HYDRAULIC GEOMETRY RELATIONSHIPS FOR URBAN STREAMS THROUGHOUT THE PIEDMONT OF NORTH CAROLINA1

ABSTRACT: Hydraulic geometry relationships, or regional curves, relate bankfull stream channel dimensions to watershed drainage area. Hydraulic geometry relationships for streams throughout North Carolina vary with hydrology, soils, and extent of development within a watershed. An urban curve that is the focus of this study shows the bankfull features of streams in urban and suburban watersheds throughout the North Carolina Piedmont. Seventeen streams were surveyed in watersheds that had greater than 10 percent impervious cover. The watersheds had been developed long enough for the streams to redevelop bankfull features, and they had no major impoundments. The drainage areas for the streams ranged from 0.4 to 110.3 square kilometers. Cross‐sectional and longitudinal surveys were conducted to determine the channel dimension, pattern, and profile of each stream and power functions were fitted to the data. Comparisons were made with regional curves developed previously for the rural Piedmont, and enlargement ratios were produced. These enlargement ratios indicated a substantial increase in the hydraulic geometry for the urban streams in comparison to the rural streams. A comparison of flood frequency indicates a slight decrease in the bankfull discharge return interval for the gaged urban streams as compared to the gaged rural streams. The study data were collected by North Carolina State University (NCSU), the University of North Carolina at Charlotte (UNC), and Charlotte Storm Water Services. Urban regional curves are useful tools for applying natural channel design in developed watersheds. They do not, however, replace the need for field calibration and verification of bankfull stream channel dimensions.     

Putting Precaution to Debate – about the Precautionary Principle and Participatory Technology Assessment

Technology assessment (TA) as aninstitution was introduced nearly thirty yearsago as an instrument to render possible themaking of responsible decisions concerning newtechnological options. Another recentdevelopment however has been the introductionof participatory technology assessment (pTA),mainly connected to the growing insight thatthe evaluation of technological options withrespect to their risks and benefits, is not –only – a scientific question. This paper willfocus on the questions, to what degree theideas of technology assessment and thePrecautionary Principle are connected and how.Without naming it explicitly, the PrecautionaryPrinciple is put to debate in the``TA-arrangement on the cultivation oftransgenic herbicide resistant crops,'organized by the Science Centre, Berlin. Fromthe perspective of ethical clarification, someunique features concerning theconceptualization of the discoursive procedureand reconstruction of the argumentation processin order to come to results have to beanalyzed. Finally the performance and resultsof the pTA-arrangement are reflected in thelight of the Precautionary Principle andconclusions are drawn.     

Thermal manikin measurements--exact or not?

According to the European prestandard ENV 342:1998, the thermal insulation of cold-protective clothing is measured with a thermal manikin. Systematic studies on the reproducibility of the values, measured with different types of clothing on the commonly used standing and walking manikins, have not been reported in the literature. Over 300 measurements were done in 8 different European laboratories. The reproducibility of the thermal insulation test results was good. The coefficient of variation was lower than 8%. The measured clothing should fit the manikin precisely, because poorly fitting clothing gave an error in the results. The correlation between parallel and serial insulation values was excellent and parallel values were about 20% lower than serial ones. The influence of ambient conditions was critical only in the case of air velocity. The reproducibility of thermal insulation test results in a single laboratory was good, and the variation was lower than 3%.     

Washing away poverty: Water, democracy and gendered poverty eradication in South Africa

This article discusses ways in which the South African Government and grassroots organizations envisage and implement democracy achieved since 1994 in the field of water resources management. The focus is on the democratic, political and economic freedom and equality in resource rights for poor black women, who are central to poverty eradication. While the new water policy and law provide an enabling framework for achieving these goals, implementation on the ground encounters both new opportunities and constraints. This is illustrated by several cases of establishing South Africa's new water management institutions: catchment management agencies and water user associations. The important nexus between state‐led democratization of water resources management and bottom‐up grassroots movements is also discussed. The article concludes that the Government's affirmative and targeted intervention is indispensable for redressing gender inequalities and eradicating poverty.     

WATER QUALITY SAMPLING SCHEMES FOR VARIABLE FLOW CANALS AT REMOTE SITES1

ABSTRACT: Growing interest in water quality has resulted in the development of monitoring networks and intensive sampling for various constituents. Common purposes are regulatory, source and sink understanding, and trend observations. Water quality monitoring involves monitoring system design; sampling site instrumentation; and sampling, analysis, quality control, and assurance. Sampling is a process to gather information with the least cost and least error. Various water quality sampling schemes have been applied for different sampling objectives and time frames. In this study, a flow proportional composite sampling scheme is applied to variable flow remote canals where the flow rate is not known a priori. In this scheme, historical weekly flow data are analyzed to develop high flow and low flow sampling trigger volumes for auto‐samplers. The median flow is used to estimate low flow sampling trigger volume and the five percent exceedence probability flow is used for high flow sampling trigger volume. A computer simulation of high resolution sampling is used to demonstrate the comparative bias in load estimation and operational cost among four sampling schemes. Weekly flow proportional composite auto‐sampling resulted in the least bias in load estimation with competitive operational cost compared to daily grab, weekly grab sampling and time proportional auto‐sampling.     

The design and use of strategic planning arenas

This paper takes a close look at communication, process, power and institutional arrangements in the context of strategic planning. It introduces an eight step process for structuring strategic thinking and acting and develops the concept of “arenas” as a very influential — yet often very subtle — exercise of power over the course of a strategic planning process.     

Integrating product quality and environmental performance through innovation—the l'oréal case

Meeting the demands of today's marketplace has become an increasingly complex challenge for corporations in all industries. The consumer is demanding high-quality products, low cost, and more recently, a new variable: environmental performance. Customers will not accept sacrifices in quality or cost to help businesses meet regulatory requirements or develop environmentally sound products. They want it all. Consequently, companies are faced with the complex task of balancing cost, quality, and environmental performance.     

Effects of biodegradable plastic components on metabolism of an estuarine benthos

We examined the metabolic response of an estuarine benthic community to additions of three materials being considered for use in manufacture of biodegradable substitutes for plastics. Diver-collected cores containing benthos were dosed with 59 g/m² of three test materials, cornstarch, a bacterial polyester (PHBV), and ethylene vinyl alcohol (EVOH), or left undisturbed as controls. Fluxes of dissolved nutrients (ammonia, nitrate + nitrite, phosphate, silica) and dissolved inorganic carbon (DIC) were similar in control cores and cores dosed with EVOH during a 1-month test period at 20°C. Fluxes in cores dosed with starch and PHBV differed significantly from controls but not from each other. After 2 weeks of incubation, production of DIC was higher in cores containing starch and PHBV, while efflux of ammonia, nitrate, and nitrite was reduced. After 4 weeks of incubation, production of DIC was similar among all treatments and controls, while efflux of ammonia was high in the starch- and PHBV-containing cores compared to controls and cores with EVOH. Fluxes of silica and phosphate were similar in all cores during the experiment. These results indicate that both starch and PHBV are carbon-rich substrates readily metabolized by the benthic community but that their presence significantly alters normal nutrient exchange patterns. This response is expected because of the high carbon-to-nitrogen ratio of starch and PHBV and indicates that impacts of these two materials would be similar. However, the high biological oxygen demand of such materials and resulting disturbance of normal nutrient regeneration patterns of the benthos (delayed ammonia efflux and potential stimulation of denitrification) must be considered in developing strategies for their disposal.Paper presented at the Biodegradable Materials and Packaging Conference, September 22–23, 1993, Natick, Massachusetts.     

Evaluating cumulative effects on wetland functions: A conceptual overview and generic framework

This article outlines conceptual and methodological issues that must be confronted in developing a sound scientific basis for investigating cumulative effects on freshwater wetlands. We are particularly concerned with: (1) effects expressed at temporal and spatial scales beyond those of the individual disturbance, specific project, or single wetland, that is, effects occurring at the watershed or regional landscape level; and (2) the scientific (technical) component of the overall assessment process. Our aim is to lay the foundation for a research program to develop methods to quantify cumulative effects of wetland loss or degradation on the functioning of interacting systems of wetlands. Toward that goal we: (1) define the concept of cumulative effects in terms that permit scientific investigation of effects; (2) distinguish the scientific component of cumulative impact analysis from other aspects of the assessment process; (3) define critical scientific issues in assessing cumulative effects on wetlands; and (4) set up a hypothetical and generic structure for measuring cumulative effects on the functioning of wetlands as landscape systems.We provide a generic framework for evaluating cumulative effects on three basic wetland landscape functions: flood storage, water quality, and life support. Critical scientific issues include appropriate delineations of scales, identification of threshold responses, and the influence on different functions of wetland size, shape, and position in the landscape.The contribution of a particular wetland to landscape function within watersheds or regions will be determined by its intrinsic characteristics, e.g., size, morphometry, type, percent organic matter in the sediments, and hydrologic regime, and by extrinsic factors, i.e., the wetland's context in the landscape mosaic. Any cumulative effects evaluation must take into account the relationship between these intrinsic and extrinsic attributes and overall landscape function. We use the magnitude of exchanges among component wetlands in a watershed or larger landscape as the basis for defining the geographic boundaries of the assessment. The time scales of recovery for processes controlling particular wetland functions determine temporal boundaries. Landscape-level measures are proposed for each function.     

A vibroacoustic model of selected human larynx diseases.

With the present development of digital registration and methods for processing speech it is possible to make effective objective acoustic diagnostics for medical purposes. These methods are useful as all pathologies and diseases of the human vocal tract influence the quality of a patient's speech signal. Diagnostics of the voice organ can be defined as an unambiguous recognition of the current condition of a specific voice source. Such recognition is based on an evaluation of essential acoustic parameters of the speech signal. This requires creating a vibroacoustic model of selected deformations of Polish speech in relation to specific human larynx diseases. An analysis of speech and parameter mapping in 29-dimensional space is reviewed in this study. Speech parameters were extracted in time, frequency and cepstral (quefrency) domains resulting in diagrams that qualified symptoms and conditions of selected human larynx diseases. The paper presents graphically selected human larynx diseases.