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191.
192.
Despite an array of policies at the federal and state level aimed at regulating stormwater discharges, engineered solutions
enforced by local governments often fall short of meeting water quality standards. Although the implications of land use planning
and development regulations are important for stormwater management, they are often overlooked as critical initial steps to
improving water quality. This study explores the role of ‘form-based’ regulations as tools for achieving urban planning and
water quality objectives. Form-based codes are a new generation of development codes aimed at regulating urban development
based on urban form and density, rather than land use. We present an exploratory case study of the feasibility of form-based
codes in the Jordan Lake Watershed in North Carolina, a rapidly growing region where fragmented local governments face stringent
nutrient reduction standards under new state regulations. Through program analysis and interviews, we explore the viability
of form-based codes for reducing development impacts on Jordan Lake’s water quality. We consider the legal feasibility of
code enforcement, regional and local barriers and opportunities, and implementation given existing regulatory frameworks.
Our findings suggest that high quality information and data modeling are foundational to gaining support for a consensus agreement
on the sources and degree of water quality impairment. Furthermore, implementing form-based solutions for water quality is
greatly aided by (1) experienced regional planning bodies that have regulatory authority, and (2) local governments whose
staff are experienced in implementing complex development ordinances, reviewing architectural renderings, and communicating
development requirements with the public and developers. 相似文献
193.
S. Åkesson Lennart Karlsson Göran Walinder Thomas Alerstam 《Behavioral ecology and sociobiology》1996,38(5):293-302
Extensive ringing data from a coastal site (Falsterbo Bird Observatory) in southwesternmost Sweden were used to investigate
the occurrence of reverse autumn migration among 20 passerine bird species of widely different migration categories. The data
demonstrate that reverse migration is a widespread and regular phenomenon among nocturnal as well as diurnal migrants and
among irruptive migrants, temperate zone migrants, and long-distance migrants destined for tropical winter quarters. The reoriented
movements were directed approximately opposite to the normal migration direction, i.e. between NNW and ENE from the coast
and towards inland. Median distances of reverse movements varied between 9 and 65 km. Some individuals of irruptive and partial
migrants settled to winter in the reverse direction. Bird species with relatively small fat reserves at capture were more
likely to perform reverse migratory movements than species with larger fat deposits. In two species birds performing forward
migration were significantly heavier within 10 days after capture than individuals performing reverse movements. The reoriented
movements probably are of adaptive significance for birds confronted with the sea and pre-disposed to refuelling during migration.
A bimodal orientation mechanism will bring the birds from an area with high competition for food and high predation risk to
more suitable resting and feeding grounds before resuming migration in the forward direction and crossing the barrier.
Received: 11 July 1995/Accepted after revision: 19 November 1995 相似文献
194.
Torunn Berg Oddvar Røyset Eiliv Steinnes 《Environmental monitoring and assessment》1994,31(3):259-273
Trace elements and the main components in precipitation were measured at three background sites in Norway. The work is based on weekly samples from 1989 and 1990. Principal component analysis was used to detect the covariation of the chemical components in the data set. Dominant factors are long-range atmospheric transport of anthropogenic components to Norway, crustal material, and marine sources. Different local sources also exist. The interpretation of seasonal variations in the data set is eased by studying the changes in the factor scores throughout the year. Distinct seasonal patterns are shown for some of the factors, in particular those representing soil dust and atmospheric transport from the marine environment. 相似文献
195.
Urban and industrialised societies usually involve little connection between consumers and the resource base upon which the production of goods depends. Changing this situation could potentially enhance social and ecological sustainability. This study explored ecological aspects of the educational role of local food supply, with the aim of identifying signs of enhanced consumer understanding or awareness of the ecology of food production resulting from producer–consumer interaction. A series of qualitative interviews were carried out with customers at a farmers’ market in Stockholm. The results showed that the interviewees were mainly concerned with quality, price and taste, and not production conditions. In addition, a number of interviewees experienced a sense of trust when shopping at the market. We found few examples of contributions to ecological knowledge among customers at the market, but there were some examples of learning opportunities. The local food supplied by the market reminded customers of the seasonality of production. Stallholders also provided information on how to store, prepare and cook vegetables, which may encourage a change in diet that is preferable from an environmental standpoint. 相似文献
196.
Henrik Åhman 《Local Environment》2013,18(10):1153-1166
Since the late 1980s, much of the debate on sustainability has been dominated by ecological perspectives. However, the last decade has seen an increasing interest in the social aspects of sustainability. While, to some extent, general consensus has been reached regarding the definitions of ecological sustainability, the definition of social sustainability is still in the making. Therefore, there is a need for conceptual frameworks and theoretical constructs in order to develop the understanding of social sustainability further. This article addresses the lack of theorisation and is composed of three different sections. The first section is a literature overview covering some of the most influential texts on social sustainability. The second section introduces and relates a number of existing, polemically constructed theoretical frameworks. In the third section, Jacques Derrida's theory of différance is used to suggest a way of understanding the relationship between the oppositional positions identified in the frameworks. 相似文献
197.
Göran I. Ågren 《Ecological modelling》1981,12(4):281-295
This paper analyses the effect of variations in the elimination rates of four elimination models. Three types of variations are studied: (1) a periodic change between two elimination rates; (2) changes between two elimination rates at random times; and (3), an elimination rate varying smoothly in time, generated by having the elimination rate vary exponentially with temperature and a sinusoidally varying temperature. The elimination process is described by four different models: (1) a single compartment; (2) two compartments in parallel; (3) two compartments in series; and (4) the Goldstein-Elwood model. It is shown that for all 12 cases, the solutions can be given the same form as with constant elimination rates through reinterpretation of the parameters. As a special case, the use of elimination methods to estimate respiration is discussed and a possible source of error is pointed out. 相似文献
198.
Jonathan P. Park John B. Moeschler Eileen Rawnsley Susan Z. Berg Doris H. Wurster-Hill 《黑龙江环境通报》1989,9(7):501-504
Prenatal diagnosis of trisomy 20 mosaicism in this case was based on cytogenetic analysis of cultured amniotic fluid cells (23/52 cells were trisomy 20 representing cells from each of four primary cultures). The pregnancy continued to term and the mosaicism was confirmed in the phenotypically normal male neonate by analysis of cultured foreskin fibroblasts (7/49 cells + 20) and placental cells 20/20 cells + 20) whereas the peripheral lymphocytes were cytogenetically normal (20/20 cells were 46,XY). This represents the first confirmation of trisomy 20 mosaicism in a phenotypically normal full-term neonate. 相似文献
199.
Michael Matson Craig P. Berg 《Journal of the American Water Resources Association》1981,17(1):122-128
ABSTRACT: On June 15, 1977, an unusual brightness anomaly was detected in the north arm of Great Salt Lake, Utah, on NOAA-5 Very High Resolution Radiometer (VHRR) visible band imagery and on Landsat-2 multispectral visual band imagery. Retrospective inspection of NOAA-3, 4, and 5 satellite imagery from 1974–77 revealed 12 previous cases of the anomaly, whereas post monitoring documented nine other cases through May 1978. Comparison of lake levels in the north arm with meteorological parameters leads to the conclusion that the anomalous brightness is associated with wind induced seiches in the north arm. Apparently the wind induces a lower water depth, turbulence, and mixing throughout the water column in the western third of the north arm, thus increasing the brightness of the surface waters chiefly from sediment resuspension. 相似文献
200.
It is shown that the error in an estimate of the population respiration should generally not exceed 10% if the mean body weight is used instead of the full weight distribution. A convenient mathematical formulation of the Krogh-curve is given such that the commonly used exponential temperature dependence (Q10 law) of the respiration rate is only a special case. A formula is derived which expresses the effect of a cyclic temperature relative to a constant temperature on the respiration of an animal, the respiration rate of which follows a Krogh-curve. This formula is shown to provide good estimates of annual population respiration both for cases where the population biomass can be considered as constant over the year and when its variation can be approximated with a sinusfunction. Our methods of estimating population respiration are shown to compare favourably with earlier shortcut methods. 相似文献