SENSITIVITY OF HIGH-ELEVATION STREAMS IN THE SOUTHERN BLUE RIDGE PROVINCE TO ACIDIC DEPOSITION1

ABSTRACT: The Southern Blue Ridge Province, which encompasses parts of northern Georgia, eastern Tennessee, and western North Carolina, has been predicted to be sensitive to impacts from acidic deposition, owing to the chemical composition of the bedrock geology and soils. This study confirms the predicted potential sensitivity, quantifies the level of total alkalinity and describes the chemical characteristics of 30 headwater streams of this area. Water chemistry was measured five times between April 1983 and June 1984 at first and third order reaches of each stream during baseflow conditions. Sensitivity based on total alkalinity and the Calcite Saturation Index indicates that the headwater streams of the Province are vulnerable to acidification. Total alkalinity and p11 were generally higher in third order reaches (mean, 72 μeq/θ and 6.7) than in first order reaches (64 μeq/θ and 6.4). Ionic concentrations were low, averaging 310 and 340 μeq/θ in first and third order reaches, respectively. A single sampling appears adequate for evaluating sensitivity based on total alkalinity, but large temporal variability requires multiple sampling for the detection of changes in pH and alkalinity over time. Monitoring of stream water should continue in order to detect any subtle effects of acidic deposition on these unique resource systems.     

PARAMETRIC ESTIMATION OF COVARIANCES OF REGIONALIZED VARIABLES1

ABSTRACT: The usefulness of stochastic models in describing the spatial variability of hydrogeologic quantities, such as permeability, storativity, piezometric head, seepage velocity, and solute concentrations is now widely recognized. In practice, these quantities are represented as the sum of a well-structured component, or drift, and a more erratic fluctuation component which is described statistically through its covariance function. This paper reviews some of the most recent and most promising methods for the estimation of parameters of these covariances from existing data. They are maximum likelihood, restricted maximum likelihood, minimum-variance unbiased quadratic estimation, and minimum-norm (weighted least squares) estimation. The applicability of such methods to conditional and unconditional probability problems is discussed.     

PUBLIC PARTICIPATION IN WATERSHED MANAGEMENT: COMBINING NOMINAL GROUP PROCESS AND MICROCOMPUTERS1

ABSTRACT: The growing concern for public participation in water resource decision-making has invited researchers to improve and develop reliable, quick, and inexpensive techniques for measuring public preferences. It is increasingly clear that traditional participation mechanisms, though useful, are no longer sufficient in providing the level of participation desired by many. A combination of microcomputer technology with Nominal Group Process (a step-by-step process ending in ranked recommendations) offers numerous possibilities for active participatory planning. Efforts at participation occurring through a well developed and defined process cannot be successful without a sensitivity to the conceptual, methodological, and pragmatic problems involved. This paper prefaces presentation of an alternative active process technique with discussion of the theoretical basis of participatory democracy and the frustration with practical implementation procedures.     

Considerations for preserve design based on the distribution of rare plants in Great Smoky Mountains National Park,USA

Park design principles are proposed on the basis of consideration and analysis of rare plant species in Great Smoky Mountains National Park, USA. Rare species richness can be used as a simple measure of preservation success. A semilogartihmic species-area model for the Smokies was used in this analysis. Species richness would increase logarathmically with expansion of the national park area. An analysis of the relationship between species richness and the distribution of geologic and topographic features in the national park was also reported. An asymptotic relation was documented for the accumulation of newly recorded rare and endangered vascular plant species in the Smokies region up to 1978. Several multiple regression linear models predicted rare vascular plant species richness in Great Smoky Mountains National Park from area and topographic variates.Preserve design criteria can be based upon species-area, environmental gradient, and natural features distribution patterns for the specific taxa and biogeographic region under consideration. In addition, natural history characteristics for particular vulnerable species must be assessed. Rather than concentrating on the preservation of undocumented immigration and extinction processes, preserve design should be directed towards protecting geographic components and gradient patterns characteristic of a region.     

O&M SPENDING LEVELS IN THIRD WORLD IRRIGATION SYSTEMS: EXPLORING ECONOMIC ALTERNATIVES1

ABSTRACT: Third World irrigation and drainage systems have experienced major declines recently in both capability and performance. This is due initially to working them well beyond their design capaci-capacities; scouring, sedimentation, and overtopping result. Chronic O&M underfunding then adds heavily to this worsening malaise. International donors have assisted irrigation departments with rehabilitation projects and programs to improve O&M effectiveness on a grand (billions of dollars) scale. Despite their historical propensity to examine, almost fastidiously, program economic justifications (B/C, IRR, etc), the donors apparently have glossed over two basic analytic elements for (a) more spending on O&M as distinct from an equivalent spending on other means to provide farmers with an m³ of water; and (b) different levels of O&M spending on canals and drains. Surely those different levels provide differing benefits, in total, and at the margin. Which level is most economic? This paper identifies these latter analytical issues, posits methodologies key to an O&M spending level analysis, and discusses the information base. Particular attention is paid to identifying relevant costs and benefits, and to suggesting supplementary criteria for O&M spending level selection. The paper is an exercise in delineation of an imminently practical area of irrigation engineering economics.     

Sustainability and the post-modern city: some guidelines for urban planning and transport practice in an age of uncertainty

Summary Sustainability is one of the key concepts that is associated with post-modernism. The old world with its modernist assumptions was based on increasing consumption of fossil fuels and other resources, reducing the natural and the diverse to simple, American-style mass production, with a strong state-based, large-scale approach to providing infrastructure. That old way no longer works but no way forward is obviously apparent. This paper looks at how the uncertainties produced by post-modernism can be put to advantage in providing a more sustainable postmodern city. It is suggested that the key principles are recognizing values, maximizing diversity and crossing boundaries. These are developed into some guidelines for urban planning and transport practice.This paper was delivered at the Global Forum '94 Academic Conference, Manchester, UK.     

Forestry policy and woodfuel markets in Malawi

Forestry and energy policies in Malawi place the blame for the country's high rate of deforestation on the demand for woodfuel. The government has been involved in a range of questionable supply-side initiatives, as well as in a number of interventions in woodfuel markets, with the objective of slowing rates of deforestation. It seeks to encourage farmers to grow woodfuel to meet market demands, and has provided subsidies to do so. The Forest Department has kept prices for firewood from its plantations low, both in order to discourage the market for wood from free resources and because of concerns about the impact of high producer prices on the urban poor. In doing so, the government is less able to rely on the market to provide producers with the incentive to plant trees to meet market demands. In any event, the market accounts for a relatively small proportion of total woodfuel demand. Policies do not distinguish between rural household demands and the specific market demands which are having the greatest impact on deforestation: woodfuel for urban markets, for tobacco curing, and for small industries. These, coupled with the expansion of the estate sector, have had afar greater impact on woodland clearance than rural, subsistence woodfuel demands. Rural household energy demands need to be addressed from a much broader perspective which considers the household's larger needs for tree based products or outputs: income, food, fibre, fodder, soil fertility, as well as for fuel .     

SOIL EROSION AWARENESS AND USE OF CONSERVATION TILLAGE FOR WATER QUALITY CONTROL1

Water pollution through loss of topsoil from farmland continues to be a major problem, despite nearly 50 years of providing farmers technical and financial assistance for soil and water conservation. The technology for controlling erosion and water pollution is available, but farmers have been slow in implementing control practices. Past research has shown that farmers tend to be unaware of the seriousness of the erosion problem on their own operations. Using a random sample of farmers from central Iowa, the relationship is examined between awareness of a soil erosion problem and the use of conservation tillage. Results indicate that awareness of a soil erosion problem effects the use of conservation tillage, and that awareness can be enhanced by experiential educational strategies such as the development and implementation of a soil and water conservation plan.