk. The hydraulic modelling approach used iSIS-Flow to undertake a series of numerical experiments, where the input hydrographs from each tributary were shifted individually and the effect on downstream peak stage assessed. Both these approaches found that the Upper Eden and Eamont sub-catchments were the most important in explaining downstream flood risk. The Eamont sub-catchment was chosen for future analysis as:(1) it was shown to have a significant impact on downstream flood risk; and (2) it had range of data and information needed for modelling land use changes. The second part of this thesis explored the land management scenarios that could be used to reduce flood risk at the catchment scale. The scenarios to be tested were determined through a stakeholder participation approach, whereby workshops were held to brainstorm and prioritise land management options, and then to identify specific locations within the Eamont sub-catchment where they could tested. There were two main types of land management scenarios chosen: (1) landscape-scale changes,including afforestation and compaction; and (2) channel modification and floodplain storage scenarios, including flood bank removal and wet woodland creation. The hydrological model CRUM3 was used to test the catchment scale land use changes,while the hydraulic model iSIS-Flow was used to test the channel and floodplain scenarios. It was found that through changing the whole of a small sub-catchment(Dacre Beck), the scenarios of reducing compaction and arabilisation could reduce catchment scale (2400 km2) flood risk by up to 3.5% for a 1 in 175 year flood event(January 2005). Changing localised floodplain roughness reduced sub-catchment (Lowther) peak stage by up to 0.134 m. This impact diminished to hardly any effect on peak flow magnitudes at the sub-catchment scale (Eamont). However, these scenarios caused a delay of the flood peak by up to 5 hours at the sub-catchment scale, which has been found to reduce peak stage at Carlisle by between 0.167 m to 0.232 m, corresponding to a 5.8% decrease in peak discharge. A key conclusion is that land management practices have been shown to have an effect on catchment scale flooding, even for extreme flood events. However, the effect of land management scenarios are both spatially and temporally dependent i.e. the same land management practice has different effects depending on where it is implemented, and when implemented in the same location has different effects on different flood events.

In this minithesis I have investigated overlapping mandates as a source of management failure in water management in South Africa in general and Eerste River Catchment in particular. I analysed major legislation which deals with water management to find out how duties and responsibilities are apportioned in the various pieces of legislation. I also undertook an exercise of evaluating roles and responsibilities played by various organs of state in water management from national government, Provincial Government of the Western Cape through to local government, in this case the Municipality of Stellenbosch and the City of Cape Town. It emerged that there were a number of areas of overlap, ambiguously defined mandates, conflict and that these were impeding on decision making in water management. In order to test the framework built above, I then applied it in the Plankenbrug River, a tributary of the Eerste River. Through analysis of newspaper clippings over a period of 4 years I was able to reconstruct conflict over ill-defined mandates in the various aspects of the management of the catchment which showed that
there were differences in roles of the different state organs operating in the catchment. Water management conflict emanated from lack of congruence in the various legislation and differences in the interpretation of legislation. The various state organs seem to be aware of the constitutional duty of cooperative government that engenders state organs to work co-operatively in order to meet their developmental mandates. It seems however that the state organs were merely interested to be seen to be in conformity with this duty more than actually solving the issue as this was seen as something to be tackled at a higher level.

This thesis presents an approach for generating long synthetic sequences of single-site daily rainfall which can incorporate low-frequency features such as drought, while still accurately representing the day-to-day variations in rainfall. The approach is implemented in a two-stage process. The first stage is to generate the entire sequence of rainfall occurrence (i.e. whether each day is dry or wet). The second stage is to generate the rainfall amount on all wet days in the sequence. The models used in both stages are nonparametric (they make minimal general assumptions rather than specific assumptions about the distributional and dependence characteristics of the variables involved), and ensure an appropriate representation of the seasonal variations in rainfall. A key aspect in formulation of the models is selection of the predictor variables used to represent the historical features of the rainfall record. Methods for selection of the predictors are presented here. The approach is applied to daily rainfall from Sydney and Melbourne. The models that are developed use daily-level, seasonal-level, annual-level, and multi-year predictors for rainfall occurrence, and daily-level and annual-level predictors for rainfall amount. The resulting generated sequences provide a better representation of the variability associated with droughts and sustained wet periods than was previously possible. These sequences will be useful in catchment water management studies as a tool for exploring the potential response of catchments to possible future rainfall.

The Waipara catchment, North Canterbury, New Zealand is currently experiencing rapid intensification in land use from pastoral farming to viticultural, horticultural and lifestyle activities. This intensification has lead to escalating demand for water which has created challenges for the Waipara community and the water managers. Sustainable and effective management requires both a thorough understanding of the physical environment and consideration of the needs of society. This study has been undertaken to assist management by quantifying the water resources, determining current water use and identifying the key issues facing management. Limited precipitation and high evapo-transpiration rates dominate the area's water resources resulting in very limited runoff and significant soil moisture deficits over the summer months. The surface water resources of the area are over allocated with potential abstraction rates far exceeding normal summer flows. The last five years has seen the rapid development of groundwater as landowners look for alternative irrigation supplies. The groundwater resources are very complicated and highly variable consisting of small discrete buried river channels. Recharge rates are very low which questions the long term sustainability of groundwater resource. There is a need to move towards integrated catchment management where science and the community work together to create workable and appropriate solutions. The Waipara community are already highly active in water management. Similarly, recent science has improved understanding of the resources. Water managers need to cease the opportunity and begin the process of developing a holistic catchment management plan.

River catchments are an obvious scale for soil and water resources management, since their shape and characteristics control the pathways and fluxes of water and sediment. Digital Elevation Models (DEMs) are widely used to simulate overland water paths in hydrological models. However, all DEMs are approximations to some degree and it is widely recognised that their characteristics can vary according to attributes such as spatial resolution and data sources (e.g. contours, optical or radar imagery). As a consequence, it is important to assess the ‘fitness for purpose’ of different DEMs and evaluate how uncertainty in the terrain representation may propagate into hydrological derivatives. The overall aim of this research was to assess accuracies and uncertainties associated with seven different DEMs (ASTER GDEM1, SRTM, Landform Panorama (OS 50), Landform Profile (OS 10), LandMap, NEXTMap and Bluesky DTMs) and to explore the implications of their use in hydrological analysis and catchment management applications. The research focused on the Wensum catchment in Norfolk, UK. The research initially examined the accuracy of the seven DEMs and, subsequently, a subset of these (SRTM, OS 50, OS10, NEXTMap and Bluesky) were used to evaluate different techniques for determining an appropriate flow accumulation threshold to delineate channel networks in the study catchment. These results were then used to quantitatively compare the positional accuracy of drainage networks derived from different DEMs. The final part of the thesis conducted an assessment of soil erosion and diffuse pollution risk in the study catchment using NEXTMap and OS 50 data with SCIMAP and RUSLE modelling techniques. Findings from the research demonstrate that a number of nationally available DEMs in the UK are simply not ‘fit for purpose’ as far as local catchment management is concerned. Results indicate that DEM source and resolution have considerable influence on modelling of hydrological processes, suggesting that for a lowland catchment the availability of a high resolution DEM (5m or better) is a prerequisite for any reliable assessment of the consequences of implementing particular land management measures. Several conclusions can be made from the research. (1) From the collection of DEMs used in this study the NEXTMap 5m DTM was found to be the best for representing catchment topography and is likely to prove a superior product for similar applications in other lowland catchments across the UK. (2) It is important that error modelling techniques are more routinely employed by GIS users, particularly where the fitness for purpose of a data source is not well-established. (3) GIS modelling tools that can be used to test and trial alternative management options (e.g. for reducing soil erosion) are particularly helpful in simulating the effect of possible environmental improvement measures.

Thesis (M.ScEng.)--Stellenbosch University, 2001.
ENGLISH ABSTRACT: Historically, urban waterresources have too often been managed without recognition that the flow in a river integrates many landscape and biological features. This has often resulted in the elimination of natural processes and their replacement by man-made streamlined structures with the effects of increased urbanisation being primarily addressed from an engineering and economics point of view to the detriment of environmental and social issues. Catchment Management, as legislated in the Water Act, No. 36 of 1998, is a management approach to address the negative consequences of an urban stormwater design philosophy restricted to flood restriction. It is a systems approach that integrates engineering and scientific skills, socio-economic concerns, and environmental constraints within a new multidisciplinary decision-making process that recognises the different components of the hydrological and aquatic cycles are linked, and each component is affected by changes in every other component. In order to make effective management decisions, catchment managers require tools to provide reliable information about the performance of alternative arrangements of stormwater management facilities and to quantify the effects of possible management decisions on the water environment. A deterministic hydrological model is such a tool, which provides the link between the conceptual understanding of the physical catchment characteristics and the empirical quantification of the hydrological, water quality and ecological response. In order to provide effective computer based decision support, the hydrological model must be part of an integrated software application in which a collection of data manipulation, analysis, modelling and interpretation tools, including GIS, can be efficiently used together to manage a large potion of the overall decision process. This decision support system must have a simple and intuitive user interface able to produce easily interpreted output. It must have powerful graphical presentation capabilities promoting effective communication and be designed to solve ill-structured problems by flexibly combining statistical analysis, models and data. The Great Lotus River canal, situated on the Cape Flats, Cape Town, has been designed and controlled through extensive canalisation and the construction of detention pond facilities to avoid the flooding of urban areas of the catchment. This approach has resulted in these channels becoming stormwater drains, transporting waste and nutrients in dissolved and particulate forms, and reducing their assimilatory capacity for water quality improvement. In order to investigate the use of hydrological modelling in decision support for Catchment Management, the semi-distributed, physically based model, SWMM, was applied to the Great Lotus River canal. SWMM consists of a number of independent modules allowing the hydrological and hydraulic simulations of urban catchments and their conveyance networks on an event or continuous basis. In order to ease the application of the Fortran based SWMM model, the GUl, PCSWMM98, was developed by Computational Hydraulics Inc (CH!). This provides decision support for SWMM through large array of tools for file management, data file creation, output visualisation and interpretation, model calibration and error analysis and storm dynamic analysis thus easing any simulations with SWMM. In addition, PCSWMM was developed with a GIS functionality for graphically creating, editing and/or querying SWMM model entities and attributes, displaying these SWMM layers with background layers and dynamic model results, and exporting data to SWMM input files thus providing an interface between a GIS and SWMM. In terms of Catchment Management, the above DSS can be used effectively to assist decisionmaking. This is to address tensions between the fundamental catchment management considerations of physical development, social considerations and maintaining ecological sustainability. It is at the stages of Assessment and Planning that the model can play the most significant role in providing decision support to the Catchment Management process. Assessment in the Catchment Management process refers to the collection, storage, modelling and interpretation of catchment information. It is in this quantification, interpretation and assessment of catchment information that a hydrological model contributes to an increase in knowledge in the Catchment Management process. In identifying and quantifying, at a sufficient temporal and spatial scale, the dominant cause and effect relationships in the urban physical environment, a hydrological model is able to highlight the main contributing factors to an issue. This is used in the Planning stage of the Catchment Management process and when combining these contributing factors with assessments of the socio-economic and administrative environments, enables the prioritisation of the principal issues requiring attention in a Catchment Management Strategy. It is possible to link the multiple decision-making requirements of Catchment Management with the abilities of a hydrological model to provide information on these requirements in a conceptual framework. This framework consists of the fundamental catchment considerations of Physical Development, Environmental Management and Social Development and resolves these considerations into the various management issues associated with each consideration ~s well as its management solution. The management solutions are linked to the model through formulating the solution in terms of the model parameters and perturbing the affected parameters in ways to simulate the management solution. This results in model output and graphical interpretation of the effects of the suggested management solution. A comparison between the simulated effects of each management solution allows the Catchment Management body to identify optimal management solutions for the various management Issues. The present model of the Great Lotus River catchment is sufficient to simulate the overland and subsurface flows from individual parts of the catchment and to route these flows and associated pollutant loadings to the catchment outlet. At its present level of complexity, the finely discretised model subcatchment and conveyance network provides decision support for Catchment Management through the simulation, at a pre-feasibility stage, of various Catchment Management issues and their proposed solutions. Given more detailed canal and drainage network dimensions and water quality data, it is possible for the model to incorporate hydraulic calculation routines to assess the implications of alternative river rehabilitation techniques and waste management strategies. This would allow greater capability in assessing the role of the various BMPs in ameliorating stormwater impacts and pollutant loading. In addition, a detailed level survey of the stormwater pipe and canal network could result in hydrological modelling being utilised to identify critical areas where stormwater upgrading would be necessary. In order to facilitate future complex, finely discretised catchment hydrological models, it is imperative that complete and detailed drainage patterns and stormwater network characteristics are available. In addition, to minimise model generation costs and time of model setup, this spatially representative data must be captured in a GIS for rapid inclusion into the model. Furthermore, complete spatially representative precipitation datasets are necessary to ensure that model error is reduced. These two issues of available spatial data and comprehensive precipitation records are crucial for the generated models to function as effective decision support systems for Catchment Management.
AFRIKAANSE OPSOMMING: Histories is stedelike waterbronne te dikwels bestuur sonder inagneming dat die vloei van die rivier baie landskap- en biologiese kenmerke insluit. Dit het dikwels daartoe gelei dat natuurlike prosesse uitgeskakel is en vervang is deur mensgemaakte, stroombelynde strukture waarvan die effek van toenemende verstedeliking hoofsaaklik aangespreek word vanuit 'n ingenieurs- en ekonomiese oogpunt tot nadeel van omgewings- en sosiale kwessies. Opvangsgebiedsbestuur, soos bepaal deur die Waterwet, Wet 36 van 1998, is 'n bestuursbenadering om die negatiewe gevolge van 'n stedelike stormwaterontwerpfilosofie wat beperk is tot vloedbeperking aan te spreek. Dit is 'n stelselbenadering wat ingenieurs- en wetenskaplike vaardighede, sosio-ekonomiese probleme en omgewingsbeperkings integreer in 'n nuwe multidissiplinêre besluitnemingsproses wat erkenning daaraan gee dat die verskillende komponente van die hidrologiese en watersiklusse verbind is, en elke komponent beïnvloed word deur veranderings in elke ander komponent. Om doeltreffende bestuursbesluite te neem, benodig opvangsgebiedsbestuur die hulpmiddels om betroubare inligting oor die prestasie van alternatiewe moontlikhede VIr stormwaterbestuurfasiliteite en om die effek van moontlike bestuursbesluite op die wateromgewing te kwantifiseer. 'n Deterministiese hidrologiese model is so 'n hulpmiddel wat die skakel daarstel tussen die konseptueie begrip van die fisiese opvangsgebiedskenmerke en die empiriese kwantifisering van die water-, waterkwaliteit- en ekologiese reaksie. Om doeltreffende rekenaarbesluitnemingsteun te verskaf, moet die hidrologiese model deel wees van 'n geïntegreerde sagteware-aanwending waarin 'n versameling datamanipulasie-, analise-, modellerings- en interpreteringshulpmiddels, insluitend GIS, doeltreffend saam gebruik kan word om 'n groot deel van die algehele besluitnemingsproses te bestuur. Hierdie besluitnemingsteunstelsel moet 'n eenvoudige en intuïtiewe gebruikersvlak hê wat in staat is om maklik interpreteerbare uitsette te lewer. Dit moet goeie grafiese voorleggingsvermoëns hê wat doeltreffende kommunikasie vergemaklik en ontwerp wees om swak gestruktureerde probleme deur die buigsame samevoeging van statistiese analise, modelle en data op te los. Die Groot Lotusrivierkanaal op die Kaapse Vlakte, Kaapstad is ontwerp en word beheer deur uitgebreide kanalisasie en die konstruksie van detensiedamfasiliteite om die oorstroming van stedelike opvangsgebiede te vermy. Hierdie benadering het daartoe gelei dat hierdie kanale stormwaterafvoerpype geword het wat afval en nutriënte in opgelosde en partikelvorm vervoer en hulle assimilasievermoë vir die verbetering van waterkwaliteit verminder. Om die gebruik van hidrologiese modelle in besluitnemingsteun vir Opvangsgebiedsbestuur te ondersoek, is die semi-verspreide, fisiesgebaseerde model, SWMM, op die Groot Lotusrivierkanaal toegepas. SWMM bestaan uit 'n aantalonafhanklike modules wat die hidrologiese en hidroulika simulasies van stedelike opvangsgebiede en hulle vervoemetwerke per geleentheid of deurlopend monitor. Om die aanwending van die Fortran gebaseerde SWMM model te vergemaklik is die GUl, PCSWMM98 deur Computational Hydraulics Inc (CHD ontwikkel. Dit verskaf besluitnemingsteun vir SWMM deur 'n groot aantal hulpmiddels vir lêerbestuur, die skep van datalêers, uitsetvisualisering en interpretasie, modelkalibrasie, foutanalise en stormdinamikaanalise om enige simulasies met SWMM te vergemaklik. Daarby is PCSWMM ontwikkel met 'n GIS funksionaliteit vir die grafiese daarstelling, redigering en/of navraagfunksie van SWMM model entiteite en kenmerke, wat hierdie SWMM vlakke met agtergrondvlakke en dinamiese modelresultate vertoon en data in SWMM inset1êers plaas en op daardie manier 'n koppelvlak tussen 'n GIS en SWMM verskaf. Volgens Opvangsgebiedsbestuur kan bogenoemde DSS doeltreffend gebruik word in besluitneming. Dit IS om die spanning tussen fundamentele opvangsgebiedsbestuursoorwegings van fisiese ontwikkeling, sosiale oorwegings en ekologiese volhoubaarheid aan te spreek. Dis in die stadiums van Waardebepaling en Beplanning wat die model die belangrikste rol kan vervul in die verskaffing van besluitnemingsteun vir die Opvangsgebiedsbestuursproses. Waardebepaling in die Opvangsgebiedbestuursproses verwys na die versameling, berging, modellering en interpretasie van opvangsgebiedsinligting. Deur hierdie kwantifisering, interpretasie en waardebepaling van opvangsgebiedsinligting dra 'n hidrologiese model by tot 'n verhoging in kennis in die Opvangsgebiedsbestuur. Deur die identifisering en kwantifisering, op 'n ruim genoeg tydelike en ruimtelike skaal, van die dominante oorsaak en gevolg verhoudings in die stedelike fisiese omgewing, kan die hidrologiese model die hoof bydraende faktore uitlig. Dit word gebruik in die Beplanningsfase van die Opvangsgebiedproses en wanneer hierdie bydraende faktore by die waardebepaling van die sosio-ekonomiese en administratiewe omgewings saamgevoeg word, maak dit moontlik om die belangrike kwessies wat aandag behoort te kry in 'n Opvangsgebiedsbestuurstrategie in volgorde van voorrang te plaas. Dit is moontlik om die verskeidenheid besluitnemingsvereistes van Opvangsgebiedsbestuur met die vermoëns van 'n hidrologiese model te koppel om inligting oor hierdie vereistes in 'n konseptuele raamwerk te verskaf. Die raamwerk bestaan uit die fundamentele opvangsgebiedsoorwegings van Fisiese Ontwikkeling, Omgewingsbestuur en Sosiale Ontwikkeling en los hierdie oorwegings op in die verskillende bestuursaangeleenthede wat met elke oorweging en die bestuuroplossing geassosieer word. Die bestuursoplossings word aan die model gekoppel deur die formulering van die oplossing volgens die modelparameters en versteuring van die relevante parameters op sekere manier om die bestuursoplossing te simuleer. Dit lei tot modeluitset en grafiese interpretasie van die effek van die voorgestelde bestuursoplossing. 'n Vergelyking tussen die gesimuleerde effek van elke bestuursoplossing laat die Opvangsgebiedsbestuursliggaam toe om die optimale bestuursoplossings vir die verskeie bestuursaangeleenthede te identifiseer. Die huidige model van die Groot Lotusrivieropvang is genoegsaam om die bo- en ondergrondse vloei vanaf individuele dele van die opvangsgebied te simuleer en om die watervloei en geassosieerde besoedelstofladings na die opvangsgebiedsuitlaatplek te lei. Op sy huidige vlak van kompleksiteit verskaf die fyn gediskretiseerde model subopvangsgebied en vervoernetwerk besluitnemingsteun aan Opvangsgebiedsbestuur deur die simulasie, teen 'n voor-lewensvatbaarheidstudie, van verskeie opvangsgebiedsbestuurkwessies en die voorgestelde oplossings. Indien meer gedetailleerde kanaal- en dreineringsnetwerkdimensies- en waterkwaliteitdata ingevoer word, is dit moontlik vir die model om hidroulikaberekeningsroetines te inkorporeer om die implikasies van alternatiewe rivierrehabilitasietegnieke en afvalbestuurstrategieë te beoordeel. Dit sou die vermoë verbeter om die waarde van die verskeie BMPs te bepaal om die impak van stormwater en besoedelstoflading te versag. Daarby kan 'n gedetailleerde vlakopname van die stormwaterpyp en -kanaalnetwerk daartoe lei dat hidrologiese modelle gebruik kan word om kritieke areas te identifiseer waar stormwateropgradering nodig is. Om toekomstige komplekse, gediskretiseerde opvangsgebiedshidrologiese modelle te verbeter, is dit noodsaaklik dat volledige en gedetailleerde dreineringspatrone en stormwaternetwerkkenmerke beskikbaar is. Om die model-ontwikkelingskoste en tyd bestee aan die opstel van 'n model te minimiseer, moet hierdie ruimtelik verteenwoordigende data ingelees word in 'n GIS vir vinnige insluiting in die model. Daarbenewens is volledige, ruimtelik verteenwoordigende presipitasie datastelle nodig om te verseker dat modelfoute verminder word. Hierdie twee kwessies van beskikbare ruimtelike data en omvattende presipitasierekords is van die uiterste belang sodat die gegenereerde modelle as doeltreffende besluitnemingsteun vir Opvangsgebiedsbestuur kan funksioneer.

Flooding is one of the most significant issues facing the UK and Europe. New approaches are being sought to mitigate its impacts, and distributed, catchment-based techniques are becoming increasingly popular. These employ a range of measures, often working with the catchment’s natural processes, in order to improve flood resilience. There remains a lack of conclusive evidence, however, for the impacts of these approaches on the storm runoff, leading to considerable uncertainty in their effectiveness in terms of mitigating flood risk. A new modelling framework for design, assessment, and uncertainty estimation of such distributed, nature-based schemes is developed. An implementation of a semidistributed runoff model demonstrates robustness to spatio-temporal discretisation. Alongside a new hydraulic routing scheme, the model is used to evaluate the impacts on flood risk of in-channel measures applied within an 29 km2 agricultural catchment. Maximum additional channel storage of 70,000 m3 and a corresponding reduction of 11% in peak flows is seen. This, however, would not have been insufficient to prevent flooding in the event considered. Further modifications allow simulation of the impacts of wider measures employing natural processes. This is applied within an uncertainty estimation framework across the headwaters of three mixed-use catchments, ranging in size from 57 km2 to 200km2 , across a series of extreme storm events. A novel surface routing algorithm allows simulation of large arrays distributed features that intercept and store fast runoff. The effect of the measures can be seen across even the most extreme events, with a reduction of up to 15% in the largest peak, albeit that this large impact was associated with a low confidence level. The methodology can reflect the uncertainty in application of natural flood risk management with a poor or incomplete evidence base. The modelling results demonstrate the importance of antecedent conditions and of the timings and magnitudes of a series of storm events. The results shows the benefits of maximizing features’ storage utilisation by allowing a degree of “leakiness” to enable drain-down between storms. An unanticipated result was that some configurations of measures could synchronise previously asynchronous subcatchment flood waves and have a detrimental effect on the flood risk. The framework shows its utility in both modelling and evaluation of catchment-based flood risk management and in wider applications where computational efficiency and uncertainty estimation are important.

The improvement of water quality in the streams of the Glenelg Hopkins catchment is a priority of the Glenelg Hopkins regional strategy. A major source of water pollution in the region is linked to agricultural activities as high nutrient levels from runoff have the potential to increase the incidence of blue-green algae in the waterways. Land use change, reduced rainfall, more frequent extreme rainfall events and higher temperatures associated with climate change are likely to exacerbate this trend. Water testing data of the Total Phosphorus (TP) levels in the Hopkins River and at other sites within the Hopkins Catchment indicate increasing incidence of TP above the Environment Protection Authority's target levels for extended periods of each year. Earlier research indicated that phosphorus in runoff increases when pasture fertility increases and that fertiliser management practices should be considered as an element of preventative action for reducing nutrient pollution. During our research, a survey was undertaken in the Hopkins River catchment, to determine the current management of phosphorus (P) fertilisers on grazing and mixed enterprise farms, the attitude of farmers to natural resource management and their understanding of nutrient pollution. The survey also gathered information on the way farmers made fertiliser management decisions. If cooperation relating to phosphorus fertiliser application could be facilitated between groups of farmers, it may be possible to reduce nutrient runoff into the Hopkins waterways. Cooperative game theory has successfully been used worldwide in the resolution of environmental problems where there is an economic impact to the decision making process. In this project, the amount of phosphorus applied per hectare was used in a cooperative game theory model assessing the potential for cooperative action on phosphorus management by groups of farmers, based on the trade off between the economic cost of pollution to the region waterways and the economic production benefits to the individual. The outcome of this work was individual optimal strategies for fertiliser application, allowing individual farmers to reduce their impact of agricultural production on the health of the catchment. Involving the farmer groups, while undertaking the project, raised awareness amongst the farming population of the regional nutrient pollution caused by runoff from agricultural land, and enlisted their assistance towards adopting a cooperative approach to the problem. In addition, the results have been mapped using a Geographical Information System (GIS) for visual presentation and to demonstrate the use of this process in natural resource management with the farmer groups.

Much of the UK’s water environment is degraded due to centuries of intensive land management. Driven by the combined pressures of EU targets for water quality, climate change, urbanisation, and population growth the requirement for better management of water resources has led to the adoption of catchment scale management. Despite fewer funding opportunities available to catchment organisations government expectations remain high. Spatial technologies have much to offer to aid collaboration between catchment organisations and stakeholders in their aims to improve the water environment, but research evaluating the application of low cost spatial technologies to support the Catchment Based Approach within the UK has to date been limited. Through three case studies this thesis explored how spatial technologies could support the development of future sustainable and multifunctional river catchment landscapes. The methodology of each case study retained a practitioner focus and evaluated both practitioner interaction with the technologies and the technology development itself. The research examined the strengths and weaknesses of spatial technology in practice and identified barriers to wider adoption by the catchment partnerships and rivers trusts. Results indicate untapped potential for spatial technologies to support the Catchment Based Approach (CaBA) but three barriers to adoption exist. First, there are technological restrictions which need to be overcome with further development. Secondly, significant resources are required, and thirdly, the disruptive influence of technology on institutional structure must be accommodated. Even with the suggested further development the spatial technologies evaluated in this thesis remain outside of the scope of many catchment institutions in terms of skill, understanding of best practice and the resources to support implementation. The future of our water environment and the wider landscape is constrained not by those carrying out the work but the lack of funds and governance frameworks for catchment institutions to work together.

This thesis reports the results of a three year cross disciplinary investigation of the water resources of a small headwater catchment and their role existing and future in the livelihoods of the local community. In addition the potential for micro-catchment management to improve the water resources and water based livelihoods of the catchment community was also examined. Physical examination of the shallow aquifer revealed higher than expected levels of groundwater recharge, matched by high levels of naturally occurring discharge. A groundwater modelling study suggested that this discharge was caused by both deep and shallow rooted vegetation, rather than by drainage losses, and that the catchment aquifer was largely isolated from any larger regional groundwater system. Research into the historical development of the catchment community revealed an ongoing process of agricultural intensification, driven by increasing population and expectations. One manifestation of this intensification is a rapid development of groundwater resources for small scale irrigation. The study suggested that the increased development of and reliance on water points exploiting shallow groundwater resources could lead to increased risk in dry periods associated with generally low groundwater levels. The work highlighted the crucial importance of correct siting and design of water points if widespread failure is to be avoided. However, it also suggested that irrigated agriculture could be sustainably increased at least ten-fold by using suitably sited high yielding water points. Finally, a prototype decision support system was developed using Bayesian Belief Networks, and this was used to integrate the physical and human aspects of the study within a single framework. This framework was then used to examine the likely affects on livelihoods of adopting a micro-catchment management approach to managing groundwater resources.

Internationally, water resources are facing increasing pressure due to over-exploitation and pollution. Integrated Water Resource Management (IWRM) has been accepted internationally as a paradigm for integrative and sustainable management of water resources. However, in practice, the implementation and success of IWRM policies has been hampered by the lack of availability of integrative decision support tools, especially within the context of limited resources and observed data. This is true for the Crocodile River Catchment (CRC), located within the Mpumalanga Province of South Africa. The catchment has been experiencing a decline in water quality as a result of the point source input of a cocktail of pollutants, which are discharged from industrial and municipal wastewater treatment plants, as well as diffuse source runoff and return flows from the extensive areas of irrigated agriculture and mining sites. The decline in water quality has profound implications for a range of stakeholders across the catchment including increased treatment costs and reduced crop yields. The combination of deteriorating water quality and the lack of understanding of the relationships between water quantity and quality for determining compliance/non-compliance in the CRC have resulted in collaboration between stakeholders, willing to work in a participatory and transparent manner to create an Integrated Water Quality Management Plan (IWQMP). This project aimed to model water quality, (combined water quality and quantity), to facilitate the IWQMP aiding in the understanding of the relationship between water quantity and quality in the CRC. A relatively simple water quality model (WQSAM) was used that receives inputs from established water quantity systems models, and was designed to be a water quality decision support tool for South African catchments. The model was applied to the CRC, achieving acceptable simulations of total dissolved solids (used as a surrogate for salinity) and nutrients (including orthophosphates, nitrates +nitrites and ammonium) for historical conditions. Validation results revealed that there is little consistency within the catchment, attributed to the non-stationary nature of water quality at many of the sites in the CRC. The analyses of the results using a number of representations including, seasonal load distributions, load duration curves and load flow plots, confirmed that the WQSAM model was able to capture the variability of relationships between water quantity and quality, provided that simulated hydrology was sufficiently accurate. The outputs produced by WQSAM was seen as useful for the CRC, with the Inkomati-Usuthu Catchment Management Agency (IUCMA) planning to operationalise the model in 2015. The ability of WQSAM to simulate water quality in data scarce catchments, with constituents that are appropriate for the needs of water resource management within South Africa, is highly beneficial.

Recent policy changes, such as the EU Water Framework Directive, have transformed catchment management to consider connected socio-ecological systems at the catchment scale, and integrate concept of public participation. However, there is relatively little research exploring how effective these changes have been in altering existing practices of management. Adopting a transdisciplinary approach, this thesis investigates a range of perspectives to explore existing participatory practices in current catchment management, and understand how we can integrate alternative knowledges and perspectives. The research employs diverse social and physical science methods, including participant led interviews and participatory mapping, numerical flood modelling, and the creation of a participatory competency group. The research finds that, despite the participatory policy turn, established supracatchment scale drivers continue to dictate top-down practices of everyday catchment management, excluding local communities from decision-making power. In contrast, participation in managing extreme events is actively encouraged, with the development of community resilience a key objective for management agencies. However, the research findings suggest that a similar lack of meaningful participation in knowledge creation and decision-making restricts resilience building. Based on these findings, the research explores practical ways in which participation and resilience can be embedded in ICM, using the typically expert-led practice of numerical flood modelling to show how existing practices of knowledge creation can be enhanced. The thesis also demonstrates how new practices of knowledge creation, based on social learning, can be used to develop new, more effective ways of communicating flood risk and building local resilience. The thesis proposes a new framework for the management of connected socio-ecological catchment systems, embedding evolutionary resilience as a practical mechanism by which public participation and the management of everyday and extreme events could be unified to develop more effective and sustainable catchment management and more resilient communities.

Enacted in 1998, the New South African Water Act has introduced a new approach to water resource management, founded on the principle of decentralization of the management of water resources to regional and local levels and the public participation. The approach has been captured in the new National Water Act (Act 36 of 1998), which allows the establishment of Catchment Management Agencies. The overall purpose of this study was to understand the trends of public participation in the establishment of Catchment Management Agencies in South Africa, by presenting the case of the Berg Catchment Management Agency.

The implementation of the EU Water Framework Directive (2000/60/EC) (WFD), enacted to monitor and recover the quality of water bodies, is a good example of catchment management requiring a wider scope of understanding with regard to the chemical, ecological and quantitative status of river catchments. It has caused water management to shift from a local to a river basin scale and therefore requires a better understanding of emission sources of dangerous substances and their contribution to water quality at the catchment level. Metals include dangerous substances of continued and growing concern. The hazardous properties of metals reflect their ability to substitute for essential elements in biological systems, resulting in a disturbance of the biological functions of animals and humans. This thesis aimed to identify ways of assessing sources of metals at the catchment level for the implementation of the WFD. Different approaches were proposed to estimate impacts of emission sources on levels of metals in water bodies. Potential anthropogenic sources of metals and metalloids in receiving waters were identified at the catchment level. Of the metal sources, effluents from wastewater treatment plants, sediments in a water body and diffuse metal sources were selected in order to further evaluate their contributions to the quality of water bodies, using or developing simple methods to estimate these. Case studies demonstrated the effectiveness and reliability of the calculations used. Overall findings of the work highlighted the need to identify all the pressures of pollutant inputs and to assess their relative importance to the deterioration of water quality for compliance with the WFD. To this end, it is recommended that source assessment should be incorporated into the process of river basin management under the WFD. Source assessment can facilitate the performance of water management stages and the improvement of the quality of surface water bodies.

Water companies are continually adopting catchment management as a way of improving the quality of raw water prior to treatment. The catchments from which raw water is abstracted are often heterogeneous which regularly presents multiple pollutant issues and variability in the spatial distribution of pollutant-contributing areas. For catchment management to be effective, it is crucial that water companies select and target appropriate interventions at multi-pollutant high risk areas. Within this thesis a conceptual framework is developed to disaggregate and compare multiple pollutant risks in drinking water catchments to aid water companies in this decision making process. A review of pollutant processes highlights links between pollutants often mitigated using catchment management and therefore confirms the feasibility for a multi- pollutant framework. Criteria were developed with water industry catchment management professionals to determine framework requirements. No current framework or model fully meets these criteria.

'Water stress' is a term used when the pressures of urbanisation and the uncertainty of climate change on hydrological limits and capacities can no longer be overcome by traditional supply-oriented engineering responses because of their economic and environmental costs. It can be argued that the key alternative water policy responses are occurring with the changing role of development and Catchment Management Planning (CMPg) to a more 'catchment consciousness' water management model. In England and Wales the emergence of 'water stress' in the 1990s has coincided with the national launch of CMPg and renewed interest in development and water issues. Thus the research question sought to investigate how the National Rivers Authority (NRA) as a statutory environmental agency sought to improve and integrate river management by extending its influence to development planning through Catchment Management Planning (CMP) between 1991 and 1996. The particular areas of outcome focused on were water quality improvement, water resource management and flood protection, major NRA functions. The research findings demonstrated that there were different types of development response linked to water issues, scale of implementation and potential contribution to city form. The most important factor in the type of response was the water issue, with the flooding relationship being most advanced and water resources the least. The CMPg process assisted by supporting the promotion of water policies in DPs and creating a new context (involving stakeholder involvement and consensus building) in which to implement these policies. CMPg was found to be having the greatest impact in areas where no previous consensus over particular water issues had existed, and thus had begun to act as a new arena for debate on the problems and solutions required.

By the adoption of Integrated Water Resource Management (IWRM), South Africa has significantly changed its water management regime and the institutions governing water in this country. These changes were first introduced by the National White Policy Paper on Water in South Africa in 1997 and subsequently the National Water Act in 1998. One of the key components of IWRM is the decentralisation of water management to a regional or catchment level and the introduction of public participation in the water management sector. With the enactment of the NWA South Africa incorporated IWRM in its legal system and a decade on, authorities are now turning to its implementation. The NWA introduces Catchment Management Agencies (CMAs) in water management and gives them authority over water management at a catchment level. Initially there were nineteen (19) and this number has since been reduced to nine (9) due to a number of factors. South African authorities are now seeking ways in which they can effectively decentralise water to a catchment level, including delegating and assigning some of the functions currently held by the Minster to CMAs. Using Victoria, Australia as a comparative study, this study investigates how water management can best be decentralised to a catchment level; it starts off by investigating the theory of decentralisation and its pros and cons; then sets off to investigate water management has been decentralised in Australia from the national level, to state level and catchment level; it then investigates the role of Rural Water Authorities in Victoria and compares them to Catchment Management Agencies in South Africa. Finally the work highlights the water management regime and the various stakeholders in water management South Africa from a national level to a catchment level and the challenges facing South Africa in term of WRM; and then makes recommendations and a conclusion based on its research findings and the South African socio-economic and political context.

On-site sewage systems, such as septic tank-absorption trenches, are used by approximately 20 000 people who live within the catchments that supply Sydney??s drinking water. These systems discharge sewage, treated to varying degrees depending on the system type and level of maintenance, to the environment. This can result in contamination of drinking water supplies if systems are not designed or managed appropriately. The aim of the project was to develop a methodology to define appropriate buffer distances between on-site sewage systems and waterways in Sydney??s drinking water catchments, to ensure the protection of drinking water quality. Specific objectives included: identifying the current status of on-site sewage management; assessing the effluent quality and treatment performance of septic tanks, aerated wastewater treatment systems (AWTS) with disinfection and an amended material sand mound; and development of an appropriate methodology for delineating buffer distances and assessing development applications. Viruses were used as a focus for delineating the buffer distances due to their mobility and robustness in the environment, and the potential health consequences of their presence in drinking water. A Quantitative Microbial Risk Assessment (QMRA) model was developed to calculate the cumulative impact of the on-site sewage systems in the Warragamba catchment based on data from literature and experiments, with consideration of virus loads from sewage treatment plants within the catchments. The model enabled consideration of what was a tolerable impact in terms of the resulting infections within the community. The QMRA the tolerable loads of viruses from the Warragamba catchment were 108 viruses per year in raw water and 104 viruses per year in treated water. A log reduction method was developed to facilitate individual site development assessments. This method was compared to other management approaches to development assessment: fixed minimum buffer distances of 100m, reducing failure rates to zero, and the use of a preferred system. Each of these methods had a limit for how much they could reduce virus loads to the catchment due to either failure or short buffer distances at some sites. While the log reduction method is limited by the failure rates, the method provides a quantitative measure of risk by which maintenance inspections can be prioritised.

In the water utility sector, traditional asset management focusses on the maintenance and provision of physical assets (infrastructure) that allow water companies to deliver their services, meet their customers’ expectations and achieve their economic objectives. Nevertheless, the serviceability of the sector heavily depends on natural elements (e.g. rain, land). The importance of Natural Capital (i.e. the natural systems and their deriving ecosystem services) has been at the core of policy recommendations which have shaped regulatory changes in the water sector of England and Wales. Water companies are now required to explicitly account for and report their inter-dependencies on the natural environment and adopt systems-oriented approaches in their Asset Management Programmes (AMPs). These reforms will enable the sector to become resilient to the environmental and societal challenges faced at urban and rural contexts. Responding to the regulatory demands, the research introduces a novel and structured approach for integrating natural capital in the asset management portfolio of the water industry. The work is built on a transdisciplinary research framework and demonstrates that a new scale needs to be considered for the implementation of Holistic Asset Management: the water basin or catchment. A Catchment Metabolism modelling schema was created, grounded on the principles of Integrated Catchment Management and ecosystems services. The schema is based on the robust synthesis of concepts, tools and methods from a spectrum of disciplines. These include Industrial Ecology, Water Accounting, Environmental Regional Input-Output Analysis, hydrology, software engineering and functional modelling. Catchment Metabolism introduces a holistic perspective in asset management and expands its scope. The schema enables the conceptualisation, modelling and management of catchments as complex asset systems. It, thus, forms the ground for structured collaboration among experts for integrated water resources planning and decision-making. The schema allows for the design and implementation of catchment-based strategies and the assessment of their environmental performance. An industrial case study for a pilot catchment system (Poole Harbour Catchment) is used to demonstrate the application of the Catchment Metabolism. Alternative strategies for nitrogen pollution mitigation are assessed. The application of winter cover crops across the catchment appears to be the optimum strategy. The case study demonstrates the practical and modular implementation of the schema, reveals its methodological strengths and limitations and evaluates its applicability in the asset management planning and decision-making of the water sector.

Water is a constantly changing resource by way of the hydrological cycle. It is unevenly distributed and crosses boundaries of all kinds i.e. political, social, cultural and natural. Samoa is a small developing state in the Pacific Region that is facing rapid pressure with its water resource availability. Consequently, access to and use of water resources has created tensions between water resources regulators, water utilities and villages. Therefore, managing and governing of water becomes a challenging process that has to take into account the complexity of both nature and society. With the emergence of the Integrated Water Resources Management (IWRM) framework, a greater social acceptance and importance has been given to catchment scale management and governance. Nowadays, many countries including Samoa, have embraced this appealing concept where catchments are seen as natural units for water governance and management. This study used a social qualitative approach, aimed to investigate the implementation of catchment management and examine local community perceptions of catchment management, using Apia Catchment as case study. It is based on a conceptual framework of the concept of scale i.e. set out in recent debates and ideas in the arena of catchment scale water governance and management. The primary data was collected from community focus groups within two villages of Apia Catchment, and semi-structured interviews with government agencies involved in the Water and Sanitation Sector programmes. The findings revealed a shift in water resources management and governance and a spatial scale mismatch in Apia Catchment management. According to government officials, the catchment approach is a ‘management tool’ adopted to improve the coordination between water users and to promote local ownership of catchment activities amongst individual villages. However, several challenges arose around land ownership, monetary cost, community resistance and issues outside of catchment areas when implementing catchment management. Despite the challenges that government officials encountered and the concerns raised by the communities, catchment scale management is still being adopted in Samoa. With the adoption of catchment management, many individual villages within Apia Catchment are expected to make decisions collectively. However, some local groups have concerns about the use of the term ‘boundary’, the possibility of the government taking over their land and the proposed catchment-based authority taking precedence over pre-existing cultural hierarchy. Overall, this research reveals that catchment management is often viewed or seen by government as a ‘one size fits all’ notion that ignores the range of the socio-ecological realities on the ground. This study shows that in order to design better water resources policies and strategies that are fully applicable and workable for Samoa, it is very important to identify these mismatches in scales (e.g. spatial and administrative) and levels (e.g. national and local). Understanding scales and associated levels is critical to understanding the whole system and can reduce possible consequences of mismatches due to lack of interaction and collaboration between levels and scales. Local villages have expressed their opinions on how to enhance catchment management and this could perhaps be useful for government in terms of implementation. Based on the results, recommendations are made for water resources managers to assess the importance of different levels and their interactions but, more importantly, to consider how local communities perceive catchment management.

This PhD thesis was developed in the context of contemporary challenges within water policy and governance; specifically the issue of managing diffuse pollution risk in fresh water catchments. As highlighted in the European Water Framework Directive (WFD) diffuse pollution poses a major risk in many European catchments where the sustainability of the ecosystems and water uses is compromised by intensive agriculture. The challenge for catchment management is the tricky nature of diffuse pollution. It is what you would term a ‘wicked problem’ or ‘Post Normal Science’ wherein the facts are uncertain, values are in dispute, stakes are high and decision-making is urgent (Funtowicz and Ravetz, 1993; Patterson et al., 2013). In response to the WFD the UK Government have proposed the Catchment Based Approach (CaBA) which represents a paradigmatic shift in approaches to water management; from a ‘command and control’ approach (i.e. the historic practice of direct regulation) to a participatory governance approach (i.e. devolution of power and involvement local stakeholders) (Dryzek, 2005; Müller-Grabherr et al., 2014). The project had two aims. The practical aim was to identify the drivers and barriers to delivering the CaBA. The academic aim was to employ the relational concept of ambiguity to explore why and how catchment stakeholders understand, frame and respond to diffuse pollution risk differently. In order to address these aims Timothy embedded himself in Loe Pool Forum (www.loepool.org) for four years. Loe Pool Forum (LPF) are a voluntary catchment partnership, based in West Cornwall, working to address the risk of diffuse pollution through taking a CaBA at the WFD waterbody scale. The methodology was directed by Participatory Action Research (PAR) and underpinned by ethnography. PAR enabled Timothy to work collaboratively to engender positive change within LPF while ethnography generated data upon how partnership and participatory working happens in practice. New insights into the geographies of risk stemmed from the application of ambiguity as the conceptual lever. Ambiguity is a dimension of uncertainty which accounts for the relational properties of risk. Ambiguity is defined as the simultaneous presence of multiple frames of reference about a certain phenomenon (Brugnach et al., 2007). Timothy examined ambiguity from three different directions. Firstly, where the ambiguities are in catchment management and how local partnerships negotiate them. Secondly, how risk frames are produced by both water scientists and the agricultural community. Thirdly, what the drivers and barriers are to delivering the CaBA. By thinking through risk relationally this thesis provides new insights into the practice of catchment management and the socio-cultural geographies around the water-environment.

Over the past decade, South African and Namibian governments have initiated processes of water-sector reform via new legislation (RSA, 1998; GRN, 2004), designed to promote increased equity, efficiency and economic and environmental sustainability of water resources. These objectives correspond to those of the discourse of integrated water resource management (Heyns, 2005; Woodhouse, 2008). Institutional reform is a key feature of the recent legislation. Participatory institutions are being formed, which are aligned to hydrological spatial units, such as water-user associations and basin management committees. These institutional spaces represent 'communities' of learning (Wenger, 1998; Johnson, 2007), and synergise with the concept of 'social learning' that links collective interaction and learning to concerted action in the collective and environmental interest (Roling & \Vagemakers, 1998; Keen et al., 2005; Pahl-\Vostl et al., 2007a; Ison et al., 2007). Drawing on the 'constant comparison' principle of grounded theory (Glaser, 1992), the thesis explores this concept of social learning using two case studies: the South African Kat River Water User Association (KatRWUA) and the Namibian Kuiseb Basin Management Committee (KuisebBMC). A multi-method research approach was used to elicit qualitative information, with data-collection methods including semi-structured interviews, ethnographic observation and secondary data sources (Denzin & Lincoln, 2002). Subsequent data analysis revealed a mismatch between the nature and outcomes of social learning processes within the case studies and the ideals of socially and environmentally sustainable behaviour, which are desired by both the integrated water-resource management discourse and by the South African and Namibian national Water Acts. Social learning, as a process for achieving these goals of social equity and sustainable social behaviour, was prevented by the five Ps: power relations, politics, personality, precedence, and the past.

[eng] Soil erosion is a natural process that encompasses weathering, transport and deposition of soil particles. These processes are essential in terrestrial geochemical cycles. However, the on- and off-site erosion effects are considered to be one of the most important causes of terrestrial and aquatic ecosystems degradation. The characteristics of the Mediterranean region are marked by complex relationships between natural, human, biotic and abiotic variables. In addition, an irregular rainfall distribution, strong seasonality and the physiographic landscape characteristics promote divergent responses in erosion rates and sediment yields. In this context, the Mediterranean basin has the highest sediment yields in all of Europe. In addition, it is emerging as a hot spot point in Global Change dynamics, especially with reference to climate and land use change, which could generate an increase in erosive and sediment transport processes. At the catchment scale, sediment transfer occurs in hill slopes, between hill slopes and channels or within channels. Information on the nature and relative contribution of sediment sources is a key aspect with regard to designing and implementing erosion control strategies in catchments. The main objective of this thesis is to identify erosion and sediment transport processes in two Mediterranean catchments affected by different global change processes at different spatio-temporal scales, improving current techniques for sediment origin determination (i.e., reducing uncertainties, time and cost) so it can better implemented in catchment management plans. For this purpose, the hydro-sedimentary dynamics and the origin of the sediments has been investigated on the island of Mallorca (Spain), in two small catchments; the Sa Font de la Vila catchment -4.8 km2, affected by wildfires - and the Es Fangar catchment (3.4 km2), affected by land use changes. The combination of sediment fingerprinting and hydro-sedimentary monitoring made it possible to assess its hydro-sedimentary dynamics during the study period. In Sa Font de la Vila, results showed a gradual decrease in contribution from burned sources over time, while in Es Fangar the contributions from crops dominated throughout the study period, without substantial changes. Sediment yields were 6.3 t km2 yr-1 and 4.5 t km2 yr-1 for Sa Font de la Vila and Es Fangar respectively, low results in comparison with other Mediterranean catchments. This was mainly attributed to the calcareous lithology, land uses (in Es Fangar catchment), vegetation recovery (in Sa Font de la Vila catchment) and agricultural terraces. The use of soil colour parameters as tracers was successfully evaluated in the two catchments, confirming its suitability as a fast and inexpensive tracer, even in fire-affected catchments. Furthermore, the strong correlations between the measurements made with a spectro-radiometer and a scanner make colour even more accessible for its implementation in catchment management plans. The experiment on tracer conservatism confirmed that in-channel changes suffered by all the analysed tracers (coefficient of variation x̄ 8.1 ± 8.8%) were generally lower than their spatial variability within the catchment (coefficient of variation x̄ 16.3 ± 18.5%). Furthermore, the colour parameters were the least variable tracers (i.e. the most conservative). with a coefficient of variation of 2.6 ± 2.2%. Finally, it was not possible to identify the activation patterns of different sediment sources combining hydro-sedimentary monitoring and sediment fingerprinting. This was probably caused by Es Fangar's catchment stability in terms of the origin of the suspended sediment. Es Fangar catchment sediment source stability is attributed to lithological characteristics, land uses and the presence of agricultural terraces in the study area. However, events of higher magnitude could exceed the sedimentary (dis)connectivity thresholds of the rest of the sources, promoting a sediment cascade effect. The results presented in this thesis are relevant and represent an advance in the optimization of the sediment fingerprinting technique. Despite some limitations that need to be further investigated, hydro-sedimentary monitoring and sediment fingerprinting used in combination was shown to be very useful for integrated catchment management plans in Mediterranean environments.
[spa] La erosión es un proceso natural que comprende la meteorización, transporte y depósito de partículas del suelo. Estos procesos son esenciales dentro de los ciclos geoquímicos terrestres. Sin embargo, los efectos in situ y ex situ de la erosión se consideran una de las causas más importantes de la degradación de la calidad en ecosistemas terrestres y acuáticos. Las características de la región mediterránea están marcadas por relaciones complejas entre variables naturales, humanas, bióticas y abióticas. Además, una distribución irregular de las lluvias, una marcada estacionalidad y las características fisiográficas del paisaje promueven respuestas divergentes en las tasas de erosión y producción de sedimentos. En este contexto, la cuenca Mediterránea presenta los rendimientos de sedimento más altos de toda Europa. Además, se perfila como un punto crítico de la dinámica del Cambio Global, especialmente en lo que respecta al Cambio Climático y de uso del suelo, lo que podría generar un aumento de los procesos erosivos y de transporte de sedimento. A escala de cuenca de drenaje, la transferencia de sedimentos ocurre en laderas, entre laderas y canales o dentro de canales. La información sobre la naturaleza y contribución relativa de las fuentes de sedimento es un aspecto clave para diseñar e implementar estrategias de control de la erosión en cuencas de drenaje. El objetivo principal de esta tesis es identificar procesos de erosión y transporte de sedimentos en dos cuencas mediterráneas afectadas por diferentes procesos de cambio global a diferentes escalas espacio-temporales, mejorando las técnicas actuales para la determinación del origen de los sedimentos (es decir, reducir incertidumbres, tiempo y costo) para su mejor implementación en planes de gestión de cuencas de drenaje. Para ello, se investigó la dinámica hidro-sedimentaria y el origen de los sedimentos en dos pequeñas cuencas de drenaje de la isla de Mallorca (España); Sa Font de la Vila -4,8 km2, afectada por incendios forestales - y Es Fangar (3,4 km2), afectada por cambios de usos del suelo. La combinación de la técnica sediment fingerprinting y monitoreo hidro-sedimentario continuo permitió evaluar su dinámica hidro-sedimentaria durante el período de estudio. En Sa Font de la Vila, los resultados mostraron una disminución paulatina de las aportaciones de fuentes quemadas a lo largo del tiempo, mientras que en Es Fangar las aportaciones de las zonas de cultivos dominaron durante todo el período de estudio sin cambios sustanciales. Los rendimientos de sedimentos fueron 6,3 t km2 a-1 y 4,5 t km2 a-1 para Sa Font de la Vila y Es Fangar respectivamente, bajos en comparación con otras cuencas mediterráneas. Esto se atribuyó principalmente a la litología calcárea de las cuencas, los usos del suelo (en Es Fangar), la recuperación de la vegetación (en Sa Font de la Vila) y la presencia de terrazas agrícolas. El uso de parámetros de color como trazadores se evaluó con éxito en las dos cuencas, lo que confirma su idoneidad para su uso como un trazador rápido y económico, incluso en cuencas afectadas por incendios. Además, las fuertes correlaciones entre las medidas tomadas con un espectro-radiómetro y un escáner, hacen del color un trazador muy accesible para su implementación en planes gestión. El experimento sobre conservación de las propiedades de los trazadores mostró variaciones bajas en la mayoría de los trazadores analizados (coeficiente de variación x̄ 8,1 ± 8,8%). Estas fueron generalmente menores que su propia variabilidad espacial dentro de la cuenca (coeficiente de variación x̄ 16,3 ± 18,5%). Además, los parámetros de color fueron los trazadores menos variables (i.e. más conservadores) con un coeficiente de variación de 2,6 ± 2,2%. Finalmente, no fue posible identificar los patrones de activación de diferentes fuentes de sedimentos combinando el monitoreo hidro-sedimentario y sediment fingerprinting. Esto fue causado principalmente por la estabilidad de la cuenca de Es Fangar en términos de origen de sedimentos en suspensión. La estabilidad de las fuentes de sedimentos se atribuyó a las características litológicas, usos del suelo y la presencia de terrazas agrícolas en el área de estudio. Sin embargo, eventos de mayor magnitud podrían superar los umbrales de (des)conectividad sedimentaria del resto de fuentes consideradas y activarlas. Los resultados que presenta esta tesis son relevantes y suponen un avance en la optimización de la técnica sediment fingerprinting. Pese a algunas limitaciones que se han de seguir investigando, se demostró que la combinación de monitoreo hidro-sedimentario y sediment fingerprinting es de gran utilidad para los planes de gestión integrada de cuencas de drenaje Mediterráneas.
[cat] L'erosió és un procés natural que comprèn la meteorització, transport i dipòsit de partícules sòl. Aquests processos són essencials dins dels cicles geoquímics terrestres. No obstant això, els efectes in situ i ex situ de l'erosió es consideren una de les causes més importants de la degradació de la qualitat en ecosistemes terrestres i aquàtics. Les característiques de la regió mediterrània estan marcades per relacions complexes entre variables naturals, humanes, biòtiques i abiòtiques. A més, una distribució irregular de les pluges, una marcada estacionalitat i les característiques fisiogràfiques del paisatge promouen respostes divergents en les taxes d'erosió i la producció de sediments. En aquest context, la conca Mediterrània presenta els rendiments de sediment més alts de tot Europa. A més, es perfila com un punt crític de la dinàmica del Canvi Global, especialment pel que fa a el Canvi Climàtic i usos del sòl, la qual cosa podria generar un augment dels processos erosius i de transport de sediment. A escala de conca de drenatge, la transferència de sediments es dona en vessants, entre vessants i canals o dins els canals. La informació sobre la naturalesa i contribució relativa de les fonts de sediment és un aspecte clau per dissenyar i implementar estratègies de control de l'erosió en conques de drenatge. L'objectiu principal d'aquesta tesi és identificar processos d'erosió i transport de sediments en dues conques mediterrànies afectades per diferents processos de Canvi Global a diferents escales espai-temporals, millorant les tècniques actuals per a la determinació de l'origen dels sediments (és a dir, reduir incerteses, temps i cost) per a la seva millor implementació en plans de gestió de conques de drenatge. Per a això, es va investigar la dinàmica hidro-sedimentària i l'origen dels sediments en dos petites conques de drenatge de l’illa de Mallorca (Espanya); Sa Font de la Vila -4,8 km2, afectada per incendis forestals - i Es Fangar (3,4 km2), afectada per canvis d'usos del sòl. La combinació de la tècnica sediment fingerprinting i monitoratge hidro-sedimentari va permetre avaluar la seva dinàmica hidro-sedimentària durant el període d'estudi. A Sa Font de la Vila, els resultats van mostrar una disminució gradual de les aportacions de fonts cremades al llarg del temps, mentre que a Es Fangar les aportacions de fonts de cultius van dominar durant tot el període d'estudi sense canvis substancials. Els rendiments de sediments van ser 6,3 t km2 a-1 i 4,5 t km2 a-1 per a Sa Font de la Vila i Es Fangar respectivament, baixos en comparació amb altres conques mediterrànies. Això es va atribuir principalment a la litologia calcària de les conques hidrogràfiques, els usos de terra (a Es Fangar), la recuperació de la vegetació (a Sa Font de la Vila) i la presència de terrasses agrícoles. L'ús de paràmetres de color com a traçadors es va avaluar amb èxit en les dues conques, la qual cosa confirma la seva idoneïtat per al seu ús com un traçador ràpid i econòmic, fins i tot en conques afectades per incendis. A més, les fortes correlacions entre les mesures preses amb un espectre-radiòmetre i un escàner, fan del color un traçador molt accessible per a la seva implementació en plans gestió. L'experiment sobre conservació de les propietats dels traçadors, va mostrar variacions baixes en la majoria dels traçadors analitzats (coeficient de variació x̄ 8,1 ± 8,8%). Aquestes van ser generalment menors que la seva pròpia variabilitat espacial dins de la conca (coeficient de variació x̄ 16,3 ± 18,5%). A més, els paràmetres de color van ser els traçadors menys variables (i.e. més conservadors) amb un coeficient de variació de 2,6 ± 2,2%. Finalment, no va ser possible identificar els patrons d'activació de diferents fonts de sediments combinant el monitoratge hidro-sedimentari i sediment fingerprinting. Això va ser causa principalment a l'estabilitat de la conca d'Es Fangar en termes d'origen de sediments en suspensió. L'estabilitat de les fonts de sediments s'atribueix a les característiques litològiques, usos de sòl i la presència de terrasses agrícoles en l'àrea d'estudi. No obstant això, esdeveniments de major magnitud podrien superar els llindars de (des)connectivitat sedimentària de la resta de fonts considerades i activar-les. Els resultats que presenta aquesta tesi són rellevants i suposen un avanç en l'optimització de la tècnica sediment fingerprinting. Malgrat algunes limitacions que s'han de seguir investigant, es va demostrar que la combinació de monitorització hidro-sedimentari i sediment fingerprinting és de gran utilitat per als plans de gestió integrada de conques de drenatge Mediterrànies.

Wetlands are an important part of the landscape as hydrogeomorphological ecosystems. Over the centuries their importance has not received relevant attention; instead they have been treated as wastelands impeding development for maximum economic benefits. Research evidence from different parts of the world has influenced the change of such negative perceptions to an extent that the issue of wetlands' rehabilitation/restoration, conservation and management is firmly on the global agenda and local agendas of various countries, as evidenced by the adoption of the Ramsar Convention in 1971, and the Working for Water and Working for Wetlands programmes of the South African government. The aim of this research was to investigate the hydrological and geomorphological functions of a headwater wetland located in the Featherstone Kloof Catchment near Grahamstown, South Africa. The research was based on the hypotheses that wetlands store sediments, attenuate floods, store water and prolong downstream flows. A literature survey was conducted to gauge the state of knowledge about wetlands, particularly their hydrogeomorphology. An attempt was made to locate the study area within the broad historical and spatial context using a number of methods, including the radiocarbon dating of wetland sediments, the review of relevant literature and the analysis of historical hydroclimatic data. The results revealed that the wetland has existed for approximately 2000 years - as the oldest radiocarbon date obtained was 1850±50 BP. An analysis of more than a century (+120 years) long Grahamstown rainfall series indicated a steady fluctuation of rainfall around the mean, with regular decada1 cycles of wet and dry spells. Years with more rain below average were more common than those with higher rainfall, and storms events were quite common in the III area over the period. The distribution of seasons in the area over a calendar year period was demonstrated through the use of evaporation data. An intensive monitoring of hydrological and geomorphological variables was carried out using a combination of methods. The topography of the instrumented site was determined using a Total Station from reference benchmarks. Hydrological measurements included a nest of forty-eight piezometers for water table monitoring, and streamflow gauges at the upstream and downstream limits of the study site. Soil stratigraphic analysis was carried out through field techniques and laboratory measurements. A survey of wetland sediments was carried out after the main floods events. Data generated were used to analyse relationships between various variables and their role on the functioning of the wetland. The water balance of the wetland was quantified. The results indicated that the wetland was able to perform the cited hydrogeomorphological functions to some extent. For example, one of the key findings of this research is that the wetland was important in sustaining base flows under normal circumstances. However, the wetland did little to attenuate large floods. The results also revealed some important questions that require further research, including the role played by extreme flood events in altering wetland characteristics, the contribution of each water balance component in the hydrological functioning of wetlands, and importance of quantifying sediment budgets of headwater wetlands. The study demonstrated the complex nature of the wetland hydro geomorphology and that certain questions about wetlands require direct field monitoring to be better understood.
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High pressure on water from competing users has changed the past perception of water as gift to water as a resource that requires sustainable management. Management of water resource needs active stakeholders’ involvement for its sustainability. Many organizations along with the national water policy have been calling for active stakeholders’ involvement for management of the resource.  In Usangu catchment conflicts over accessing water between farmers and pastoralists and between upstream and downstream have been common. Water allocation in the catchment has been done without involving stakeholders and adequate consideration of the rivers’ carrying capacity. This study focuses on stakeholders’ involvement in Usangu catchment. Six villages in three sub-catchments were studied and data were collected using questionnaire through face to face interview and focus group discussion. The study found that there is limited stakeholders’ involvement in Usangu catchment. In some places involvement is at basic stage, in other places there is no involvement. Interaction within stakeholders’ category was documented, while no stakeholders’ interaction between sub-catchments was discovered. Moreover, some challenges for active involvement were noted, such as lack of coordination between institutions operating in the catchment, high illiteracy rate and lack of awareness, and with lack of legislation support. The issue of limited stakeholders’ involvement in Usangu catchment is complicated, there is no single and comprehensive solution; integration of different approaches which are cross-sectoral in nature is needed for sustainable water management.

 

Bushfire is, in terms of human lives lost, property destroyed, and damage to natural systems, by far the most urgent environmental problem in Australia. This thesis tries to answer a number of questions about bushfire behaviour, history, effects, and management, in the Wungong Catchment of Western Australia. It does so by an overtly cross-disciplinary approach, involving a mixture of the three main streams of human knowledge, namely the humanities, natural science, and social science.First, I offer a literature review of several hundred books and papers drawn from the three main streams of knowledge mentioned above. The review includes some discussion of ‘bushfire epistemology’, a currently vague and neglected matter.The concept of ‘place’ is important to humans, so I then give a straightforward geographical description of Wungong Catchment, with some mention of the history of bushfire. To describe the vegetation, I use inductive statistics, and a method developed by me from the ideas of Delaunay (1929) and Dirichlet (1850). Given that there are hundreds of plant species within the catchment, I use a landscape approach, and only sketch the main tree species, and two iconic plants, the balga and the djiridji, both of which are important to the original custodians of the catchment, the Nyoongar people. There is discussion of other people’s research into the effect of bushfire on seed banks, and the flowering intervals of some plants of the jarrah forest.To see if Western Australia is anomalous, or fits into the worldwide pattern of humans using fire as a landscape management tool, I then examine some records of bushfire in other lands, including Africa, Madagascar, India, and Europe. The thesis then looks at the history of fire in the jarrah forest of Western Australia, based on observations by early European explorers and settlers from 1826 onward, the views of various foresters, and some opinions of current Nyoongar Elders.Using a mixture of natural science, applied mathematics, and archaeology, I give the results of cleaning the stems of those ancient plants called grasstrees, or balga (Xanthorrhoea spp.). These carry the marks of former bushfires, stretching back to 1750. They confirm historical reports of frequent fire in the jarrah forest, at 2-4 year intervals, and a recent decline in fire frequency. This contradicts the view, held by some, that European arrival increased the frequency of fire.As support for the balga findings, I present a simple mathematical model of self-organization in bushfire mosaics. It shows how lengthy bushfire exclusion can lead to disastrous situations, in which large areas of landscape become flammable and unstable. It shows how frequent, patchy burning can maintain a stable bushfire mosaic, with mild, beneficial fires. In the next chapter, I offer mathematical suggestions on how current unstable mosaics can be restabilized, by careful reintroduction of such burning.In dry, south-western Australia, water supply is an important topic, and a better understanding of the hydrological effects of bushfire may help with both bushfire and water management. I draw upon the natural science of forest hydrology, and the effects of fire in catchments. The evidence comes not only from Australia, but also from the United States, and South Africa.Turning to social science, I introduce Professor Peter Checkland’s ‘Soft Systems Methodology’, and suggest how it could be applied in resolving complicated conflict about bushfire management. I finish in legal style, with a summing up, and a verdict on the use of bushfire as a land management tool in Wungong Catchment, and possibly in other flammable landscapes.

Concerns have been raised on the deterioration of heather moorland due to management in the UK. A study was therefore conducted on the impacts of moorland management on the soils and hydrology of a catchment on Dartmoor. Soil moisture was measured gridwise using TDR on 19 occasions. At 23 sites within this grid, physical properties of the topsoil were obtained. At three locations, tensiometer nests were installed, recording soil suction at 10 cm depth intervals. At the catchment scale, stream discharge and rainfall were recorded. Grazing densities within the watershed were estimated and the observed patterns were related to vegetation types. Results from the TDR grid showed that in dry conditions, soil moisture patterns are heterogeneous in contrast to a more uniform pattern in wet periods. A threshold soil moisture content of about 0.60 cm3 cm-3 divides the two conditions. The exponential relationship between average hillslope soil moisture content and stream discharge also revealed the division between wet and dry states. A regression analysis showed that during dry conditions, the vegetation plays a significant role in determining the soil water status. During wet conditions, topography becomes more important. In these conditions, the soil water movement is mainly lateral, whereas in the dry state, this is vertical in the soil profile. Tensiometer data showed that most soil water movement is in the topsoil. Analyses suggested that soil moisture under vegetation classes associated with higher grazing pressures is higher in similar topographic conditions. Soil bulk density is higher and the total porosity is lower near the soil surface. This suggests that less rainfall is required to reach the soil moisture threshold and water will be transported laterally down the slope. A heather burning experiment revealed that the direct effect of temperature is shallow. Soil moisture levels do not change over the course of the burn. However, in dry situations during summer, soil moisture contents under burned plots are higher than under unburned vegetation probably due to reduced transpiration. If this effect is similar at the hillslope scale, when the soil is wetting up, the soil moisture threshold value could be reached at an earlier stage and accelerated lateral water movement could be the result. It can be concluded therefore, that moorland management could accelerate water movement on the hillslopes causing higher discharge peaks in wet periods and consequently low flows in summer. However, the effects are subtle and encouraging vegetation heterogeneity could play a role in buffering water to prevent loss to the stream.

The intention of this study was to investigate the two most significant sources of dissolved organic carbon (DOC) to drinking water supplies; peatlands and algae. For two drinking water reservoirs in north Wales, Llyn Cefni and Llyn Alaw, markedly different seasonal trends were recorded, and these were linked to contrasting aspects of the lake's catchment and the meteorological conditions experienced during the two surveys. For Llyn Cefni, the DOC signatures for the inflowing streams and lakes correlated significantly, Afon Erddreiniog (R2=0.585, p<0.01) and Afon Cefni (R2=0.784, p<0.001), indicating a strong flux of terrestrial DOC into the lake from a nearby peatland. Much less of a seasonal trend in DOC was recorded at Llyn Alaw, with concentrations averaging 10.7 mg L 1, reflecting the absence of a peaty catchment. DOC derived from autochthonous production was also shown to be influential. Both lakes experienced nitrate depletion during the summer of the surveys, falling from 12.7 mg L-1 in Llyn Cefni and 6.5 mg L"' in L lyn Alaw to undetectable levels, suggesting extreme eutrophy, although the lack of detectable phosphate at Llyn Alaw may be why the growth of algal blooms was much less prevalent than at Llyn Cefni. A new type of floating constructed wetlands (FCW) was shown to Offer a potential solution 'to the production of algal blooms in the reservoirs, whereby over a four-week period, the FCWs were able to reduce algal growth by 80%, through sequestration of the key nutrients nitrate and phosphate and possibly due to the direct inhibitory properties of phenolic compounds on the algae. Furthermore, it was discovered that 8 Phragmites aus/ralis plants is the ideal number to maximise nutrient uptake and minimise algal growth in 70 litres of water. Studies in Finland and Malaysia were undertaken to highlight the importance of peatland management practices, as' vast areas of the world's boreal and tropical peatlands have been drained for agricultural purposes. The study in Finland showed that although there was noconsistent response in DOC export potential with drainage across the sites of contrasting nutrient status, a significant correlation was observed between DOC and the water content of the soil, R2 = 0.59 (p< 0.001), indicating that as the water-table height falls the DOC export potential of the soil increases. It was also considered that the trend in DOC is driven by changes in soil pH and the resulting suppression of the key carbon regulating enzyme phenol oxidase; where acidity has increased following drainage phenol oxidase activity has declined and the concentration of DOC released has increased, conforming the view that phenol oxidase acts as an `enzymic latch' in peatlands. The study in Malaysia recorded a 40% greater export potential of DOC from the oil palm soil and more than twice the DOC concentration in drainage waters compared to the undisturbed peat soil. The activity of the key hydrolytic enzyme ß-glucosidase was 25% higher in the oil palm soil than the undisturbed peat. This may be due to an improved soil organic matter quality at the oil palm site and suggests that increased activity of this enzyme may have been crucial for mobilising DOC from the soil matrix. The repercussions of these studies are discussed with emphasis on the potential impacts of a changing climate.

Four artificial tracers were applied to a small headwater catchment in south western British Columbia to study runoff generated from topographically distinct landscape units. The seven hectare catchment is located in the University of British Columbia Malcolm Knapp Research Forest at low elevation (190-280 masl). A weir, multiple tipping bucket rain gauges and several piezometers were used to collect hydrological data. Three separate landscape units were identified based on topography, soil properties and proximity to the stream. The units included an area of shallow slope and deep soil, a riparian area along the intermittent stream channel and an area of very shallow soil with bedrock outcrops on a steep slope. Tracers used included rhodamine-WT, uranine, sodium chloride and potassium bromide. A suite of ion selective and fluorometric probes were used along with automated water sampling to monitor tracer breakthrough. The collected samples were analysed in the lab to validate the field measurements. Tracers were dissolved in solution and applied aerially with a backpack sprayer at the onset of forecasted precipitation events to facilitate rapid infiltration into the soil. The first application took place January 4th, 2006. Measurements were then taken continuously until March 20th, 2006, when a second round of tracers was applied to the landscape units. During the first measurement period, 532 mm of precipitation fell below the forest canopy over 75 days. During the second 78 day measurement period, 290 mm of rain fell. It was found that the overall wetness of the catchment affected travel times significantly. Large storms during the first, significantly wetter, application period exhibited similar lag times from peak event discharge to tracer arrival between the different landscape units. During small precipitation events and under dryer conditions, travel times were greatest in the area of shallow slope and deep soils. These lag times are indicative of longer pathways and perhaps the non-initiation of preferential flow below certain thresholds. In general, it was concluded that delineating catchments into groups of similar landscape units based on physical characteristics may be a promising new approach to explaining catchment runoff response.

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)

It is now widely believed that globally averaged temperatures will rise significantly over the next 100 years as a result of increasing atmospheric concentrations of greenhouse gases (GHG) such as carbon dioxide. Responses to the threat of future climate change are both adaptations to new climate conditions, and mitigation of the magnitude of change. Mitigation can be achieved both through reducing emissions of greenhouse gases and by increasing storage of carbon in the earth system. In particular it is thought that there is potential for increased storage of carbon on land in soils and growing vegetation. There is now a need for research on the potential impacts of changing land use on terrestrial carbon storage, in particular as rapid land use and land cover change has taken place in most of regions of world over the past few decades due to accelerated industrialization, urbanization and agricultural practice. This thesis has developed a novel methodology for estimating the impacts of land use and land cover change (LULCC) on terrestrial carbon storage using Geographic Information Systems and Optimization modelling, using a regional case study (the Tamar Valley Catchment, southwest England) and drawing entirely on secondary data sources (current distributions of soils and vegetation). A series of scenarios for future land cover change have been developed, for which carbon storage, GHG and energy emissions amount have been calculated over the short, medium and long term (2020, 2050 and 2080). Results show that in this region, improving permanent grassland and expanding forestry land are the best options for increasing carbon storage in soils and biomass. The model has been validated using sensitivity analysis, which demonstrates that although there is uncertainty within the input parameters, the results remain significant when this is modelled within the linear programme. The methodology proposed here has the potential to make an important contribution to assessing the impacts of policies relating to land use at the preparation and formulation stages, and is applicable in any geographic situation where the appropriate secondary data sources are available.

This study was undertaken to research the principles and practices behind increased pasture productivity on Longslip Station, Omarama. A range of landscape - soil - climate - plant systems were identified, then analysed and the legume responses measured. By isolating cause and effect and appreciating the driving variables of each system, lessons learnt could be reliably and objectively transferred to the rest of the farm. Extrapolation to the balance of the property (15,150 ha) permitted immediate large-scale development and engendered confidence to lending institutions, Lands Department, catchment authorities and ourselves. Soil (land) cannot be well managed and conserved unless it is mapped reliably and its characteristics measured and interpreted by skilled observers (Cutler, 1977). Soil resource surveys, and their interpretation, are an essential ingredient of rational resource evaluation and planning. This thesis is a figurative and comparative survey and study of the soil catenary bodies, resident vegetation, legume establishment and pasture production characteristics of a 400 hectare catchment, in relation to, and as influenced by soil landscape unit, slope component, altitude, aspect and time. The inherent diversity in landform, soil properties and vegetation communities in a single catchment in the high country has not previously been fully studied or appreciated. This has lead to blanket recommendations for fertilizer, seed and management regimes both within and between properties and even regions. This study reports on the diversity of, yet predictable change in soil properties with slope position (upper, middle and lower) aspect and altitude in terms of both soil physical properties e.g. soil depth and water holding capacity and soil chemical properties such as pH, BS%, %P, %S, %N and %C. The composition of the resident vegetation and its differential response to oversowing and topdressing and subsequent change through time is reported and discussed. Finally an epilogue gives an insight into the problems and frustrations of farming practices in the high country from a motivation and personal perspective and political point of view that it is essential to come to terms with.

The physical, chemical and biological characteristics of five southern English chalk streams in neighbouring catchments were investigated seasonally over two years. At the catchment scale, the five chalk rivers had very similar physio-chemical properties. Differences between years and between seasons were much greater than those between rivers or within-river longitudinal differences. Elevated inorganic nutrient concentrations, relative to reportedly 'pristine' systems, indicated some degree of catchment water quality deterioration in all five rivers. The effect of physical habitat degradation (channel overwidening and sedimentation) on river biota was investigated at a within-river, reach scale. The increased proportion of fine sediment within the coarse gravel substratum had a marked effect on invertebrate communities. Overwidening, however, was found to have little impact over the two years. Communities showed a high degree of stability between years, and between individual catchments, reflecting the high overall biological stability of these aquifer-fed river systems. Habitat manipulation experiments at the within-reach scale demonstrated the importance of substratum characteristics to macroinvertebrate communities. Invertebrate colonisation of newly exposed substrata over time was quantitatively and qualitatively different for coarse and fine particles - a function of shifting resource utilisation and microhabitat preferences. The relatively long time taken to fully colonise new substrata demonstrated the weak ability of chalk stream invertebrate communities to respond rapidly to changes in habitat, reflecting the stable physical nature of natural chalk streams and the vulnerability of their communities to anthropogenic disturbance.

Philosophiae Doctor - PhD
The research problem for this study is the limited and unsuccessful implementation of the IWRM concept. This thesis has argued that comprehensive assessment of physical and socioeconomic conditions is essential to provide explanation on factors that limit the successful execution of the IWRM approach. It has further argued that the local IWRM works as proxy for full and successful implementation of the IWRM approach.To contextualise this thesis, the prevailing physical and socioeconomic factors in Malawi in relation to current management and usage of water resources were explained.With 1,321m3 per capita per year against index thresholds of 1,700-1,000m3 per capita per year, this study showed that Malawi is a physically water stressed country but not physically water scarce country although economically it is a water scarce country. This novelty is against some literature that present Malawi as a water abundant country.Again, this study showed that executing a full and successful IWRM in Malawi remains a challenge because of the prevailing socioeconomic situation in terms of water policies,water laws, institutions and management instruments. These aspects have not been reformed and harmonised to facilitate a successful operation of the IWRM approach.The main water-related problem in Malawi is the mismanagement of the available water resources. This is largely due to the lack of implementing management approaches which can generate systematic data for practical assessment of water resources to guide the coordinated procedure among water stakeholders working in catchments. This lack of implementing a coordinated management approach commonly known as integrated water resources management (IWRM) can be attributed to various reasons that includei) lack of comprehensive assessment of factors that can explain lack of successful IWRM implementation at catchment level and ii) lack of methods to demonstrate data generation and analysis on quantity, quality and governance of water that show practical operation of IWRM at community level using groundwater as a showcase among others.This study revealed that introducing local IWRM requires a prior knowledge of the evolution and role of the full IWRM concept in the international water policy which aimed at addressing broader developmental objectives. Globally, the current status of the IWRM concept has potential to address such broader developmental objectives, but sustaining IWRM projects where they have been piloted showed slow progress. Basing on the factors that slow such a progress, local IWRM approach has emerged as a proxy to execute the full IWRM as demonstrated in chapter 8 in this thesis. However, the observed lack of sustainable resources to fund continual functioning of local IWRM activities will defeat its potential solution to water management challenges. The main threat for sustainable local IWRM activities is the tendency of national governments to decentralise roles and responsibilities to local governments and communities without the accompanying financial resources to enable the implementation of the local participation, investments and initiatives at local level. If this tendency could be reversed, the contribution by local IWRM towards solving management problems in the water sector will be enormous. Chapter four has provided the general case-study approach used in this study in terms of research design, data collection methods, data analysis methods, ethical consideration and limitation of the current study within the context of water resource management with a focus on groundwater management.Using geologic map, satellite images, photographs and hydrogeologic conceptual model, the following results emerged: 1) that the Upper Limphasa River catchment has fractured rock aquifer with limited permeability and storage capacity; 2) The topographic nature and north-south strikes of the lineaments explained the north-south flow direction of groundwater in the catchment; 3) The drainage system observed in the Kandoli and Kaning’ina Mountains to the east and west of the Upper Limphasa River catchment respectively (Fig. 5.1; Fig.5.2) formed a groundwater recharge boundary; 4)The regional faults in the same mountains (Fig. 5.1; Fig.5.2) formed structural boundar as well as hydrogeologic boundary which controlled flow direction of the groundwater;5) the hydrogeologic conceptual model showed the existence of the forested weathered bedrock in the upland areas of the entire catchment which formed no-flow boundary and groundwater divide thereby controlling the water flow direction downwards (Fig. 5.9);6) The major agricultural commercial activities existed in Lower Limphasa catchment while only subsistence farming existed in Upper Limphasa catchment. This knowledge and visualization from the map (Fig. 5.3) and conceptual model (Fig.5.9) showed interactions between upland and lowland areas and the role of physical factors in controlling groundwater flow direction in the catchment. It also provided the enlightenment on implications of socioeconomic farming activities on water management. These insights enabled this study to recommend the need for expedited implementation of holistic effective management for sustainable water utilization.Using different physical factors, water scarcity indices and methodologies, this study showed that Malawi is a physically water stressed as well as an economic water scarce country. This novelty is against some literature that present Malawi as a water abundant country. Again, despite the high proportion (85%) of Malawians relying on groundwater resource, groundwater availability (storage in km3) is relatively low (269 km3 in Table 6.10) compared to other countries within SADC and Africa. Given the complexity of groundwater abstraction, the available groundwater for use is further reduced for Malawians who depend on such a resource for their domestic and productive livelihoods. Such insights provided the basis for discussing the need for IWRM.Although daily statistics on groundwater demand (i: 21.20 litres; 116.91 litres;80,550.99 litres), use (ii: 16.8 litres; 92.55 litres; 63,766.95 litres) and abstracted but not used (iii: 4.4; 24.36; 16,784.04 litres) were relatively low per person, per household and per sub-catchment respectively, such statistics when calculated on monthly basis (i.Demand: 636 litres; 3,507.30 litres; 2,416,529.70 litres; ii.Use:504 litres; 2,776.5 litres;1, 913, 008.5 litres iii. Abstracted but not used: 132 litres; 730 litres; 503, 521.2); and on yearly basis (i. Demand: 7,632 litres; 42,087.6 litres; 28,998,356.4 litres; ii. Use: 6,048 litres; 33,318 litres; 22, 956, 102 litres; iii: Abstracted but not used: 1,584 litres; 8,769.6 litres; 6,042,254.4 litres) per person, per household and per sub-catchment provided huge amount of groundwater (Table 6.5). Given the limited storage capacity of fractured rock aquifer in the basement complex geology, the monthly and yearly groundwater demand and use on one hand and abstracted but not used on the other was considered enormous. With the population growth rate of 2.8 for Nkhata Bay (NSO, 2009) and the observed desire to intensify productive livelihoods activities coupled with expected negative effects of climate change, the need to implement IWRM approach for such groundwater resource in the study catchment remains imperative and is urgently needed.In addition to identifying and describing factors that explain the limited groundwater availability in the study catchment, the study developed a methodology for calculating groundwater demand, use and unused at both households and sub-catchment levels.This methodology provided step-by-step procedure for collecting data on groundwater demand and use as a tool that would improve availability of data on groundwater.Implications of such results for IWRM in similar environments were discussed. Despite the time-consuming procedure involved in using the developed methodology, the calculations are simple and interpretation of results is easily understood among various stakeholders. Hence, such an approach is recommended for the IWRM approach which requires stakeholders from various disciplines to interact and collaborate. Nonetheless, this recommends the use of this method as its further refinement is being sought. The analysis on groundwater quality has shown that the dominant water type in the aquifers of Upper Limphasa catchment was Ca-HCO3, suggesting that the study area had shallow, fresh groundwater with recent recharged aquifer. Analyses on physicochemical parameters revealed that none of the sampled boreholes (BHs) and protected shallow dug wells (PSWs) had physical or chemical concentration levels of health concern when such levels were compared with 2008-World Health Organisation(WHO) guidelines and 2005-Malawi Bureau of Standards (MBS). Conversely, although the compliance with 2008-WHO and 2005-MBS of pathogenic bacteria (E.coli) in BHs water was 100% suggesting that water from BHs had low risk and free from bacteriological contamination, water from PSWs showed 0% compliance with 2008-WHO and 2005-MBS values implying high risk to human health. The overall assessment on risk to health classification showed that PSWs were risky sources to supply potable water, hence the need to implement strategies that protect groundwater.On the basis of such findings, the analysis in this study demonstrated the feasibility of using IWRM approach as a platform for implementing environmental and engineering interventions through education programmes to create and raise public awareness on groundwater protection and on the need for collaborative efforts to implement protective measures for their drinking water sources. The use of different analytical methods which were applied to identify the exact sources of the observed contaminants in the PSWs proved futile. Therefore, this study concluded that rolling-out PSWs either as improved or safe sources of drinking water requires further detailed investigations.However, this research recommended using rapid assessment of drinking water-quality (RADWQ) methods for assessing the quality of groundwater sources for drinking. Despite the study area being in the humid climatic region with annual rainfall above 1,000 mm, many of the physical factors were not favourable for availability of more groundwater in the aquifers. Such observation provided compelling evidence in this study to commend the local IWRM as a proxy for the full IWRM implementation for sustainable utilization of such waters. Although institutional arrangements, water laws and water policy were found problematic to facilitate a successful implementation of full IWRM at national level in Malawi, this thesis demonstrated that local institutional arrangements, coordination among institutions, data collection efforts by local community members (active participation), self-regulation among local community committees were favourable conditions for a successful local IWRM in the Upper Limphasa River catchment. This research recommends continuation of such local participation, investment and initiatives as proxy for the full and successful IWRM beyond the study catchment. However, the observed lack of financial resource from central government to facilitates local IWRM activities were seen as counterproductive.In addition, this thesis recommended further studies which should aim at improving some observed negative implications of self-regulations on community members and the limited decentralisation elements from the Department of Water Development.Finally, one of the contributions from this study is the scientific value in using different methods to assess the quality of groundwater as presented in chapter 7. The second value is the demonstration of applying practical techniques to evaluate factors that explain the amount of groundwater storage in the aquifers that can be understood by water scientists, water users, water developers and water managers to implement IWRM collaboratively using groundwater as a showcase. The third contribution is the provision of the procedure to systematically generate data on demand (abstraction) and use of groundwater in unmetered rural areas which has the potential to guide water allocation process in the catchment. Fourthly, the thesis has provided a hydrogeologic conceptual model for the first time for Limphasa River catchment to be used as a visual tool for planning and developing management practices and addressing current water problems.Fifthly, the study has shown how local IWRM works at community level as a proxy for the full implementation of IWRM despite the absence of Catchment Management Agencies. The last contribution is the dissemination of results from this study made through publications and conference presentations as outlined in the appendix.