No description available.

No description available.

The aim of the study was to establish the effects of human-induced watershed changes on strearnflows. The research hypothesised that land use change influences base flows. Enjoro river in Kenya was used as the case study. In the 1940s, the watershed was characterised with a sparse population, forestry and large scale conservative agriculture. The river regime was naturally perennial. Between 1960 and 1990 land subdivision, intensive cultivation, urbanisation, and deforestation changed such stable ecosystem Several approaches were used to evaluate the perceived cause-effect relations in the watershed. The time series of the flows, rainfall, and other climatic records were used to infer effects of changed physical characteristics in the watershed. Quantitative evaluation of the changes was accomplished by simple graphs, homogeneity tests, satellite imagery and model simulations of hydrologic variables. Analysis of the data series before and after the presumed changes provided an understanding of the variability masked in the hydrologic system. These comparisons allowed for the determination of the period in which the watershed changes influenced the river regime. The combinede ffect of humana nd natural factors decreasedth e river basef lows. A 30% increase in deforestation, 20% in agriculture and 10.4% in urbanisation was observed- Water availability decreased from a runoff coefficient of 22% in the 1960s, 10% in the 1970s and 8% in the 1980s. This progressive decline in runoff developed into hydrologic drought regime in the 1980s. Normalized difference vegetation index (NDVI) predicted well the flow changes in the watershed. Simulations of rainfall and flow supported the changes observed in the hydrologic variables. The optimised parameters with HYRROM showed 'store' parameters (SS, RDEL, GDEL) to be sensitive to changes in vegetation cover especially during the dry years of 1965,1973 and 1984. The model simulated some parameters in the watershed which could be used to infer changes in strearnflows due changes in land use. It was however, difficult to estimate and to validate long-term model parameters because of limited data and the contrasting geography of the region which induced hydrologic variability. The model did not isolate effects of specific land uses, although it predicted the observed flows. There is evidently, a need for future research on the problem. The investigation demonstrated the difficulty in identifying differences in strearnflows from watersheds undergoing simultaneous physical changes and human interventions. Since a specific effect of a particular land use change could not be isolated independently, continued research on the development of an integrating watershed coefficient is recommended. Remote sensing techniques should be incorporated in the development of integrating watershed coefficients.

The advent of high fuel costs and the increasing crowding of shipping lanes have initiated considerable interest in ship automatic pilot systems, that not only hold the potential for reducing propulsion losses due to steering, but also maintain tight control when operating in confined waterways. Since the two requirements differ significantly in terms of control specification it is natural to consider two separate operating modes. Conventional autopilots cannot be used efficiently here, partly because the original design catered for good gyrocompass heading control only, and partly because the requirement of reducing propulsion losses cannot be easily translated into control action in such schemes. Linear quadratic control can be used to design a dual mode autopilot. The performance criterion to be minimised can readily be related to either the propulsion losses while course-keeping, or to the change of heading while manouevring, and therefore, the same controller can be used for both functions. The designed control system is shown, from the computer simulation study, to perform satisfactorily in disturbed seas. However, the need for detailed knowledge of the ship dynamics in the controller design implies that time-consuming ship trials may be required. Hence an alternative method of design using adaptive self-tuning control is studied. Because the self-tuning approach combines controller design and coefficient identification in such a way that the two processes proceed simultaneously, only the structure of the equation of ship motion is needed. As in the case of quadratic control, a well specified performance criterion is firmly linked to the design so that a closely controlled optimal performance results.

Many countries in the Third World are faced with the grave problem of providing adequate housing in sufficient quantity at a low cost in line with their economies and the resources of the people. From early ages soil has been used as a major building material for low cost dwellings and more recently, by using cement or lime as a soil stabiliser, reasonable building blocks have been produced. These blocks have been produced using a relatively low compacting pressure and have proved to be of limited satisfaction. Stabilised blocks are weak in the 'wet state' after dernoulding, and prone to damage whilst 'green'; however, after controlled curing, the undamaged blocks are generally usable. From experience it has been observed that the lime stabilised blocks deteriorate rapidly in a hot/wet climate whereas there is hardly any deterioration in a hot/dry climate. Manually operated block making machines have used a compacting pressure of around 2 MN/rn 2 and research has demonstrated that with a machine operating with a compacting pressure of 10 MN/rn2 good quality, durable stabilised soil building elements could be produced.

No description available.

No description available.

The purpose of this thesis is to explore bicycle use and attitudes towards cycling through case study analyses in Halifax Regional Municipality and the Region of Waterloo. There are two main sections of analyses; the first investigates factors that have been shown by previous research to be associated with cycling behavior for each of the study areas, and the second focuses on the results of a bicycle survey administered for the purpose of this research. The statistical analysis in Part 1 applies Fisher’s Exact Test to reveal statistically significant associations in the survey data. These two sections of analysis are compared and the following conclusions offered: 1. Cycling use is likely associated with city size, density, weather, topography, age, and gender. 2. Cycling trip purpose in Halifax is associated with weather; in Waterloo, trip purpose is associated with weather, gender, and employment. 3. Cycling use in Waterloo is associated with weather, age, gender, employment, and income. 4. There is strong evidence that the provision of bicycle infrastructure has a strong association with bicycle use. In the context of increasing bicycle use, the principal finding is the association between the provision of bicycle infrastructure and increased cycling use. In Waterloo, where the rate of cycling use is higher than in Halifax, there is approximately twice the total number of kilometres of on-street bicycle routes and respondents reported living significantly closer to bike paths, lanes, or trails. In Halifax, where cycling use is less common, respondents expressed much more concern regarding inadequate cycling infrastructure and an overall dissatisfaction with the quality of cycling facilities. These findings reaffirm the previous research suggesting that the provision of more bicycle lanes, paths, route signage, and parking facilities is associated with higher rates of bicycle use among the general public.

The effect transit investments can have on surrounding land uses has been studied in planning literature. Often it is argued that high-density, more sustainable development occurs around stations on newly constructed transit lines. This study examines the impacts of the Yonge-University-Spadina line on development in the north ends of the city of Toronto. This study is guided by three objectives. First, the research aims to determine the extent of the differences in built form and densities between the two study sites. Second, the thesis explains why these differences have emerged and what factors have shaped the evolution of the two sites. Based on the first two analyses, the research provides recommendations to encourage intensified, transit-oriented development in areas that currently do not reflect these principles. A variety of methods are used to achieve these objectives including: an analysis of empirical census data, a comparison of land uses and built form through archive and current photographs, a property value comparison, a transit ridership analysis, a review of archive newspaper articles, an examination of previous and existing policy documents, and a review of previously conducted interviews with Toronto area developers and municipal officials. This study concludes that the Yonge line has experienced significantly more growth over time than the Spadina line. It finds that the policy provisions that dictate development along the Yonge line are much more conducive to intensified growth. As a result, recommendations are made that the city establishes a similar policy framework for land around the Spadina line so that obstacles to potential for intensified growth may be eliminated. More specifically, the thesis identifies contemporary monetary and policy incentives to developers to encourage sustainable development.

Psychotherapy research indicates that metaphors are often used to express a client's meaningful experience. This study measured the impact of client-generated metaphors on in-session experiencing. The research question explored whether client-generated metaphor use would be associated with greater in-session experiencing as rated by the Experiencing Scale (EXP; Klein, Mathieu-Coughlan, & Kiesler, 1986). It was also asked whether metaphor use would increase the subsequent experiencing of a client. Forty-seven client-generated metaphor events were randomly selected from 47 psychotherapy transcripts of clients in therapy with counsellors-in-training. For each metaphor event, a pre-metaphor and post-metaphor client utterance was selected. A total of 140 utterances were compared using a repeated-measure analysis of variance. Results indicate that client-generated metaphors are not significantly different from pre-metaphor or post-metaphor client utterances. The role of language and the clinical importance of metaphor use in psychotherapy were discussed.