Effect of high-frequency wind on intraseasonal SST variabilities over the mid-latitude North Pacific region during boreal summer     

Lu Wang  Tim Li  Tianjun Zhou 《Climate Dynamics》2015,45(9-10):2607-2617

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Long‐term streamflow trends in the middle reaches of the Yellow River Basin: detecting drivers of change          下载免费PDF全文

Zhaoliang Gao  Lu Zhang  Xiaoping Zhang  Lei Cheng  Nick Potter  Tim Cowan  Wenju Cai 《水文研究》2016,30(9):1315-1329

The catchments in the Loess Plateau, in China's middle reaches of the Yellow River Basin, experienced unprecedented land use changes in the last 50 years as a result of large‐scale soil conservation measure to control soil erosion. The climate of the region also exhibited some levels of change with decreased precipitation and increased temperature. This study combined the time‐trend analysis method with a sensitivity‐based approach and found that annual streamflow in the Loess Plateau decreased significantly since the 1950s and surface runoff trends appear to dominate the streamflow trends in most of the catchments. Annual baseflow exhibited mostly downward trends, but significant upward trends were also observed in 3 out of 38 gauging stations. Mean annual streamflow during 1979?2010 decreased by up to 65% across the catchments compared with the period of 1957?1978, indicating significant changes in the hydrological regime of the Loess Plateau. It is estimated that 70% of the streamflow reduction can be attributed to land use change, while the remaining 30% is associated with climate variability. Land use change because of the soil conservation measures and reduction in precipitation are the key drivers for the observed streamflow trends. These findings are consistent with results of previous studies for the region and appear to be reasonable given the accelerated level of the soil conservation measures implemented since the late 1970s. Changes in sea surface temperature in the Pacific Ocean, as indicated by variations in El Niño–Southern Oscillation and phase shifts of the Pacific Decadal Oscillation, appear to have also affected the annual streamflow trends. The framework described in this study shows promising results for quantifying the effects of land use change and climate variability on mean annual streamflow of catchments within the Loess Plateau. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

The 2020 national seismic hazard model for the United Kingdom     

Mosca  I.  Sargeant  S.  Baptie  B.  Musson  R. M. W.  Pharaoh  T. C. 《Bulletin of Earthquake Engineering》2022,20(2):633-675

Bulletin of Earthquake Engineering - We present updated seismic hazard maps for the United Kingdom (UK) intended for use with the National Annex for the revised edition of Eurocode 8. The last...  相似文献   

Assessment of rainfall-generated shallow landslide/debris-flow susceptibility and runout using a GIS-based approach: application to western Southern Alps of New Zealand   总被引：3，自引：0，他引：3  

Theodosios Kritikos  Tim Davies 《Landslides》2015,12(6):1051-1075

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The Holme Pierrepont sand and gravel and the timing of Middle and Late Devensian floodplain aggradation in the English Midlands     

Andy J. Howard  John N. Carney  Malcolm T. Greenwood  David H. Keen  Tim Mighall  Charlotte O’Brien  Emma Tetlow 《Proceedings of the Geologists' Association. Geologists' Association》2011,122(3):419-431

This paper provides the first detailed, multi-proxy environmental record for the character of Lateglacial conditions in the lowest Pleistocene terrace of the main valley floor of the River Trent at Holme Pierrepont near Nottingham. The analysis of pollen, plant, insect and mollusc remains preserved within organic channels near the base of the terrace, named the Holme Pierrepont Sand and Gravel by the British Geological Survey (historically known as the Floodplain Terrace), provided evidence of cool, though not fully arctic climatic conditions and a largely treeless landscape, roamed by large herbivores. Radiocarbon dating indicates that these sediments were deposited during the Loch Lomond Stadial (Younger Dryas GS-1). Comparison of these dates from Holme Pierrepont with those from morphostratigraphically similar deposits in the wider Trent catchment suggests that the Holme Pierrepont Sand and Gravel may have been laid down in two separate pulses of braidplain aggradation either side of the ‘Last Glacial Maximum’. It has been demonstrated from historical documentation and riverine archaeological evidence that the middle Trent has been particularly sensitive to changing flood frequency and magnitude associated with climatic oscillations during the late Holocene; this study demonstrates that such sensitivity appears to extend back into the late Pleistocene. The timing of fluvial aggradation recorded at Holme Pierrepont agrees broadly with that recorded from other sites across England and north-west Europe.  相似文献   

Modelled and measured concentrations of peroxy radicals and nitrate radical in the U.S. Gulf Coast region during TexAQS 2006     

Roberto Sommariva  Tim S. Bates  Daniel Bon  Daniel M. Brookes  Joost A. de Gouw  Jessica B. Gilman  Scott C. Herndon  William C. Kuster  Brian M. Lerner  Paul S. Monks  Hans D. Osthoff  Alex E. Parker  James M. Roberts  Sara C. Tucker  Carsten Warneke  Eric J. Williams  Mark S. Zahniser  Steven S. Brown 《Journal of Atmospheric Chemistry》2011,68(4):331-362

Measurements of total peroxy radicals (HO₂?+?RO₂) and nitrate radical (NO₃) were made on the NOAA research vessel R/V?Brown along the U.S. Gulf Coast during the TexAQS 2006 field campaign. The measurements were modelled using a constrained box-model based upon the Master Chemical Mechanism (MCM). The agreement between modelled and measured HO₂?+?RO₂ was typically within ??40% and, in the unpolluted regions, within 30%. The analysis of the model results suggests that the MCM might underestimate the concentrations of some acyl peroxy radicals and other small peroxy radicals. The model underestimated the measurements of NO₃ by 60?C70%, possibly because of rapid heterogeneous uptake of N₂O₅. The MCM model results were used to estimate the composition of the peroxy radical pool and to quantify the role of DMS, isoprene and alkenes in the formation of RO₂ in the different regions. The measurements of HO₂?+?RO₂ and NO₃ were also used to calculate the gas-phase budget of NO₃ and quantify the importance of organic peroxy radicals as NO₃ sinks. RO₂ accounted, on average, for 12?C28% of the total gas-phase NO₃ losses in the unpolluted regions and for 1?C2% of the total gas-phase NO₃ losses in the polluted regions.  相似文献   

Projection of Future Precipitation Change over China with a High-Resolution Global Atmospheric Model   总被引：10，自引：0，他引：10  

FENG Lei  ZHOU Tianjun  WU Bo  Tim LI  Jing-Jia LUO 《大气科学进展》2011,28(2):464-476

Projections of future precipitation change over China are studied based on the output of a global AGCM, ECHAM5, with a high resolution of T319 (equivalent to 40 km). Evaluation of the model’s performance in simulating present-day precipitation shows encouraging results. The spatial distributions of both mean and extreme precipitation, especially the locations of main precipitation centers, are reproduced reasonably. The simulated annual cycle of precipitation is close to the observed. The performance of the model over eastern China is generally better than that over western China. A weakness of the model is the overestimation of precipitation over northern and western China. Analyses on the potential change in precipitation projected under the A1B scenario show that both annual mean precipitation intensity and extreme precipitation would increase significantly over southeastern China. The percentage increase in extreme precipitation is larger than that of mean precipitation. Meanwhile, decreases in mean and extreme precipitation are evident over the southern Tibetan Plateau. For precipitation days, extreme precipitation days are projected to increase over all of China. Both consecutive dry days over northern China and consecutive wet days over southern China would decrease.  相似文献   

Times for (Un)sustainability? Challenges and opportunities for developing behaviour change policy. A case-study of consumers at home and away     

Stewart Barr  Gareth Shaw  Tim Coles 《Global Environmental Change》2011,21(4):1234-1244

This paper examines the assertion that individuals with seemingly high levels of commitment to the environment at home may also be those engaged in less sustainable leisure and tourism behaviours, including a high dependency on air travel. This potential difference in environmental commitments between different consumption settings is placed within the context of recent policy developments that have seen the rise of segmentation as a commonly applied technique used to understand and encourage pro-environmental behaviours through the notion of ‘sustainable lifestyles’ and social marketing campaigns. Using data derived from a questionnaire of consumers in the UK, three distinctive, empirically-defined ‘lifestyle’ groups are identified, based on the respondents’ environmental behaviours. Significant differences emerged in reported environmental commitments according to their consumption setting. Those with higher levels of commitment in and around the home also tended to be those who flew furthest and most frequently, whilst those with moderate-to-high commitments ‘at home’ often failed to transfer these activities to their holiday environments. The paper concludes by arguing that both academics and policy-makers need to address the role of different consumption settings in which behaviours are undertaken and the ways in which these relate to underlying social practices within these settings.  相似文献   

Victim pressure, institutional inertia and climate change adaptation: The case of flood risk   总被引：2，自引：0，他引：2  

Tim Harries  Edmund Penning-Rowsell   《Global Environmental Change》2011,21(1):188-197

Interviews were conducted with risk managers in a case-study area in England to determine the factors influencing the choice between more traditional, engineering based, adaptation to flood risk and those focussing on vulnerability reduction. The findings of in-depth analysis of these interviews have implications for climate change adaptation as a whole. They suggest that government policies to implement a broader range of adaptation measures might be hampered by institutional cultures formed when structural, engineered approaches were the norm. Political decentralisation and the fashion for public consultation exacerbate this effect, leaving decision-makers more responsive to the influence of those directly affected by natural hazards than they are to the needs of the wider population or to policy pronouncements by government.  相似文献   

Sediment dynamics and geohazards off Uruguay and the de la Plata River region (northern Argentina and Uruguay)   总被引：1，自引：0，他引：1  

Sebastian Krastel  Gerold Wefer  Till J. J. Hanebuth  Andrew A. Antobreh  Tim Freudenthal  Benedict Preu  Tilmann Schwenk  Michael Strasser  Roberto Violante  Daniel Winkelmann 《Geo-Marine Letters》2011,31(4):271-283

The continental margin off Uruguay and northern Argentina is characterized by high fluvial input by the de la Plata River and a complex oceanographic regime. Here we present first results from RV Meteor Cruise M78/3 of May?CJuly 2009, which overall aimed at investigating sediment transport processes from the coast to the deep sea by means of hydroacoustic and seismic mapping, as well as coring using conventional tools and the new MARUM seafloor drill rig (MeBo). Various mechanisms of sediment instabilities were identified based on geophysical and core data, documenting particularly the continental slope offshore Uruguay to be locus of submarine landsliding. Individual landslides are relatively small with volumes <2km³. Gravitational downslope sediment transport also occurs through the prominent Mar del Plata Canyon and several smaller canyons. The canyons originate at a midslope position, and the absence of buried upslope continuations strongly suggests upslope erosion as main process for canyon evolution. Many other morphological features (e.g., slope-parallel scarps with scour geometries) and abundant contourites in a 35-m-long MeBo core reveal that sediment transport and erosion are controlled predominantly by strong contour currents. Despite numerous landslide events, their geohazard potential is considered to be relatively small, because of their small volumes and their occurrence at relatively deep water depths of more than 1,500?m.  相似文献