Sequential impacts of Polynesian and European settlement on vegetation and environmental processes recorded in sediments at Whangapoua Estuary, Great Barrier Island, New Zealand

Whangapoua Estuary, Great Barrier Island, New Zealand, is central to a proposed Marine Reserve, and is currently managed for conservation by the Department of Conservation. This paper describes the sequential impacts of Maori and European people on the process of estuarine vegetation succession in time and space, and the rate of estuarine sedimentation. Multiple cores from one estuary gave confidence in assessing the temporal sequence of vegetation change, but bioturbation and other disturbance factors made it difficult to interpret ¹⁴C dates from the estuarine environment. The modern vegetation zonation pattern on the estuary is an active succession, which has been generated by rapid estuary in-filling, probably initiated as a consequence of erosion following Maori burning of the adjacent forest. European forest clearance for agriculture resulted in a further increase in estuarine sedimentation, and may have re-activated earlier sediments trapped in adjacent swamps. The combined effects of two phases of human exploitation have resulted in large-scale loss of nutrients and top-soil from catchments throughout Great Barrier Island. Conservation management of the estuary should take account of the anthropogenic impacts that have driven the plant succession and created the current vegetation zonation pattern. This pattern is neither static nor ‘natural’, but rather an on-going response to the changing human activities in the surrounding catchment.     

Management of adverse effects of a public water supply well field on the aquatic habitat of a stratified drift stream in eastern Connecticut.

A study was conducted to determine the effect of water withdrawals from the University of Connecticut's (Storrs) water supply wells on the fisheries habitat of the Fenton River adjacent to the well field. The study was designed to investigate the relationships between in-stream flow and selected fish habitat in the section of the Fenton River situated in the main zone of influence of the pumping field. With the aid of historical data, new data collection, and mathematical simulation modeling, the relation between the magnitude and timing of groundwater withdrawals on the stage and flow of water in the stream was derived. Fish sampling and habitat modeling were used to assess the effects of human influence on certain reaches of the Fenton River. Among the various water management scenarios studied, several are presented that would optimize water withdrawals, while minimizing adverse effects on the stream flow and in-stream habitat.     

聚合物燃烧放热的通风

本文在小尺寸试件燃烧实验的基础上,着重研究了几种典型聚合物燃烧时放热参数的变化规律及其通风影响,通过实验数据的拟合和分析,揭示了燃烧放热、通风条件和燃料种类之间复杂的关系,给出了由放热参数决定的可燃性区域,得到了一些新的结论,有助于材料放热特性认识和室内火分析的进一步深入。     

RASTER-BASED HYDROLOGIC MODELING OF SPATIALLY-VARIED SURFACE RUNOFF1

ABSTRACT: The proliferation of watershed databases in raster Geographic Information System (GIS) format and the availability of radar-estimated rainfall data foster rapid developments in raster-based surface runoff simulations. The two-dimensional physically-based rainfall-runoff model CASC2D simulates spatially-varied surface runoff while fully utilizing raster GIS and radar-rainfall data. The model uses the Green and Ampt infiltration method, and the diffusive wave formulation for overland and channel flow routing enables overbank flow storage and routing. CASC2D offers unique color capabilities to display the spatio-temporal variability of rainfall, cumulative infiltrated depth, and surface water depth as thunderstorms unfold. The model has been calibrated and independently verified to provide accurate simulations of catchment response to moving rainstorms on watersheds with spatially-varied infiltration. The model can accurately simulate surface runoff from flashfloods caused by intense thunderstorms moving across partial areas of a watershed.     

Cash-based interventions: lessons from southern Somalia

Commodity distributions, the predominant relief response, are subject to growing criticism, while donors and humanitarian actors are increasingly viewing cash-based interventions as a viable alternative. This paper aims to contribute to the current debate on cash-based interventions by drawing on the experience of Action Contre la Faim in southern Somalia, where it has implemented cash for work programmes since 2004. The authors conclude that cash-based interventions are a feasible option in complex emergencies as well as in highly insecure environments as long as appropriate modalities are employed and objectives are clearly set in accordance with the needs and the context. Cash as a relief response offers wide-reaching possibilities for the future from both the perspective of the donor/agency and the standpoint of the beneficiary. It enables the beneficiaries to take control of the relief themselves and to adapt it to their individual requirements in a timely manner.     

Minimizing predation risk in a landscape of multiple predators: effects on the spatial distribution of African ungulates

Studies that focus on single predator-prey interactions can be inadequate for understanding antipredator responses in multi-predator systems. Yet there is still a general lack of information about the strategies of prey to minimize predation risk from multiple predators at the landscape level. Here we examined the distribution of seven African ungulate species in the fenced Karongwe Game Reserve (KGR), South Africa, as a function of predation risk from all large carnivore species (lion, leopard, cheetah, African wild dog, and spotted hyena). Using observed kill data, we generated ungulate-specific predictions of relative predation risk and of riskiness of habitats. To determine how ungulates minimize predation risk at the landscape level, we explicitly tested five hypotheses consisting of strategies that reduce the probability of encountering predators, and the probability of being killed. All ungulate species avoided risky habitats, and most selected safer habitats, thus reducing their probability of being killed. To reduce the probability of encountering predators, most of the smaller prey species (impala, warthog, waterbuck, kudu) avoided the space use of all predators, while the larger species (wildebeest, zebra, giraffe) only avoided areas where lion and leopard space use were high. The strength of avoidance for the space use of predators generally did not correspond to the relative predation threat from those predators. Instead, ungulates used a simpler behavioral rule of avoiding the activity areas of sit-and-pursue predators (lion and leopard), but not those of cursorial predators (cheetah and African wild dog). In general, selection and avoidance of habitats was stronger than avoidance of the predator activity areas. We expect similar decision rules to drive the distribution pattern of ungulates in other African savannas and in other multi-predator systems, especially where predators differ in their hunting modes.     

Anaerobic biodegradability and methanogenic toxicity of key constituents in copper chemical mechanical planarization effluents of the semiconductor industry

Copper chemical mechanical planarization (CMP) effluents can account for 30-40% of the water discharge in semiconductor manufacturing. CMP effluents contain high concentrations of soluble copper and a complex mixture of organic constituents. The aim of this study is to perform a preliminary assessment of the treatability of CMP effluents in anaerobic sulfidogenic bioreactors inoculated with anaerobic granular sludge by testing individual compounds expected in the CMP effluents. Of all the compounds tested (copper (II), benzotriazoles, polyethylene glycol (M(n) 300), polyethylene glycol (M(n) 860) monooleate, perfluoro-1-octane sulfonate, citric acid, oxalic acid and isopropanol) only copper was found to be inhibitory to methanogenic activity at the concentrations tested. Most of the organic compounds tested were biodegradable with the exception of perfluoro-1-octane sulfonate and benzotriazoles under sulfate reducing conditions and with the exception of the same compounds as well as Triton X-100 under methanogenic conditions. The susceptibility of key components in CMP effluents to anaerobic biodegradation combined with their low microbial inhibition suggest that CMP effluents should be amenable to biological treatment in sulfate reducing bioreactors.     

A Preliminary Risk Assessment Protocol for Renegade Nanoparticles Deployed During Nanoremediation

The NanoRem European research project aims to support and develop the appropriate use of nanotechnology for contaminated land remediation by facilitating practical, economic, and exploitable nanotechnology for in situ remediation. This can only be achieved in parallel with a comprehensive understanding of the environmental risk‐benefit balance for the use of the nanoparticles (NPs) being investigated. While the NanoRem NPs could have a significant toxicity this is likely to be less potent than NPs currently being released into the environment, such as those from a variety of antibacterial products. The NanoRem NPs are likely to interact with the aquifer matrix, each other, and groundwater chemistry to rapidly cease to be mobile and are unlikely to penetrate into the aquifer more than a few meters from the point of injection. In terms of the source‐pathway‐receptor paradigm, the NanoRem NPs are cautiously presumed to represent a hazard (i.e., source). At least one receptor, in the form of not yet polluted groundwater, is present at all the NanoRem case study sites. While there are considerable uncertainties particularly with regards to the transport of NanoRem NPs, the ability of NPs to penetrate far into the formation is likely to be very limited. The relatively short travel distances reported in the literature for a variety of NP types and geological conditions suggest that the pathways are at best very limited in extent. Overall, this means that in many cases the level of risk renegade NPs can pose to the environment or human health is at most minimal. A qualitative protocol developed for the NanoRem field trials can demonstrate that injecting NanoRem NPs into contaminated groundwater poses a minimal level of risk due to the reduced pathway. ©2016 Wiley Periodicals, Inc.     

The behavior of heterotypic resting schools of juvenile grunts (Pomadasyidae)

Resting schools of juvenile grunts (less than 12 cm length), composed primarily of Haemulon flavolineatum and H. plumieri, were studied from 1972 to 1976 on a series of patch reefs surrounded by seagrass beds on the northeast coast of St. Croix, U.S. Virgin Islands. Juvenile grunts form large inactive multispecies schools in reef areas by day. Repeated censuses over several years reveal that certain parts of the reef, particularly those with large formations of the corals Porites porites and Acropora palmata, are traditional schooling areas. When the fishes reach a size of about 15 cm, the H. plumieri form homotypic schools which roam the patch reefs but are no longer associated with particular formations of coral. In contrast, larger H. flavolineatum are uncommon on the patch reefs and they may move offshore to deeper water. The schools of juvenile grunts migrate some distance away (often 100 to 300 m) into seagrass-covered areas to feed on invertebrates at dusk each day. The routes which are followed into the seagrass beds are precise and persist over years. At dawn the grunts return to the reef on the same routes. Mass marking and release experiments show that juvenile grunts will move over long distances (approximately 3 km) to reach a home reef.     

Diffusive wave models for operational forecasting of channel routing at continental scale

Operational forecast models require robust, computationally efficient, and reliable algorithms. We desire accurate forecasts within the limits of the uncertainties in channel geometry and roughness because the output from these algorithms leads to flood warnings and a variety of water management decisions. The current operational Water Model uses the Muskingum-Cunge method, which does not account for key hydraulic conditions such as flow hysteresis and backwater effects, limiting its ability in situations with pronounced backwater effects. This situation most commonly occurs in low-gradient rivers, near confluences and channel constrictions, coastal regions where the combined actions of tides, storm surges, and wind can cause adverse flow. These situations necessitate a more rigorous flow routing approach such as dynamic or diffusive wave approximation to simulate flow hydraulics accurately. Avoiding the dynamic wave routing due to its extreme computational cost, this work presents two diffusive wave approaches to simulate flow routing in a complex river network. This study reports a comparison of two different diffusive wave models that both use a finite difference solution solved using an implicit Crank–Nicolson (CN) scheme with second-order accuracy in both time and space. The first model applies the CN scheme over three spatial nodes and is referred to as Crank–Nicolson over Space (CNS). The second model uses the CN scheme over three temporal nodes and is referred to as Crank–Nicolson over Time (CNT). Both models can properly account for complex cross-section geometry and variable computational points spacing along the channel length. The models were tested in different watersheds representing a mixture of steep and flat topographies. Comparing model outputs against observations of discharges and water levels indicated that the models accurately predict the peak discharge, peak water level, and flooding duration. Both models are accurate and computationally stable over a broad range of hydraulic regimes. The CNS model is dependent on the Courant criteria, making it less computational efficient where short channel segments are present. The CNT model does not suffer from that constraint and is, thus, highly computationally efficient and could be more useful for operational forecast models.