Spatial variability in the hyporheic zone refugium of temporary streams

A key ecological role hypothesized for the hyporheic zone is as a refugium that promotes survival of benthic invertebrates during adverse conditions in the surface stream. Many studies have investigated use of the hyporheic refugium during hydrological extremes (spates and streambed drying), and recent research has linked an increase in the abundance of benthic invertebrates within hyporheic sediments to increasing biotic interactions during flow recession in a temporary stream. This study examined spatial variability in the refugial capacity of the hyporheic zone in two groundwater-dominated streams which flow permanence varied over small areas. Two non- insect taxa, Gammarus pulex and Polycelis spp. Were common to both streams and were investigated in detail. Hydrological conditions in both streams comprised a four- month period of flow recession and low flows, accompanied by reductions in water depth and wetted width. Consequent declines in submerged benthic habitat availability were associated with increases in population densities of mobile benthic taxa, in particular G. pulex

A Design, Analysis and Evaluation Model to Support the Visualization Designer-User

Existing visualization design and evaluation frameworks rest on a distinction between the designer and the user. However, there is little explicit guidance on design, analysis and evaluation when the designer is the user. A simple solution to this problem is for the researcher (who combines the designer and user roles) to be clear about which activity they are conducting at which point in time. To support the researcher, we propose a design, analysis and evaluation model. This model complements existing visualization design and evaluation frameworks. We have adopted this model in our ongoing research into uncertainty in crowdsourced crisis information

Characterising Locality Descriptions in Crowdsourced Crisis Information

Humanitarian organisations are reluctant to use information from social media when responding to crises or conflicts, identifying trust and accuracy as principal concerns. However, the Geographic Information Science literature contains significant research into uncertainty, research we draw upon here to characterise locality descriptions in incident reports related to the 2010 earthquake in Haiti. We do so using a classification developed to georeference locality descriptions in MaNIS, the Mammal Networked Information System. We found that although there are similarities between the datasets, crowdsourced crisis information presents significant challenges with respect to vagueness, ambiguity and precision (resolution)

Time and energy dependence of the cosmic ray gradient in the outer heliosphere

Pioneers 10 and 11, now 35 and 18 AU from the Sun, continue to extend our knowledge of the spatial dependence of cosmic ray intensities in the heliosphere. Radial gradients measured from these spacecraft by UCSD detectors which have integral energy responses above thresholds of 80 and 500 MeV/nucleon are reported. An average gradient of 2%/AU typifies the data set as a whole, but there are time and energy dependences that deviate from this value. With operating lifetimes of 13 and 12 years, respectively, for the two spacecraft, the time dependence was followed for over a solar cycle. The higher energy channel shows less modulation on all time scales. At the start of the present cycle, the gradient is lower than the average value during the last solar cycle