@article{12646,
  abstract     = {Assessment of water resources from remote mountainous catchments plays a crucial role for the development of rural areas in or in the vicinity of mountain ranges. The scarcity of data, however, prevents the application of standard approaches that are based on data-driven models. The Hindu Kush–Karakoram–Himalaya mountain range is a crucial area in terms of water resources, but our understanding of the response of its high-elevation catchments to a changing climate is hindered by lack of hydro-meteorological and cryospheric data. Hydrological modeling is challenging here because internal inconsistencies—such as an underestimation of precipitation input that can be compensated for by an overestimation of meltwater—might be hidden due to the complexity of feedback mechanisms that govern melt and runoff generation in such basins. Data scarcity adds to this difficulty by preventing the application of systematic calibration procedures that would allow identification of the parameter set that could guarantee internal consistency in the simulation of the single hydrological components. In this work, we use simulations from the Hunza River Basin in the Karakoram region obtained with the hydrological model TOPKAPI to quantify the predictive power of discharge and snow-cover data sets, as well as the combination of both. We also show that short-term measurements of meteorological variables such as radiative fluxes, wind speed, relative humidity, and air temperature from glacio-meteorological experiments are crucial for a correct parameterization of surface melt processes. They enable detailed simulations of the energy fluxes governing glacier–atmosphere interaction and the resulting ablation through energy-balance modeling. These simulations are used to derive calibrated parameters for the simplified snow and glacier routines in TOPKAPI. We demonstrate that such parameters are stable in space and time in similar climatic regions, thus reducing the number of parameters requiring calibration.},
  author       = {Pellicciotti, Francesca and Buergi, Cyrill and Immerzeel, Walter Willem and Konz, Markus and Shrestha, Arun B.},
  issn         = {1994-7151},
  journal      = {Mountain Research and Development},
  number       = {1},
  pages        = {39--50},
  publisher    = {International Mountain Society},
  title        = {{Challenges and uncertainties in hydrological modeling of remote Hindu Kush–Karakoram–Himalayan (HKH) basins: Suggestions for calibration strategies}},
  doi          = {10.1659/mrd-journal-d-11-00092.1},
  volume       = {32},
  year         = {2012},
}

@article{12647,
  abstract     = {Accurate quantification of the spatial distribution of precipitation in mountain regions is crucial for assessments of water resources and for the understanding of high-altitude hydrology, yet it is one of the largest unknowns due to the lack of high-altitude observations. The Hunza basin in Pakistan contains very large glacier systems, which, given the melt, cannot persist unless precipitation (snow input) is much higher than what is observed at the meteorological stations, mostly located in mountain valleys. Several studies, therefore, suggest strong positive vertical precipitation lapse rates; in the present study, we quantify this lapse rate by using glaciers as a proxy. We assume a neutral mass balance for the glaciers for the period from 2001 to 2003, and we inversely model the precipitation lapse by balancing the total accumulation in the catchment area and the ablation over the glacier area for the 50 largest glacier systems in the Hunza basin in the Karakoram. Our results reveal a vertical precipitation lapse rate that equals 0.21 ± 0.12% m−1, with a maximum precipitation at an elevation of 5500 masl. We showed that the total annual basin precipitation (828 mm) is 260% higher than what is estimated based on interpolated observations (319 mm); this has major consequences for hydrological modeling and water resource assessments in general. Our results were validated by using previously published studies on individual glaciers as well as the water balance of the Hunza basin. The approach is more widely applicable in mountain ranges where precipitation measurements at high altitude are lacking.},
  author       = {Immerzeel, Walter Willem and Pellicciotti, Francesca and Shrestha, Arun B.},
  issn         = {1994-7151},
  journal      = {Mountain Research and Development},
  keywords     = {General Environmental Science, Development, Environmental Chemistry},
  number       = {1},
  pages        = {30--38},
  publisher    = {International Mountain Society},
  title        = {{Glaciers as a proxy to quantify the spatial distribution of precipitation in the Hunza basin}},
  doi          = {10.1659/mrd-journal-d-11-00097.1},
  volume       = {32},
  year         = {2012},
}