Interindustry, or input-output analysis is a widely used economic tool in regional analysis. This study investigates the relative worth of alternative types of input data for such models. Primary data are defined as first-hand, or survey data; secondary data are defined as second-hand, or published data. Procurement of primary data is generally much more expensive than for secondary data. Most regional economists have long held that, in general, primary data are superior to secondary data for regional investigations. This study attempts to assess the value of primary versus secondary data in view of the wide variation in collection costs. Two recently published input-output studies for the 1958-60 Arizona economy were utilized to accomplish this goal. One model used mostly primary data; the second model was compiled entirely from secondary data sources. Following careful considerations of base-period differences, geographical overlap, and sector definitions, two models-- the ARZ and the CRB--were constructed from the two source studies so as to be commensurable for statistical comparisons. The ARZ model was derived from the source study that was compiled entirely from secondary data sources; the CRB model was compiled from the source study that used mostly primary input data. Several nonparametric statistical tests were utilized on several components of the ARZ and CRB models to test for statistical similarities and dissimilarities. In general, analyses indicate strong statistical similarity between the two derived models for aggregative I-0 characteristics such as entire matrices and output multipliers, but less similarity for less aggregative components such as sub-matrices and columns of matrices. For example, comparisons between entire technical and between interdependency matrices fail to reject the null hypothesis of no median difference at the alpha level of 5 per cent. At still more unaggregated component analysis, such as for columns within technical and interdependency columns a reasonable degree of statistical similarity persisted. One chapter (V) focuses on the two derived models as they relate to water resources planning implications for Arizona. Results are similar to those for the non-water analyses; however, in the case of weighted water multipliers the similarities between the ARZ and CRB models are remarkably close. Based on an assumed short-run change of 10 per cent in deliveries to final demand for all sectors in the economy, the models differed in predictions of induced aggregate water requirements by only 9000 acre-feet of water, or less than 2 per cent. Results from the study cast doubt on the commonly held assumption of primary-data supremacy in regional interindustry studies. Results also indicate that the most important component for regional economic analysis is the final demand for each sector rather than the interindustry flows. This follows from the narrow clustering of values for output multipliers consistently observed in regional I-0 studies, and reaffirmed in this study. Therefore, students of regional economies are advised to spend marginal resources (money, time, energy) compiling more accurate final demand vectors rather than developing more accurate endogenous interindustry flows.

With the population of urban areas rapidly increasing, a much greater demand is being placed on existing water supplies. The arid southwestern region of the United States, in particular, is experiencing large population increases while possessing limited water resources. Tucson is a representative city in the region facing problems of providing an adequate water supply to the public in the future. Presently, Tucson is being supplied entirely with groundwater. Increases in population and industrial activities, however, have caused a steady decline of the groundwater table in the Tucson Basin. The reclamation of wastewater and the importation of water have been studied as alternatives in alleviating the annual decline of the groundwater table. Problems still exist, however, preventing the immediate use of both aforementioned supplies of water. In developing the water resources of an area, every possible source of water must be evaluated. A source which has not received much attention, but which merits much attention, is the water occurring as urban runoff following intense storms. In order to evaluate the potential of urban runoff as a water supply, the study includes investigations of water quality, water treatment through storage and coagulation, and problems involved with the utilization of storm water. Samples of runoff from three diversified urban watersheds in the Tucson area were analyzed for bacterial, mineral, pesticide, solids, and chemical oxygen demand concentrations. The watersheds were characterized according to the percentage of the total area devoted to a particular land use. In addition, the hydrologic characteristics of each storm were tabulated. Correlation coefficients were determined between the quality parameters and the watershed and hydrological characteristics. Development of regression equations equating quality parameters as a function of both watershed and hydrological characteristics was also undertaken. The final analysis of the quality study involved the determination of relationships between quality parameters of chemical oxygen demand, total coliforms and suspended solids and the point of time on the hydrograph at which runoff was sampled. Prior to beneficial use of the urban runoff, treatment to varying degrees will be required. In the second phase of this study, the efficiency of treatment by the simple methods of storage and alum coagulations was studied. Five gallon samples were collected from randomly selected storms and used either in the storage or coagulation study. Changes in chemical oxygen demand, solids and bacterial concentrations were evaluated at selected intervals during storage for a period of a week. Jar test studies utilizing varying doses of alum were undertaken on water collected from each of the watersheds, determining the efficiency of chemical oxygen demand, turbidity, and total coliform removals. The final phase of the study involved discussion of the problems attendant with the planning and design of treatment facilities. Included in this phase were sections involving water quality standards and the related treatment processes, waste sludge production and treatment methods, and costs pertaining to treatment. Legal aspects of appropriating the urban runoff were considered and the possible conflicts between upstream and downstream interests noted. The study concluded with a demonstration of the application of dynamic programming for optimally planning the location and capacity of storage treatment facilities at urban sites.

No description available.

The increasing demand for water to provide for South Africa's growing population has resulted in increasing pressure being placed on the country's limited water resources. Water developments however cannot be undertaken without considering the water resource base and the key policy frameworks that governs its use and protection. The Department of Water Affairs and Forestry as the custodian of water resources in the country initiated the implementation of the National Water Act during 1999. It has therefore the mandate to ensure that the protection, use, development, conservation, management and control of water resources be achieved in an equitable, efficient and sustainable manner, to the benefit of society at large. The National Water Act prescribes that the Minister of the Department of Water Affairs and Forestry develop a system for the classification of all significant water resources to ensure its protection and sustainable utilisation. The classification system is to be used to determine the class and resource quality objectives of all significant water resources. In the absence of a formal classification system, a framework was developed through this research study in order to guide both the development of a classification system and the implementation, hence ensuring an overarching structure within which intergrated water resource management can be achieved. The main goal of this framework was to seek an appropriate balance between protecting significant water resources and at the same time promoting water resource utilisation in support of socio-economic development. This framework was executed in the preliminary determination of the Reserve for the Thukela River catchment to ensure that informed and calculated decision-making processes are followed once significant water resources are classified.

Pinch Analysis, in the broadest sense, is concerned with the optimal use of resources (material or energy) in a multi-process system. Pinch Analysis based techniques have emerged for water systems over the past decade. A major assumption that has been made in applying these techniques is that a process system can be segregated into a set of process streams and a set of water streams. With this distinction in place, only the water streams are considered in the Pinch Analysis with the process streams represented implicitly. This approach has obvious limitations in situations where a clear distinction between process streams and water streams cannot be made. The chlor-alkali process is an example of a system in which the clear distinction between process streams and water streams cannot be made. Water is intrinsically involved in the process, serving as a carrier medium for raw materials and eventually becoming part of the products produced by the complex. Hydrochloric acid and caustic soda are reagents which are both used within and produced by the complex. These reagents are required by the process at a range of concentrations and the concentrated reagent is diluted to the required concentrations using demineralised water. Within the chlor-alkali complex, a number of effluents containing the reagent species are available and are typically sent to drain. It is conceivable that these effluents might be recovered and used for dilution purposes instead of demineralised water. This would bring about a reduction in the amount of water and concentrated reagent used and the amount of effluent produced by the complex. Given the economic value of these reagents relative to water, their recovery, if feasible, is likely to dominate the optimal water-use and effluent generation strategy. Current Water Pinch Analysis theory relies on the distinction being made between process streams and water streams and does not consider the recovery of reagents or the presence of desirable species within the system. In addition, the assumption is made that species are non-reactive; reactive species such as hydrogen chloride and sodium hydroxide, fall outside the scope of the current theory. The objectives of this study have included the development of an approach which is able to address these limitations of the existing theory. This approach, termed Combined Water and Materials Pinch Analysis seeks to identify optimal use strategies for raw materials and reagents, in addition to water-use and effluent generation. The approach combines mathematical programming with conceptual insights from Water Pinch Analysis. The approach is based on the optimisation of a superstructure which represents the set of all possible flow configurations for water, reagents and raw materials between the various operations within the process system; this problem is solved as a nonlinear programming (NLP) problem using standard optimisation tools. The application of the developed approach to the Sasol Polymers chlor-alkali complex at Umbogintwini, south of Durban, has been a further objective of this study. Given the variety of process operations present within the complex, which differ both in terms of their physical structure and function, individual process models for these operations were required. These models were described in terms of four basic functional elements, namely, mixing, flow separation, component separation and reaction, and incorporated into the superstructure. Given the complexity of the problem, the process system was divided into three subsystems which were optimised in isolation from each other. These results were subsequently integrated to reflect the performance of the subsystems in combination with each other. The results showed a potential reduction of 14% in water-use and 42% in effluent production by the complex, relative to the existing operating configuration. Amongst other savings in material use, the results indicated a 0.2% reduction in the use of salt, a 1.6% reduction caustic soda use and an 8.3% reduction in the use of hydrochloric acid. Economically, the potential saving identified was R 945 727 per annum, based on operating costs in the year 2000. The final objective of this study was the interpretation of the pinch as it relates to the Combined Water and Materials Pinch Analysis problem. A general definition of the pinch was proposed; according to this definition, the pinch corresponds to that constraint or set of constraints which limits the performance of the system, that is, prevents it from further improvement. For the Combined Water and Materials Pinch Analysis problem, this performance is measured in terms of the operating cost. This definition is thus a departure from its usual thermodynamic interpretation of the pinch; in addition, the pinch is defined in terms of a constraint or a set of constraints instead of a point. These constraints are identified by an analysis of the marginal values provided by the optimisation algorithm. Marginal values are also used as a means of identifying process interventions which may be effected such that the performance of the system may be improved further. / Thesis (M.Sc.Eng.)-University of Natal, 1989.

The pulp and paper industry holds a reputation in the public eye for being a large consumer of water. This dissertation analyses water usage within the industry with a particular application to the South African pulp and paper industry. Unlike in other paper-producing countries, water in South Africa is a scarce commodity with a wide range of consumers. Faced with this, it is important for the leaders of the paper industry to have a tool with which to manage water consumption. This dissertation analyses the water usage aspects (including volumes needed and water quality needed) of the different processes, as well as the impact of different products, describing the reasons for water usage in each process. The application of best available technologies for water reduction is discussed. A theoretical or expected range and norm for water usage for each of seventeen South African mills is derived, based on each mill's particular processes, capacities and products. The actual water usage by each mill was surveyed by personally interviewing personnel at each mill. Comparisons are made between expected and actual water usage, and the total daily water consumption of the industry is derived. Only two mills operate below the expected norm level, most smaller mills operate close to the norm level, while five of the larger mills need to apply various techniques to reduce their water usage. The approximation of mill water usage to the predicted or expected norm clearly supports the hypothesis that water usage can be predicted by analysing process and capacity, and indicates that this dissertation can be used as a tool to manage water usage within the industry. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2004.

The pulp and paper industry holds a reputation in the public eye for being a large consumer of water. This dissertation analyses water usage within the industry with a particular application to the South African pulp and paper industry. Unlike in other paper-producing countries, water in South Africa is a scarce commodity with a wide range of consumers. Faced with this, it is important for the leaders of the paper industry to have a tool with which to manage water consumption. This dissertation analyses the water usage aspects (including volumes needed and water quality needed) of the different processes, as well as the impact of different products, describing the reasons for water usage in each process. The application of best available technologies for water reduction is discussed. A theoretical or expected range and norm for water usage for each of seventeen South African mills is derived, based on each mill's particular processes, capacities and products. The actual water usage by each mill was surveyed by personally interviewing personnel at each mill. Comparisons are made between expected and actual water usage, and the total daily water consumption of the industry is derived. Only two mills operate below the expected norm level, most smaller mills operate close to the norm level, while five of the larger mills need to apply various techniques to reduce their water usage. The approximation of mill water usage to the predicted or expected norm clearly supports the hypothesis that water usage can be predicted by analysing process and capacity, and indicates that this dissertation can be used as a tool to manage water usage within the industry. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2004.

The pulp and paper industry holds a reputation in the public eye for being a large consumer of water. This dissertation analyses water usage within the industry with a particular application to the South African pulp and paper industry. Unlike in other paper-producing countries, water in South Africa is a scarce commodity with a wide range of consumers. Faced with this, it is important for the leaders of the paper industry to have a tool with which to manage water consumption. This dissertation analyses the water usage aspects (including volumes needed and water quality needed) of the different processes, as well as the impact of different products, describing the reasons for water usage in each process. The application of best available technologies for water reduction is discussed. A theoretical or expected range and norm for water usage for each of seventeen South African mills is derived, based on each mill's particular processes, capacities and products. The actual water usage by each mill was surveyed by personally interviewing personnel at each mill. Comparisons are made between expected and actual water usage, and the total daily water consumption of the industry is derived. Only two mills operate below the expected norm level, most smaller mills operate close to the norm level, while five of the larger mills need to apply various techniques to reduce their water usage. The approximation of mill water usage to the predicted or expected norm clearly supports the hypothesis that water usage can be predicted by analysing process and capacity, and indicates that this dissertation can be used as a tool to manage water usage within the industry. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2004.

<p>The aim of this investigation was to provide a framework or strategy for prioritising and implementing regional groundwater monitoring in the Olifants-Doorn Water Management (WMA) area. The general approach was to attempt to reconcile monitoring requirements with existing resources, while investigating the hypothesis that regional monitoring should focus on resource status monitoring. Groundwater science needs to focus on clarifying the sustainability options available to the stakeholders, and monitoring the chosen option. This can best be done by adopting an adaptive management approach to both the management of the groundwater resources, and the management of the monitoring programme.</p>

The following pages recount the struggle and criticism that went into bringing the first imported water to Los Angeles, the reasons the water was necessary, the legal bases on which water was acquired, and the end results on the distant Owens River Valley.