Discharge and suspended sediment in the meltwater of Gangotri Glacier, Garhwal Himalaya, India

Abstract

Discharge and suspended sediment were measured throughout the ablation seasons between May and October 1999 and 2000 in the proglacial stream that drains the Gangotri Glacier into the Ganges River basin. During the observation periods in 1999 and 2000, the total discharge volume was estimated to be 581.87 and 547.47 x 10 6 m', respectively, and the total suspended sediment was 165.62 and 104.99 x 10 4 t, respectively. The lower discharge and suspended sediment in the 2000 season are in response to lower snow and glacier icemelt. A large part of the total discharge volume and suspended sediment was contributed between July and September when solar radiation is strong. Marked variations were noticed in the mean daily discharge and suspended sediment concentrations in different months under the influence of seasonal flushing events during both the study years. However, the mean daily discharge and suspended sediment concentration are more loosely correlated on the seasonal scale in 2000. The rate of decline of suspended sediment is much greater than that of the discharge in both years. Key words meltwater discharge; suspended sediments; discharge volume; Gangotri Glacier; Garhwal Himalaya; India Débits et matières en suspension dans les eaux de fonte du glacier de Gangotri, Himalaya du Garhwal, Inde ' échelle de la saison pour 1 ' année 2000. Le taux de décroissance de la teneur en matières en suspension est bien plus élevé que celui des volumes écoulés pour les deux années.Mots clefs débits de fonte; matières en suspension; volumes écoulés; glacier de Gangotri, Inde

Suspended sediment from the Gangotri Glacier: Quantification, variability and associations with discharge and air temperature

“…2 In other words, SSC was found to be dependent on the amount of meltwater draining from the glacier, which in turn depends on the prevailing air temperature. So, fluctuation in air temperature or cloud cover was found to affect the pattern of SSC in meltwater (Shcheglova and Chizhov, 1981;Kumar et al, 2002). A sudden decrease in flow from 6 September to 13 September 2002 was due to extremely bad weather conditions such as high rainfall (222.8 mm) and low air temperature 3.8 8C.…”

“…It is estimated that the present sediment yield of the Ganga-Brahmaputra Rivers system together is about one billion tonnes per year (Subramanian, 1993) in comparison to the global annual sediment of 15 billion tonnes per year (Milliman and Meade, 1983). According to Maybeck (1976), three major Himalayan Rivers, namely the Brahmaputra, the Ganges and the Indus carry about 9% of the total annual load from the continents to the oceans worldwide Most of the Himalayan glaciers are debris covered (Bishop et al, 1998) and the rivers originating from these glacierized areas transport sediment at a very high rate (Bruijnzeel and Bremmer, 1989;Hasnain, 1996;Hasnain and Thayyen, 1999;Kumar et al, 2002;Singh et al, 2003). The geologically young age of the Himalayan mountain system, which is undergoing fast uplift and has large and active glaciers, supports the high sedimentation (Hasnain and Chauhan, 1993).…”

Particle size characteristics of suspended sediment transported in meltwater from the Gangotri Glacier, central Himalaya — An indicator of subglacial sediment evacuation

“…Research has shown that most Himalayan glaciers are debris covered (Bishop et al, 1998;Shroder et al, 2000), which can impact ablation and meltwater production. Nevertheless, during summer months the snow and glacier meltwater runoff transports suspended sediments along englacial, supraglacial, and subglacial pathways at very high rates (Derbyshire, 1984;Li et al, 1984;Bruijnzeel and Bremmer, 1989;Owen and Derbyshire, 1989;Hasnain and Thayyen, 1999;Benn and Owen, 2002;Kumar et al, 2002). It is of vital importance for understanding glacier dynamics and sediment evacuation patterns (Swift et al, 2005;Haritashya et al, 2006a), reservoir analysis (Morris, 1995;Jain et al, 2003), hydrological modeling (Hannah and Gurnell, 2001;Hock, 2003;Singh et al, 2008), hydroelectric power generation (Bezinge et al, 1989;, irrigation (Butz, 1989), and so forth.…”

Glacier systems and seasonal snow cover in six major Asian river basins: hydrological role under changing climate

“…Case studies from single glaciers in the HKH region, although few in number (Fujita and Nakawo 1997;Fujita et al , 2001aBhutiyani 1999;Mihalcea et al 2006;Mayer et al 2006;Kumar et al 2002;Tangborn and Rana 2000;Swaroop et al 2001;Hasnain and Thayyen 1999;Thayyen et al 2007;Thayyen and Gerdan 2010), are suitable for calculations of specific glacier runoff rates.…”