Spatial Analysis of Environmental Change Impacts on Wheat Production in Mid-Lower North, South Australia

Three environmental change scenarios (the best scenario, the most likely scenario and the worst scenario) were used by the APSIM (Agricultural Production System sIMulator) Wheat module to study the possible impacts of future environmental change (climate change plus pCO₂ change) on wheat production in the Mid-Lower North of South Australia. GIS software was used to manage spatial-climate data and spatial-soil data and to present the results. Study results show that grain yield (kg ha⁻¹) was adversely affected under the worst environmental change scenario (−100% ∼ −42%) and the most likely environmental change scenario (−58% ∼ −3%). Grain nitrogen content (% N) either increased or decreased depending on the environmental change scenarios used and climate divisions (−25% ∼ +42%). Spatial variability was found for projected impact outcomes within climate divisions indicating the necessity of including the spatial distribution of soil properties in impact assessment.     

Vertical and lateral organization of a carbonate deep-water slope marginal to a submarine fan system, Miocene, southern Turkey

Organization is recognized in the forereef–deep water slope–submarine fan system of the Burdigalian-Langhian Kaplankaya Formation. A basinwards transition from a prograding shelfal reef complex, through forereef talus, deep-water slope and laterally encroaching bypass deep-water clastic system is described, although the deep-water slope makes up the bulk of the succession. Considerable thickness variations occur between the reef and deep-water clastic complexes; these are controlled by sea-floor topography, carbonate foreslope gradient and degree of mass wasting off the platform and foreslope. The vertical and lateral heterogeneity of the Kaplankaya deep-water slope system is described from a number of localities along a 40-km-long and up to 3-km-wide exposed section of the northern margin of the Miocene Adana Basin, a foreland basin setting resulting from thrust sheet loading from the north during the Tauride Orogeny. Detailed field mapping is supplemented with vertical sedimentary logs, photomosaics, palaeontological and petrological data to investigate stratal variation, diagnostic architectural elements, controls on slope progradation, differential timing of basinward encroachment of the reefal complex and lateral onlap of the deep-water clastic system onto the slope. Three-dimensional models are presented showing the vertical and lateral facies associations in different parts of the deep-water slope system, and provide a basis for architectural prediction of geometry and relative position in such environments.     

Nekton community response to a large-scale Mississippi River discharge: Examining spatial and temporal response to river management

Freshwater flow is generally held to be one of the most influential factors affecting community structure and production in estuaries. In coastal Louisiana, the Caernarvon Freshwater Diversion (CFD) is managed to control freshwater discharge from the Mississippi River into Breton Sound basin. Operational since 1991, CFD has undergone several changes in management strategy including pulsed spring flooding, which was introduced in 2001. We used a 20-yr time series of fisheries-independent data to investigate how variation in freshwater inflow (i.e., pre- and post-CFD, and pre and post spring pulsing management) influences the downstream nekton community (abundance, diversity, and assemblage). Analyses of long-term data demonstrated that while there were effects from the CFD, they largely involved subtle changes in community structure. Spatially, effects were largely limited to the sites immediately downstream of the diversion and extended only occasionally to more down-estuary sites. Temporally, effects were 1) immediate (detected during spring diversion events) or 2) delayed (detected several months post-diversion). Analysis of river management found that pulsed spring-time inflow resulted in more significant changes in nekton assemblages, likely due to higher discharge rates that 1) increased marsh flooding, thus increasing marsh habitat accessibility for small resident marsh species, and 2) reduced salinity, possibly causing displacement of marine pelagic species down estuary.     

Remote sensing mapping of the regeneration of coastal natural habitats in Singapore: Implications for marine conservation in tropical cities

Rapid urbanization has resulted in the loss of coastal and marine habitats in cities worldwide. The effective conservation of urban coastal ecosystems requires detailed knowledge of their spatial distribution, necessitating high-resolution mapping. Our study produces a high-resolution coastal and marine habitat map and shoreline map for the tropical city-state of Singapore created through pixel-based supervised classification of satellite imagery, bathymetry data and expert ground knowledge. These maps can be used as a base reference for multiple applications including ecological research, conservation and urban planning. They also help identifiy trends in the extent of key coastal habitats, providing insight into their differing levels of vulnerability to loss and potential for restoration to ensure long-term resilience. The method used for mapping shoreline typologies and resulting insights gained, can guide other rapidly urbanizing coastal cities on strategies to assemble useful spatial knowledge for effective conservation of their urban coastal ecosystems.     

Repeated century-scale droughts over the past 13,000 yr near the Hudson River watershed, USA

Long-term sediment and ground-penetrating radar data from Davis Pond, a small lake near the Hudson River valley, reveal past droughts in a historically humid region that presently supplies water to millions of people in and around New York City. A minimum of eleven sandy paleoshoreline deposits in the lake date from 13.4 to 0.6 cal ka BP. The deposits span 1500 to 200 yr between bracketing radiocarbon ages, and intrude into lacustrine silts up to 9.0 m below the modern lake surface in a transect of six sediment cores. Three low stands, ca. 13.4–10.9, 9.2 and 8.2 cal ka BP indicate low regional moisture balance when low temperatures affected the North Atlantic region. Consistent with insolation trends, water levels rose from ca. 8.0 cal ka BP to present, but five low stands interrupted the rise and are likely associated with ocean–atmosphere interactions. Similar to evidence from other studies, the data from Davis Pond indicate repeated multi-century periods of prolonged or frequent droughts super-imposed on long-term regional trends toward high water levels. The patterns indicate that water supplies in this heavily populated region have continuously varied at multiple time scales and confirm that humid regions such as the northeastern United States are more prone to severe drought than historically expected.     

Provenance of the northern part of the Kahramanmaraş Peripheral Foreland Basin (Miocene,S Turkey)

The Miocene Kahramanmara? Peripheral Foreland Basin (KPFB) resemble to classic foreland basin model, with small differences. In the classic model, both the accretionary wedge and foredeep extend lengthways parallel to the plate margin. In addition, accretionary wedge includes wedge top basin or piggy back basin that extends parallel to foredeep. However, the accretionary wedge of the KPFB contains small half-graben type basins that obliquely intersect the plate margin between the Arabian Plate and the Anatolide–Taurides Platform (due to the irregular shape of the plate boundary). Tectonic lineaments controlled the shape and orientation of these basins and larger main depocentre of the KFPB, which were predominantly filled with deep-sea sediments. This paper focuses on the provenance of features of the KFPB, predominantly was fed from the northern basin margin, while also aiming to resolve the complex basin evolution that occurred during the Miocene.Clasts of Palaeozoic and Mesozoic limestone and ophiolites are common components of the confined deep-water clastic systems, which evolved as elongated trenches in the north-western sector of the KPFB during the Early-Middle Miocene. During the Middle Miocene, continuous thrusting of the northern basin margin to south caused depocentre migration to south-east, through the basin interior. At that time, the north-east and central depocentres of the KPFB were filled primarily by clasts of ophiolite and metamorphic units. The tectonic control on basin fill architecture can be observed anywhere in the KFPB. The principal tectonic features controlled the geometry and orientation of the canyon, the channel geometry of the deep-water slope on the northern basin margin, the frequency and distribution of slump-slide-debris flows and the overall pattern of sedimentation cycles in the stratigraphy of the slope and the central basin floor. Some basin sectors have continuously reactivated and as a result, different sediment entry points with substantial local accumulation of sediment and deformation have evolved on the slope and basin floor. Three scales of provenance were used to investigate the source rock: (a) field-based observation and analysis of conglomerate clasts, (b) modal analysis of sandstone facies and (c) geochemical analysis, all of which were in agreement.     

Circumspection, reciprocity, and optimal carbon prices

Assessments of the benefits of climate change mitigation—and thus of the appropriate stringency of greenhouse gas emissions abatement—depend upon ethical, legal, and political economic considerations. Global climate change mitigation is often represented as a repeated prisoners’ dilemma in which the net benefits of sustained global cooperation exceed the net benefits of uncooperative unilateral action for any given actor. Global cooperation can be motivated either by circumspection—a decision to account for the damages one’s own actions inflict upon others—or by the expectation of reciprocity from others. If the marginal global benefits of abatement are approximately constant in total abatement, the domestically optimal price approaches the global cooperative optimum linearly with increasing circumspection and reciprocity. Approximately constant marginal benefits are expected if climate damages are quadratic in temperature and if the airborne fraction of carbon emissions is constant. If, on the other hand, damages increase with temperature faster than quadratically or carbon sinks weaken significantly with increasing CO₂ concentrations, marginal benefits will decline with abatement. In this case, the approach to the global optimum is concave and less than full circumspection and/or reciprocity can lead to optimal domestic abatement close to the global optimum.     

Alma and E-merlin Data Transmission Systems: Lessons for Ska

ALMA, EVLA and e-MERLIN use high data rate optical fibre links based on commercially available 10 Gbps opto-electronics. This paper describes the systems designed by NRAO and JBO staff to be used in ALMA and e-MERLIN. ALMA has a requirement for a 120 Gbps data rate per telescope, requiring the use of 12 lasers in the 1550 nm telecommunication band, with maximum link lengths around 20 km. e-MERLIN has a lower bandwidth and requires 30 Gbps links per telescope and therefore three lasers per telescope; however, the link lengths reach up to around 400 km, and amplification, de-dispersion and regeneration are required. Dense wavelength division multiplexing is used to avoid fibre management problems and save fibre costs. The design criteria and experience gained in these projects is very relevant to SKA as the proposed configuration of the antenna elements maps well to the link lengths used here. The chosen data rate will be a major cost driver.