Future Sustainability Challenges in Hindu Kush-Himalaya - Impact of Global Changes on Mountains: Responses and Adaptation - page 235

Figure 10.6. Predicted percentage of glacial melts contributing to basin fl ows in the Himalayan
basins (Data from Xu et al. 2008. Shape fi les superimposed on background image from ESRI
ArcGlobe 10.0 from UNEP 2012a).
Color image of this figure appears in the color plate section at the end of the topic.
￿ The climate of the HKH is not uniform and strongly infl uenced by
the South Asian monsoon and the mid-latitude westerlies. Glacial
meltwater has relative importance to the basins' hydrology (NAS 2012).
￿ If all the Himalayan glaciers were to disappear, there would be about
a 33% reduction in annual fl ow in the west, whereas the decline in the
east would be only about 4-18% compared to the 1990 levels (Rees and
Collins 2006).
￿ Precipitation has direct infl uence on Himalayan glacier catchment (the
catchments where the glacier melt water contributes to the river fl ow
during the period of annual high fl ows produced by monsoon) rather
than mass balance changes of the glacier (Thayyen and Gergan 2010).
￿ Glacial melt contribution is minor in monsoon dominated catchments
of the Ganges and Brahmaputra (Kaser et al. 2010).
￿ Precipitation dominates inter-annual runoff variation in a Himalayan
glacier catchment (Thayyen and Gergan 2010).