THE ROLE OF AGRICULTURAL GROUNDWATER CONSERVATION IN ACHIEVING ZERO OVERDRAFT IN ARIZONA1

ABSTRACT: The elimination of groundwater overdraft was a key feature of the 1980 Arizona Groundwater Management Act. To achieve this goal, the Arizona Department of Water Resources identified several Active Management Areas and developed urban, industrial, and agricultural water conservation plans. This study examines the reductions in groundwater use through agricultural water conservation in the Phoenix Active Management Area (AMA). Linear programming models are developed to analyze changes in groundwater use and net returns to agriculture over a 38-year period, 1990 to 2025, for farming areas in the Phoenix AMA. Results indicate that the agricultural conservation program provides only modest groundwater savings under a wide range of scenarios. The low level of savings is partly due to the current economically efficient use of water. Other policy measures such as retiring agricultural land may be necessary if the Phoenix AMA is to meet its overdraft reduction goals; even if urban water conservation goals are met.     

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.     

Participative governance and integrated coastal management. An experiment of dialogue in an insular community at isle-aux-coudres (Quebec, Canada)

This paper is about an Integrated Coastal Management Project on an island, Isle-aux-Coudres, located in the St-Lawrence Estuary (Québec, Canada). It is based on data collected from 2003 to 2007 on the participatory aspects of the project such as: types of stakeholders, relationships between stakeholders, time dedicated to dialogue, consensus versus negotiation, and outcomes. We analyze the way concerns evolved into actions and the relationship between dialogue and actions during the project. We conclude that the difficulty is to join together the differences around various stakes, without forcing the consensus, or negating problems and conflicts.     

Kriging method evaluation for assessing the spatial distribution of urban soil lead contamination

Describing contaminant spatial distribution is an integral component of risk assessment. Application of geostatistical techniques for this purpose has been demonstrated previously. These techniques may provide both an estimate of the concentration at a given unsampled location, as well as the probability that the concentration at that location will exceed a critical threshold concentration. This research is a comparative study between multiple indicator kriging and kriging with the cumulative distribution function of order statistics, with both local and global variograms. The aim was to determine which of the four methods is best able to delineate between "contaminated" and "clean" soil. The four methods were validated with a subset of data values that were not used in the prediction. Method performance was assessed by calculating the root mean square error (RMSE), analysis of variance, the proportion of sites misclassified by each method as either "clean" when they were actually "contaminated" or vice versa, and the expected loss for each misclassification type. The data used for the comparison were 807 topsoil Pb concentrations from the inner-Sydney suburbs of Glebe and Camperdown, Australia. While there was very little difference between the four methods, multiple indicator kriging was found to produce the most accurate predictions for delineating "clean" from "contaminated" soil.     

Capital assets and intercultural borderlands: socio-cultural challenges for natural resource management

In their design or implementation, many natural resource management (NRM) programs ignore critical socio-cultural dimensions of the challenge to advance sustainability. Building on particular ideas about culture and human ecosystems, we combine the strengths of the capital assets model of sustainability and the idea of intercultural borderlands to respond to this gap. To advance our thesis about the utility of these tools, we critically reviewed and analysed a cross-disciplinary literature relating to the socio-cultural dimensions of NRM. This paper stems from that labour and examines particular tensions that arise in land management as a result of Australians' specific colonial and postcolonial legacies. These tensions--related to ethnicity, gender, population, age and health--are among the threads in the larger tapestry that comprises the socio-cultural dimensions of NRM. For the Australian case, they are central, longstanding and persistent, and thus worthy of analysis; and they are applicable in general terms to other places with similar histories of settlement and land use.     

Hedonic Analysis of Effects of a Nonnative Invader (<Emphasis Type="Italic">Myriophyllum heterophyllum</Emphasis>) on New Hampshire (USA) Lakefront Properties

Introduced species are a major threat to the planet's ecosystems and one of the major causes of species extinction. This study deals with some of the economic impacts of one of these "invaders," variable milfoil. Variable milfoil can clog water-bodies, cause boating and swimming hazards, and crowd out native species. This study analyzed the effects of variable milfoil on shoreline property values at selected New Hampshire lakes. Results indicate that property values on lakes experiencing milfoil infestation may be considerably lower than similar properties on uninfested lakes. Results are highly sensitive to specification (variable selection) of the hedonic equation.     

Comparison of discharge silver concentrations from electrolytic plating and metallic replacement silver recovery units

Silver-based photographic X-ray film is made of solid crystals of silver chloride or silver bromide suspended in a gelatin and then coated on a film. During the X-ray developing process, the image is processed and the nonimage areas containing solid silver chloride or silver bromide crystals are removed in a solution called the fixer. There may be local environmental regulations that regulate the amount of silver discharged from a facility. To meet these regulations, many facilities have added silver recovery units to their processes. Two different types of recovery processes are in use in a large hospital and three clinics under study. All of the units were claimed by their respective manufacturers to be able to recover silver down to concentrations of 5 mg/L. This concentration would ensure that the building that houses each unit would meet the local county limit of 0.5 mg/L silver for total building silver discharge. The hypothesis for this research is that one system, newer and more expensive, consisting of so-called electrolytic plating units (EPUs) (which are followed by so-called metallic replacement units [MRUs] as a backup), will have better silver recovery than MRUs alone. A total of six units were sampled, three EPUs (in combination with MRUs) and three MRUs. The units were sampled once or twice a day for 10 days for a total of 17 samples from each. The samples then were analyzed by inductively coupled plasma spectroscopy, and an analysis of variance was performed on the results. The range for the electrolytic plating unit/metallic replacement unit combinations was 0.20-99.9 mg/L (mean of 35.15 mg/L; median of 33.8 mg/L). The range for the MRUs alone was 7.2-1112 mg/L (mean of 565.5 mg/L; median of 720 mg/L). Many individual results exceeded 5 mg/L, such that extensive dilution would be required to ensure the building effluent did not exceed 0.5 mg/L. It is suggested that the metallic replacement units be changed to EPUs (with metallic replacement backup units) because they had better silver recovery. Also, the EPU combinations need to be sampled regularly to ensure that their silver concentrations are at acceptable levels.     

Lessons from an Evaluation of a Boater Outreach Program for Manatee Protection

Watercraft collisions account for 25–30% of manatee deaths annually in Florida. Education and outreach interventions for boaters are strategies for reducing manatee mortality. We evaluated the effectiveness of the Manatee Watch program by surveying primary boat users whose boats were approached by Manatee Watch. We compared the attitudes, knowledge, and behavioral intentions of boaters who received Manatee Watch materials with a control group of boaters observed by the Florida Marine Research Institute in Tampa Bay during 1999–2001. Results of the 51-item telephone survey with 499 boaters indicated that the Manatee Watch intervention had little effect on boater’s attitudes, knowledge, and behaviors regarding manatees. However, individual attitude scores were positively correlated with safe boating behaviors in shallow waters including maintaining a slower speed and watching out for manatees. Overall knowledge about manatees was correlated with one manatee-safe boating behavior. To improve efficacy, educators should (a) incorporate evaluation into the planning stages of program development; (b) target messages to influence boaters’ attitudes toward manatees and ecosystem health, and their feelings of ownership and empowerment; (c) facilitate active participation of the boaters; and (d) increase the duration and variety of intervention.     

Land Use, Spatial Scale, and Stream Systems: Lessons from an Agricultural Region

We synthesized nine studies that examined the influence of land use at different spatial scales in structuring biotic assemblages and stream channel characteristics in southeastern Minnesota streams. Recent studies have disagreed about the relative importance of catchment versus local characteristics in explaining variation in fish assemblages. Our synthesis indicates that both riparian- and catchment-scale land use explained significant variation in water quality, channel morphology, and fish distribution and density. Fish and macroinvertebrate assemblages can be positively affected by increasing the extent of perennial riparian and upland vegetation. Our synthesis is robust; more than 425 stream reaches were examined in an area that includes a portion of three ecoregions. Fishes ranged from coldwater to warmwater adapted. We suggest that efforts to rehabilitate stream system form and function over the long term should focus on increasing perennial vegetation in both riparian areas and uplands and on managing vegetation in large, contiguous blocks. Minnesota Cooperative Fish and Wildlife Research Unit is jointly sponsered by U.S. Geological Survey Biological Resources Division, the University of Minnesota, The Minnesota Department of Natural Resources, and the Wildlife Management Institute.