A framework for assessing the sustainability of brownfield developments

In England, the development of urban brownfield sites is a significant planning policy aimed at supporting urban regeneration and protecting the countryside. Brownfield sites are required, in policy, to be developed in a sustainable way. However, determining what this means in practice is unclear. This paper presents a framework for assessing the sustainability of brownfield developments, devised to clarify the stakeholders in land reuse and establish how sustainability can be achieved on reused sites. The framework has been used in research investigating the sustainability of five brownfield developments in England. The performance of the framework in this research is assessed and its potential practical use outlined.     

INTERACTIONS BETWEEN LAND USE AND URBAN WATER RESOURCES PLANNING1

ABSTRACT The patterns of land use and their relationship to urban water resources are examined from the point of view of population growth, consumer behavior, and preferences of price, income, and land use controls. The changes that need to be made in present social attitudes or water resources laws to satisfy the desired new developments are examined. Several implementation methods that are feasible and effective for changing urban development patterns are considered as well as models for assessing alternate development plans. The needs for research are outlined.     

Relative effects of land use and near-stream chemistry on phosphorus in an urban stream

Elevated levels of P in urban streams can pose significant water quality problems. Sources of P in urban streams, however, are difficult to identify. It is important to recognize both natural and anthropogenic sources of P. We investigated near-stream chemistry and land use factors on stream water P in the urbanizing Johnson Creek watershed in Portland, OR, USA. We sampled stream water and shallow groundwater soluble reactive P (SRP) and total P (TP) and estimated P flux at 13 sites along the main stem of Johnson Creek, with eight sites in urban land use areas and five sites in nonurban land use areas. At each site, we sampled the A and B horizons, measuring soil pH, water-soluble P, acid-soluble P, base-soluble P, total P, Fe, and Al. We found continuous input of P to the stream water via shallow groundwater throughout the Johnson Creek watershed. The shallow groundwater P concentrations were correlated with stream water P within the nonurban area; however, this correlation was not found in the urban area, suggesting that other factors in the urban area masked the relationship between groundwater P and stream water P. Aluminum and Fe concentrations were inversely correlated with shallow groundwater P, suggesting that greater P adsorption to Al and Fe oxides in the nonurban area reduced availability of shallow groundwater P. Using stepwise multiple regression analysis, however, we concluded that while riparian soil chemistry was related to stream water P, land use patterns had a more significant relationship with stream water P concentrations in this urbanizing system.     

Urban Land Use,Channel Incision,and Water Table Decline Along Coastal Plain Streams,North Carolina1

Abstract: This study evaluates the effects of urban land use on stream channels and riparian ground‐water levels along low‐order Inner Coastal Plain streams in North Carolina. Six sites with stream catchments of similar size (1.19‐3.46 km²) within the Tar River Basin were selected across an urban land use gradient, as quantified by a range of catchment total impervious area (TIA; 3.8‐36.7%). Stream stage and ground‐water levels within three floodplain monitoring wells were measured manually and using pressure transducers from May 2006‐June 2007. Channel incision ratio (CIR), the ratio of bank height to bankfull height, was also measured at each monitoring site and along stream reaches within the study area (12 urban and 12 rural sites). Riparian ground‐water levels were inversely related to catchment TIA (%). As TIA (%) and stormwater runoff increased, the degree of stream channel incision increased and riparian ground‐water tables declined. In urban floodplains (>15% TIA), the median ground‐water level was 0.84 m deeper than for the rural settings (<15% TIA). This has resulted in a shift to drier conditions in the urban riparian zones, particularly during the summer months. CIR was found to be a reliable surface indicator of “riparian hydrologic drought” in these settings.     

Groundwater Vulnerability,Brownfield Redevelopment and Land Use Planning

An understanding of groundwater vulnerability in urban watersheds is important for the prevention of both surface water and groundwater contamination and can therefore be a useful tool in brownfield redevelopment and land use planning. Although industrial activity in southeastern Michigan has historically been restricted to the urbanized sections of metropolitan Detroit, new industrial development is rapidly taking place in rural and undeveloped areas. Although environmentalists and urban planners agree that industrial site recycling in urban centres (a.k.a. brownfield redevelopment) is preferable to developing green areas, many older sites remain undeveloped due to real and perceived risks. Using a PC-based geographic information system, a conceptual model of solute transport in soil was developed to evaluate potential impacts to both groundwater and surface water quality resulting from industrial development. The model was used to create a map of groundwater vulnerability within the Rouge River watershed of southeastern Michigan. The map has been used to pin-point several rural and undeveloped areas where groundwater quality is threatened by proposed development. It has also clearly demonstrated that many older brownfield sites, within the City of Detroit, are located on materials that have a much lower vulnerability to groundwater contamination and may therefore be far less costly to redevelop than greenfield sites in undeveloped areas of the watershed.     

Sustainability speak: Discourse and practice paradigms in subdivision design

Abstract

In the last decade the concept of sustainable development has been widely embraced as the key to environmentally friendly development. However, in many instances the physical sustainability side of the equation stops at a rhetorical level and the ensuing developments fail to respond to ecological imperatives or to protect existing ecological values. Nowhere is this failure more evident than at the urban fringes of Melbourne, Australia, where residential land estate developments relentlessly engulf degraded agricultural lands that often contain the remnants of vegetative and hydrological ecological systems.

This paper postulates that while landscape design practitioners claim the ‘authority of nature’ (and, by extension, the land) for their design inspiration, in reality narrow practice foci and instrumental approaches have meant that the design of estates and subdivisions often make only token reference to ecological underpinnings. It is argued that instrumental influences on design decision-making are embedded in landscape-architectural professional culture and glossed over with an elusive rhetoric of care and concern for the environment. It is further postulated that individual expressions of interest in the land and its systems can make a substantive contribution to sustainable design practice and practical outcomes.     

Sustainability speak: Discourse and practice paradigms in subdivision design

In the last decade the concept of sustainable development has been widely embraced as the key to environmentally friendly development. However, in many instances the physical sustainability side of the equation stops at a rhetorical level and the ensuing developments fail to respond to ecological imperatives or to protect existing ecological values. Nowhere is this failure more evident than at the urban fringes of Melbourne, Australia, where residential land estate developments relentlessly engulf degraded agricultural lands that often contain the remnants of vegetative and hydrological ecological systems.

This paper postulates that while landscape design practitioners claim the 'authority of nature' (and, by extension, the land) for their design inspiration, in reality narrow practice foci and instrumental approaches have meant that the design of estates and subdivisions often make only token reference to ecological underpinnings. It is argued that instrumental influences on design decision-making are embedded in landscape-architectural professional culture and glossed over with an elusive rhetoric of care and concern for the environment. It is further postulated that individual expressions of interest in the land and its systems can make a substantive contribution to sustainable design practice and practical outcomes.     

WATER QUALITY IN SHALLOW ALLUVIAL AQUIFERS,UPPER COLORADO RIVER BASIN,COLORADO, 19971

ABSTRACT: Shallow ground water in areas of increasing urban development within the Upper Colorado River Basin was sampled for inorganic and organic constituents to characterize water‐quality conditions and to identify potential anthropogenic effects resulting from development. In 1997, 25 shallow monitoring wells were installed and sampled in five areas of urban development in Eagle, Grand, Gunnison, and Summit Counties, Colorado. The results of this study indicate that the shallow ground water in the study area is suitable for most uses. Nonparametric statistical methods showed that constituents and parameters measured in the shallow wells were often significantly different between the five developing urban areas. Radon concentrations exceeded the proposed USEPA maximum contaminant level at all sites. The presence of nutrients, pesticides, and volatile organic compounds indicate anthropogenic activities are affecting the shallow ground‐water quality in the study area. Nitrate as N concentrations greater than 2.0 mg/L were observed in ground water recharged between the 1980s and 1990s. Low concentrations of methylene blue active substances were detected at a few sites. Total coliform bacteria were detected at ten sites; however, E. coli was not detected. Continued monitoring is needed to assess the effects of increasing urban development on the shallow ground‐water quality in the study area.     

Understanding the role of land use in urban stormwater quality management

Urbanisation significantly impacts water environments with increased runoff and the degradation of water quality. The management of quantity impacts are straight forward, but quality impacts are far more complex. Current approaches to safeguard water quality are largely ineffective and guided by entrenched misconceptions with a primary focus on 'end-of-pipe' solutions. The outcomes of a research study presented in the paper, which investigated relationships between water quality and six different land uses offer practical guidance in the planning of future urban developments. In terms of safeguarding water quality, high-density residential development which results in a relatively smaller footprint would be the preferred option. The research study outcomes bring into question a number of fundamental concepts and misconceptions routinely accepted in stormwater quality management. The research findings confirmed the need to move beyond customary structural measures and identified the key role that urban planning can play in safeguarding urban water environments.     

MODELED IMPACTS OF DEVELOPMENT TYPE ON RUNOFF VOLUME AND INFILTRATION PERFORMANCE1

ABSTRACT: Development type has emerged as an important focal point for addressing a wide range of social, cultural, and environmental concerns related to urban growth. Low impact development techniques that rely heavily on infiltration practices are increasingly being used to manage storm water. In this study, four development types (conventional curvilinear, urban cluster, coving, and new urbanism) were modeled both with and without infiltration practices to determine their relative effects on urban runoff. Modeling was performed with a modified version of the Natural Resources Conservation Service (NRCS) runoff method that enables evaluation of infiltration practices. Model results indicate that urban cluster developments produce the smallest volume of runoff due to the large portion of land kept in a natural condition. Infiltration practices are most effective for small storms and in developments with Hydrologic Group A soils. Significant reductions in runoff can be achieved in all four development types if infiltration practices treat many impervious surfaces. As more infiltration practices are implemented, the differences in runoff among development types diminish. With a strategic combination of site layout and infiltration design, any development type can reduce hydrologic impacts, allowing developers to consider other factors, such as convenience, marketability, community needs, and aesthetics.     

Soil chemical changes resulting from irrigation with water co-produced with coalbed natural gas

Land application of coalbed natural gas (CBNG) co-produced water is a popular management option within northwestern Powder River Basin (PRB) of Wyoming. This study evaluated the impacts of land application of CBNG waters on soil chemical properties at five sites. Soil samples were collected from different depths (0-5, 5-15, 15-30, 30-60, 60-90, and 90-120 cm) from sites that were irrigated with CBNG water for 2 to 3 yr and control sites. Chemical properties of CBNG water used for irrigation on the study sites indicate that electrical conductivity of CBNG water (EC(w)) and sodium adsorption ratio of CBNG water (SAR(w)) values were greater than those recommended for irrigation use on the soils at the study sites. Soil chemical analyses indicated that electrical conductivity of soil saturated paste extracts (EC(e)) and sodium adsorption ratio of soil saturated paste extracts (SAR(e)) values for irrigated sites were significantly greater (P < 0.05) than control plots in the upper 30-cm soil depths. Mass balance calculations suggested that there has been significant buildup of Na in irrigated soils due to CBNG irrigation water as well as Na mobilization within the soil profiles. Results indicate that irrigation with CBNG water significantly impacts certain soil properties, particularly if amendments are not properly utilized. This study provides information for better understanding changes in soil properties due to land application of CBNG water. These changes must be considered in developing possible criteria for preserving fragile PRB ecosystems.     

Water-smart growth planning: linking water and land in the arid urbanizing American West

Linking water and land is essential in planning for the future of the western United States. We propose the concept of ‘water-smart growth’ and explore its implications through incorporating water considerations into the SLEUTH land-use model. The urban growth trajectory in Cache County, Utah, is modeled from 2007 to 2030 under four different scenarios: current trend; smart growth; water-smart growth with moderate implementation; and water-smart growth with full implementation. Comparisons of simulation results illustrate the extent and ways in which water-smart growth would alter current established land-use growth patterns. The approach represents an initial step to better integrate land and water in urban growth modeling and planning. This study's purposes are to provide improved understanding and representation of linkages between water and land in urbanizing environments, offer insights from a set of modeled options, and demonstrate the significance of integrating land and water in planning practices.     

EXPORT COEFFICIENT MODELING TO ASSESS PHOSPHORUS LOADING IN AN URBAN WATERSHED1

ABSTRACT: An export coefficient modeling approach was used to assess the influence of land use on phosphorus loading to a Southern Ontario stream. A model was constructed for the 1995–1996 water year and calibrated within ± 3 percent of the observed mean concentration of total phosphorus. It was found that runoff from urban areas contributed most to the loading of phosphorus to the stream. When the model was assessed by running it for the 1977–1978 water year, using water quality and land use data collected independently, agreement within ± 7 percent was obtained. The model was then used to forecast the impact of future urban development proposed for the watershed, in terms of phosphorus loading, and to evaluate the reduction in loading resulting from several urban best management practices (BMP). It was determined that phosphorus removal will have to be applied to all the urban runoff from the watershed to appreciably reduce stream phosphorus concentration. Of the BMP designs assessed, an infiltration pond system resulted in the greatest phosphorus load reduction, 50 percent from the 1995–1996 baseline.     

WATER SUPPLY AND URBAN GROWTH PLANNING: A PARTNERSHIP1

ABSTRACT As urban expansion outstrips water supplies, the usual solution is to build pipelines to bring in water from sources farther afield. Such water supplies may act as either a leader of urban development or as a follower. In either case, this engineering approach to the provision of water has fostered less than optimal utilization of regional water and land resources for urban growth. More efficient utilization of these resources is achieved when water supply development and urban growth planning are conjoint activities. Water supply planners and land use planners, working together, are able to generate and evaluate the full range of urban development options, including water demand management through conservation. Preferred regional growth plans are achieved using the best mix of water supply and urban growth. The result is a reduced rate of water supply development and a reduction of urban expansion on prime lands. This partnership approach is demonstrated for the Calgary Region under two levels of water conservation.     

Australian natural resources policy: Water and land

This paper reviews the significance of water/soils management problems as they are perceived, identified or acted upon by a range of institutions in Australian society. Reference is made to state/Commonwealth perspectives or land degradation, the fragmented responsibility in institutional arrangements and the political aspects of current land use planning issues. There is a lack of broad consensus on environmental problems and how to solve them. Emergent issues in water planning include the increasing importance of environmental river flows, urban water demand management, and the sunderstanding of the changing mechanisms of water allocation. The importance of scientific knowledge in natural resource agency decision making is found contentious in view of the varying roles of technical experts in organizations and the base line of political expediency. Requirements of effective policy making and monitoring of implementation highlight some of the ‘intractable’ problems in water and land management.     

重庆市土地储备制度的融资选择

城市土地储备制度的运行必须以连续的资金流为保汪，但是传统的融资渠道，如财政拨款和银行贷款已不能满足当前城市土地整理及开发中巨大的资金需求。以重庆市为例，从分析重庆市城市土地利用状况和土地市场特点出发，运用PPP模式和ABS模式，提出土地信托和土地债券的概念，得出一条创新的城市土地储备制度融资渠道，以加强城市抵御各方面风险的能力。     

An optimization model for integrated urban planning: development and application to Algeria's Reghaïa and Heraoua municipalities

In this paper, I develop an optimization model for integrated urban planning for land use at the municipality level, in which decisions arise from an area-based weighted-GDP maximisation algorithm whose weights represent the sustainability and implementability of the land uses. The model favours the involvement of stakeholders in urban governance, but does not use complicated assessment procedures for non-economic indicators or relative weights to combine economic, social and environmental indicators; instead, the integration between economic activities and environmental status is represented objectively and non-linearly by referring to initial and sustainability conditions. The model accounts for both human and environmental dynamics by adopting a spatial structure that permits compromises between economic information (available at a macro level) and ecological information (available at a micro level). A single value is attached to each urban governance, with an elicitation of future decisions (including acceptance of the status quo) and the ability to provide an evaluation of past decisions: some environmental policies are considered. The model’s predictions are based on reasonably reliable knowledge that can be easily collected, with reliability determined by calculating the confidence level. The resulting urban governance can then be presented and further analysed within a geographical information system. A case study of the model’s application to Algeria’s Regha?a and Heraoua municipalities provides insights into optimal urban governance, with and without water quantity or quality policies, in terms of resource sustainability, sectoral development, and pollution sustainability. I also assess the previous master plan in terms of the land uses suggested by the model.     

Hazardous waste management and community involvement in Canada: the case of Montreal's rural-urban fringe

The urban fringe is recognized as the arena of many conflicts involving land uses and values. The development and operation of hazardous waste facilities give rise to numerous conflicts and confrontations. An analysis of three cases in Montreal's rural-urban fringe based on a review of articles in the regional press demonstrates the utility of a common conceptual framework based on the awareness cycle which is represented in five phases. The application of the sustainable development concept to the hazardous wastes issue requires adopting approaches emphasizing participation of all the actors and interests involved, right from project design to the closure and dismantling of the facility. The fundamental challenge is that of promoting the excellence of the various stakeholders in terms of the quality of their participation in order to achieve sustainable acceptability of the project, often in a modified form compared to its initial conception.Dr Pierre André is Assistant Professor and Dr Christopher R. Bryant is Full Professor in the Département de Géographie, Université de Montreal. Romain Coté has completed an MSc degree in the Hygiène du milieu et de l'environnement programme at the Université de Montreal.     

Is Denser Greener? An Evaluation of Higher Density Development as an Urban Stormwater‐Quality Best Management Practice1

Abstract: A simple spreadsheet model was used to evaluate potential water quality benefits of high‐density development. The question was whether the reduced land consumed by higher density development (vs. standard suburban developments) would offset the worse water quality generated by a greater amount of impervious surface in the smaller area. Total runoff volume and per acre loadings of total phosphorous, total nitrogen, and total suspended solids increased with density as expected, but per capita loadings and runoff decreased markedly with density. For a constant or given population, then, higher density can result in dramatically lower total loadings than more diffuse suburban densities. The model showed that a simple doubling of standard suburban densities [to 8 dwelling units per acre (DUA) from about 3 to 5 DUA] in most cases could do more to reduce contaminant loadings associated with urban growth than many traditional stormwater best management practices (BMPs), and that higher densities such as those associated with transit‐oriented development could outperform almost all traditional BMPs, in terms of reduced loadings per a constant population. Because higher density is associated with vibrant urban life, building a better city may be the best BMP to mitigate the water quality damage that will accompany the massive urban growth expected for the next several decades.     

Water Quality Signals from Rural Land Use and Exurbanization in a Mountain Landscape: What's Clear and What's Confounded?

In mountainous landscapes with high climatic and geomorphic variability, how do rural land uses and exurbanization alter hydrology and water quality? We evaluated effects of rural land use and exurbanization on streamflows, suspended sediment concentrations and loads, specific conductance, and summer water temperatures in 12 streams and rivers within the Upper Little Tennessee River basin in the southern Appalachian Mountains. Eleven streams featured low levels of development (>61% forest cover) but differed in land use patterning, basin size, annual precipitation, and watershed morphology. One urban stream, located within the largest town in the basin, provided the high development comparative endpoint. Even low levels of rural development and exurbanization were associated with substantial increases in suspended sediment concentrations, sediment loads, and summer stream temperature daily maxima and diurnal variation. Observed summer temperature increases were much larger than would be expected due to global climate change over the next century. Specific conductance was idiosyncratic among the smaller streams. These water quality changes were not accompanied by streamflow changes that were discernible amid the high natural variation in precipitation and geomorphology. The water quality findings suggest the need for applying the best management practices, including riparian buffers, to even low levels of rural development.