scholarly journals Glacier contribution to streamflow in two headwaters of the Huasco River, Dry Andes of Chile

2011 ◽  
Vol 5 (4) ◽  
pp. 1099-1113 ◽  
Author(s):  
S. Gascoin ◽  
C. Kinnard ◽  
R. Ponce ◽  
S. Lhermitte ◽  
S. MacDonell ◽  
...  
Keyword(s):  
Quantitative Assessment ◽  
Hydrological Regime ◽  
Snow Accumulation ◽  
Glacier Area ◽  
Glacier Surface ◽  
Headwater Catchments ◽  
Glacier Meltwater ◽  
Glacier Runoff ◽  
Change Impact ◽  
The Mean

Abstract. Quantitative assessment of glacier contribution to present-day streamflow is a prerequisite to the anticipation of climate change impact on water resources in the Dry Andes. In this paper we focus on two glaciated headwater catchments of the Huasco Basin (Chile, 29° S). The combination of glacier monitoring data for five glaciers (Toro 1, Toro 2, Esperanza, Guanaco, Estrecho and Ortigas) with five automatic streamflow records at sites with glacier coverage of 0.4 to 11 % allows the estimation of the mean annual glacier contribution to discharge between 2003/2004 and 2007/2008 hydrological years. In addition, direct manual measurements of glacier runoff were conducted in summer at the snouts of four glaciers, which provide the instantaneous contribution of glacier meltwater to stream runoff during summer. The results show that the mean annual glacier contribution to streamflow ranges between 3.3 and 23 %, which is greater than the glaciated fraction of the catchments. We argue that glacier contribution is partly enhanced by the effect of snowdrift from the non-glacier area to the glacier surface. Glacier mass loss is evident over the study period, with a mean of −0.84 m w.e. yr−1 for the period 2003/2004–2007/2008, and also contributes to increase glacier runoff. An El Niño episode in 2002 resulted in high snow accumulation, modifying the hydrological regime and probably reducing the glacier contribution in favor of seasonal snowmelt during the subsequent 2002/2003 hydrological year. At the hourly timescale, summertime glacier contributions are highly variable in space and time, revealing large differences in effective melting rates between glaciers and glacierets (from 1 mm w.e. h−1 to 6 mm w.e. h−1).

scholarly journals Glacier contribution to streamflow in two headwaters of the Huasco River, Dry Andes of Chile

2010 ◽  
Vol 4 (4) ◽  
pp. 2373-2413 ◽  
Author(s):  
S. Gascoin ◽  
C. Kinnard ◽  
R. Ponce ◽  
S. Lhermitte ◽  
S. MacDonell ◽  
...  
Keyword(s):  
Quantitative Assessment ◽  
Hydrological Regime ◽  
Snow Accumulation ◽  
Glacier Area ◽  
Glacier Surface ◽  
Headwater Catchments ◽  
Glacier Meltwater ◽  
Glacier Runoff ◽  
Change Impact ◽  
The Mean

Abstract. Quantitative assessment of glacier contribution to present-day streamflow is a prerequisite to the anticipation of climate change impact on water resources in the Dry Andes. In this paper we focus on two glaciated headwater catchments of the Huasco Basin (Chile, 29° S). The combination of glacier monitoring data for five glaciers (Toro 1, Toro 2, Esperanza, Guanaco, Estrecho and Ortigas) with five automatic streamflow records at sites with glacier coverage of 0.4 to 11% allows the estimation of the mean annual glacier contribution to discharge between 2003 and 2008. In addition, direct manual measurements of glacier runoff were conducted in summer at the snouts of four glaciers, which provide the instantaneous contribution of glacier meltwater to stream runoff during summer. The results show that the mean annual glacier contribution to streamflow ranges between 3.3 and 23%, which is greater than the glaciated fraction of the catchments. We argue that glacier contribution is partly enhanced by the effect of snowdrift from the non-glacier area to the glacier surface. Glacier mass loss is evident over the study period, with a mean of −0.84 m w.e. y−1 for the period 2003–2008, and also contributes to increase glacier runoff. An El Niño episode in 2002 resulted in high snow accumulation, modifying the hydrological regime and probably reducing the glacier contribution in favor of seasonal snowmelt during the subsequent 2002–2003 hydrological year. At the hourly timescale, summertime glacier contributions are highly variable in space and time, revealing large differences in effective melting rates between glacierets and glaciers.

scholarly journals Change in the Extent of Glaciers and Glacier Runoff in the Chinese Sector of the Ile River Basin between 1962 and 2012

Water ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1668
Author(s):  
Larissa Kogutenko ◽  
Igor Severskiy ◽  
Maria Shahgedanova ◽  
Bigzhang Lin
Keyword(s):  
Early Spring ◽  
Glacier Area ◽  
Index Method ◽  
Glacier Surface ◽  
Vegetative Period ◽  
Ice Melt ◽  
Total Runoff ◽  
Initial Area ◽  
Glacier Runoff ◽  
The 1960S

Change in glacier area in the Kuksu and Kunes river basins, which are tributaries to the internationally important Ile River, were assessed at two different time steps between 1962/63, 1990/93, and 2010/12. Overall, glaciers lost 191.3 ± 16.8 km2 or 36.9 ± 6.5% of the initial area. Glacier wastage intensified in the latter period: While in 1962/63–1990/93 glaciers were losing 0.5% a−1, in 1990/93–2010/12, they were losing 1.2% a−1. Streamflow of the Ile River and its tributaries do not exhibit statistically significant change during the vegetative period between May and September. Positive trends were observed in the Ile flow in autumn, winter, and early spring. By contrast, the calculation of the total runoff from the glacier surface (including snow and ice melt) using temperature-index method and runoff forming due to melting of multiyear ice estimated from changes in glacier volume at different time steps between the 1960s and 2010s, showed that their absolute values and their contribution to total river runoff declined since the 1980s. This change is attributed to a strong reduction in glacier area.

scholarly journals Analysis of a 3 year meteorological record from the ablation zone of Morteratschgletscher, Switzerland: energy and mass balance

2000 ◽  
Vol 46 (155) ◽  
pp. 571-579 ◽  
Author(s):  
J. Oerlemans
Keyword(s):  
Heat Flux ◽  
Sensible Heat Flux ◽  
Longwave Radiation ◽  
Solar Radiation Pressure ◽  
Turbulent Energy ◽  
Snow Accumulation ◽  
Shortwave Radiation ◽  
Glacier Surface ◽  
The Mean ◽  
Snow Temperature

AbstractSince 1 October 1995, an automatic weather station has been operated on the tongue of Morteratschgletscher, Switzerland. The station stands freely on the ice, and sinks with the melting glacier surface. It is located at 2100 m a.s.l., and measures air temperature, wind speed and direction, incoming and reflected solar radiation, pressure and snow temperature. A sonic ranger, mounted to stakes drilled into the ice, measures surface height from which melt rates and snow accumulation can be derived. In this paper the data for the period 1 October 1995 to 30 September 1998 are used to evaluate the surface energy balance. The turbulent energy fluxes are calculated with the bulk method. The turbulent exchange coefficient Ch is used as a control parameter. With Ch = 0.00127 the calculated melt equals the observed melt, which is 17.70 m w.e. over the 3 years. When averaged over the time when melting occurs (i.e. 35% of the time), the mean surface heat flux equals 191 W m−2. Net shortwave radiation contributes 177 W m−2, net longwave radiation −25 W m−2, the sensible-heat flux 31 W m−2 and the latent-heat flux 8 W m−2.

Voronoi Analysis of a Soccer Game

2004 ◽  
Vol 9 (3) ◽  
pp. 233-240 ◽  
Author(s):  
S. Kim
Keyword(s):  
Collective Behavior ◽  
Quantitative Assessment ◽  
The Other ◽  
Analysis Method ◽  
Random System ◽  
Soccer Game ◽  
Voronoi Polygons ◽  
The Mean

This paper describes a Voronoi analysis method to analyze a soccer game. It is important for us to know the quantitative assessment of contribution done by a player or a team in the game as an individual or collective behavior. The mean numbers of vertices are reported to be 5–6, which is a little less than those of a perfect random system. Voronoi polygons areas can be used in evaluating the dominance of a team over the other. By introducing an excess Voronoi area, we can draw some fruitful results to appraise a player or a team rather quantitatively.

Can the mass balance of the entire glacier area of the Tien Shan be estimated?

1992 ◽  
Vol 16 ◽  
pp. 173-179
Author(s):  
M.B. Dyurgerov ◽  
M.G. Kunakhovitch ◽  
V.N. Mikhalenko ◽  
A. M. Sokalskaya ◽  
V. A. Kuzmichenok
Keyword(s):  
Mass Balance ◽  
Vertical Profile ◽  
River Basins ◽  
Annual Runoff ◽  
Snow Accumulation ◽  
Tien Shan ◽  
Exponential Dependence ◽  
Glacier Area ◽  
Equilibrium Line Altitude ◽  
Boundary Area

The total area of glacierization of the Tien Shan in the boundary area of the USSR is about 8000 km2. The computation of mass balance was determined for this area in 12 river basins.In computation procedure, the vertical profile of snow accumulation in these regions and exponential dependence of variation of ablation with altitude are used. Thus the mass balance in each basin, bn, was calculated on the basis of these curves and represented in its relation with the equilibrium line altitude (ELA). It is shown that the relation ELA = f(bn) is linear when the range of bn values is close to zero, and in all altitude intervals this relation can be described by hypsographic curves, in all basins bn positive up to an ELA elevation of 3450 to 3500 m a.s.l. For average annual altitude of ELA, bn is negative for all regions. So the glaciers of these mountains add about 4 km3 of water to the total annual runoff.

Hydrological regime, water availability and land use/land cover change impact on the water balance in a large agriculture basin in the Southern Brazilian Amazon

2021 ◽  
Vol 108 ◽  
pp. 103224
Author(s):  
Tárcio Rocha Lopes ◽  
Cornélio Alberto Zolin ◽  
Rafael Mingoti ◽  
Laurimar Gonçalves Vendrusculo ◽  
Frederico Terra de Almeida ◽  
...  
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Water Balance ◽  
Land Cover Change ◽  
Water Availability ◽  
Hydrological Regime ◽  
Brazilian Amazon ◽  
Land Use Land Cover ◽  
Change Impact

Comparison of Postoperative Pain between Laser-Assisted Uvulopalatoplasty, Uvulopalatopharyngoplasty, and Radiofrequency Volumetric Tissue Reduction of the Palate

2000 ◽  
Vol 122 (3) ◽  
pp. 402-409 ◽  
Author(s):  
Robert J. Troell ◽  
Nelson B. Powell ◽  
Robert W. Riley ◽  
Kasey K. Li ◽  
Christian Guilleminault
Keyword(s):  
Quantitative Assessment ◽  
Sleep Disordered Breathing ◽  
The Other ◽  
Narcotic Analgesics ◽  
Pain Medications ◽  
Pain Scales ◽  
Analgesic Medication ◽  
The Mean ◽  
Radiofrequency Volumetric Tissue Reduction ◽  
Tissue Reduction

OBJECTIVES: This study compares the posttreatment discomfort between laser-assisted uvulopalatoplasty (LAUP), uvulopalatopharyngoplasty (UPPP), and radiofrequency volumetric tissue reduction (RFVTR) of the palate through the use of visual analog pain scales and a quantitative assessment of the analgesic medication taken. METHODS: In one group, LAUP (n = 10) or UPPP (n = 9) was used to treat patients' snoring or sleep-disordered breathing (SDB), and the other group underwent RFVTR (n = 22). RESULTS: The mean numbers of days with pain after RFVTR, LAUP, and UPPP were 2.6, 13.8, and 14.3 days, respectively. Narcotic analgesics were required in the RFVTR, LAUP and UPPP groups in 9%, 100%, and 100% of the subjects, respectively. The mean number of these days requiring narcotic pain medications for RFVTR, LAUP, and UPPP was 0.2, 11.8, and 12.4 days, whereas the total narcotic equivalent was 0.3, 7.4 and 29.6 days, respectively. CONCLUSION: RFVTR of the soft palate produced less posttreatment pain than LAUP or UPPP. LAUP and UPPP appeared to show little difference in the severity or duration of posttreatment discomfort.

scholarly journals Spatial and temporal variability in isotope composition of recent snow in the vicinity of Vostok station, Antarctica: implications for ice-core record interpretation

2002 ◽  
Vol 35 ◽  
pp. 181-186 ◽  
Author(s):  
Alexey A. Ekaykin ◽  
Vladimir Ya. Lipenkov ◽  
Narcisse I. Barkov ◽  
Jean Robert Petit ◽  
Valerie Masson-Delmotte
Keyword(s):  
Isotope Composition ◽  
Ice Core ◽  
Snow Accumulation ◽  
Spatial And Temporal Variability ◽  
Weak Correlation ◽  
Ice Core Record ◽  
Vostok Station ◽  
The Mean ◽  
Mean Annual Air Temperature ◽  
Snow Samples

AbstractContinuous, detailed isotope (δD and δ18O) profiles were obtained from eight snow pits dug in the vicinity of Vostok station, Antarctica, during the period 1984– 2000. In addition, snow samples taken along the 1km long accumulation-stake profile were measured to determine spatial variability in isotope composition of recent snow. the stacked δD time series spanning the last 55 years shows only weak correlation with the mean annual air temperature recorded at Vostok station. Significant oscillations of both snow accumulation and snow isotope composition with the periods 2.5, 5, 20 and, possibly, ~102 years observed at single points are interpreted in terms of drift of snow-accumulation waves of various scales on the surface of the ice sheet.

scholarly journals Climate change impact on water resource extremes in a headwater region of the Tarim basin in China

2011 ◽  
Vol 15 (11) ◽  
pp. 3511-3527 ◽  
Author(s):  
T. Liu ◽  
P. Willems ◽  
X. L. Pan ◽  
An. M. Bao ◽  
X. Chen ◽  
...  
Keyword(s):  
Climate Change ◽  
Water Resources ◽  
Ground Water ◽  
Climate Change Impact ◽  
Snow Accumulation ◽  
Tarim River Basin ◽  
Hydrological Models ◽  
Snow Melting ◽  
Change Impact ◽  
Ipcc Sres

Abstract. The Tarim river basin in China is a huge inland arid basin, which is expected to be highly vulnerable to climatic changes, given that most water resources originate from the upper mountainous headwater regions. This paper focuses on one of these headwaters: the Kaidu river subbasin. The climate change impact on the surface and ground water resources of that basin and more specifically on the hydrological extremes were studied by using both lumped and spatially distributed hydrological models, after simulation of the IPCC SRES greenhouse gas scenarios till the 2050s. The models include processes of snow and glacier melting. The climate change signals were extracted from the grid-based results of general circulation models (GCMs) and applied on the station-based, observed historical data using a perturbation approach. For precipitation, the time series perturbation involves both a wet-day frequency perturbation and a quantile perturbation to the wet-day rainfall intensities. For temperature and potential evapotranspiration, the climate change signals only involve quantile based changes. The perturbed series were input into the hydrological models and the impacts on the surface and ground water resources studied. The range of impact results (after considering 36 GCM runs) were summarized in high, mean, and low results. It was found that due to increasing precipitation in winter, snow accumulation increases in the upper mountainous areas. Due to temperature rise, snow melting rates increase and the snow melting periods are pushed forward in time. Although the qualitive impact results are highly consistent among the different GCM runs considered, the precise quantitative impact results varied significantly depending on the GCM run and the hydrological model.

scholarly journals Characterization of Canadian High Arctic glacier surface albedo from MODIS C6 data, 2001–2016

2017 ◽  
Author(s):  
Colleen A. Mortimer ◽  
Martin Sharp
Keyword(s):  
Large Scale ◽  
Surface Albedo ◽  
Temporal Trends ◽  
Principal Component ◽  
High Arctic ◽  
Shortwave Radiation ◽  
Glacier Surface ◽  
Annual Variations ◽  
The Mean ◽  
Moderate Resolution Imaging Spectroradiometer

Abstract. Inter-annual variations and longer-term trends in the annual mass balance of glaciers in Canada's Queen Elizabeth Islands (QEI) are largely attributable to changes in summer melt. The largest source of melt energy in the QEI in summer is net shortwave radiation, which is modulated by changes in glacier surface albedo. We used measurements from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensors to investigate large scale spatial patterns and temporal trends and variability in the summer surface albedo of QEI glaciers and their relationship to observed changes in glacier surface temperature from 2001 to 2016. Mean summer black-sky shortwave broadband albedo (BSA) decreased at a rate of 0.029 ± 0.025 decade-1 over that period. Larger reductions in BSA occurred in July (−0.050 ± 0.031 decade-1). No change in BSA was observed in either June or August. Most of the decrease in BSA, which was greatest at lower elevations around the margins of the ice masses, occurred between 2007 and 2012 when mean summer BSA was anomalously low. The First Principal Component of the 16-year record of mean summer BSA was well correlated with the mean summer North Atlantic Oscillation Index, except in 2006, 2010, and 2016. During this 16-year period, the mean summer LST increased by 0.046 ± 0.036 °C yr-1 and the BSA record was negatively correlated (−0.64, p 

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