Evaluating the effect of snow and ice melt in an Alpine headwater catchment and further downstream in the River Rhine     

Nadine Junghans  Johannes Cullmann  Matthias Huss 《水文科学杂志》2013,58(6):981-993

Abstract

The runoff regime of glacierized headwater catchments in the Alps is essentially characterized by snow and ice melt. High Alpine drainage basins influence distant downstream catchments of the Rhine River basin. In particular, during the summer months, low-flow conditions are probable with strongly reduced snow and ice melt under climate change conditions. This study attempts to quantify present and future contributions from snow and ice melt to summer runoff at different spatial scales. For the small Silvretta catchment (103 km²) in the Swiss Alps, with a glacierization of 7%, the HBV model and the glacio-hydrological model GERM are applied for calculating future runoff based on different regional climate scenarios. We evaluate the importance of snow and ice melt in the runoff regime. Comparison of the models indicates that the HBV model strongly overestimates the future contribution of glacier melt to runoff, as glaciers are considered as static components. Furthermore, we provide estimates of the current meltwater contribution of glaciers for several catchments downstream on the River Rhine during the month of August. Snow and ice melt processes have a significant direct impact on summer runoff, not only for high mountain catchments, but also for large transboundary basins. A future shift in the hydrological regime and the disappearance of glaciers might favour low-flow conditions during summer along the Rhine.

Citation Junghans, N., Cullmann, J. & Huss, M. (2011) Evaluating the effect of snow and ice melt in an Alpine headwater catchment and further downstream in the River Rhine. Hydrol. Sci. J. 56(6), 981–993.  相似文献   

Calving retreat and proglacial lake growth at Hooker Glacier,Southern Alps,New Zealand     

Clare M. Robertson  Martin S. Brook  Kat A. Holt  Ian C. Fuller  Douglas I. Benn 《New Zealand geographer》2013,69(1):14-25

Hooker Glacier in the central Southern Alps of New Zealand has undergone significant downwasting and recession (～2.14 km) during the last two centuries. High retreat rates (51 m a^?1 1986–2001, 43 m a^?1 2001–2011) have produced a large (1.22 km²) proglacial lake. We present a retreat scenario for Hooker Glacier. A retreat scenario predicts that the glacier terminus will stabilise >3 km up‐valley of the current lake outlet after 2028 when ice velocity equals calving rate.  相似文献   

重庆忠县翠屏山西晋崖墓出土宝玉石和玻璃饰品的工艺初探     

吴沫 《地质科学译丛》2013,(2):56-64

利用显微镜对重庆忠县翠屏山西晋时期崖墓出土的玛瑙珠、琥珀饰品和玻璃珠的表面痕迹进行了显微观察,对它们的加工工艺进行了分析和探讨。其中,玛瑙珠在粗磨过程中应使用了粒径较大、粒度不均匀的石英砂粒,导致玛瑙珠的外形不规整,表面多大而深的凹坑;琥珀饰品的钻孔外缘和表面存在较多应力裂纹,显示当时的玉匠对琥珀的加工尚不能克服琥珀性脆、怕热的缺点;玻璃珠至少可见铸造——切削成形、缠珠和直管切割3种制作工艺。这些饰品的特点反映了西晋时期平民社会所使用的饰品的面貌和工艺水平,为中国古代宝玉石和玻璃器的断代以及工艺研究提供了新的信息。  相似文献   

天山乌鲁木齐河源1号冰川退缩地植物群落演替规律及机理研究     

刘光琇  李师翁  伍修锟  张昺林  张宝贵  龙昊知  台喜生  李忠勤 《冰川冻土》2012,34(5):1134-1141

以空间代时间的方法, 研究了天山乌鲁木齐河源1号冰川退缩地植物群落的演替. 结果表明, 1号冰川退缩地现代冰期冰碛物上共出现被子植物15科50种, 以菊科、 禾本科、 石竹科和莎草科为主. 植物群落演替可明显分为4个阶段, 并且表现出菊科→石竹科→禾本科→莎草科的基本演替规律. 在时间序列上, 物种数、 物种丰富度、 物种个体数、 多样性指数和群落盖度等重要值都与演替时间呈显著正相关. 该区域内植物种的分布主要受风力种子传播驱动, 种子小而多、 易于通过风力传播、 且株型低矮抗逆性强的植物种类优先出现, 而土壤发育程度则是植物群落演替的直接决定因素.  相似文献   

Changes in inland lakes on the Tibetan Plateau over the past 40 years     

Yue Fang  Weiming Cheng  Yichi Zhang  Nan Wang  Shangmin Zhao  Chenghu Zhou  Xi Chen  Anming Bao 《地理学报(英文版)》2016,26(4):415-438

Inland lakes and alpine glaciers are important water resources on the Tibetan Plateau. Understanding their variation is crucial for accurate evaluation and prediction of changes in water supply and for retrieval and analysis of climatic information. Data from previous research on 35 alpine lakes on the Tibetan Plateau were used to investigate changes in lake water level and area. In terms of temporal changes, the area of the 35 alpine lakes could be divided into five groups: rising, falling-rising, rising-falling, fluctuating, and falling. In terms of spatial changes, the area of alpine lakes in the Himalayan Mountains, the Karakoram Mountains, and the Qaidam Basin tended to decrease; the area of lakes in the Naqu region and the Kunlun Mountains increased; and the area of lakes in the Hoh Xil region and Qilian Mountains fluctuated. Changes in lake water level and area were correlated with regional changes in climate. Reasons for changes in these lakes on the Tibetan Plateau were analyzed, including precipitation and evaporation from meteorological data, glacier meltwater from the Chinese glacier inventories. Several key problems, e.g. challenges of monitoring water balance, limitations to glacial area detection, uncertainties in detecting lake water-level variations and variable region boundaries of lake change types on the Tibetan Plateau were discussed. This research has most indicative significance to regional climate change.  相似文献   

1960-2010年黑河流域冰川变化的遥感监测   总被引：8，自引：6，他引：2  

别强  强文丽  王超  何磊  赵传燕 《冰川冻土》2013,35(3):574-582

利用1960年地形图、 1990年、 2000年和2010年TM影像, 采用基于冰雪指数(NDSII)和原始波段的面向对象解译方法, 提取黑河流域4个时期的冰川分布, 结合30 m分辨率的DEM数据, 利用遥感、 地理信息系统技术对冰川的时空分布变化及原因和不确定性进行分析. 结果表明: 从1960-2010年50 a间黑河流域上游冰川持续退缩, 面积共减少138.90 km², 减少率为35.6%, 平均每年减少2.78 km², 祁连山中段冰川属于强烈退缩型. 祁连山中段黑河流域冰川主要分布在海拔4 200~5 300 m之间, 冰川分布下限为海拔4 000 m; 冰川退缩主要发生在低海拔地区, 冰川的退缩上限为海拔4 600 m.气温的显著上升是研究区冰川退缩的关键因素, 气候持续变暖将会导致冰川退缩加剧.  相似文献   

Sedimentation and morphological changes at Yuantuojiao Point,estuary of the North Branch,Changjiang River   总被引：3，自引：1，他引：2  

XIE Li  ZHANG Zhenke  ZHANG Yunfeng  WANG Yaping  HUANG Xianjin 《海洋学报(英文版)》2013,32(2):24-34

The North Branch, separated by the Chongming Island, was once the main channel in the estuary of the Changjiang River. Reclamation and a decrease in runoff to the North Branch had led to the narrowing and shallowing of the channel. The Yuantuojiao Point is located at the intersecting point connecting the North Branch of the Changjiang River and the Jiangsu coastline. Erosion cliffs are developed between the typical silty-muddy tidal flat and the salt marsh occupied by Spartina alterniflorea, and this has changed rapidly over the past few years. The sediment grain size analysis results of the surficial and two core samples indicate that the Yuantuojiao Point tidal flat experienced continuous accretional processes. Based upon 137 Cs analysis results of the YT and YY Cores sampled from the tidal flat at the Yuantuojiao Point, the average sedimentation rate of the YT Core was 2.30 cm/a from 1963 to 2007, and 2.38 cm/a from 1954 to 2007 for the YY Core. The sedimentation rates of both core locations have declined since the 1960s corresponding to the seaward reclamation at the Yuantuojiao Point. The average sedimentation rates at the Yuantuojiao Point were similar to that of the silty-muddy tidal flat at the northern Jiangsu coast, but lower than that of the south of the Changjiang River Estuary. According to field morphological investigations from 2006 to 2008 on the salt marsh at the Yuantuojiao Point, cliffs retreated markedly by storm surges and disappeared gradually because of the rapid sedimentation on the silty-muddy tidal flat. The maximum annual retreat reached 10 m. The recent sedimentation and morphological changes of the Yuantuojiao Point tidal flat not only displayed the retreat of the salt marsh and the disappearance of cliffs, but also was accompanied by rapid sedimentation of the silty-muddy tidal flat and the salt marsh, indicating the responses to the tidal currents, storm surges, Spartina alterniflorea trapping sediments and large-scale reclamation. The sediment grain size and their trends, southward coastal flow, and sandspits of the longshore bars suggest that the main sediment source at the Yuantuoijao Point, estuary of the North Branch was possibly from the Changjiang River before 1958, since then, it has been from the south of the submarine radial sand ridges of the southern Huanghai Sea (Yellow Sea).  相似文献   

RATES OF SLOPE DECLINE,TALUS GROWTH AND CLIFF RETREAT ALONG THE SHOMYO RIVER IN CENTRAL JAPAN: A SPACE‐TIME SUBSTITUTION APPROACH     

HIROYUKI OBANAWA  YUICHI S. HAYAKAWA  YUKINORI MATSUKURA 《Geografiska Annaler: Series A, Physical Geography》2009,91(4):269-278

On the basis of a space–time substitution, rates of cliff retreat and talus development overthe pasttens ofthousands of years were quantified for valley‐side slopes along the Shomyo River with a known rate of waterfall recession. Detailed profiles of the valley‐side slopes were obtained at 19 sites along the river by map reading and field survey, and the morphologic characteristics of the slopes were then measured. By combining the locations of the slopes with the recession rate of Shomyo Falls, it is estimated that the growth rate of the talus slope is 3.9–7.2 mm/yr, the rate of decline of the cliff is 2.0–4.0 × 10^?4 deg/yr, and the retreat rate of the cliff top is 6.2–11.6 mm/yr.  相似文献   

科其喀尔冰川表碛区冰崖消融的度日因子研究   总被引：1，自引：1，他引：0  

韩海东  王建  王欣  张鹏飞 《冰川冻土》2009,31(4):620-627

度日因子.冰崖坡向的变化也对度日因子产生了影响,总体表现为NEE-SE方向及SW-W方向的度日因子较大,NWW-N-NE方向的较小,S方向的最小,这主要与该地区的辐射、气温等气象条件的变化特征有关.研究还表明,冰崖的坡度对度日因子的影响较小.  相似文献   

东亚夏季风对山西省夏季降水的影响   总被引：1，自引：0，他引：1  

李智才  宋燕  武永利  王沛涛 《气候与环境研究》2010,15(6):797-807

利用NCEP1948～2007年逐日再分析资料、中国600站1960～2007年逐月降水资料和山西省1960～2007年65个测站的逐月、逐日降水资料,确立了850hPa112.5°E上候平均的假相当位温(θse)为340K和候平均的经向风为南风且南风风速≥2.5m·s-1等值线同时通过35°N的日期,将其作为山西省夏季风建立的时间,以θse≥340K的持续候数与平均持续候数相比的标准化值构造为东亚夏季风对山西省影响的强度指数I,可以较好地表征东亚季风区夏季风的强度和降水的空间分布,也可以较好地反映山西省夏季降水的强度和空间分布。该季风指数的年代际变化特征和线性趋势表明,自20世纪70年代以来东亚夏季风对山西省的影响有明显减弱的趋势,并且在1967年季风指数突变性地由强变弱。对山西省夏季风的建立和撤退时间的分析表明,近60年来东亚夏季风对山西省的影响时间越来越短。最后,分析了强弱夏季风指数年大气环流场的异常特征。  相似文献