COMPARISON OF METHODS TO ESTIMATE DEEP PERCOLATION RATES1

ABSTRACT: Deep percolation rates are normally estimated from a water balance. Results are presented of a study undertaken to evaluate three alternative methods of estimating percolation below the root zone when knowledge about the history of applied water and evapotranspiration are not available. The alternative methods are: 1) use of Darcy's equation to calculate deep percolation rate; 2) measurement of the soil temperature prof and calculation of the deep percolation rate from the shape of the temperature depth curve; and 3) measurement of the tritium concentration in the soil water and its relationship to the history of the tritium concentration in rainfall. At the principal study site, the Darcy velocity of flow ranged from 9 cm per year determined by the temperature method, to 40 cm per year determined by the tritium method. Darcy's equation to calculate seepage rates resulted in an estimation of deep seepage of 18 cm per year. An average deep percolation rate at the principal study site of 22 cm per year was determined using the average of all three methods. Results for other sites based on the temperature method indicated a lower seepage rate.     

Green defaults: Information presentation and pro-environmental behaviour

There is inconsistency in many people's choice of electricity. When asked, they say they prefer a ‘green’ (i.e., environmentally friendly) source for this energy. Yet, although green electricity is available in many markets, people do not generally buy it. Why not? Motivated by behavioural decision research, we argue that the format of information presentation drastically affects the choice of electricity. Specifically, we hypothesise that people use the kind of electricity that is offered to them as the default. We present two natural studies and two experiments in the laboratory that support this hypothesis. In the two real-world situations, there was a green default, and most people used it. In the first laboratory experiment, more participants chose the green utility when it was the default than when ‘grey’ electricity was the default. In the second laboratory experiment, participants asked for more money to give up green electricity than they were willing to pay for it. We argue that changing defaults can be used to promote pro-environmental behaviour. Potential policy-making applications of this work are discussed.     

Assessment of heavy metals in the particulate matter of two Brazilian metropolitan areas by using <Emphasis Type="BoldItalic">Tillandsia usneoides</Emphasis> as atmospheric biomonitor

Purpose  

The aims of this paper were to quantify the heavy metals (HM) in the air of different sites in Rio de Janeiro (RJ) and Salvador (SA) using Tillandsia usneoides (Bromeliaceae) as a biomonitor, and to study the morphology and elemental composition of the air particulate matter (PM) retained on the Tillandsia surface.     

Priority-Setting Tool Applied to Canada's Landbirds Based on Concern and Responsibility for Species

Abstract: As a contribution to Partners in Flight–Canada, the Canadian Wildlife Service developed a ranking system to help set priorities for landbird species. Two complementary species lists were generated: one with scores for "concern" representing vulnerability and population trend, and one for "responsibility" for regionally characteristic fauna. The concern score gave equal weight to vulnerability, a composite score based on abundance and breadth of range, and population trend, because its purpose was to give early warning of potential problems. Responsibility scores were scale-free and were assigned for the season in which the species is most abundant. Other systems for identifying species of concern may be more appropriate for other jurisdictions or organisms, but the responsibility ranking is widely applicable. This system is a coarse filter that generates preliminary ranks; additional information should be considered in deciding how to allocate scarce resources for conservation. Unrefined results are nonetheless useful for a variety of purposes, as illustrated by the scores for Canadian landbirds. About 25% of Canada's high-responsibility species are also of high concern. These high-concern species are not associated with specific habitats or migration patterns. Conservation of species ranking high on concern and responsibility merits cooperation with the United States and Mexico in particular. The scores identified improved monitoring as a priority conservation activity for Canada.     

Factors influencing movement probabilities of big brown bats (Eptesicus fuscus) in buildings.

We investigated movements of female big brown bats (Eptesicus fuscus) roosting in maternity colonies in buildings in Fort Collins, Colorado (USA), during the summers of 2002, 2003, and 2005. This behavior can be of public health concern where bats that may carry diseases (e.g., rabies) move among buildings occupied by people. We used passive integrated transponders (PIT tags) to mark individual bats and hoop PIT readers at emergence points to passively monitor the use of building roosts by marked adult females on a daily basis during the lactation phase of reproduction. Multi-strata models were used to examine movements among roosts in relation to ambient temperatures and ectoparasite loads. Our results suggest that high ambient temperatures influence movements. Numbers of mites (Steatonyssus occidentalis) did not appear to influence movements of female bats among building roosts. In an urban landscape, periods with unusually hot conditions are accompanied by shifting of bats to different buildings or segments of buildings, and this behavior may increase the potential for contact with people in settings where, in comparison to their more regularly used buildings, the bats may be more likely to be of public concern as nuisances or health risks.     

Rückstände ausgewählter Humanarzneimittel in Oberflächenwasserkörpern im Einzugsgebiet Halle (Saale)

A method for the determination of 16 selected pharmaceuticals in surface water using LC-MS/MS has been developed Methods from literature were adapted within the scope of this study. The limit of quantification of 13 out of 16 analytes is below 10 ng/l. The analysis of samples from the Saale river and lakes around Halle demonstrated that Carbamacepin (Median 207 ng/l) and Diclofenac (Median 196 ng/l) are detectable at various sampling stations along the river. The wastewater path was identified as the most relevant source for pharmaceutical residues entering the environment. Besides, the results reveal increased levels of several substances in some smaller anabranches and brooks.     

Mining,water and human rights: making the connection

The minerals industry interacts with water in many different ways that can affect the environment and communities. In the context of emerging debates about the status of access to water as a distinct human right and the mining industry’s engagement with human rights discourses, this article highlights points of disconnection between technical, scientific and engineering-based approaches to water management on the one hand and human rights perspectives on the other. We argue that greater understanding and emphasis on the intersecting nature of water and human rights is important from a sustainable development perspective. Better connections will increase the likelihood that mining companies will respect human rights, avoid or mitigate adverse social and environmental risks that occur through their interaction with water and collaboratively identify water-related development opportunities. Discursive, organisational, political and conceptual barriers of these various disconnects are considered and strategies for strengthening points of connection provided.