Restoration of Lithuanian independence, land reform, radically changed farming structure and strawberry growing potential has conditioned an increase of modern strawberry plantation. Irrigation is a rather important precondition for the commercial cultivation of fruit and berries in Lithuania. The new farm structure requires new, mainly small-scale irrigation systems. Strawberry water consumption and the soil water dynamics during strawberry growing period stated performing pilot research and additional yield which had been got because of the irrigation influence allows to measure optimal irrigation regime of the strawberry based on research. The aim of the work was to investigate dynamics of strawberry evapotranspiration in the Middle Lithuania and in the course of experiments, with respect to development peculiarities and productivity, to determine optimal irrigation regime for the strawberry grown in loamy soils. In the summary is presented strawberry evapotranspiration results maintaining optimal soil moisture conditions with irrigation; analysis of reference evapotranspiration methods; determination of their interaction degree and evaluation of the possibilities to introduce reference evapotranspiration models in calculation of the evapotranspiration of strawberries; quantitative evaluation of the influence of meteorological factors on the amount of the water consumed by strawberries and analysis of strawberry evapotranspiration calculation methods; evaluation of soil... [to full text]

South African commercial plantations occupy an estimated 1.5 million hectares of the country and as the demands for timber products increase, this area is expected to increase. However, further expansion is limited, not only by the suitability of land, but also by the pressures from other water users. As a result the need has arisen for simulation models that can aid decisionmakers and planners in their evaluation of the water requirements of forestry versus competing land uses at different spatial scales. Different models exist to perform such tasks and range from simple empirical models to more complex physically-based models. The policies of the National Water Act (1998) relating to forestry serve to highlight the requirements of a model used for the assessment of afforestation impacts and these are discussed in this document. There is a perception that physically-based distributed models are best suited for estimation of afforestation impacts on a catchment's water yield since their physical basis allows for extrapolation to different catchments without calibration. Furthermore, it is often stated that the model parameters have physical meaning and can therefore be estimated from measurable variables. In this regard, a review of physically-based modelling approaches and a comparison of two such hydrological models forms the main focus of this dissertation. The models evaluated were the South African ACRU model and the Australian topography-based Macaque model. The primary objective of this research was to determine whether topography-based modelling (Macaque model) provides an improved simulation of water yield from forested catchments, particularly during the low flow period, compared to a physically-based model (ACRU model) that does not explicitly represent lateral sub-surface flow. A secondary objective was the evaluation of the suitability of these models for application in South Africa. Through a comparison of the two models' structures, the application of the models on two South African catchments and an analysis of the simulation results obtained, an assessment of the different physically-based modelling approaches was made. The strengths and shortcomings of the two models were determined and the following conclusions were drawn regarding the suitability of these modelling approaches for applications on forested catchments in South Africa:• The ACRU model structure was more suited to predictive modelling on operational catchments, whilst the more complex Macaque model's greatest limitation for application in South Africa was its high input requirements which could not be supported by the available data. • Despite data limitations and uncertainty, the Macaque model's topography-based representation of runoff processes resulted in improved low flow simulations compared to the results from the ACRU simulations, indicating that there are benefits associated with a topographically-based modelling approach. • The Macaque model's link to the Geographic Information System, Tarsier, provided an efficient means to configure the model, input spatial data and view output data. However, it was found that the ACRU model was more flexible in terms of being able to accurately represent the spatial and temporal variations of input parameters. Based on these findings, recommendations for future research include the. verification of internal processes of both the ACRU and Macaque models. This would require the combined measurement of both catchment streamflow and processes such as evapotranspiration. For the Macaque model to be verified more comprehensively and for its application in operational catchments it will be necessary to improve the representation of spatial and temporal changes in precipitation and vegetation parameters for South African conditions. / Thesis (M.Sc.)-University of Natal ,Pietermaritzburg, 2002.

The challenges facing small scale irrigation development in South Africa are varied and complex. This complexity is exacerbated by the many years of systematic neglect, in tandem with material and intellectual impoverishment of the majority of participants in this agricultural sector. Attempting to juggle sustainable development of small scale agriculture and environmental and socio-economic advancement is difficult, but there is sufficient evidence in the literature to suggest that small scale agriculture is increasing not only in South Africa but in Sub-Saharan Africa (Collier and Field, 1998) There is no doubt that this observed increase in irrigated communal gardens result from their increasingly important role of providing food security and as means of augmenting family income. Hence the government,NGO' s and other private sector organisations have increased their support for these small scale agricultural initiatives. Small scale agriculture is therefore increasingly becoming a common land use, and with this increased support, it is likely to become a major water user, particularly as it is located in close proximity to the water source. Hence both practices and processes for small scale agriculture require careful study. Irrigation practices have been studied in KwaZulu-Natal where small scale community gardens are continuously developing. The study included two locations near Pietermaritzburg. The first, at Willowfontein, involved irrigation by furrow , and the second, at Taylors Halt, involved irrigation by hand, using containers. The dynamics of the subsurface flow was monitored using tensiometry and modelled in detail using a two dimensional, soil physics model, Hydrus-2D, to evaluate the application efficiency. This study consisted of three parts viz: socio-economic system appraisal, technical measurement and monitoring, and modelling. Important findings obtained include the following: The highlighting of pertinent socio-economic issues governing water use and allocation and other operations in developing small scale agricultural conditions, including constraints to the development of this sector under the conditions described. The demonstration of the use of reasonably inexpensive, but sophisticated measuring techniques to observe the soil water processes in small scale community gardening practices. Accurate simulations of soil water infiltration,redistribution and uptake using the Hydrus2D model. With these successful simulations, together with the results of the social system appraisal, more efficient irrigation scenarios are proposed and evaluated. The development of a methodology that could be used to assess small scale irrigation efficiencies, with computer simulation models used as tools to conduct such an assessment. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2001.

The eMpofana riparian rehabilitation project (eMRRP) is a pilot project started by Umgeni Water (UW) to demonstrate how effective the removal of invasive alien vegetation is in improving the water yield of a catchment. The disturbance of the country's vulnerable wetland and riparian zones is a major factor contributing to water· stress. The study area was eMpofana riparian areas of Kwazulu-Natal midlands. The study was conducted to establish perceptions of property owners and project employees on eMpofana riparian rehabilitation project with regard to control of invasive alien vegetation. Apart from· these two categories of stakeholders, others whose perceptions were included in the study are one official each from MONDI, SAPPI, the National Working for Water Programme (WFWP) and Kwazulu Natal Nature Conservation Services. However, property owners and project employees were· the main respondents of study. Although all .stakeholders play a crucial role in the project, property owners were selected because clearing takes place on their properties. Similarly project employees perceptions were vital as they are physically involved in clearing invader species and are direct beneficiaries of the project through job creation; To enable interviewees to give their perceptions on various steps on the project cycle; the following key issues were selected; Awareness, Process, Water, Biodiversity, . Tourism, Capacity building, Support, and Sustainability of control of alien invasive plants. Based on these key issues, a questionnaire was drawn. There were fifty-two respondents: 25 property owners and 27 project employees.. The approach used in the study was survey research, and social science methods were employed. Survey research was chosen for this research because of its capacity to provide appropriate data on perceptions of stakeholders of the eMpofana project. The method is useful in a variety of situations such as providing solution to a problem of public policy, provide required data for managing a business or simply for testing hypotheses developed by scientists in the social world. The questions on awareness of the eMpofana riparian rehabilitation project (eMRRP). and the National Working for Water Programme{WFWP) revealed low awareness levels of the two projects. Almost half (48%) property owners indicated little awareness of the national WFWP and almost the same percentage i.e. 42% had little awareness of the provincial WFWP. Also 96% of eMpofana project employees indicated no awareness of the WFW national level and 70% said they were not aware of the WFW provincial level. Given that WFW is a national programme with over 200 alien plant control progratmhes countrywide, one wonder why awareness was so low among the respondents. As for involvement in the project conceptualisation, none of the respondents interviewed indicated involvement in that project phase. However all the project employees indicated that the project was successful (85% very successful and 15% successful). Fifty six per cent property ~wners indicated very strong 'support mainlybecause ofreestablishment of biodiversity through ridding the riparian areas of iilvader species. Ninety-five per cent of the project workers indicated that UW solely supports the eMpofana project and that that support is mainly financial. As for job creation, 88% project workers were of the view that eMpofana riparian project was very successful in creating jobs. It is worth noting that both property owners and the employees shared the same view on water users and project employees being the main beneficiaries of the project. The impact of clearing invader species oil water by the eMRRP was rated as being very significant. Moreover, 52% employees and 44% property owners felt that the project's main beneficiaries were water users in the cities and property owners themselves. As for linkage with the National WFW programme, the perceptions of property owners and project employees revealed a general preference for eMpofana project to continue running independently. On. succesSes achieved in various project phases, most property owners felt the planning phase of the project was the most successful, even though most of them were not involved in the phase. Thirty per cent of the employees felt execution was successful followed by financing, 30%. As the responses from both property owners and employees show, most respondents (property owners and project employees) were of the view that the project goal of reinstating biological diversity was very important. The property owners were of the view that the re-establishment of the naturalness of the area would contribute favourably towards tourism in the area, which they rated very high. The rating explain why property owners also rated biodiversity conservation and the naturalness of the area equally high. On the other hand, Umgeni Water's top priority is water security and the differing priorities between UWs and eMRRP could be seen as a weakness of the project. However, as a holistic view of biodiversity conservation necessitates protection of water resource in the area, the difference could be synchronised to become a strength ofthe eMRRP (see recommendations). The eMRRP has opportunities on a number of areas such as the opportunity to participate in the national campain on control of invader species by teaming up with WFWP and other stakeholders. Also joinirig this partnership would accord eMRRP stakeholders the pride of contributing to the national campaign on control of invader species. Although there is marked success made by UW in planning, financial support, job creation, gender equity in the eMRRP, there is need to address sustainability of the project. In conclusion, it is clear that the eMRRP started off with most stakeholders having low awareness ofits activities and those ofWFW Programme. However, by clearing invasive alien plants in eMpofana riparian areas, the project has gained support from property owners and its employees. Property owners support the project mainly because of possible re-establishment of naturalness of the area (biological diversity) and the employees give their support mainly because of the employment that they receive. However, the goal of sustainability of the eMRRP is likely to remain elusive as long as priorities are not harmonised: property owners' priority (based on benefits drawn) is biodiversity conservation whereas that of UW is water security. / Thesis (M.Env.Dev.)-University of Natal, Pietermaritzburg, 2000.

A simplified process-based model simulating growth and water use in forest plantations was utilised to predict the growth of Pinus elliottii in South African forest plantations. The model is called 3-PG (Physiological Principles in Predicting Growth) and predicted the growth of trees by simulating physiological processes that determine growth and water use, and the way trees are affected by the physical conditions to which they are subjected, and with which they react. Pinus elliottii growth data recorded in 301 sample stands around South Africa were sourced from forestry companies. A selection procedure reduced the number of stands to 44, where 32 were used to parameterise 3-PG and 12 were reserved for testing the final model parameters. This was accomplished by matching model output to observed data. All stand simulations were initialised at age four years and continued to the maximum age of recorded growth. A provisional set of parameter values provided a good fit to most stands and minor adjustments of the specific leaf area (σ), which was assigned a value of 5 m2.kg-1, were made, bringing about an improved fit. The predictions of mean DBH, Height, and TPH were relatively good, achieving R2 of 0.8036, 0.8975, and 0.661 respectively, while predictions of stem volumes were worse (R2 =0.5922, n=32). The 3-PG model over-predicted DBH in 20 stands, while modelled volume predictions improved substantially in thinned stands (R2 =0.8582, n=14) compared to unthinned stands (R2 =0.3456, n=18). The height predictions were generally good producing an R2 =0.8975. The final set of 3-PG parameter values was then validated against growth data from the 12 independent stands. The predictions of mean DBH, Height, and TPH were relatively good, achieving R2 of 0.8467, 0.7649, and 0.9916 respectively, while predictions of stem volumes were worse (R2 =0.5766, n=12). The results of this study demonstrated the potential for 3-PG to respond to many growth factors and to predict growth and water use by trees with encouraging realism. Patterns of changing leaf area index (L) over time, responses to drought, and annual evaporation patterns all look realistic. Consequently, 3-PG is judged to have potential as a strategic forestry tool. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2011.

Conserving the earth's precious water supply is of increasing importance in light of the growing population and climate dynamics; therefore, this study focuses on identifying those exotic species that are best suited for the changing climate and environment of the Lower Kanawha Valley Region in West Virginia without compromising the water sustainable qualities once exhibited by the indigenous species. This task was accomplished by reviewing, analyzing, and evaluating the plant hydraulics and habitat matching characteristics associated with the identified native and exotic species. These species were limited to those produced or found in the local nurseries and garden centers in the designated region, thereby providing a practical and water sustainable plant list for the local homeowners and design professionals. The final list of species was translated into a master planting design of an arboretum displaying and demonstrating water conservation on the grounds of the Hurricane Valley Park. / Department of Landscape Architecture

[Truncated abstract] Understanding the ecohydrological dynamics of native vegetation can provide a benchmark for future efforts to restore landscape hydrology and allow predictions of potential landscape responses to climate uncertainty and associated changes in vegetation cover. The key drivers of evapotranspiration (Et) involved in maintaining a hydrological balance that minimises deep drainage in semi-arid ecosystems operate at a range of scales, and in this thesis I assessed the water relations of functionally and taxonomically diverse plant communities in south-western Australia from the leaf-level to ecosystem scale. For three key communities; heath shrubland, mallee (small multistemmed eucalypt) -heath, and open eucalypt woodland, populating a typical catenary sequence of soil types along a slope, I addressed the following questions: 1) What are the predominant water use strategies of wheatbelt native plant communities and what underlying trade-offs determine the distribution of plant water use strategies along the topographical gradient? 2) What are the roles of soil water and hydraulic limitation in controlling the spatial and temporal dynamics of transpiration in different functional types? 3) What is the magnitude and partitioning of total Et in the woodland community and what processes determine Et fluxes on a seasonal and annual basis? 4) What are the seasonal differences in Et among contrasting community-types and how do these patterns relate to canopy attributes and transpiration capacity along the topographical gradient? A key philosophical step in working with species-rich communities was to develop the concept of 'hydraulic functional types' (HFTs) to identify groupings of species using associations of physiological and morphological traits that define their hydrological functioning. .... However, as shallow soils dried during spring and summer, Et fluxes were significantly lower at the heath site (0.35 versus 0.66 mm day-1 for the woodland in February), demonstrating that the seasonality of Et fluxes differentiates communityscale contributions to regional water balance. Land-surface exchange of water over native vegetation is by no means uniform, but varies according to the spatial and temporal availability of water along topographical gradients. In general, shallow soils present fewer opportunities for water use partitioning and favour drought hardiness and a transpiration response that tracks recent rainfall patterns, whereas deeper soils promote greater differentiation in water use strategy and support canopies responsive to atmospheric demand. This thesis provides a unique description of ecosystem water balance in a global biodiversity hotspot by viewing complex vegetation mosaics in terms of their relevant hydrological units. This information is fundamental to sustainable agroforestry and revegetation efforts and our ability to gauge possible changes in vegetation structure and function under a changing climate.

Albeit much effort having been put to review the performance trend of smallholder irrigation farmers in South Africa. However, there seems to be a paucity of information regarding the level of entrepreneurship on these farmers. Most research works on smallholder irrigation farmers have mainly focused on livelihoods trajectory providing a review on how the welfare of the rural poor has been transformed after the introduction of irrigation schemes. With most research evidence indicating a high degree of underperformance on most smallholder irrigation schemes, this research attempted to investigate the level of entrepreneurship among the small holder irrigation farmers. In order to achieve the main research objective, a sample of 110 farmers drawn from Qamata irrigation scheme was interviewed and each farmer’s performance on the nine components of entrepreneurship was assessed. The aspects assessed to determine the farmer’s entrepreneurial behaviour were: planning ability, risk taking, achievement motivation, leadership ability, Cosmo politeness, decision making, and innovativeness and farming knowledge. Basing on previous studies which indicated entrepreneurial behaviour to be influenced by several factors the study also analysed the determinants of entrepreneurship among the irrigation farmers and a binary logistic regression model was used to establish the connection between various independent variables and the farmers’ entrepreneurial performance given as a total score of the nine components. Though the findings of the study revealed a prevalently low level of entrepreneurship among the smallholder irrigation farmers on Qamata irrigation scheme, a high proportion of the respondent farmers (65.5% and 60.5%) showed to have a high degree of achievement motivation and decision making ability, respectively. The observed trend thus reflected that smallholder farmers have a potential to become entrepreneurs and are willing to succeed. The binary model results revealed that the prevailing land tenure system will be a strong determinant of the farmer’s level of entrepreneurship. Equally, levels of training in farming, motive for farming and information seeking tendency also proved to have a significant influence on the degree of farmer entrepreneurship. Based on the results of this study recommendations have thus been drawn on the need for policies and practices aimed at promoting entrepreneurship and not dependency among farmers. Key focus areas identified include: the need to revise the current land ii tenure system on irrigation schemes, intensify on entrepreneurship training for both farmers and extension officers and regular on-farm training on new technologies.

With the current implementation of the South African National Water Act (NWA) underway, comprehensive tools to assist in the efficient, fair and sustainable management of water resources are needed. Water footprints (WFs) are increasingly being recognised as a meaningful way to represent human appropriation of water resources and provide a framework for assessing the sustainability of water use. The study calculated blue, green and grey WFs for the lower Sundays River Valley (LSRV) citrus sector across dry, humid and long-term average climates for a number of cultivars. The sustainability of both the LSRV and the production process of citrus were examined through the adoption of a number of environmental, social and economic indicators. The study revealed that there was no water scarcity in the area because of an inter-basin transfer and that water pollution levels attributed to citrus production required a more comprehensive indicator than the grey WF. Results showed that navels, despite being the dominant cultivar, had the highest WF and the lowest water productivity and technical efficiency. It also provided lower benefits of income and employment in terms of water use in comparison to other cultivars. Conversely, cultivars such as lemons, which required a greater amount of water and fertiliser, were the most productive cultivar with the lowest blue, green and grey WF. The study demonstrated the complexity of decisions regarding water management and the need to assess accurately the environmental, social and economic implications of strategies to increase efficiency of water. The importance of incorporating local data and verifying WFs was also illustrated. The analysis highlighted that WF assessments could be useful for the South African government and agricultural sectors to assist in future water management decisions and promote increased collaboration between stakeholders. The study found that the adoption of local benchmarks could be useful in aiding the promotion of more efficient water use and could factor in sensitive economic and social attributes. WFs in conjunction with other economic and social indicators could also be used to evaluate the sustainability of current and future allocations pertaining to the implementation of the NWA. It was however noted that this requires vast amounts of accurate data.

Ethiopia has long since been an area strongly affected by drought. Although there is a relativelylarge amount of fresh water present in the country, variability in rainfall and lack ofinfrastructure lead to the result that most of the population is undersupplied with water. In thisregion where water is such a valuable commodity, the Abay River is a large, mainly untappedresource. Agriculture is the largest economic activity in Ethiopia but the productivity ofagriculture here is one of the lowest in the world, making food security a serious problem for acountry with a fast growing population. The development of irrigation projects is hoped toensure food security at the household level. The Koga Dam is a key project for the Ethiopiangovernment, as a step towards achieving food self-sufficiency at both national and regionallevels for a country that has a history of draughts and famine. If this project succeeds, it will be amodel for projects to come and proof that dams and water management can bring change to theregion, particularly concerning food security. Sedimentation is a problem for many dams aroundthe world, and especially in this region. It is likely that the volume of the Koga reservoir willdecrease over time due to reservoir siltation. Variability in climate is also predicted for the regionwhich could mean years with below average rain. These two factors combined could mean adecrease in water supply for the irrigation project in the future. This study applies existingknowledge of sedimentation and annual climate variability relative to the Koga reservoir to asimple reservoir model in order to investigate current and future annual changes in thereservoir’s volume. Climate and volume change were incorporated into the water balance model.Results showed that the dam should be capable of providing enough irrigation water to farm yearround assuming average climate and climate variability and no sedimentation. However, as lowas an 11% decrease in storage could result in the reservoir drying out for at least one month ayear. / Etiopien har sedan länge varit utsatt för vattenbrist. Trots att det finns ganska mycket sötvatten ilandet leder variation i nederbörd och brist på infrastruktur till att en stor del av befolkningensaknar vatten i tillräcklig utsträckning. När vatten är en sådan värdefull råvara är Blå Nilen(Abay floden är den inhemska beteckningen) en stor och outnyttjad resurs för regionen.Jordbruk är den största näringen i Etiopien men jordbrukets produktivitet är en av de lägsta ivärlden. Med tanke på landets snabbt växande befolkning är livsmedelsförsörjningen därför enallvarligutmaning. Utvecklingen av bevattningsprojekt förväntas trygga livsmedelsförsörjningenpå familjenivå. Kogadammen är ett centralt projekt både på nationell och på regional nivå. Denetiopiska regeringen som ser den som ett steg mot livsmedelssäkerhet mot bakgrund av landetshistoria av regnbrist och svält. Om projektet lyckas, kommer det att bli en modell för framtidaprojekt och ett bevis på att dammar och vattenförvaltning kan ge förändra situationen, särskiltmed avseende på livsmedelssäkerhet. Sedimentering är ett problem för många dammar runt om ivärlden, särskilt i denna region. Risken är stor att Kogadammens vattenvolym kommer attminska på grund av igenslamning. Klimatets variabilitet förutspås dessutom öka i regionen ochkan innebära år med såväl mindre som mer regn än idag. Sedimenteringen och den ökadenederbördsvariabiliteten kan möjligtvis innebära en minskad tillgång på bevattningsvatten iframtiden. Denna studie använde sig av befintlig kunskap om sedimentering och årligaklimatvariationer för att studera tänkbara förändringar i Kogadammens vattenvolym.Existerande data användes i en enkel reservoarmodell för att undersöka årliga volymförändringari reservoaren idag och i framtiden. Dammens månatliga vattenbalans beräknades årsvis underolika antaganden om klimat och volymförändringar. Beräkningarna visar att dammen bör kunnaleverera tillräckligt med vatten för att bevattna hela projektområdet om ingen klimatförändringeller volymminskning sker. Men om en volymminskning skulle inträffa, skulle dammensannolikt inte kunna leverera tillräckligt med vatten för bevattning under torrsäsongenmednuvarande odlingsmönster.