PM10 and surface dust source characterization in Baguio City Central Business District (CBD), Philippines

Environmental Geochemistry and Health - This study measured both PM10 and surface dust concentrations at roadside in the Central Business District of Baguio City. A total of 66 PM10 filters and 25...     

Freshwater fish diversity hotspots for conservation priorities in the Amazon Basin

Conserving freshwater habitats and their biodiversity in the Amazon Basin is a growing challenge in the face of rapid anthropogenic changes. We used the most comprehensive fish-occurrence database available (2355 valid species; 21,248 sampling points) and 3 ecological criteria (irreplaceability, representativeness, and vulnerability) to identify biodiversity hotspots based on 6 conservation templates (3 proactive, 1 reactive, 1 representative, and 1 balanced) to provide a set of alternative planning solutions for freshwater fish protection in the Amazon Basin. We identified empirically for each template the 17% of sub-basins that should be conserved and performed a prioritization analysis by identifying current and future (2050) threats (i.e., degree of deforestation and habitat fragmentation by dams). Two of our 3 proactive templates had around 65% of their surface covered by protected areas; high levels of irreplaceability (60% of endemics) and representativeness (71% of the Amazonian fish fauna); and low current and future vulnerability. These 2 templates, then, seemed more robust for conservation prioritization. The future of the selected sub-basins in these 2 proactive templates is not immediately threatened by human activities, and these sub-basins host the largest part of Amazonian biodiversity. They could easily be conserved if no additional threats occur between now and 2050.     

Determinants of household fuel choices among Nigerian family heads: are there gender-differentiated impacts?

The consensus in the literature holds that female-headed households (FHHs) are more vulnerable to social and economic exclusion than male-headed households (MHHs). This paper investigates the socioeconomic determinants of household cooking fuel choices across MHHs and FHHs, using the rich Nigerian Demographic Health Survey data. Using the exogenous switching treatment effect regression (ESTER) technique, the study is able to unravel differences in socioeconomic effects of gender inequality on cooking fuel choices in Nigeria. The results validate the energy ladder hypothesis in the Nigerian case and show that the choices of dirty fuel (biomass) is more prevalent among the de-jure FHH when compared with the de-facto FHH and MHHs. Also, the probability of biomass-use among MHHs would have fallen by 1.3% if MHHs had similar socioeconomic attributes as the FHHs. In the same vain for FHHs, the probability of kerosene-use would have increased by 2%. The study observed no gender gap in kerosene-use. Thus, the established gender gap in biomass- and kerosene-use would have reduced to 6.7% and 2.8%, respectively, if the de-facto FHHs had same socioeconomic attributes as the de-jures. Considering the traditional gendered household division of labor within the households, de-jure FHHs’ energy choices may be due to limited economic opportunities that guarantees cleaner energy options.

     

Cost‐effectiveness of conservation payment schemes for species with different range sizes

Payments to compensate landowners for carrying out costly land‐use measures that benefit endangered biodiversity have become an important policy instrument. When designing such payments, it is important to take into account that spatially connected habitats are more valuable for many species than isolated ones. One way to incentivize provision of connected habitats is to offer landowners an agglomeration bonus, that is, a bonus on top of payments they are receiving to conserve land if the land is spatially connected. Researchers have compared the cost‐effectiveness of the agglomeration bonus with 2 alternatives: an all‐or‐nothing, agglomeration payment, where landowners receive a payment only if the conserved land parcels have a certain level of spatial connectivity, and a spatially homogeneous payment, where landowners receive a payment for conserved land parcels irrespective of their location. Their results show the agglomeration bonus is rarely the most cost‐effective option, and when it is, it is only slightly better than one of the alternatives. This suggests that the agglomeration bonus should not be given priority as a policy design option. However, this finding is based on consideration of only 1 species. We examined whether the same applied to 2 species, one for which the homogeneous payment is best and the other for which the agglomeration payment is most cost‐effective. We modified a published conceptual model so that we were able to assess the cost‐effectiveness of payment schemes for 2 species and applied it to a grassland bird and a grassland butterfly in Germany that require the same habitat but have different spatial‐connectivity needs. When conserving both species, the agglomeration bonus was more cost‐effective than the agglomeration and the homogeneous payment; thus, we showed that as a policy the agglomeration bonus is a useful conservation‐payment option.     

Assessing relative vulnerability to sea-level rise in the western part of the Mekong River Delta in Vietnam

The Mekong River Delta in Vietnam plays a crucial role for the region in terms of food security and socioeconomic development; however, it is one of the most low-lying and densely populated areas in the world. It is vulnerable to seawater incursion, flood risk, and shoreline change, exacerbated as a consequence of sea-level rise (SLR) related to climate change. This study examined the Kien Giang coast in the western part of the delta, comprising seven coastal districts (namely Ha Tien, Kien Luong, Hon Dat, Rach Gia, Chau Thanh, An Bien, and An Minh), the economy of which is important in terms of agriculture and aquaculture. The analytical hierarchical process (AHP) method of multi-criteria decision making was integrated directly into geographic information systems (GIS) to derive a composite vulnerability index that indicated areas most likely to be vulnerable to SLR. The hierarchical structure comprised three key components: exposure (E), sensitivity (S), and adaptive capacity (A), at level 1. At the next level, 8 sub-components were mapped: seawater incursion, flood risk, shoreline change, population characteristics, land use/land cover, and socioeconomic, infrastructure, and technological capability, beyond which a further 22 variables (level 3) and 24 sub-variables (level 4) related to vulnerability were also mapped. Variables were assigned weights for incorporation into AHP pairwise comparisons after discussion with stakeholders. Maps were generated to visualise areas where the relative vulnerability was very low, low, moderate, high, and very high. Societal data were generally only available at district level; however, several regional patterns emerged. Relatively high exposure to flooding and inundation, salinity, and moderate loss of mangroves occurred along the coastal fringe of each district. This western section of the delta, which is low-lying and remote from the distributaries that carry sediment to the coast, appears to be particularly vulnerable. The most sensitive areas tended to be ethnic households engaged in rice cultivation and with moderate population density. The least adaptable areas consisted of high numbers of poor households, with low income, and moderate densities of transport, irrigation and drainage systems. Most coastal districts were determined to be moderately to relatively highly vulnerable, with scattered hotspots along the coast.     

Bibliometric analysis of simulated driving research from 1997 to 2016

Objective: The objective of this study was to explore the evolution footprints of simulated driving research in the past 20 years through rigorous and systematic bibliometric analysis, to provide insights regarding when and where the research was performed and by whom and how the mainstream content evolved over the years.

Methods: The analysis began with data retrieval in Web of Science with defined search terms related to simulated driving. BibExcel and CiteSpace were employed to conduct the performance analysis and co-citation network analysis; that is, probe of the performance of institutes, journals, authors, and research hotspots.

Results: A total of 3,766 documents were filtered out and presented an exponential growth from 1997 to 2016. The United States contributed the most publications as well as international collaborations followed by Germany and China. In addition, several universities in The Netherlands and the United States dominated the list of contributing institutes. The leading journals were in transportation and ergonomics. The leading researchers were also recognized among the 8,721 contributing authors, such as J. D. Lee, D. L. Fisher, J. H. Kim, and K. A. Brookhuis. Finally, the co-citation analysis illuminated the evolution of simulated driving research that covered the following topics roughly in chronological order: task-induced stress, drivers with neurological disorders, alertness and sleepiness while driving, trust toward driving assistance systems, driver distraction, the effect of drug use, the validity of simulators, and automated driving.

Conclusions: This article employed bibliometric tools to probe the contributing countries, institutes, journals, authors, and mainstream hotspots of simulated driving research in the past 20 years. A systematic bibliometric analysis of this field will help researchers realize the panorama of global simulated driving and establish future research directions.     

Impacts of climate change on the hydrology of two Natura 2000 sites in Northern Greece

Greece is included among the most vulnerable regions of Europe by climate change on account of higher temperature and reduced rainfall in areas already facing water scarcity. With respect to wetland systems, many ephemeral ones are expected to disappear and several permanent to shrink due to climate change. As regards two specific wetlands of Greece, the change in hydroperiod of Cheimaditida and Kerkini lakes due to climate change was studied. Lakes’ water balance was simulated using historical climate data and the emission scenarios Α1Β for the period 2020–2050 and Α1Β and Α2 for the period 2070–2100. Future climate scenarios, based on emission scenarios A1B and A2, were provided in the context of the study of Climate Change Impacts Study Committee. The surface area of Lake Cheimaditida will undergo a substantial decrease, initially by 20 % during the period 2020–2050 and later until 37 % during the period 2070–2100. In Lake Kerkini, the surface area will decrease, initially by 5 % during the period 2020–2050 and later until 14 % during the period 2070–2100. Climate change is anticipated to impact the hydroperiod of the two wetlands, and the sustainable water management is essential to prevent the wetland’s biodiversity loss.     

Investigating the effect of compression on solute transport through degrading municipal solid waste

The effect of applied compression on the nature of liquid flow and hence the movement of contaminants within municipal solid waste was examined by means of thirteen tracer tests conducted on five separate waste samples. The conservative nature of bromide, lithium and deuterium tracers was evaluated and linked to the presence of degradation in the sample. Lithium and deuterium tracers were non-conservative in the presence of degradation, whereas the bromide remained effectively conservative under all conditions. Solute diffusion times into and out of less mobile blocks of waste were compared for each test under the assumption of dominantly dual-porosity flow. Despite the fact that hydraulic conductivity changed strongly with applied stress, the block diffusion times were found to be much less sensitive to compression. A simple conceptual model, whereby flow is dominated by sub-parallel low permeability obstructions which define predominantly horizontally aligned less mobile zones, is able to explain this result. Compression tends to narrow the gap between the obstructions, but not significantly alter the horizontal length scale. Irrespective of knowledge of the true flow pattern, these results show that simple models of solute flushing from landfill which do not include depth dependent changes in solute transport parameters are justified.     

A new economic instrument for financing accelerated landfill aftercare

The key aspects of landfill operation that remain unresolved are the extended timescale and uncertain funding of the post-closure period. This paper reviews the topic and proposes an economic instrument to resolve the unsustainable nature of the current situation. Unsustainability arises from the sluggish degradation of organic material and also the slow flushing of potential pollutants that is exacerbated by low-permeability capping. A landfill tax or aftercare provision rebate is proposed as an economic instrument to encourage operators to actively advance the stabilization of landfilled waste. The rebate could be accommodated within existing regulatory and tax regimes and would be paid for: (i) every tonne of nitrogen (or other agreed leachate marker) whose removal is advanced via the accelerated production and extraction of leachate; (ii) every tonne of non-commercially viable carbon removed via landfill gas collection and treatment. The rebates would be set at a level that would make it financially attractive to operators and would encourage measures such as leachate recirculation, in situ aeration, and enhanced flushing. Illustrative calculations suggest that a maximum rebate of up to ～€50/tonne MSW would provide an adequate incentive.