GLACIER MELT RESPONSE AND ANNUAL HYDROLOGICAL IMPACT THROUGHOUT TWENTY-FIRST CENTURY FOR MAJOR RIVER BASINS ORIGINATING IN HIGH MOUNTAIN ASIA

AbstractThe Indus Basin is referred to as a “water tower” which ensures water storage and supply to sustain environmental and human needs downstream by a balanced combination of precipitation, snow, glaciers, and surface water. The Upper Indus Basin (UIB) combines the high mountain ranges of the Hindukush, Karakoram, and Himalaya (HKH); this unique region is largely controlled by seasonal meltwater associated with snow and glacier melt during the summer months. The present study seeks to evaluate changes in hydrological and meteorological variable data collected through a network of 35 hydrometric and 15 climatic stations, respectively, across the UIB, Jehlum, and Kabul river basins in Pakistan. The Innovative Trend Significance Test (ITST) in combination with the Modified-Mann-Kendall (MMK) test was used for seeking trends, while Sen’s method was applied for the slope determination of detected trends over four periods of differing lengths (T1: 1961–2013; T2: 1971–2013; T3: 1981–2013; and T4: 1991–2013). Significant decreases were observed in the mean summer and distinct months of (June–August) temperature (Tmean) at most of the stations during T1, while significant increases were dominant over the shorter T4. The mean precipitation (Pmean) was observed as significantly negative at ten stations during July; however, positive trends were observed in August and September. For streamflow, significantly upward trends were observed for mean summer, June and July flows (snowmelt dominant) during T1 and T2, within the glacier-fed basins of Hunza, Shigar, and Shyok; in contrast, streamflow (glacier melt dominant) decreased significantly in August and September over the most recent period T4. For snow-fed basins, significant increases were observed in summer mean flows at Indus at Kachura, Gilgit at Gilgit, and Alam Bridge, Astore at Doyian during (T1–T3). In particular, a stronger and more prominent signal of decreasing flows was evident in T4 within the predominantly snow-fed basins. This signal was most apparent in summer mean flows, with a large number of stations featuring significant downward trends in Jehlum and Kabul river basins. The present study concludes that the vulnerability of this region related to water stress is becoming more intense due to significantly increased temperature, reduced precipitation, and decreasing summer flows during T4.

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Extinction debt of high-mountain plants under twenty-first-century climate change

Nature Climate Change ◽

10.1038/nclimate1514 ◽

2012 ◽

Vol 2 (8) ◽

pp. 619-622 ◽

Cited By ~ 365

Author(s):

Stefan Dullinger ◽

Andreas Gattringer ◽

Wilfried Thuiller ◽

Dietmar Moser ◽

Niklaus E. Zimmermann ◽

...

Keyword(s):

Climate Change ◽

First Century ◽

High Mountain ◽

Extinction Debt ◽

Twenty First Century ◽

Mountain Plants

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Twenty-first century glacier slowdown driven by mass loss in High Mountain Asia

Nature Geoscience ◽

10.1038/s41561-018-0271-9 ◽

2018 ◽

Vol 12 (1) ◽

pp. 22-27 ◽

Cited By ~ 66

Author(s):

Amaury Dehecq ◽

Noel Gourmelen ◽

Alex S. Gardner ◽

Fanny Brun ◽

Daniel Goldberg ◽

...

Keyword(s):

Mass Loss ◽

First Century ◽

High Mountain ◽

Twenty First Century

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Dynamically Downscaled High-Resolution Hydroclimate Projections for Western Canada

Journal of Climate ◽

10.1175/jcli-d-14-00174.1 ◽

2015 ◽

Vol 28 (2) ◽

pp. 423-450 ◽

Cited By ~ 20

Author(s):

Andre R. Erler ◽

W. Richard Peltier ◽

Marc D’Orgeville

Keyword(s):

River Basin ◽

Regional Scale ◽

Winter Precipitation ◽

First Century ◽

Climate Projections ◽

Western Canada ◽

Model Version ◽

Major River ◽

Twenty First Century ◽

The Impact

Abstract Accurate identification of the impact of global warming on water resources in major river systems represents a significant challenge to the understanding of climate change on the regional scale. Here, dynamically downscaled climate projections for western Canada are presented, and impacts on hydrological variables in two major river basins, the Fraser and Athabasca, are discussed. These regions are both challenging because of the complexity of the topography and important because of the economic activity occurring within them. To obtain robust projections of future conditions, and to adequately characterize the impact of natural variability, a small initial condition ensemble of independently downscaled climate projections is employed. The Community Earth System Model, version 1 (CESM1), is used to generate the ensemble, which consists of four members. Downscaling is performed using the Weather Research and Forecasting Model, version 3.4.1 (WRF V3.4.1), in a nested configuration with two domains at 30- and 10-km resolution, respectively. The entire ensemble was integrated for a historical validation period and for a mid-twenty-first-century projection period [assuming representative concentration pathway 8.5 (RCP8.5) for the future trajectory of greenhouse gases]. The projections herein are characterized by an increase in winter precipitation for the mid-twenty-first-century period, whereas net precipitation in summer is projected to decrease, due to increased evapotranspiration. In the Fraser River basin, a shift to more liquid precipitation and earlier snowmelt will likely reduce the seasonal variability of runoff, in particular the spring freshet. In the Athabasca River basin, winter precipitation and snowmelt may increase somewhat, but increasing evapotranspiration may lead to reduced streamflow in late summer.

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Model-Based Estimation of Dynamic Effect on Twenty-First-Century Precipitation for Swiss River Basins

Journal of Climate ◽

10.1175/jcli-d-11-00191.1 ◽

2012 ◽

Vol 25 (8) ◽

pp. 2897-2913 ◽

Cited By ~ 4

Author(s):

James V. Rudolph ◽

Katja Friedrich ◽

Urs Germann

Keyword(s):

Daily Precipitation ◽

Heavy Precipitation ◽

River Basins ◽

First Century ◽

Total Precipitation ◽

Dynamic Effects ◽

Synoptic Pattern ◽

Synoptic Patterns ◽

Study Results ◽

Twenty First Century

Abstract Projections of twenty-first-century precipitation for seven Swiss river basins are generated by linking high-resolution (2 km × 2 km) radar-estimated precipitation observations to a global climate model (GCM) via synoptic weather patterns. The use of synoptic patterns characterizes the effect of changes in large-scale circulation, or dynamic effects, on precipitation. In each basin observed total daily precipitation received during advective synoptic patterns is shown to be dependent on the basin’s general topographic aspect. Across all basins convective synoptic patterns follow the same trend in total daily precipitation with cyclonic patterns consistently producing a larger amount of precipitation than anticyclonic patterns. Identification of synoptic patterns from a GCM for the twenty-first century [Community Climate System Model, version 3.0, (CCSM3)] shows increasing frequency of anticyclonic synoptic patterns, decreasing frequency of cyclonic patterns, and constant frequency of advective patterns over Switzerland. When coupled with observed radar-estimated precipitation for each synoptic pattern, the changes in synoptic pattern frequencies result in an approximately 10%–15% decrease in decadal precipitation over the course of the twenty-first century for seven Swiss river basins. The study results also show an insignificant change in the future (twenty-first century) probability of exceeding the current (2000–08) 95th quantile of total precipitation. The lack of a trend in exceeding the 95th quantile of precipitation in combination with a decreasing trend in total precipitation provides evidence that dynamic effects will not result in increased frequency of heavy precipitation events, but that heavy precipitation will account for a greater proportion of total precipitation in Swiss river basins by the end of the twenty-first century.

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Simulation and Projection of Arctic Freshwater Budget Components by the IPCC AR4 Global Climate Models

Journal of Hydrometeorology ◽

10.1175/jhm575.1 ◽

2007 ◽

Vol 8 (3) ◽

pp. 571-589 ◽

Cited By ~ 97

Author(s):

Vladimir M. Kattsov ◽

John E. Walsh ◽

William L. Chapman ◽

Veronika A. Govorkova ◽

Tatyana V. Pavlova ◽

...

Keyword(s):

Arctic Ocean ◽

River Discharge ◽

First Century ◽

The Arctic ◽

Assessment Report ◽

The Arctic Ocean ◽

Major River ◽

Freshwater Budget ◽

Twenty First Century ◽

Ipcc Ar4

Abstract The state-of-the-art AOGCM simulations have recently (late 2004–early 2005) been completed for the Intergovernmental Panel on Climate Change (IPCC) in order to provide input to the IPCC’s Fourth Assessment Report (AR4). The present paper synthesizes the new simulations of both the twentieth- and twenty-first-century arctic freshwater budget components for use in the IPCC AR4, and attempts to determine whether demonstrable progress has been achieved since the late 1990s. Precipitation and its difference with evapotranspiration are addressed over the Arctic Ocean and its terrestrial watersheds, including the basins of the four major rivers draining into the Arctic Ocean: the Ob, the Yenisey, the Lena, and the Mackenzie. Compared to the previous [IPCC Third Assessment Report (TAR)] generation of AOGCMs, there are some indications that the models as a class have improved in simulations of the Arctic precipitation. In spite of observational uncertainties, the models still appear to oversimulate area-averaged precipitation over the major river basins. The model-mean precipitation biases in the Arctic and sub-Arctic have retained their major geographical patterns, which are at least partly attributable to the insufficiently resolved local orography, as well as to biases in large-scale atmospheric circulation and sea ice distribution. The river discharge into the Arctic Ocean is also slightly oversimulated. The simulated annual cycle of precipitation over the Arctic Ocean is in qualitative agreement between the models as well as with observational and reanalysis data. This is also generally the case for the seasonality of precipitation over the Arctic Ocean’s terrestrial watersheds, with a few exceptions. Some agreement is demonstrated by the models in reproducing positive twentieth-century trends of precipitation in the Arctic, as well as positive area-averaged P–E late-twentieth-century trends over the entire terrestrial watershed of the Arctic Ocean. For the twenty-first century, three scenarios are considered: A2, A1B, and B1. Precipitation over the Arctic Ocean and its watersheds increases through the twenty-first century, showing much faster percentage increases than the global mean precipitation. The arctic precipitation changes have a pronounced seasonality, with the strongest relative increase in winter and fall, and the weakest in summer. The river discharge into the Arctic Ocean increases for all scenarios from all major river basins considered, and is generally about twice as large as the increase of freshwater from precipitation over the Arctic Ocean (70°–90°N) itself. The across-model scatter of the precipitation increase for each scenario is significant, but smaller than the scatter between the climates of the different models in the baseline period.

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