Carbon stock assessment of mangrove ecosystems in Batticaloa Lagoon,Sri Lanka,with different degrees of human disturbances

This article presents a carbon stock assessment to illustrate the organic carbon distribution and storage within mangrove ecosystems in Sri Lanka. The living tree biomass and soil carbon pools were investigated in three sites with varying degree of human disturbance in Batticaloa Lagoon. Soil carbon content was derived by the Walkley Black method from soil samples and mangrove trees were measured for calculations in general allometric equations. The mangroves that were extremely converted into a shrimp farm in Kokkaddicholai recorded a carbon (C) stock of 100.9 kg m‐2. Dominated by the poisonous Excoecaria agallocha stands, the regenerating mangroves in Manmunai Bridge Island hosted the largest C stock measuring 786.4 kg C m‐2. The Kannankudah site—dominated by Avicennia marina, Lumnitzera racemosa and Excoecaria agallocha stands, recorded a C stock of 593.1 kg C m‐2. Cuts and stumps indicated wood harvesting for local livelihoods. The soil C content pool contributed most significantly to the total C stock, with the top 30 cm containing the largest C concentration in all soil profiles. The soil carbon content was highest (5.1 per cent) in Kannankudah, second highest (3.6 per cent) in the disturbed but regenerating forest at Manmunai Bridge Island, and the lowest (0.3 per cent) at the converted site of Kokkaddicholai.     

Advancing development projects through mega-events: the 2010 football World Cup and bus rapid transit in South Africa

In 2010, the focus of the sporting world was on South Africa, the first African country to host a Football World Cup, and the largest mega-event ever held on the continent. Mega-events like the World Cup have become instruments for governments seeking material improvements to highways and telecommunications as well as the more elusive nation-building and sanguine legacies. Whereas the literature typically concentrates on stadia and sports-related infrastructure, this paper focuses on bus rapid transit (BRT) as an “indirect legacy” to understand the way in which cities exploit the financial and political capital made available to advance projects long delayed behind more pressing endeavors. The compressed time horizons, unlocked financing and focused planning can be a “mixed blessing” however by limiting the scope of the project to the event. The paper concludes that in South Africa advancing development through the World Cup reinforced state authority and legitimacy.     

Exploring pathways for sustainable water management in river deltas in a changing environment

Exploring adaptation pathways into an uncertain future can support decisionmaking in achieving sustainable water management in a changing environment. Our objective is to develop and test a method to identify such pathways by including dynamics from natural variability and the interaction between the water system and society. Present planning studies on long-term water management often use a few plausible futures for one or two projection years, ignoring the dynamic aspect of adaptation through the interaction between the water system and society. Our approach is to explore pathways using multiple realisations of transient scenarios with an Integrated Assessment Meta Model (IAMM). This paper presents the first application of the method using a hypothetical case study. The case study shows how to explore and evaluate adaptation pathways. With the pathways it is possible to identify opportunities, threats, timing and sequence of policy options, which can be used by policymakers to develop water management roadmaps into the future. By including the dynamics between the water system and society, the influence of uncertainties in both systems becomes clearer. The results show, among others, that climate variability rather than climate change appears to be important for taking decisions in water management.     

Response Surface Designs for Scenario Management and Uncertainty Quantification in Reservoir Production

Response surface experimental designs provide a framework for evaluating sensitivities and assessing uncertainties in reservoir-production forecasts for continuous parameters (i.e. permeability, flow rate, etc.). In this paper, the method is extended in order to integrate both continuous and discrete parameters (i.e. fault status: open/close, injection scheme: SWAG/WAG, etc.). This paper presents an appropriate experimental designs approach, notably the regression models associated with, and the statistical interpretation (sensitivity study, Monte Carlo simulations, etc.). The method has been successfully applied to a reservoir oil-production simulation problem. The objective was to define the best production scheme by optimizing the well-completion level. This application has highlighted the advantages of this new approach, both in terms of decreasing simulation cost and improving the interpretation quality.     

Pelagic petroleum pollution off the south-west coast of Puerto Rico

Petroleum pollution in the form of floating tar balls and dissolved or dispersed hydrocarbons has been monitored off the south-west coast of Puerto Rico on a weekly basis since November 1980. Tar ball abundance estimates agree well with previously published data for the area. Dissolved/dispersed hydrocarbon concentrations are close to, but below, those found in the Mediterranean Sea and considerably lower than those for more polluted areas. Tar ball abundance is closely related to the intensity of southerly winds. Dissolved/dispersed hydrocarbon concentrations are highest during the fall and coincident with the highest surface water temperatures.     

Revision and recalibration of existing shock classifications for quartzose rocks using low‐shock pressure (2.5–20 GPa) recovery experiments and mesoscale numerical modeling

A combination of shock recovery experiments and numerical modeling of shock deformation in the low‐shock pressure range from 2.5 to 20 GPa for two dry sandstone types of different porosity, a completely water‐saturated sandstone, and a well‐indurated quartzite provides new insights into strongly heterogeneous distribution of different shock features. (1) For nonporous quartzo‐feldspathic rocks, the traditional classification scheme (Stöffler 1984 ) is suitable with slight changes in pressure calibration. (2) For water‐saturated quartzose rocks, a cataclastic texture (microbreccia) seems to be typical for the shock pressure range up to 20 GPa. This microbreccia does not show formation of PDFs but diaplectic quartz glass/SiO₂ melt is formed at 20 GPa (~1 vol%). (3) For porous quartzose rocks, the following sequence of shock features is observed with progressive increase in shock pressure (1) crushing of pores, (2) intense fracturing of quartz grains, and (3) increasing formation of diaplectic quartz glass/SiO₂ melt replacing fracturing. The formation of diaplectic quartz glass/SiO₂ melt, together with SiO₂ high‐pressure phases, is a continuous process that strongly depends on porosity. This experimental observation is confirmed by our concomitant numerical modeling. Recalibration of the shock classification scheme results in a porosity versus shock pressure diagram illustrating distinct boundaries for the different shock stages.     

Shatter cones and planar deformation features confirm Santa Marta in Piauí State,Brazil, as an impact structure

A total of 184 confirmed impact structures are known on Earth to date, as registered by the Earth Impact Database . The discovery of new impact structures has progressed in recent years at a rather low rate of about two structures per year. Here, we introduce the discovery of the approximately 10 km diameter Santa Marta impact structure in Piauí State in northeastern Brazil. Santa Marta is a moderately sized complex crater structure, with a raised rim and an off‐center, approximately 3.2 km wide central elevated area interpreted to coincide with the central uplift of the impact structure. The Santa Marta structure was first recognized in remote sensing imagery and, later, by distinct gravity and magnetic anomalies. Here, we provide results obtained during the first detailed ground survey. The Bouguer anomaly map shows a transition from a positive to a negative anomaly within the structure along a NE–SW trend, which may be associated with the basement signature and in parts with the signature developed after the crater was formed. Macroscopic evidence for impact in the form of shatter cones has been found in situ at the base around the central elevated plateau, and also in the interior of fractured conglomerate boulders occurring on the floor of the surrounding annular basin. Planar deformation features (PDFs) are abundant in sandstones of the central elevated plateau and at scattered locations in the inner part of the ring syncline. Together, shatter cones and PDFs provide definitive shock evidence that confirms the impact origin of Santa Marta. Crystallographic orientations of PDFs occurring in multiple sets in quartz grains are indicative of peak shock pressures of 20–25 GPa in the rocks exposed at present in the interior of the crater. In contrast to recent studies that have used additional, and sometimes highly controversial, alleged shock recognition features, Santa Marta was identified based on well‐understood, traditional shock evidence.