Ammonia emissions from swine houses in the southeastern United States

Ammonia (NH3) from confined animal feeding operations is emitted from several sources including lagoons, field applications, and houses. This paper presents studies that were conducted to evaluate NH3 emissions from swine finisher and sow animal houses in the southeastern USA. Management and climate variables including animal weight, feed consumption, housing gutter water temperature, total time fans operated per day, house air temperature, house ambient NH3 concentration, and animal numbers were measured to determine their individual and combined effect on NH3 emissions. Ammonia emissions varied on daily and seasonal bases with higher emissions during warmer periods. For finishers, the summertime housing emissions on a per-animal basis were 2.4 times higher than wintertime (7.0 vs. 3.3 g NH3 animal(-1) d(-1)) or 3.2 times higher when compared on an animal unit (AU) basis (1 AU = 500 kg) because of climate and animal size differences between measurement periods. For summertime, the emission factor for the finishing pigs was 7.8 times higher than for sows on an animal basis and 25.6 times higher on an AU basis. Simple models were developed for housing emissions based on (i) all measured factors that were independent of each other and (ii) on three commonly measured management factors. The two models explained 97 and 64%, respectively, of variations in emissions. Ammonia emissions were found to be somewhat less than other studies on the same type housing due to more representative housing concentration measurements and calibration of exhaust fans; thus, emission factors for these type houses will be less than previously thought.     

Walking to school: Community design and child and parent barriers

The roles of community design and parent and child perceptions of walkability to school are tested for associations with walking in three communities: a walkable new urbanist community, a mixed community (standard suburban community where the walk to school traversed part of the new urbanist community), and less walkable standard suburban community. Perceived environmental barriers to walking to school are measured and compared for fifth graders (n = 193) and their parents (n = 177). Results showed that children and parents often agreed on walking barriers, except an interaction showed that — in the less walkable community — parents perceived worse barriers than did their children. Perceptions of barriers increased from walkable, to mixed, to less walkable communities. Students walked more when they attended the school in the walkable community, they lived near school, parents and children perceived fewer barriers to walking, and children had lower BMI scores, net of demographic controls. Thus the walk to school is embedded within multiple types of supports, all of which should be addressed to encourage walking to school.     

Valuing the benefits of the urban forest: a spatial hedonic approach

This paper measures the benefits of the urban forest by examining its effect on housing prices. A Geographic Information System is used to develop a measure of the urban forest, the Normalised Difference Vegetation Index, from satellite imagery and to construct other variables from a variety of sources. Spatial hedonic housing price models for the Indianapolis/Marion County area are estimated. The models indicate that greener vegetation around a property has a positive, significant effect on housing price, holding everything else constant. This effect is dominated by measures at the neighborhood level. These findings indicate that property owners value the urban forest, at least in part, by the premium they pay to live in neighborhoods with greener, denser vegetation. These findings also indicate that public action to maintain and enhance the urban forest may be warranted. Planners and urban foresters can use these findings to inform public and policy debates over urban forestry programs and proposals.     

Walking routes to school in new urban and suburban neighborhoods: An environmental walkability analysis of blocks and routes

We assessed environmental and perceptual correlates of walking and walkability for fifth graders from three communities attending two schools: A new urban/LEED-ND pilot community, mixed, and standard suburban community. Irvine-Minnesota Inventory (IMI) walkability audits showed that new urban blocks provided more traffic safety, pleasurability, crime safety, density, and diversity. New urban routes offered greater traffic safety, accessibility, pleasurability, crime safety, and diversity, but suburban routes had greater housing density, net of controls (parental education, rooms in the home, home ownership, parent preference for child to walk to school). Parents and children perceived new urban routes to be more walkable and children walked more when they lived on more walkable routes. The suburban hierarchical street design exposed children to varied traffic safety conditions by funneling their walks from cul-de-sacs to arterials. The new urban routes to a centrally located school passed by pleasant open spaces, suggesting how community organization can create better walking conditions.     

Assessing determinants of industrial waste reuse: The case of coal ash in the United States

Devising effective strategies to facilitate waste reuse depends on the solid understanding of reuse behaviors. However, previous studies of reuse behavior have been limited in scope, focusing mostly on household recycling behaviors or very limited types of industrial wastes. To gain a better understanding of the business reuse behaviors, this study examined the impact of various factors in technical, economic, regulatory, and behavioral categories in the case of coal ash generated in the United States. The results of fixed effect models for fly ash and bottom ash particularly showed the significance role of the behavioral factor. In both models, a proxy variable, which represents knowledge sharing among the power plants or the utility's decision-making, turned out to be statistically significant and had the largest coefficient estimates among a group of variables. This finding may imply that the characteristics of waste reuse behavior are determined more by business decision-making behaviors than by market or institutional factors. However, the role of the behavioral variable was stronger in the bottom ash models than in the fly ash models. While the reuse of bottom ash was determined primarily by the behavioral variable, fly ash reuse was determined by more diverse factors including economic and regulatory variables. This could be explained by material characteristics in relation to competing resources and the nature of reuse applications.     

Calibration Catchment Selection for Flood Regionalization Modeling1

Wan Jaafar, Wan Zurina, and Dawei Han, 2012. Calibration Catchment Selection for Flood Regionalization Modeling. Journal of the American Water Resources Association (JAWRA) 48(4): 698‐706. DOI: 10.1111/j.1752‐1688.2012.00648.x Abstract: There are two unsolved problems in flood regionalization model development related to the quantity and quality of calibration catchments: (1) how many calibration catchments should be used? and (2) how to select the calibration catchments? This study explores these two questions through a case study on the median annual maximum flood (QMED) model in the United Kingdom. It has been found that the chance of developing a good QMED model decreases significantly when the number of calibration catchments drops below a critical number (e.g., 60 in the case study). However, no significant improvement is achieved if the number of calibration catchments is above it. This number could be used as a benchmark for choosing randomly selected calibration catchments. Across a broad range of calibration catchment numbers, there are good and poor calibrated models regardless of calibration catchment numbers. High quality models could be developed from a small number of calibration catchments and also poor models from a large number of calibration catchments. This indicates that the number of calibration catchments may not be the dominating factor for developing a high quality regionalization model. Instead, the information content could be more important. The study has demonstrated that the standard deviation values between the best and poorest groups are distinctive and could be used in choosing appropriate calibration catchments.     

Modelling land use change with generalized linear models--a multi-model analysis of change between 1860 and 2000 in Gallatin Valley, Montana

This paper develops an approach to modelling land use change that links model selection and multi-model inference with empirical models and GIS. Land use change is frequently studied, and understanding gained, through a process of modelling that is an empirical analysis of documented changes in land cover or land use patterns. The approach here is based on analysis and comparison of multiple models of land use patterns using model selection and multi-model inference. The approach is illustrated with a case study of rural housing as it has developed for part of Gallatin County, Montana, USA. A GIS contains the location of rural housing on a yearly basis from 1860 to 2000. The database also documents a variety of environmental and socio-economic conditions. A general model of settlement development describes the evolution of drivers of land use change and their impacts in the region. This model is used to develop a series of different models reflecting drivers of change at different periods in the history of the study area. These period specific models represent a series of multiple working hypotheses describing (a) the effects of spatial variables as a representation of social, economic and environmental drivers of land use change, and (b) temporal changes in the effects of the spatial variables as the drivers of change evolve over time. Logistic regression is used to calibrate and interpret these models and the models are then compared and evaluated with model selection techniques. Results show that different models are 'best' for the different periods. The different models for different periods demonstrate that models are not invariant over time which presents challenges for validation and testing of empirical models. The research demonstrates (i) model selection as a mechanism for rating among many plausible models that describe land cover or land use patterns, (ii) inference from a set of models rather than from a single model, (iii) that models can be developed based on hypothesised relationships based on consideration of underlying and proximate causes of change, and (iv) that models are not invariant over time.     

Residents' perception of local brownfields in rail corridor area in the City of Roanoke: the effect of people's preconception and health concerns factors

This article examines preferences of residents for nearby brownfield sites and the factors affecting preferences. 200 residents in neighborhoods along the railyard in the City of Roanoke, Virginia, participated in a survey of their preferences for different brownfield scenes. Results indicate that scenes with historical landmarks and maintained landscapes received the highest ratings, regardless of preconceptions and health concerns. These are viewed less critically and thus could mask possible harms. In contrast, scenes with scruffy vegetation and rundown buildings revealed mixed preferences. For these types, participant preferences for change versus preservation fluctuated. Lastly, scenes with industrial remnants were preferred the least. Participants tended to associate these types with toxic pollutants that may adversely affect health. This suggests that planners need to convince people that these sites can be reused if they are cleaned up. The results are used to develop more effective engagement strategies for increasing support for brownfield redevelopment projects.     

From socioeconomic disparity to environmental injustice: the relationship between housing unit density and community green space in a medium city in Pakistan

Rapid urbanisation, lack of proactive planning and improper allocation of resources may result in socio-economic disparity among and within cities, causing social unrest and environmental injustice in the neighbourhoods. This study aims to examine whether the planning standards for housing schemes in Pakistan are able to maintain equitable access to green spaces within the cities. Ten residential sites in Sheikhupura city with different housing unit sizes and densities were selected for the study. The supply of urban green infrastructure in housing scheme has been assessed: (i) by comparing the percentage of green spaces, including community parks and open spaces and street landscape; and (ii) by calculating per dwelling unit and per capita share of green spaces. These indicators have been studied against the housing density and population density of the schemes by applying correlation and linear regression models. The results show that all the housing schemes plans provide for similar amounts of green space as a percentage of total area. The per capita share of green spaces is very low in high-density areas, but interestingly, the street landscape has a higher potential to contribute to the overall landscape in high-density neighbourhoods, compensating for low per capita green space. Housing unit density and population density must be incorporated in planning standards so planners can effectively devise a mix of community parks, street landscape and private green spaces to help maintain per capita green spaces, and hence environmental resource equality in different parts of the city.     

Natural Behavior, Animal Rights, or Making Money – A Study of Swedish Organic Farmers' View of Animal Issues

A questionnaire study was performed among Swedish organic livestock farmers to determine their view of animal welfare and other ethical issues in animal production. The questionnaire was sent to 56.5% of the target group and the response rate was 75.6%. A principal components analysis (exploratory factor analysis) was performed to get a more manageable data set. A matrix of intercorrelations between all pairs of factors was computed. The factors were then entered into a series of multiple regression models to explain five dependent variables. Respondents were well educated and had long experience of farming. 81% were full-time farmers. They generally had a very positive attitude towards organic animal husbandry. They considered allowing animals their natural behavior a central aim, which is in accordance with organic philosophy. Farmers tended to be less approving of concepts like animal rights, dignity, and intrinsic value. When analyzing correlations between the factors, two groups of farmers emerged that were only partially correlated, representing different attitudes and behavioral dispositions. These may be interpreted as two subpopulations of organic livestock farmers in Sweden: those who saw organic farming as a lifestyle (``pioneer attitude') and entrepreneurs, who considered making money and new challenges more important. Their view of animal welfare differed. While the pioneers considered natural behavior a key issue, this was less important to the entrepreneurs, who also had a more approving attitude towards invasive operations such as castration and were more critical of the organic standards.     

Green Houses for the Growth Region

The new housing growth programme planned for England and Wales between now and 2016 could provide the government with an opportunity to build housing to significantly higher environmental performance (EP) standards. Equally, if the government continues with its current strategy a great opportunity could be missed. This paper considers and critically analyses the government's approach to ensuring higher EP standards in new housing. Using Greenwich Millennium Village as a case study it assesses the likely outcomes of the approach. It suggests how regulation, fiscal incentives and educational programmes could help to deliver better EP amongst housing and households in the growth region.     

Environmental quality and council house sales: A case study of North Tyneside,UK

Summary The residential environments in British urban areas are divided between those dominated by public sector (local authority) housing and those properties which are owner-occupied. It is widely recognised that the environmental quality of local authority housing estates varies considerably. It may be expected, therefore, that the United Kingdom 1980 Housing Act, which encouraged the tenants of public sector housing to purchase the dwellings they rented from local authorities, would have a differential impact, according to the environmental quality of those estates. However, this relationship has not been previously explored. Most studies have related sales to a range of socio- economic variables. Whilst these may effectively indicate ability to buy they do not necessarily indicate willingness to buy. It is argued that the latter may be more closely related to factors such as the quality of the local environment. Findings from the North Tyneside area in northern England suggest that the spatial pattern of sales is more closely related to an index of environmental quality than one composed largely of socio-economic variables. Some of the implications of this finding for policy in relation to public sector housing are then discussed. It is suggested that if the ultimate objective of the Housing Act is to promote a larger private sector, then initially this may require a considerably larger public sector involvement in environmental improvement.Dr Michael Barke, is the senior author, Principal Lecturer in Geography and Acting Head of the Department of Environment at Newcastle upon Tyne Polytechnic. He has published a number of articles on aspects of urban change in North-East England. Ms Julie Rowlands is a graduate in Environmental Studies from the same Polytechnic and currently studying for professional qualifications in urban and regional planning in Perth, Western Australia.     

Does salt marsh fertilization enhance shellfish production? An application of flow analysis

The method of flow analysis, which is similar to economic input-output analysis, is presented as a means of making flow models of ecological systems more useful to environmental managers. This paper considers as an illustration the extent to which nitrogen fertilizer added toSpartina salt marsh sediments can enhance shellfish growth. Nitrogen flow models of both the Barataria Bay salt marsh complex of coastal Louisiana and the Sippewissett Marsh of western Cape Cod are analyzed. The analysis shows the transfer of added nitrogen to shellfish growth viaSpartina growth, decomposition, and detrital feeding to be considerably less efficient than its transfer toSpartina growth itself. These results are similar for both marsh systems, despite their great physical differences and despite the inclusion of considerably more microbial processing of nitrogen in the Barataria Bay model than in the Sippewissett models. The results suggest that the most efficient mechanism by which added nitrogen could enhance shellfish growth in salt marshes may have to bypass the route through theSpartina life cycle.     

ASSESSMENT OF POSSIBLE IMPACTS OF CLIMATE CHANGE IN AN URBAN CATCHMENT1

ABSTRACT: Stationarity of rainfall statistical parameters is a fundamental assumption in hydraulic infrastructure design that may not be valid in an era of changing climate. This study develops a framework for examining the potential impacts of future increases in short duration rainfall intensity on urban infrastructure and natural ecosystems of small watersheds and demonstrates this approach for the Mission/Wagg Creek watershed in British Columbia, Canada. Nonstationarities in rainfall records are first analyzed with linear regression analysis, and the detected trends are extrapolated to build potential future rainfall scenarios. The Storm Water Management Model (SWMM) is used to analyze the effects of increased rainfall intensity on design peak flows and to assess future drainage infrastructure capacity according to the derived scenarios. While the framework provided herein may be modified for cases in which more complex distributions for rainfall intensity are needed and more sophisticated stormwater management models are available, linear regressions and SWMM are commonly used in practice and are applicable for the Mission/Wagg Creek watershed. Potential future impacts on stream health are assessed using methods based on equivalent total impervious area. In terms of impacts on the drainage infrastructure, the results of this study indicate that increases in short duration rainfall intensity may be expected in the future but that they would not create severe impacts in the Mission/Wagg Creek system. The equivalent levels of imperviousness, however, suggest that the impacts on stream health could be far more damaging.     

Scale Effects on Spatially Varying Relationships Between Urban Landscape Patterns and Water Quality

Scientific interpretation of the relationships between urban landscape patterns and water quality is important for sustainable urban planning and watershed environmental protection. This study applied the ordinary least squares regression model and the geographically weighted regression model to examine the spatially varying relationships between 12 explanatory variables (including three topographical factors, four land use parameters, and five landscape metrics) and 15 water quality indicators in watersheds of Yundang Lake, Maluan Bay, and Xinglin Bay with varying levels of urbanization in Xiamen City, China. A local and global investigation was carried out at the watershed-level, with 50 and 200 m riparian buffer scales. This study found that topographical features and landscape metrics are the dominant factors of water quality, while land uses are too weak to be considered as a strong influential factor on water quality. Such statistical results may be related with the characteristics of land use compositions in our study area. Water quality variations in the 50 m buffer were dominated by topographical variables. The impact of landscape metrics on water quality gradually strengthen with expanding buffer zones. The strongest relationships are obtained in entire watersheds, rather than in 50 and 200 m buffer zones. Spatially varying relationships and effective buffer zones were verified in this study. Spatially varying relationships between explanatory variables and water quality parameters are more diversified and complex in less urbanized areas than in highly urbanized areas. This study hypothesizes that all these varying relationships may be attributed to the heterogeneity of landscape patterns in different urban regions. Adjustment of landscape patterns in an entire watershed should be the key measure to successfully improving urban lake water quality.     

ACCURACY AND PRECISION OF NRCS MODELS FOR SMALL WATERSHEDS1

ABSTRACT: In the last 30 years, the National Resource Conservation Service's TR‐55 and TR‐20 models have seen a dramatic increase in use for stormwater management purposes. This paper reviews some of the data that were originally used to develop these models and tests how well the models estimate annual series peak runoff rates for the same watersheds using longer historical data record lengths. The paper also explores differences between TR‐55 and TR‐20 peak runoff rate estimates and time of concentration methods. It was found that of the 37 watersheds tested, 25 were either over‐ or under‐predicting the actual historical watershed runoff rates by more than 30 percent. The results of this study indicate that these NRCS models should not be used to model small wooded watersheds less than 20 acres. This would be especially true if the watershed consisted of an area without a clearly defined outlet channel. This study also supports the need for regulators to allow educated hydrologists to alter pre‐packaged model parameters or results more easily than is currently permitted.     

How Technology Features Influence Public Response to New Agrifood Technologies

New agrifood technologies are often difficult to grasp for the public, which may lead to resistance or even rejection. Insight into which technology features determine public acceptability of the technology could offer guidelines for responsible technology development. This paper systematically assesses the relative importance of specific technology features for consumer response in the agrifood domain in two consecutive studies. Prominent technology features were selected from expert judgment and literature. The effects of these features on consumer evaluation were tested in a consumer study (n = 745). Fictitious technologies were used to avoid any uncontrollable contextual influences that existing new technologies may evoke. Results show that technologies that were seen as more natural and newer were perceived less risky, more beneficial, and were evaluated more positively. Technologies applied to food were judged to be more beneficial, but also more risky than those applied to non-food. Technologies used in the production process were perceived to be less risky and evaluated more positively than those used in the product. Technologies owned by the market leader were perceived to be more beneficial, and evaluated more positively than those that were freely available. In a next study (n = 440), effects of the technology features on consumer response were tested for existing new agrifood technologies. This study replicated the results for perceived naturalness, perceived newness, and place in the production process where the technology is applied. However, in contrast to the first study, we did not find an effect of application area (food versus non-food) and technology ownership.     

Reusable and disposable cups: An energy-based evaluation

A group of five different types of reusable and disposable hot drink cups have been analyzed in detail with respect to their overall energy costs during fabrication and use. Electricity generating methods and efficiencies have been found to be key factors in the primary energy consumption for the washing of reusable cups and a less important factor in cup fabrication. In Canada or the United States, over 500 or more use cycles, reusable cups are found to have about the same or slightly more energy consumption, use for use, as moulded polystyrene foam cups used once and then discarded. For the same area paper cups used once and discarded are found to consume less fossil fuel energy per use than any of the other cup types examined. Details of this analysis, which could facilitate the comparative assessment of other scenarios, are presented.     

Non-transport household energy consumption in Adelaide and Melbourne

The residential sector is the third largest sector of final energy use in Australian urban areas, accounting for about 12% of the country's total final energy consumption. What are the main determinants of energy consumption in the residential sector? This paper sheds light on this question by examining non-transport summer household energy consumption in Adelaide and Melbourne. Data were collected from a survey of 200 sample households and modelled according to a conceptual framework that not only emphasises household characteristics and housing stock characteristics but also controls the macro-environment factors. The findings reveal distinctive results in Adelaide and Melbourne. In Adelaide, household characteristics are the most important contributors in explaining non-transport household energy consumption. In Melbourne, the household characteristic as represented by income is important, but housing stock characteristics provide even more explanatory power. These findings contribute to the understanding of the factors that shape residential energy consumption and have policy implications in targeting household energy savings.     

Residential satisfaction in students' housing

This paper reports the results of a study of residential satisfaction in students' housing in Nigeria. The study examined how satisfied students were and the factors which predicted residential satisfaction. Specifically, it examined whether the morphological configurations of the halls of residence would predict residential satisfaction. Data were obtained from questionnaires distributed to a sample of 1124 respondents from all the halls of residences in four residential universities in Southwestern Nigeria. The data comprised objective and subjective measures of the physical, social and management attributes of the halls of residence. These were analyzed using frequencies, factor analysis and categorical regression models. More than half (53%) of the respondents were dissatisfied with their residences and the variables which explained satisfaction were the social qualities of the residences, especially, the social densities; the kitchenette, bathroom and storage facilities and some demographic characteristics of the students. The morphological configuration of the halls of residence was also found to be a predictor of satisfaction and the characteristics which appeared most significant were the plan form and the length of the corridor. The regression model explained 65% of the variance in R². An instructive finding was that satisfaction appeared most critical in the bedroom.