Glacial-fluvial Dynamicsand Landform Evolution in Upper Beas BasinIntroduction: Glacio-fluvial phenomena like; glacial retreat, glacial brust,glacial lake outburst flood (GLOF) avalanche ,alluvion,and so on, can have disastrous consequences upon the society over short time scale(minutes,hours,days)with discharge rates of over 30000 Cumec covering within 200 km running distance (Reynolds,Richardson,2000). As glacier contain the largest reservoirs of the fresh water source. There are about 30 million Cubic km ice on our planet, which covers almost 10 percent of the world’s land area. In addition, during northern hemispherical winter, snow covers almost 60 percent of land. Available data indicates that during the Pleistocene era (during last Ice Age) the earth had experienced 46 million square km land under ice (Embelton&King, 1975). Which is more than three times the present ice cover of the earth. Evidance suggest that glaciers are constantly decreasing in size with the time & this change can profoundly affect the runoff &fresh water resources. Increasing green house effect can further accelerate the glacier depletion &man induced change in the environment. The Intergovernmental Panel on Climate Change (IPCC) of UN in 2001 has suggested that an increase in global temperature by 0.6 (+/-0.2) degree centigrade occurred during the last century. Given the present trend of global warming which has caused wide scale retreat of mountain glaciers the possibility of scarcity in water resources is but a reality.Cause for the Study: Water is the basic need of human being & will continue. At the same time in the present century the problem of global warming & resultant glacio-fluvial phenomena are not going to diminish but going to more ferrous. So to reach the dire need of future water resources and to minimize the rate of glacio-fluvial hazards, we need to work both on the structural and nonstructural stages. Considering the fact, this research “Glacio-fluvial Dynamics Causes and Consequences in the North West Himalayas”
has reasonable significance, as over a half billion of population of India is directly or indirectly dependent on the rivers that originate from the North West Himalayan Glaciers. There are over 5000 glaciers in the Himalayas and total glacier volume is approximately 2337 Cubic km and water equivalent of glacier ice as2033 Cubic km (Bhuguna, Ishamohan, 2000). Therefore any fluctuation; positive or negative, will cause disastrous consequences on population as well as on the anthropogenic activities in the Himalayan forefields.
During the last century the entire length of Himalayas witnessed glacier frontal retreat. For Instance, Gangotri glacier, since 1956 has noticed more than 1.5km frontal retreat. Such retreat has change the hydrological regime, ground water table of all the glacier fed rivers, and can cause scarcity of water resources, and can change the agricultural land as wasteland by unsorted sediment deposition. Hence the study will provide a comprehensive, synoptic, multi temporal assessment of the risk and magnitude and will also help in identifying the vulnerable aspects and their respective zones. Finally it will provide appropriate strategies for mitigation of the problems.Hypothesis:
(1) Glacial retreat, result into increased discharge rate causing deep gorges.(2) Positive mass balance (increase in ice volume) will result in a decreased fluvial discharge, thus less erosive regime of river and increased glacial processes.(3) A sharp negative mass balance (decrease in the ice volume) will cause floods such as GLOFs and thus result into extensive out wash plain. Objective:
1To map the various glacio-fluvial landforms formed by the past processes in the Upper Beas Basin.2 To measure the magnitude of processes on the base of terraces, out wash plain and gorges in the Upper Beas basin. 3 To assessthe social-economic implication of the glacio-fluvial landforms.4 Finally to assess the future behaviour of the landforms in the upper Beas Basin.Data Base:
1 Survey of India (SOI) Topographical Sheets on 1:50,000 scale2 Satellite Imageries (IRS/Cartosat Series) 3 Published research papers and articles.Methodology:
1 Determination of climate change based on temperature and rainfall data.2 Determination of past Equilibrium Line Altitude (ELA) based on SOI topo sheets surveyed mainly during 1950s&60 and terrestrial records. 3 Temporal changes in snout position based on topo sheet, landforms, and historical records.4 Calculations of present ELAs based on satellite imageries and landforms records.5 Analysis of discharge data, ground water table data.