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Glaciers are generally believed to be subjugating by global warming but the Karakoram glaciers are reportedly maintaining their balance. Earlier studies in the Karakoram and its sub-basins have mostly addressed a short span of time and used complex models to understand the phenomenon. Thus, this study is based on a long-term trend analysis of the computed runoff components using satellite data with continuous spatial and temporal coverage incorporated into a simple degree day Snowmelt Runoff Model (SRM). The trends of melt runoff components can help us understanding the future scenarios of the glaciers in the study area. The SRM was calibrated against the recorded river flows in the Hunza River Basin (HRB). Our simulations showed that runoff contribution from rain, snow, and glaciers are 14.4%, 34.2%, and 51.4%, respectively during 1995–2010. The melting during the summer has slightly increased, suggesting overall but modest glacier mass loss which consistent with a few recent studies. The annual stream flows showed a rising trend during the 1995–2010 period, while, rainfall and temperatures showed contrasting increasing/decreasing behavior in the July, August, and September months during the same period. The average decreasing temperatures (0.08 °C per annum) in July, August, and September makes it challenging and unclear to explain the reason for this rising trend of runoff but a rise in precipitation in the same months affirms the rise in basin flows. At times, the warmer rainwater over the snow and glacier surfaces also contributed to excessive melting. Moreover, the uncertainties in the recorded hydrological, meteorological, and remote sensing data due to low temporal and spatial resolution also portrayed contrasting results. Gradual climate change in the HRB can affect river flows in the near future, requiring effective water resource management to mitigate any adverse impacts. This study shows that assessment of long-term runoff components can be a good alternative to detect changes in melting glaciers with minimal field observations. [ABSTRACT FROM AUTHOR]

This study investigates the projections of precipitation and temperature at the local scale in the Upper Indus Basin (UIB) in Pakistan using six Regional Climate Models (RCMs) from CORDEX under two Representative Concentration Pathways (RCP 4.5 and RCP 8.5). For twenty-four stations spread across the study area, the Long Ashton Research Station Weather Generator, version six (LARS-WG6), was used to downscale the daily data from the six different RCMs for maximum temperature (T max ), minimum temperature (T min ), and precipitation (pr) at a spatial resolution of 0.44°. Investigations were made to predict changes in mean annual values of T max , T min , and precipitation during two future periods, i.e., the mid-century (2041-2070) and end-century (2071-2100). The model results from statistical and graphical comparison validated that the LARS-WG6 can simulate the temperature and the precipitation in the UIB. Each of the six RCMs and their ensemble revealed a continuously increased temperature projection in the basin; nevertheless, there is variation in projected magnitude across RCMs and between RCPs. The rise in average T max and T min was more significant under RCP 8.5 than RCP 4.5, possibly due to unmitigated greenhouse gas emissions (GHGs). The precipitation projections follow the non-uniform trend, i.e., not all RCMs agree on whether the precipitation will increase or decrease in the basin, and no orderly variations were detected during any future periods under any RCP. However, an overall increase in precipitation is projected by the ensemble of RCMs., (© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

This study presents a map reporting valuable information on the cryosphere of the Central Karakoram National Park (CKNP, the largest protected area of Pakistan and the highest park in the world). All the information is provided considering the CKNP as a whole, and in detail by dividing it into five basins (i.e. Shigar, Hunza, Shyok, Upper Indus, and Gilgit). The glacier inventory reports 608 ice bodies covering 3680 km2 (∼35% of the CKNP area), with a total glacier volume of ca. 532 km3. In addition, we modeled the meltwater from glacier ice ablation over the period 23 July to 9 August 2011. The total melt amount is ca. 1.5 km3. Finally, we considered glacial lakes (202 water-bodies, covering 4 km2). For these latter glacier features, we also analyzed their potentially dangerous conditions and two lakes were found having such conditions. [ABSTRACT FROM AUTHOR]

Upper Indus Basin (UIB) is critical for Pakistan's economy as it is glacial in composition and snow melt that provides 80% of the fresh water to Indus River. Decadal fluctuations in the precipitation in UIB during 1980-2010, using interpolation technique in Arc Map were explored in present study. The results provided a positive correlation between the winter precipitation and summer runoff in middle elevation basins of UIB. The map of decadal difference of mean annual rainfall (1980-2010), prepared in Arc Geographic Information System 9.0, revealed that around Gilgit, Skardu, Astore, Chilas and Bunji, was found the least difference in mean annual rainfall, i.e. of -1.68 to-2.14mm, whereas area around Kakul experienced maximum rainfall decadal difference ranged from -13.63 to -17.45mm. The study suggested that south of lesser Himalayan areas experienced maximum rainfall variability during the period 1980-2010, whereas, lesser variability in north of Himalayan areas inferred safer addition in fresh water in Indus from its glacial reserve. [ABSTRACT FROM AUTHOR]

Mountainous areas in the northern Pakistan are blessed by numerous rivers that have great potential in water resources and hydropower production. Many of these rivers are unexploited for their water resource potential. If the potential of these rivers are explored, hydropower production and water supplies in these areas may be improved. The Indus is the main river originating from mountainous area of the Himalayas of Baltistan, Pakistan in which most of the smaller streams drain. In this paper, the hydrology of the mountainous areas in northern Pakistan is studied to estimate flow pattern, long-term trend in river flows, characteristics of the watersheds, and variability in flow and water resource due to impact of climate change. Eight watersheds including Gilgit, Hunza, Shigar, Shyok, Astore, Jhelum, Swat, and Chitral, Pakistan have been studied from 1960 to 2005 to monitor hydrological changes in relation to variability in precipitation, temperature and mean monthly flows, trend of snow melt runoff, analysis of daily hydrographs, water yield and runoff relationship, and flow duration curves. Precipitation from ten meteorological stations in mountainous area of northern Pakistan showed variability in the winter and summer rains and did not indicate a uniform distribution of rains. Review of mean monthly temperature of ten stations suggested that the Upper Indus Basin can be categorized into three hydrological regimes, i.e., high-altitude catchments with large glacierized parts, middle-altitude catchments south of Karakoram, and foothill catchments. Analysis of daily runoff data (1960-2005) of eight watersheds indicated nearly a uniform pattern with much of the runoff in summer (June-August). Impact of climate change on long-term recorded annual runoff of eight watersheds showed fair water flows at the Hunza and Jhelum Rivers while rest of the rivers indicated increased trends in runoff volumes. The study of the water yield availability indicated a minimum trend in Shyok River at Yogo and a maximum trend in Swat River at Kalam. Long-term recorded data used to estimate flow duration curves have shown a uniform trend and are important for hydropower generation for Pakistan which is seriously facing power crisis in last 5 years. [ABSTRACT FROM AUTHOR]

A major proportion of flow in the Indus River is contributed by its snow- and glacier-fed river catchments situated in the Himalaya, Karakoram and Hindukush ranges. It is therefore essential to understand the cryosphere dynamics in this area for water resource management. The MODIS MOD10A2 remote-sensing database of snow cover products from March 2000 to December 2009 was selected to analyse the snow cover changes in the Hunza River basin (the snow- and glacier-fed sub-catchment of the Indus River). A database of daily flows for the Hunza River at Dainyor Bridge over a period of 40 yr and climate data (precipitation and temperature) for 10 yr from three meteorological stations within the catchment was made available to investigate the hydrological regime in the area. Analysis of remotely sensed cryosphere (snow and ice cover) data during the last decade (2000-2009) suggest a rather slight expansion of cryosphere in the area in contrast to most of the regions in the world where glaciers are melting rapidly. This increase in snow cover may be the result of an increase in winter precipitation caused by westerly circulation. The impact of global warm- ing is not effective because a large part of the basin area lies under high altitudes where the temperature remains negative throughout most of the year. [ABSTRACT FROM AUTHOR]