Climate Variability and Change—Hydrological Impacts (Proceedings of the Fifth FRIEND World
Conference held at Havana, Cuba, November 2006), IAHS Publ. 308, 2006, 473–478.
An assessment of the potential impacts of climatic
warming on glacier-fed river flow in the Himalaya
H. GWYN REES1,2
&
DAVID N. COLLINS2
1 Centre for Ecology and Hydrology, Wallingford, Oxfordshire OX10 8BB, UK
hgrees@ceh.ac.uk
2 Alpine Glacier Project, University of Salford, Greater Manchester M5 4WT, UK
Abstract A regional
hydro-glaciological model has been developed to assess the potential impacts of
climatic warming on glacier-fed river flows in the Indus and Ganges basins. The
model, applied at a 20 km ´ 20 km
grid resolution, considers glaciers contributing runoff to a cell as a single
idealized glacier that is allowed to recede through time. Using 1961–1990
climate data as input, “baseline” flow estimates were derived for every stretch
of river in either basin. A transient warming scenario of +0.06°C year-1
was then imposed for 100 years from an arbitrary start-date of 1991. Comparison
of results at 10 sites in two representative areas suggest the impacts of such
climatic warming are similar regionally, with estimates of future decadal mean
flows continually increasing at 1–4% per decade, relative to baseline, at most
sites considered. Flows peaked at only two of the sites several decades into
the model run.
Key words regional hydro-glaciological model;
climatic warming; river flow; Himalaya