Effect of warmer climate on the depletion of snow-covered area in the Satluj basin in the western Himalayan region

Abstract

The effect of warmer climate on the depletion of snow-covered area has been evaluated for the Satluj River basin located in the western Himalayan region in India. Snowmelt runoff contributes substantially to the annual streamflow of this river. In order to study the impact of three warming scenarios (T+1, T+2 and T+3°C), more than 160 new snow depletion curves were prepared for different elevation zones of the basin over a study period of nine years (1985/86-1990/91 and 1996/97-1998/99). For each zone, the relationship between the cumulative melt and snow-covered area was established and used to obtain the snow depletion curves under warmer climate. Projected snow depletion curves at the basin scale were derived by synthesizing the effect of warming for all zones. Warmer climatic conditions accelerate the melting of snow resulting in faster disappearance of seasonal snow cover from the basin. For the study basin, acceleration in depletion of snow-covered area is computed to be 20, 31 and 40 days for T+1, T+2 and T+3°C scenarios, respectively, by the end of the ablation season. The impact of warmer climate on accelerating the depletion of snowcovered area is found to be higher in the early and late parts of the ablation season. The consequences of faster disappearance of snow from the basin are discussed in terms of the hydrology and climatology of the basin.

Basin-wide assessment of temperature trends in northwest and central India / Estimation par bassin versant de tendances de température au nord-ouest et au centre de l'Inde

“…Variations in the hydrological components will have a direct influence on the available water resources, demand and supply, water quality, soil moisture, groundwater reserves and frequency of floods and droughts in a basin. Hydrological and water resources studies are carried out at the basin scale (Mirza et al, 1998;Singh & Bengtsson, 2003. Therefore, information on climate change at the basin scale is of utmost importance for the planning, development and utilization of water.…”

Climate change prediction over complex areas: spatial variability of uncertainties and predictions over the Pyrenees from a set of regional climate models

“…Moreover, the rivers in the area are highly influenced by the snow (López-Moreno and García-Ruiz, 2004). Numerous studies have suggested that the impact of climate changes on hydrology will be especially pronounced in snow-fed basins (Singh and Bengtsson, 2003;Barnett et al, 2005), such as the headwaters located in the Pyrenees.…”

Investigating the Performance of Snowmelt Runoff Model Using Temporally Varying Near-Surface Lapse Rate in Western Himalayas

“…Figure 2 shows the flow-diagram of the followed approach. SRM simulations are carried out in two ways: (i) with the annually constant value of LR taken as 0.65C/100 m, the most commonly used value of LR [6][7][8][9] and (ii) with the monthly varying values of near surface LR. For both runs, calibration has been done for 2001 and 2002 and the validation done for 2004 and 2005.…”

“…Two widely adopted snowmelt computation approaches are the temperature-index based and energy-budget based methods. However, due to the large extent and difficult accessibility of high mountainous terrain in Himalayas, most studies in the Himalayan basins have focussed on the temperature-index (T-index) based methods [6][7][8][9] . The T-index based approach, also known as the degreeday approach is a simple approach that assumes empirical relationship between air temperature and snow or ice melting rates 10 .…”

“…Most T-index based studies in Himalayan basins [6][7][8][9] have employed an annually constant value of 0.65C/ 100 m as the lapse rate parameter, which is, as mentioned earlier, a spatio-temporally average value of environmental lapse rate and not representative of the local terrain and climatic conditions. Such simplistic employment of models with constant parameters may lead to lower accuracy and larger uncertainties of the results 18,19 .…”