An insight into the current oil spills and on-site bioremediation approaches to contaminated sites in Nigeria

Environmental Science and Pollution Research - Land oil spills in Nigeria have a long history of contaminating the soil, groundwater, vegetation, and streams with spill extension being the primary...     

Periodically driven circulation near the shore of a lake

Solutions are found for a linear model of the circulation near the shore of a lake that is subject to two diurnal forcing mechanisms. The first is the day/night heating/cooling induced horizontal pressure gradient. The second is an unsteady surface stress modelling a sea breeze/gully wind pattern. The two forcing mechanisms can oppose or reinforce each other depending on their relative phase. The interplay of different dynamic balances at different times and locations in the domain lead to complex circulation patterns especially during the period of flow reversal.     

Density estimation in tiger populations: combining information for strong inference

A productive way forward in studies of animal populations is to efficiently make use of all the information available, either as raw data or as published sources, on critical parameters of interest. In this study, we demonstrate two approaches to the use of multiple sources of information on a parameter of fundamental interest to ecologists: animal density. The first approach produces estimates simultaneously from two different sources of data. The second approach was developed for situations in which initial data collection and analysis are followed up by subsequent data collection and prior knowledge is updated with new data using a stepwise process. Both approaches are used to estimate density of a rare and elusive predator, the tiger, by combining photographic and fecal DNA spatial capture-recapture data. The model, which combined information, provided the most precise estimate of density (8.5 +/- 1.95 tigers/100 km2 [posterior mean +/- SD]) relative to a model that utilized only one data source (photographic, 12.02 +/- 3.02 tigers/100 km2 and fecal DNA, 6.65 +/- 2.37 tigers/100 km2). Our study demonstrates that, by accounting for multiple sources of available information, estimates of animal density can be significantly improved.     

Formation of tidal starting-jet vortices through idealized barotropic inlets with finite length

This paper presents a surface particle image velocimetry study to investigate the dynamics of shallow starting-jet dipoles formed by tidal flow through inlets and their interaction with vorticity formed at the inlet channel lateral boundaries. Vortical structure in the flow field is identified using a local swirl strength criterion evaluated from the two-dimensional flow field. The starting jet dipole vortices and vortices formed as the lateral boundary layers are expelled during flow reversal are characterized by their trajectory, size, and circulation. Using these quantities, a model is developed to predict the size and strength of the expelled lateral boundary layer vortices based on the inlet velocity, channel length, and width of the lateral boundary layer. The expelled boundary layer vortices are found to disrupt the formation of the primary tidal jet dipole through two mechanisms. First, because the boundary layer vortices themselves form a dipole with each half of the starting-jet dipole, the starting-jet vortices are pulled apart and advected away from the inlet mouth early in the tidal cycle, resulting in a reduction in the spin-up time and the amount of vorticity input during starting-jet vortex formation. Second, the advection of each dipole away from the inlet disconnects each starting-jet vortex from the starting jet; hence, the vortices are not fed by fluid in the jet or energized by shear in the jet boundary layers. These influences of the lateral boundary layer on the starting-jet vortices’ formation and propagation are found to be a function of the channel length L, maximum velocity U, and tidal period T, resulting in a predictive value to characterize their trajectory, strength, and evolution.     

The environmental history of Chatthin Wildlife Sanctuary, a protected area in Myanmar (Burma)

We reconstructed the history of Chatthin Wildlife Sanctuary (CWS) to understand how social and economic events, and policy changes affected the sanctuary's condition. We surveyed 25 villages surrounding CWS to evaluate past and present ecological conditions, compare the results with historical accounts and identify causal relationships. During the first half of the 20th century, the primary threat was the government's reduction of old growth forest to supply fuel wood for the British-built railway. The railroad opened the area to colonization, but the villagers' impact on timber and wildlife was low. From 1945 to 1988, villagers became the primary force of landscape degradation. The post-war windfall of firearms increased hunting pressure, and populations of large mammal started to decline. With the economic decline of the 1970s and 1980s, the community's demand for game and forest products intensified, and the large mammal fauna was reduced from eleven to four species. From 1988-2003, the forests surrounding the sanctuary were fragmented and degraded. The absence of large predators rendered the park safe for livestock, and the combined effects of grazing and removal of forest products seriously degraded habitat within CWS. Major threats to CWS during the past two decades have resulted from land use decisions in which government-planned economic enterprises caused encroachment by villagers. Stabilization and recovery of this sanctuary will require management compatible with human needs, including expanded buffer zones, better core area protection, community forestry projects, and probably relocation of villages within the park.     

Enduring decisions: Evaluating environmental impacts for sustainability planning

This paper aims to establish a framework in which potential methods for evaluating environmental impacts can be considered, with particular reference to the UK planning system. To do this a number of complementary ways of conceptualising sustainable development and making it more practical are outlined. Some basic arguments about the meaning of sustainability are reviewed; and some common misconceptions about the concept exposed. The concept of sustainability constraints is outlined and a functional distinction between quantitative and qualitative constraints is proposed. The adoption of sustainability constraints based on measures of environmental capacity is proposed. These suggest significant reductions in consumption of most environmental resources. The efficiency and sufficiency strategies that would be needed to meet the proposed quantified constraints are outlined. In conclusion, evaluation processes and indicators of sustainability, including environmental foot-printing and environmental impact assessment, are discussed, offering some pointers towards the type of measures that will be needed to help implement sustainability strategies.     

Environmental policy implementation during the economic crisis: an analysis of European member state ‘leader-laggard’ dynamics

ABSTRACT

The long-standing debate on environmental policy ‘leaders’ and ‘laggards’ lends itself to a new analysis following with the advent of the 2008 economic crisis. This paper, therefore, asks the question to what extent do European Union (EU) member states have the capacity and willingness to implement EU environmental policy amid austerity, budget cuts, and rising costs over the period 2008–2014. Building upon previous studies, 26 interviews with European, Greek and United Kingdom participants and records of environmental infringements, the paper provides a contemporary picture of the environmental policy ‘leader-laggard’ dynamic in Europe. The findings demonstrate that the impact of the economic crisis seems contestable and varies amongst member states, while the reduction in environmental infringements appears to have a link with the decrease in economic activity. Although environmental policy ‘leaders’ maintain patterns of strong implementation, the improved implementation performance of some ‘laggards’ reflects a shift in their implementation patterns amid a period of intense political and economic controversies.     

What Is Source Reduction? A Critique and Comparative Analysis of Polish and American Students

/ Source reduction is recognized as the preferred form of waste management, but its definition is ambiguous. This study proposes four underlying dimensions of the source reduction concept. Source reduction is foremost a preventive activity that reduces the number or extent of environmental impacts. Second, source reduction can prevent both resource consumption and pollution generation impacts. Third, source reduction may be viewed as both a producer and consumer activity. Lastly, it may include frugal and more efficient activities. In surveys exploring these fourdimensions, Polish and American university students evaluated whether 20 activities were examples of source reduction. The American students gave higher ratings to preventive activities over adaptive activities. The Polish students most prominently rated efficient over frugal activities. Factor analysis indicated that both samples identified a group of consumer-based resource conservation activities, with the American students recognizing a cluster of recycling activities. In a separate ranking of environmental protection priorities, the Polish students endorsed pollution prevention, whereas the American students favored both efficient and frugal resource conservation. These findings suggest that the conceptualization of source reduction varies according to contextual factors and that prevention is still an obscure environmental management theme. KEY WORDS: Source reduction; Pollution prevention; Resource conservation; Frugality; Poland