Confronting Management Challenges in Highly Uncertain Natural Resource Systems: a Robustness–Vulnerability Trade-off Approach

This paper presents a framework for the study of policy implementation in highly uncertain natural resource systems in which uncertainty cannot be characterized by probability distributions. We apply the framework to parametric uncertainty in the traditional Gordon–Schaefer model of a fishery to illustrate how performance can be sacrificed (traded-off) for reduced sensitivity and hence increased robustness, with respect to model parameter uncertainty. With sufficient data, our robustness–vulnerability analysis provides tools to discuss policy options. When less data are available, it can be used to inform the early stages of a learning process. Several key insights emerge from this analysis: (1) the classic optimal control policy can be very sensitive to parametric uncertainty, (2) even mild robustness properties are difficult to achieve for the simple Gordon–Schaefer model, and (3) achieving increased robustness with respect to some parameters (e.g., biological parameters) necessarily results in increased sensitivity (decreased robustness) with respect to other parameters (e.g., economic parameters). We thus illustrate fundamental robustness–vulnerability trade-offs and the limits to robust natural resource management. Finally, we use the framework to explore the effects of infrequent sampling and delays on policy performance.     

A Method for Ensemble Wildland Fire Simulation

An ensemble simulation system that accounts for uncertainty in long-range weather conditions and two-dimensional wildland fire spread is described. Fuel moisture is expressed based on the energy release component, a US fire danger rating index, and its variation throughout the fire season is modeled using time series analysis of historical weather data. This analysis is used to characterize the seasonal trend in ERC, autocorrelation of residuals, and daily standard deviation and stochastically generate artificial time series of afternoon fuel moisture. Daily wind speed and direction are sampled stochastically from joint probabilities of historical wind speed and direction for the date range of the fire simulation period. Hundreds or thousands of fire growth simulations are then performed using the synthetic fire weather sequences. The performance of these methods is evaluated in terms of the number of ensemble member simulations, one- versus two-dimensional fire spread simulations, and comparison with results from 91 fires occurring from 2007 to 2009. Simulations were found to be in consistent agreement with observations, but trends indicate that the ensemble average of simulated fire sizes were consistently larger than actual fires whereas the farthest extent burned by fires was underestimated.     

Numerical Simulations of Wind Induced Particle Contamination in Gypsum Landfill Surroundings

The contribution presents numerical simulation of gypsum particles, lifting from a gypsum landfill. First, particle characteristics are presented, resulting from different technologies of gypsum depositing. Next, a laboratory experiment parameter validation tests are described, which served as a means of determination of mass flow of particles from the landfill. The background of the numerical simulations, used in the assessment of landfill impact on the environment, is also described. Simulations consist of two parts: simulation of a long term impact of the particles on the surrounding area, performed by implementation of the Gaussian dispersion model based computer code ISC3, and second, a CFD based simulation for assessing the flow and mass concentration fields in the vicinity of the landfill for several pre-selected flow cases. The results of both computational approaches are presented and compared. In the conclusions, a relation of the simulation results with existing environmental pollution levels is made, and recommendations for landfill management are drawn.     

Hydraulics Analysis for Groundwater Flow Through Permeable Reactive Barriers

Groundwater flow modelling is an important tool in simulating and predicting hydraulic behaviour of groundwater transporting in the domain consisted of groundwater flow zone (aquifer) and permeable reactive barriers (PRBs). The aquifer regime is modelled using the Darcy equation, whereas PRBs are simulated by the Brinkman equation. By combining the above equations, the present paper is devoted to analyse the effect of permeability of aquifer (K _aq ) and reactive media (K _p ), groundwater flow velocity, and barrier size as well as assembled style of barriers on key barrier design parameter, such as the hydraulic capture zone width. The simulations indicate that the capture zone width generally decreases with a decrease in K _p at a given K _aq ; however, there is relatively little decrease in capture zone width when the K _p of freshly installed reactive media is roughly 10 times higher than the K _aq . For a given barrier system, the absolute capture zone width increases with an increase in barrier size, whereas the increment of relative capture zone width decreases dramatically. Although the capture zone width remains relatively unchanged as groundwater flow velocity increases, it results in a shorter residence time in the reactive media that may require greater barrier thickness so that contaminant levels can be reduced to regulatory limits. In addition, the effect of parallel barriers interaction on the capture zone width should be incorporated into the design. The present paper is based on the continuous reactive barrier and homogeneous barrier system. Similar methods can be used to analyse the hydrodynamics of funnel-and-gate system and heterogeneous settings by the appropriate modification.     

Detection of Human Adenovirus,Rotavirus, and Enterovirus in Tap Water and Their Association with the Overall Quality of Water in Karachi,Pakistan

Food and Environmental Virology - Drinking water supplies in the developing world often serve as a biosphere for various organisms. Viral gastroenteritis is a neglected area of research in...     

Lead contamination in surface soil on roads from used lead–acid battery recycling in Dong Mai,Northern Vietnam

Used lead–acid battery (ULAB) recycling has caused numerous health and environmental issues in developing countries. Surface soil pollution from ULAB recycling activities has been linked with elevated levels of lead in human blood. We measured surface soil lead in and surrounding the ULAB recycling village of Hung Yen in northern Vietnam in 2011, 2013, and 2014. The data were analyzed statistically and discussed with respect to distance from the contamination source, year of measurement, contamination pathway, and countermeasures against the contamination. Transportation routes from the smelter or collection site displayed the greatest concentration of surface soil lead (median 6400–10,000 mg/kg). Surface soil lead decreased significantly with distance along the road from the ULAB recycling site, although such a decrease was not observed for rice fields, agricultural roads, or garden soil. Re-suspension and adherence by traffic were identified as key pollution pathways. Distance from the source, covering of the surface of roads, construction of walls, and position relative to the source were shown to be the most effective factors in the reduction of surface soil lead pollution. Application of a combination of these measures should result in improvement in the health of residents.     

Estimation of aerosol optical depth in relation to meteorological parameters over eastern and western routes of China Pakistan economic corridor

This study finds out seasonal and monthly variations in Aerosol Optical Depth (AOD) over eastern and western routes of China Pakistan Economic Corridor (CPEC) and the relationship between AOD and meteorological parameters (i.e., temperature, rainfall and wind speed). The Moderate Resolution Imaging Spectroradiometer (MODIS) and Multi-angle Imaging Spectroradiometer (MISR) data was used from the terra satellite for the period of 2000-2016. This study aims to overtake the conventional view of the purpose of using the satellite datasets. This study takes on to the concept that validated satellite data sets rather should be used for the analysis instead of just validation specifically for our study region. Hence, after comparing MODIS AOD with MISR AOD, only MISR AOD dataset is used for further analysis. The results show a decreasing trend of AOD in summer season, a positive relationship between temperature and AOD during winter and spring seasons whereas a positive relationship between wind speed and AOD in winter and spring seasons over eastern and western routes. Periodic analysis of MODIS AOD and MISR AOD depicts May-Aug as the peak period of aerosol concentration over central Pakistan. The inter-annual analysis shows the aerosol trend remained higher during summer season however rainfall shows the washout effect. Eastern route has higher standard deviation and larger values for aerosol prevalence as compared to western route. The trajectory analysis using the HYSPLIT model suggests the bias of air mass trajectory caused deviation in the aerosol trend in the year 2014.     

Nano-structured dynamic Schiff base cues as robust self-healing polymers for biomedical and tissue engineering applications: a review

Polymer materials are vulnerable to damages, failures, and degradations, making them economically unreliable. Self-healing polymers, on the other hand, are multifunctional materials with superior properties of autonomic recovery from physical damages. These materials are suitable for biomedical and tissue engineering in terms of cost and durability. Schiff base linkages-based polymer materials are one of the robust techniques owing to their simple self-healing mechanism. These are dynamic reversible covalent bonds, easy to fabricate at mild conditions, and can self-reintegrate after network disruption at physiological conditions making them distinguished. Here we review self-healing polymer materials based on Schiff base bonds. We discuss the Schiff base bond formation between polymeric networks, which explains the self-healing phenomenon. These bonds have induced 100% recovery in optimal cases.

     

An insight into the drag effect of water,land, and energy on economic growth across space and time: the application of improved Solow growth model

Environmental Science and Pollution Research - Economies that depend on natural resources can experience a resource drag effect when economic growth is limited by constraints on the availability of...