7,170 research outputs found
Sheetflood sedimentology and stratigraphy of the Middle Proterozoic Revett Formation Scotchman Peak proposed Wilderness Area Montana
Derivation of supply curves for catchment water effluents meeting specific salinity concentration targets in 2050: linking farm and catchment level models or âFootprints on future salt / water planesâ
The salt burden in a stream reflects the blend of salty and fresh flows from different soil areas in its catchment. Depending not only on long-run rainfall, water yields from a soil are also determined by land cover: lowest if the area is forested and greatest if cleared. Water yields under agro-forestry, lucerne pasture, perennial grass pasture, and annual pasture or cropping options span the range of water yields between the extremes of forested and cleared lands. This study explores quantitative approaches for connecting the hydrologic and economic consequences of farm-level decisions on land cover (productive land uses) to the costs of attaining different catchment level targets of water volumes and salt reaching downstream users; environmental, agricultural, domestic, commercial and industrial. This connection is critical for the resolution of the externality dilemma of meeting downstream demands for water volume and quality. New technology, new products and new markets will expand options for salinity abatement measures in the dryland farming areas of watershed catchments. The development of appropriate policy solutions to address demands for water volumes and quality depends on the possibility of inducing targeted land use change in those catchments or parts of catchments where decreased saline flows or increased fresh water flows can return the best value for money. This study provides such a link.salinity, targets, opportunity cost, concentration, dilution, effluent, externality, supply, demand, policy, water quality, new technology, new markets, Resource /Energy Economics and Policy,
Less government intervention in biodiversity management: risks and opportunities
n a changing global environment, with increasing pressure on ecosystem goods and services, biodiversity conservation is likely to become increasingly important. However, with the current global financial crisis, governments are increasingly trying to stabilise economies through spending cuts aiming to reduce national deficits. Within such an economic climate, the devolution of governance through public participation is an intrinsically appealing concept. We outline a number of challenges that explain why increased participation in biodiversity management has been and may continue to be problematic. Using as a case study the local stakeholder-driven Moray Firth Seal Management Plan in Scotland, we identify four key conditions that were crucial to the successful participatory management of a biodiversity conflict: a local champion, the emergence of a crisis point, the involvement of decision-makers, and long-term financial and institutional support. Three of the four conditions point to the role of direct government involvement, highlighting the risk of devolving responsibility for biodiversity conflict management to local communities. We argue that without an informed debate, the move towards a more participatory approach could pose a danger to hard-won policy gains in relation to public participation, biodiversity conservation and conflict management
Evolution of entanglement within classical light states
We investigate the evolution of quantum correlations over the lifetime of a
multi-photon state. Measurements reveal time-dependent oscillations of the
entanglement fidelity for photon pairs created by a single semiconductor
quantum dot. The oscillations are attributed to the phase acquired in the
intermediate, non-degenerate, exciton-photon state and are consistent with
simulations. We conclude that emission of photon pairs by a typical quantum dot
with finite polarisation splitting is in fact entangled in a time-evolving
state, and not classically correlated as previously regarded
Children Asylum Seekers Face Challenges in the United States
This article outlines U.S. policy toward children asylum seekers. It highlights the gaps in U.S. detention and asylum policy which jeopardize the protection of children. It also discusses advances made in recent years, such as issuance of the U.S. âGuidelines for Childrenâs Asylum Claimsâ which establish evidentiary, procedural, and legal standards for asylum adjudicators dealing with childrenâs claims. Finally, it suggests reforms that are necessary to bring the United States into compliance with international law and to ensure that children are provided the refuge they deserve.Cet article donne les grandes lignes de la politique des Ătats- Unis vis-Ă -vis des enfants demandeurs dâasile. Il met en exergue les lacunes de la politique amĂ©ricaine sur la dĂ©tention et le droit dâasile, qui constituent une menace pour la protection des enfants. Par ailleurs, il discute aussi des progrĂšs accomplis au cours des derniĂšres annĂ©es, comme par exemple, la dĂ©livrance par les Ătats-Unis des « Directives concernant les demandes dâasile soumises par des enfants », document qui Ă©tablit des normes procĂ©durales, juridiques et en matiĂšre de preuves Ă lâintention des juges pour le droit dâasile appelĂ©s Ă statuer sur des demandes soumises par des enfants. Pour terminer, il propose des rĂ©formes nĂ©cessaires pour amener les Ătats-Unis en conformitĂ© avec le droit international et pour assurer aux enfants la protection quâils mĂ©ritent
Quantifying methane and nitrous oxide emissions from the UK and Ireland using a national-scale monitoring network
The UK is one of several countries around the world that has enacted legislation to reduce its greenhouse gas emissions. In this study, we present top-down emissions of methane (CH4) and nitrous oxide (N2O) for the UK and Ireland over the period August 2012 to August 2014. These emissions were inferred using measurements from a network of four sites around the two countries. We used a hierarchical Bayesian inverse framework to infer fluxes as well as a set of covariance parameters that describe uncertainties in the system. We inferred average UK total emissions of 2.09 (1.65â2.67) Tg yrâ1 CH4 and 0.101 (0.068â0.150) Tg yrâ1 N2O and found our derived UK estimates to be generally lower than the a priori emissions, which consisted primarily of anthropogenic sources and with a smaller contribution from natural sources. We used sectoral distributions from the UK National Atmospheric Emissions Inventory (NAEI) to determine whether these discrepancies can be attributed to specific source sectors. Because of the distinct distributions of the two dominant CH4 emissions sectors in the UK, agriculture and waste, we found that the inventory may be overestimated in agricultural CH4 emissions. We found that annual mean N2O emissions were consistent with both the prior and the anthropogenic inventory but we derived a significant seasonal cycle in emissions. This seasonality is likely due to seasonality in fertilizer application and in environmental drivers such as temperature and rainfall, which are not reflected in the annual resolution inventory. Through the hierarchical Bayesian inverse framework, we quantified uncertainty covariance parameters and emphasized their importance for high-resolution emissions estimation. We inferred average model errors of approximately 20 and 0.4 ppb and correlation timescales of 1.0 (0.72â1.43) and 2.6 (1.9â20 3.9) days for CH4 and N2O, respectively. These errors are a combination of transport model errors as well as errors due to unresolved emissions processes in the inventory. We found the largest CH4 errors at the Tacolneston station in eastern England, which may be due to sporadic emissions from landfills and offshore gas in the North Sea
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