The quaternary beaches of Gower     

T. Neville George 《Proceedings of the Geologists' Association. Geologists' Association》1932,43(4):291-IN6

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High-pressure and high-temperature deformation experiments on polycrystalline wadsleyite using the rotational Drickamer apparatus     

Robert Farla  George Amulele  Jennifer Girard  Nobuyoshi Miyajima  Shun-ichiro Karato 《Physics and Chemistry of Minerals》2015,42(7):541-558

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The U.V. Helava Award — Best Paper Volume 63 (2008)     

George Vosselman 《ISPRS Journal of Photogrammetry and Remote Sensing》2010,65(2):155

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Development of a thresholds approach for real‐time flash flood prediction in complex geomorphological river basins     

Nektarios N. Kourgialas  George P. Karatzas  Nikolaos P. Nikolaidis 《水文研究》2012,26(10):1478-1494

Flash floods represent one of the deadliest and costliest natural disasters worldwide. The hydrological analysis of a flash flood event contributes in the understanding of the runoff creation process. This study presents the analysis of some flash flood events that took place in a complex geomorphological Mediterranean River basin. The objective of the present work is to develop the thresholds for a real‐time flash flood forecasting model in a complex geomorphological watershed, based on high‐frequency data from strategically located hydrological and meteorological telemetric stations. These stations provide hourly real‐time data which were used to determine hydrological and meteorological parameters. The main characteristics of various hydrographs specified in this study were the runoff coefficients, lag time, time to peak, and the maximum potential retention. The estimation of these hydrometeorological parameters provides the necessary information in order to successfully manage flash floods events. Especially, the time to peak is the most significant hydrological parameter that affects the response time of an oncoming flash flood event. A study of the above parameters is essential for the specification of thresholds which are related to the geomorphological characteristics of the river basin, the rainfall accumulation of an event, the rainfall intensity, the threshold runoff through karstic area, the season during which the rainfall takes place and the time intervals between the rainstorms that affect the soil moisture conditions. All these factors are combined into a real‐time‐threshold flash flood prediction model. Historical flash flood events at the downstream are also used for the validation of the model. An application of the proposed model is presented for the Koiliaris River basin in Crete, Greece. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

Timing and duration of hydrological transitions in Arctic polygonal ground from stable isotopes     

Nathan Alec Conroy  Brent David Newman  Jeffrey Martin Heikoop  George Bradford Perkins  Xiahong Feng  Cathy Jean Wilson  Stan Duane Wullschleger 《水文研究》2020,34(3):749-764

Land surface models and Earth system models that include Arctic landscapes must capture the abrupt hydrological transitions that occur during the annual thaw and deepening of the active layer. In this work, stable water isotopes (δ²H and δ¹⁸O) are used to appraise hydrologically significant transitions during annual landscape thaw at the Barrow Environmental Observatory (Utqiaġvik, Alaska). These hydrologically significant periods are then linked to annual shifts in the landscape energy balance, deduced from meteorological data and described by the microclimatic periods: Winter, Pre-Melt, Melt, Post-Melt, Summer, and Freeze-Up. The tight coupling of the microclimatic periods with the hydrological transitions supports the use of microclimatic periods as a means of linking polygonal surface water hydrology to meteorological datasets, which provides a mechanism for improving the representation of polygonal surface water hydrology in process-based models. Rayleigh process reconstruction of the isotopic changes revealed that 19% of winter precipitation was lost to sublimation prior to melting and that 23% of surface water was lost to evaporation during the first 10 days post-melt. This agrees with evaporation rates reported in a separate study using an eddy covariance flux tower located nearby. An additional 17% was lost to evaporation during the next 33 days. Stable water isotopes are also used to identify the dominant sources of surface water to various hydrogeomorphological features prevalent in polygonal terrain (a lake, a low centre polygon centre, troughs within the rims of low centre polygons, flat centre polygon troughs, a high centre polygon trough, and drainages). Hydrogeomorphologies that retained significant old water or acted as snow drifts are isotopically distinct during the Melt Period and therefore are easily distinguished. Biogeochemical changes related to the annual thaw are also reported and coupled to the hydrological transitions, which provides insight into the sources and sinks of these ions to and from the landscape.  相似文献   

Inferring autogenically induced depositional discontinuities from observations on experimental deltaic shoreline trajectories          下载免费PDF全文

Daniel Mikeš  Johan H. ten Veen  George Postma  Ronald Steel 《地学学报》2015,27(6):442-448

Palaeo shoreline is a commonly used proxy for palaeo sea level, but only if deposition is continuous and constant will shoreline trajectory T(l) completely capture sea‐level time‐series E(t). Artificial deltas were generated in the Eurotank flume facility under stepwise tectonic subsidence, periodic sea‐level fluctuation and two periodic water‐discharge scenarios, one in‐phase and the other out‐of‐phase with sea level. Independent input variables tectonic subsidence Y, sea level E and water discharge Q (controlling sediment supply S) were varied and dependent output variable shoreline trajectory T was monitored. These experiments confirm that deposition is discontinuous even for continuous sediment supply, and this hinders the inference of sea‐level curve from shoreline trajectory. These results justify the here‐developed methodology for converting shoreline trajectory from the space domain to the time domain, thereby improving the accuracy of the inferred sea‐level curve.  相似文献   

Regionalisation of the parameters of the log‐Pearson 3 distribution: a case study for New South Wales,Australia          下载免费PDF全文

Tom Micevski  André Hackelbusch  Khaled Haddad  George Kuczera  Ataur Rahman 《水文研究》2015,29(2):250-260

The index flood method is widely used in regional flood frequency analysis (RFFA) but explicitly relies on the identification of ‘acceptable homogeneous regions’. This paper presents an alternative RFFA method, which is particularly useful when ‘acceptably homogeneous regions’ cannot be identified. The new RFFA method is based on the region of influence (ROI) approach where a ‘local region’ can be formed to estimate statistics at the site of interest. The new method is applied here to regionalize the parameters of the log‐Pearson 3 (LP3) flood probability model using Bayesian generalized least squares (GLS) regression. The ROI approach is used to reduce model error arising from the heterogeneity unaccounted for by the predictor variables in the traditional fixed‐region GLS analysis. A case study was undertaken for 55 catchments located in eastern New South Wales, Australia. The selection of predictor variables was guided by minimizing model error. Using an approach similar to stepwise regression, the best model for the LP3 mean was found to use catchment area and 50‐year, 12‐h rainfall intensity as explanatory variables, whereas the models for the LP3 standard deviation and skewness only had a constant term for the derived ROIs. Diagnostics based on leave‐one‐out cross validation show that the regression model assumptions were not inconsistent with the data and, importantly, no genuine outlier sites were identified. Significantly, the ROI GLS approach produced more accurate and consistent results than a fixed‐region GLS model, highlighting the superior ability of the ROI approach to deal with heterogeneity. This method is particularly applicable to regions that show a high degree of regional heterogeneity. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

A record-breaking low ice cover over the Great Lakes during winter 2011/2012: combined effects of a strong positive NAO and La Niña     

Xuezhi Bai  Jia Wang  Jay Austin  David J. Schwab  Raymond Assel  Anne Clites  John F. Bratton  Marie Colton  John Lenters  Brent Lofgren  Trudy Wohlleben  Sean Helfrich  Henry Vanderploeg  Lin Luo  George Leshkevich 《Climate Dynamics》2015,44(5-6):1187-1213

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From the editors: special issue announcement     

George C. Lee 《地震工程与工程振动(英文版)》2008,7(3):I0001-I0001

During the past several months, we have been considering "Special Issues" on a variety of topics for the journal of Earthquake Engineering and Engineering Vibration. We are pleased to announce that the December 2008 issue will be  相似文献   

Part I. Lower dee-side and the Highland border.     

George Barrow 《Proceedings of the Geologists' Association. Geologists' Association》1912,23(5):268-273

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