Wastewater re-use for peri-urban agriculture: a viable option for adaptive water management?

Urbanization is known to spur land modification in the form of conversion of common land to human settlements. This factor, combined with climate variability, can alter the duration, frequency and intensity of storm drain overflows in urban areas and lead to public health risks. In peri-urban regions where these risks are especially high it has been argued that, when domestic wastewater is managed, better prospects for freshwater water savings through swaps between urban water supply and irrigated agriculture may be possible. As a consequence of re-use of domestic wastewater, expenditure on inorganic inputs by farmers may decline and source sustainability of water supply could be enhanced. Given the fact that, at present, approximately 20 million ha of land worldwide is being cultivated by re-using domestic wastewater, this paper draws on evidence from India to explore: (1) the economic costs–benefits of wastewater reuse in the context of hypothesized links to climate variability; (2) the role of local farming practices, market conditions and crop variety in influencing wastewater reuse in agriculture; and (3) the role of inter-governmental financing in influencing the selection of technical adaptation options for collection, treatment and disposal of wastewater.     

Detection and Classification of Motor Vehicle Noise in a Forested Landscape

Noise emanating from human activity has become a common addition to natural soundscapes and has the potential to harm wildlife and erode human enjoyment of nature. In particular, motor vehicles traveling along roads and trails produce high levels of both chronic and intermittent noise, eliciting varied responses from a wide range of animal species. Anthropogenic noise is especially conspicuous in natural areas where ambient background sound levels are low. In this article, we present an acoustic method to detect and analyze motor vehicle noise. Our approach uses inexpensive consumer products to record sound, sound analysis software to automatically detect sound events within continuous recordings and measure their acoustic properties, and statistical classification methods to categorize sound events. We describe an application of this approach to detect motor vehicle noise on paved, gravel, and natural-surface roads, and off-road vehicle trails in 36 sites distributed throughout a national forest in the Sierra Nevada, CA, USA. These low-cost, unobtrusive methods can be used by scientists and managers to detect anthropogenic noise events for many potential applications, including ecological research, transportation and recreation planning, and natural resource management.     

Food 21: a research program looking for measures and tools to increase food chain sustainability

Food 21, an interdisciplinary research program encompassing the whole agro-food chain, was conducted in Sweden during 1997-2004. The challenges undertaken were to come up with environmental tools and solutions to existing nonsustainable practices along the entire food chain. This required close collaboration between the scientists and the food chain stakeholders. A set of goals characterizing sustainable food production is presented in this paper. Synthesis and systems analysis were the main tools used to analyze the sustainability of proposed changes. In this introduction we give an overview of the Food 21 concept and highlight some results. For example, we found that organic farming and organic products were not in general superior to conventional products and practices with respect to environmental impact and product quality. We also summarize the management experiences in this article, since we consider them to be rather unique and since they contributed to the overall success of the program.     

Electrostatic effects in vortical flows

Electrostatic forces have been shown to significantly enhance the collection efficiency of cyclones. In this paper, an analytic model will be developed for the effect of an applied electric field on charged particle trajectories within a laminar, two-dimensional vortical flow. Boundary conditions for particle injection are developed and collection efficiencies are predicted.     

COMPUTER SIMULATION OF RECREATIONAL BOATING ACTIVITIES1

ABSTRACT This paper is concerned with the portion of harbor improvement planning which identifies the refuge and transient service needs at points along Lake Michigan. The travel behavior model developed to predict this use is sensitive to five criteria: boater characteristics which influence travel behavior; entry rates into the Lake from each access site; site characteristics; weather conditions; and planning parameters. The information provided by this computer model includes: the number of boaters demanding a given access point at a given time; the length of stay at that point; the probability of travel to specific access sites in given amounts of time; and those facilities used during a specified time period. The simulation modelling boat movement consists of two parts; a traffic generation routine and an activity simulation. The former schedules the entry of boats into the Lake from each site and the latter establishes the probabilistic movement of boats on the Lake. This simulation of interport movements and port activities enables the planner to investigate some impacts of alternative small boat harbor development plans.     

Does the nutrition profile of vitamins, fatty acids and microelements counteract the negative impact from organohalogen pollutants on bone mineral density in Greenland sledge dogs (Canis familiaris)?

There is a great need for understanding the impact from dietary OHCs (organohalogen compounds) on bone mineral composition - and thereby osteoporosis - in especially arctic wildlife such as polar bears (Ursus maritimus) as well as humans. For that purpose, we measured BMD (bone mineral density) by DXA scanning (g/cm(-2)) in 15 age and weight normalized sledge dog (Canis familiaris) bitches and their 26 pups divided into a control group (n=26) given 50-200 g/day clean pork (Suis scrofa) fat and a treated group (n=15) given 50-200 g/day OHC polluted minke whale (Balaenoptera acutorostrata) blubber as main lipid sources. The results showed that BMD increased significantly with age (linear regression: p<0.0001, r(2)=0.83, n=41) while no sex difference was found in the F-generation (two-way ANOVA: all p>0.3). No differences in BMD(femur) or BMD(vertebrae) between exposed and control individuals in the bitch generation were found (linear mixed effect model: both p>0.38). Likewise, no difference between exposed and control subadults and juveniles in the F-generation was found (two-way ANOVA: all p>0.33). Correlation analyses between BMD(femur), BMD(vertebrae) and groups of OHCs, respectively, did not show any statistically significant relationships nor a clear or decreasing trend (Pearson's: p: 0.07-0.78; r: -0.2-0.59; n: 10-18). As the groups were similar regarding genetics, age and sex are the only factors that can explain this observation. Either the pollutants did not have an impact on BMD using the present time frame and OHC concentrations (threshold levels not reached), or the difference in food composition (mainly vitamins and n3 fatty acids) conceal the potential OHC impact on BMD. Such information is important when evaluating the positive and negative health consequences from eating polluted marine species.