NITROGEN AND PHOSPHORUS IN SURFACE WATERS OF THE UPPER COLORADO RWER BASIN1

ABSTRACT: As part of a basinwide water-quality study, nitrogen and phosphorus data for the Upper Colorado River Basin from the Colorado-Utah State line to the Continental Divide were analyzed for spatial distributions, concentrations associated with various land uses, and temporal trends. Nitrogen and phosphorus concentrations generally increased in a downstream direction. Some nutrient concentrations were elevated at some sites in the upper parts of the basin in areas influenced by increasing urbanization. Sites were grouped according to land use and site type, and median nutrient concentrations were compared among groups. Sites within the agricultural areas of the basin generally had the highest concentrations of nitrogen and phosphorus; concentrations for main-stem, tributary, and urbanization sites were slightly lower than for the agricultural sites. Background sites, or sites with minimal land-use impacts, had very low median nutrient concentrations. Several sites with long-term data were analyzed for temporal trends in concentrations. Several statistically significant downward trends of low and moderate magnitude were observed for nitrogen and phosphorus species. No upward trends were observed in the data at any site.     

WATERSHED FUNCTIONS1

ABSTRACT: Watershed functions that dominate the hydrologic environment are identified and discussed. Hydrological and ecological functions are considered in relation to the storm and annual hydrographs, and to water quality. Two integrative watershed responses to these functions are also articulated. Since most of the Earth's water is in storage, consideration of the hydrologic cycle as movement between water storage sites enhances this functional and response characterization of the watershed which, in turn, suggests guidance and direction for the restoration of watershed functions.     

Canada shows the way

Editorial

Canada shows the way     

WATER SUPPLY COSTS FOR SMALL PRIVATE UTILITIES1

ABSTRACT: This paper examines the cost of water supply for small and mid-sized private water utilities. An econometric approach was employed in which data on utility costs and characteristics were used to estimate a total water supply cost function from which average and marginal costs were derived. The results suggest that although average and marginal costs decline with output, the rate of decline rapidly approaches zero, and unit costs therefore appear to remain relatively constant over a wide range of output. Implications of the results for pricing policy are examined.     

ESTIMATING TRANSMISSIVITY AND HYDRAULIC CONDUCTIVITY OF CHICOT AQUIFER FROM SPECIFIC CAPACITY DATA1

ABSTRACT: Specific capacity data obtained from Well Construction reports which are available from USGS offices, can provide useful estimates of tranamissivity (T), and hydraulic conductivity (K), of an aquifer. The Chicot Aquifer in Louisiana is one of the largest sources of fresh ground water in North America. Hydrologic data collected for the Chicot Aquifer indicate that specific capacity tests can be used in estimating local and regional values for T and K, if the Cooper-Jacob equation for transient flow is used with proper corrections for well loss and partial penetration. Where full scale pumping test data are scarce, specific capacity test data that are adequately distributed spatially can be used to map changes in T and K values and can be summarized statistically to indicate applicable regional values. A computer program called “TGUESS” which is available from International Ground Water Modeling Center, Holcomb Research Institute, was used in this study. The contour maps for T and K values are prepared for different well depth intervals to avoid wide variation of values.     

Assessing Public Participation Techniques for Comfort, Convenience, Satisfaction, and Deliberation

Public participatory techniques have been the focus of a large and growing body of environmental literature. There is some consensus among those who study these techniques that there is a need to develop and implement new techniques that meet certain criteria. These include that the techniques be comfortable, convenient, and satisfying to participants. Authors have also frequently called for the use of deliberative techniques, which allow participants to express and listen to a variety of perspectives regarding the issue at hand. However, the literature on public participation lacks a set of widely applicable evaluation methods to determine whether participants in techniques find them comfortable, convenient, satisfying, or deliberative. This paper reports on the implementation of two different techniques that participants scored fairly high on all of these factors, as well as the scale-based survey questions developed to measure these factors.     

Assessment of GM Crops in Commercial Agriculture

The caliber of recent discourse regarding geneticallymodified organisms (GMOs) has suffered from a lack of consensuson terminology, from the scarcity of evidence upon which toassess risk to health and to the environment, and from valuedifferences between proponents and opponents of GMOs. Towardsaddressing these issues, we present the thesis that GM should bedefined as the forcible insertion of DNA into a host genome,irrespective of the source of the DNA, and exclusive ofconventional or mutation breeding.Some defenders of the commercial use of GMOs have referred to thescientific work of GMO critics as ``junk science.' Such a claim isfalse and misleading, given that many papers critical of both theutility and safety of GMOs have been published in peer reviewedjournals by respected scientists. In contrast, there is a dearthof peer reviewed work to substantiate the frequently heardassertions of either safety or utility in GMOs. The polarity,which now characterizes much of the public discourse on GMOs,reflects not simply scientific disagreement, but alsodisagreement in underlying value assumptions. Value differencesstrongly affect the assessment of both benefit and harm fromGMOs.The concept of substantial equivalence occupies a pivotalposition in the GMO risk assessment process that is used in bothCanada and the US. A GMO judged to be substantially equivalent toa conventional product – as have all submissions to date – ispresumed to be safe enough for commercialization. The conclusionof safety – from both human health and environmental perspectives– should be based on scientific evidence, corroborated by actualexperimentation. However, regulators infer safety largely fromassumptions-based reasoning, with little or no experimentalvalidation. The judgement of safety because of substantialequivalence is a dubious argument by analogy.     

Conservation strategies for effective land management of protected areas using an erosion prediction information system (EPIS)

This research demonstrates the predictive modeling capabilities of a geographic information system (GIS)-based soil erosion potential model to assess the effects of implementing land use change within a tropical watershed. The Revised Universal Soil Loss Equation (RUSLE) was integrated with a GIS to produce an Erosion Prediction Information System (EPIS) and modified to reflect conditions found in the mountainous tropics. Research was conducted in the Zenzontia subcatchment of the Río Ayuquíla, located within the Sierra de Manantlán Biosphere Reserve (SMBR), México. Expanding agricultural activities within this area will accentuate the already high rate of soil erosion and resultant sediment loading occurring in the Río Ayuquíla. Two land-use change scenarios are modeled with the EPIS: (1) implementation of soil conservation practices in erosion prone locations; and (2) selection of sites for agricultural expansion which minimize potential soil loss. Confronted with limited financial resources and the necessity for expedient action, managers of the SMBR can draw upon the predictive capacity of the EPIS to facilitate rapid and informed land-use planning decisions.     

Taking Sustainable Cities Seriously: a comparative analysis of twenty-four US cities

After briefly reviewing some conceptual underpinnings of sustainable cities, this paper analyses and compares sustainable cities initiatives in 24 US cities. The central question addressed in the paper is why some cities seem to take sustainability more seriously than others. Numerous demographic, socioeconomic and other characteristics of the cities are correlated with an Index of Taking Sustainability Seriously, which is a composite of some 34 different variables indicating whether each city engages in specific sustainability programmes, policies or activities. Many of the standard explanations, such as the income and wealth of the community, the liberalness of the city and the growth pressures placed on the city, are found to exhibit no correlation with the seriousness of the sustainability effort. What do correlate with the Index are: reliance on manufacturing, where having more residents employed in manufacturing industries is associated with less seriousness; and, the age of the population, where cities with older populations take sustainability more seriously. This has three implications for the future development of sustainable cities. First, some of the cities that might be said to need sustainability programmes the most--cities with heavy manufacturing that are more prone to pollution production--are the least likely to take such programmes seriously. Secondly, as cities' manufacturing bases decline, they should find it increasingly feasible to engage in sustainability initiatives. And, thirdly, as the populations of cities age, policy-makers should also find it easier to support, develop and take seriously sustainability programmes.     

Fertilizer Management in Watersheds of Two Ramsar Wetlands and Effects on Quality of Inflowing Water

Two field experiments were carried out in the watersheds of two Ramsar wetland areas, Lakes Koronia and Volvi (area A) and Lakes Mikri and Megali Prespa (area B), to study the effect of application of N fertilizer on wheat yields, the quality of runoff water, and the quality of stream water. The treatments were a combination of two methods of fertilizer application (total amount in fall, and 2/3 in fall + 1/3 in spring) at three rates (0, 100, and 200 kg N/ha) with four replications. Concentrations of NH₄ ⁺, NO₃ ⁻, NO₂ ⁻, P, and Cl⁻ and pH were determined in all water samples. Runoff water quality was not influenced by fertilizer application in either area. Chemical parameters for water did not differ along the selected watercourses in area B, while in area A they were higher in the samples taken near Lake Koronia than in the samples taken upstream, indicating that the watercourses are polluted downstream by nonagricultural sources. The differences in wheat yields between the 100 and 200 kg N/ha application rates were not high. These results call for better fertilizer management in order to achieve better yields and to diminish the possibility to have negative effects to the environment.