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MALGORZATA PISARSKA-JAMROZY 《Boreas: An International Journal of Quaternary Research》2006,35(1):126-141
The study area near Chelm in Western Pomerania, NW Poland, is located between the end moraine and outwash plain of the glaciomarginal zone of the Pomeranian Phase (Weichselian glaciation). Four assemblages of deposits are exposed in the Chem pits: gravelly diamictons derived from debrisflows, sandy diamictons derived from hyperconcentrated flows, alternating sand and gravel deposited by sheetflows and sandy deposits filling shallow, braided-stream channels. The first facies association predominates in the proximal part of the transition zone and the last one in the distal part. This spectrum of facies associations, some resembling those of the end moraines and others those of the adjacent outwash plain, is considered to be unique, and is attributed to the formation of an array of coalescent ice-contact fans ('transition' fans). Architectural element analysis highlights the southwards change from debrisflow processes accompanied by sheetflows to hyperconcentrated flows and further to channelized streamflow. This transition zone in the present case is c. 1-km wide. It is suggested that analogous transitional zones, with similar or different widths, may have been developed in other glaciomarginal belts and remain to be recognized. 相似文献
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Abstract Statistical and deterministic modelling estimates of flood magnitudes and frequencies that can affect flood-plain ecology in the upper Ahuriri River catchment, a mountainous high country catchment in the New Zealand Southern Alps, were evaluated. Statistical analysis of 46 years of historical data showed that floods are best modelled by the generalized extreme value and lognormal distributions. We evaluated application of the HEC-HMS model to this environment by modelling flood events of various frequencies. Model results were validated and compared with the statistical estimates. The SCS curve number method was used for losses and runoff generation, and the model was very sensitive to curve number. The HEC-HMS flood estimates matched the statistical estimates reasonably well, and, over all return periods, were on average approximately 1% greater. However, the model generally underestimated flood peaks up to the 25-year event and overestimated magnitudes above this. The results compared well with other regional estimates, including studies based on L-moments, and showed that this catchment has smaller floods than other similarly-sized catchments in the Southern Alps. Editor D. Koutsoyiannis; Associate editor H. Aksoy Citation Caruso, B.S., Rademaker, M., Balme, A., and Cochrane, T.A., 2013. Flood modelling in a high country mountain catchment, New Zealand: comparing statistical and deterministic model estimates for ecological flows. Hydrological Sciences Journal, 58 (2), 328–341. 相似文献
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