Analytic hierarchy process (AHP) is a utility theory based decision-making technique, which works on a premise that the decision-making
of complex problems can be handled by structuring them into simple and comprehensible hierarchical structures. However, AHP
involves human subjective evaluation, which introduces vagueness that necessitates the use of decision-making under uncertainty. The vagueness is commonly handled through fuzzy sets theory, by assigning degree of membership. But, the environmental decision-making
problem becomes more involved if there is an uncertainty in assigning the membership function (or degree of belief) to fuzzy pairwise comparisons, which is referred to as ambiguity (non-specificity). In this paper, the concept of intuitionistic fuzzy set is applied to AHP, called IF-AHP to handle both vagueness and ambiguity
related uncertainties in the environmental decision-making process. The proposed IF-AHP methodology is demonstrated with an
illustrative example to select best drilling fluid (mud) for drilling operations under multiple environmental criteria. 相似文献
This article presents a comparison of sediment input by rivers and by coastal erosion into both the Laptev Sea and the Canadian Beaufort Sea (CBS). New data on coastal erosion in the Laptev Sea, which are based on field measurements and remote sensing information, and existing data on coastal erosion in the CBS as well as riverine sediment discharge into both the Laptev Sea and the CBS are included. Strong regional differences in the percentages of coastal erosion and riverine sediment supply are observed. The CBS is dominated by the riverine sediment discharge (64.45᎒6 t a-1) mainly of the Mackenzie River, which is the largest single source of sediments in the Arctic. Riverine sediment discharge into the Laptev Sea amounts to 24.10᎒6 t a-1, more than 70% of which are related to the Lena River. In comparison with the CBS, the Laptev Sea coast on average delivers approximately twice as much sediment mass per kilometer, a result of higher erosion rates due to higher cliffs and seasonal ice melting. In the Laptev Sea sediment input by coastal erosion (58.4᎒6 t a-1) is therefore more important than in the CBS and the ratio between riverine and coastal sediment input amounts to 0.4. Coastal erosion supplying 5.6᎒6 t a-1 is less significant for the sediment budget of the CBS where riverine sediment discharge exceeds coastal sediment input by a factor of ca. 10. 相似文献
Introduction Tigray, the northern region of Ethiopia (Figure 1), is located between 12°20′~14°30′N and 36° ~ 41°30′E. It is dominated by undulating topo- graphy with many mountains, plateaus, hills, depressions and limited flat lands. The elevation 相似文献
Planetary impact craters have a high degree of radial symmetry. This hampers efforts to identify the azimuthal impact direction for most craters – the radially symmetric component of an impact crater swamps any asymmetries that may be present. We demonstrate how the asymmetric component can be isolated and the direction of the asymmetries quantified using a two-dimensional eigenfunction expansion over a circular domain. The complex coefficients of expansion describe the magnitude and phase (angular alignment) of each term. From the analysis of hypervelocity impact craters formed in the laboratory, with impact angles ranging from 0° to 50° from the surface normal, we show that asymmetries which reveal the impact direction are still present at just 10° from the surface normal, and that the phase of one complex coefficient of expansion, c 11, indicates the impact direction. Analysis of the lunar crater Hadley shows bilateral symmetry in the radially asymmetric component, which may be due to oblique impact. The 31-km lunar ray crater Kepler has morphological features that indicate the azimuthal impact direction. Coefficient c 11 gives an azimuthal impact direction similar to that expected from the morphology, although post-impact gravitational collapse and slumping obscure the result to some degree. Ray craters may provide a means of testing the method for smaller 'simple' craters when data are available. 相似文献
Food-insecure households in many countries depend on international aid to alleviate acute shocks and chronic shortages. Some food security programmes (including Ethiopia’s Productive Safety Net Program–PSNP – which provides a case study for this article) have integrated aid in exchange for labour on public works to reduce long-term dependence by investing in the productive capacity and resilience of communities. Using this approach, Ethiopia has embarked upon an ambitious national programme of land restoration and sustainable land management. Although the intent was to reduce poverty, here we show that an unintended co-benefit is the climate-change mitigation from reduced greenhouse gas (GHG) emissions and increased landscape carbon stocks. The article first shows that the total reduction in net GHG emissions from PSNP’s land management at the national scale is estimated at 3.4 million?Mg?CO2e?y?1 – approximately 1.5% of the emissions reductions in Ethiopia’s Nationally Determined Contribution for the Paris Agreement. The article then explores some of the opportunities and constraints to scaling up of this impact.Key policy insights
Food security programmes (FSPs) can contribute to climate change mitigation by creating a vehicle for investment in land and ecosystem restoration.
Maximizing mitigation, while enhancing but not compromising food security, requires that climate projections, and mitigation and adaptation responses should be mainstreamed into planning and implementation of FSPs at all levels.
Cross-cutting oversight is required to integrate land restoration, climate policy, food security and disaster risk management into a coherent policy framework.
Institutional barriers to optimal implementation should be addressed, such as incentive mechanisms that reward effort rather than results, and lack of centralized monitoring and evaluation of impacts on the physical environment.
Project implementation can often be improved by adopting best management practices, such as using productive living livestock barriers where possible, and increasing the integration of agroforestry and non-timber forest products into landscape regeneration.
Thermogravimetric Fourier transform infrared spectroscopy (TG-FTIR) analyses were carried out on two sets of isolated kerogens covering a wide maturity range from low mature (0.46% Ro) through the end of oil and gas generation (maximum Ro = 5.32%). Data onweight percent and Tmax for evolution of methane, volatile tars, ethylene, SO2, NH3, CO2, and CO are reported. The Tmax of methane shows the most consistent response to increasing maturation in both sets of samples. Results are comparable to those of whole rocks from an Alaskan North Slope well analyzed previously. The collective data for both whole rocks and isolated kerogens shows a generally linear correlation between %Ro and Tmax of methane, with the exception of Ro of about 2.0% where a dip in the curve occurs. The slope of the correlation line was steeper for the predominantly terrigenous Wilcox kerogen than for more marine Colorado kerogen or for the Alaskan North Slope whole rock samples, probably reflecting differences in the chemical nature of various kerogen sets, which is also reflected by differences in the shapes of the pyrolysis curves of SO2, CO2, CO, H2O, and ethylene. These preliminary data indicate that Tmax of methane is a good maturation indicator for whole rocks and isolated kerogens up to an Ro of about 4%, which includes all of the wet gas and a considerable portion of the dry gas generation zones. This correlation was also observed for samples containing migrated bitumen, where it was not possible to obtain a reliable Tmax for the volatile tar (S2) peak. The more terrigenous Wilcox kerogens also showed a good correlation of the Tmax of ethylene with %Ro. Tmax of ammonia evolution did not correlate with maturity and occurred 100–200°C lower than previously found for whole rocks, consistent with a whole-rock source of pyrolytic ammonia for Alaskan whole rock samples. HI and OI indices were calculated in several ways and plotted to reflect kerogen type as well as both the residual oil and gas generation potential. The ratio of pyrolyzable to combustible sulfur (evolved as SO2) was independent of maturity and showed a clear difference between the more terrigenous Wilcox kerogens and the more marine Colorado kerogens. 相似文献
This paper describes a new initiative in coastal management in northeastern Tanzania. The region is within the equatorial part of the Western Indian Ocean. The priority environmental issues being faced include declining fish catches, use of destructive fishing techniques, mangrove cutting and coastal erosion. There is a widespread perception among the users of the coastal resources that management of these issues is inadequate. This programme initiative is developing flexible, community-based approaches to identifying the problems and to take achievable actions. The programme provides training in a wide range of skills and appropriate technical methods for government officials, extension workers and villagers. A collaborative process is evolving that includes participatory appraisals, village environmental committees, facilitation by government extension workers, technical advise and supervision by district technical teams, and regional-wide workshops with key players. Village initiatives taken so far include new by-laws, gear inspection, reef zoning and closures. A number of village mariculture projects are being piloted. 相似文献
Coastal change in the western Canadian Arctic is influenced by coastal morphology, relative sea-level trend and sea-ice and storm climates. The spatial variability of these factors tends to follow general east–west trends suggesting similar trends in coastal erosion hazard, processes and rates of coastal change. The spatial variability in the causes of coastal change is examined in the communities of Tuktoyaktuk, Sachs Harbour, Holman and Kugluktuk. 相似文献
Truss pontoon semi-submersible (TPS) is a new offshore structure concept in industry, where a truss spar is used to create the added mass by the heave plates. In the present paper, the effect of the heave plates on the vertical motion of the floating structure is demonstrated. A TPS is analyzed by utilizing the linear diffraction theory as well as the linear part of the Morison equation. The close agreement of the analysis results with the experimental results suggests that the simplified Morison equation can be used for the present analysis without sacrificing the quality of the results. However, good engineering judgment is required for estimating the values of the hydrodynamic coefficients as well as the amount of damping introduced in the structure. It is also found that the heave plates indeed introduce large added mass and considerable damping in the system motion in the vertical direction such that the resonant oscillation becomes less of a problem. This suggests that the TSP concept may have merits as a heave-controlled floating production structure in the deepwater development. 相似文献