IMPACT OF CLIMATE CHANGE ON GLACIERS: A CASE STUDY OF LUNANA REGION IN BHUTAN

Abstract

In the northern region of Bhutan, supra glacial ponds on some debris-covered glaciers in the 1950s have subsequently grown into moraine-dammed lakes. Also, pro-glacial lakes have expanded substantially as a result of retreat of glacier termini. Study discussed the evolution of these lakes in detail using maps, photographs, and satellite images. This explains about the climate change of Bhutan for last 15 years up till now and how it affects on the Glaciers on mountainous regions. It also tells about the formations of Glaciers and retreating rate of the Glaciers at the moment and the expansions of different Glacial lakes of Bhutan especially in Lunana region, and risk associated from potential of Glacier Lake Outburst Flood in low lying area and types of mitigations that are possibly can be provided. On top of that, it also explains the affects of climate change on glaciers and glacial lakes annually as well as seasonally have been observed. Firstly, the statistical methods were used to determine temporal trends and their spatial distribution of historical annual and seasonal precipitation and temperature series for the period of fifteen years. The method used for this, is Mann Kendall (MK), Non-parametric tests searches for detecting and assessing significant trend in climate time series, without specifying whether trend is linear or non-linear. The true slope (change per unit time) is estimated by using non-parametric procedure developed by Sen's slope (Q) Method. Secondly, the study stresses the importances of Methodologies were used for the assessment of Glacier retreat rate, expansion of Glacial Lakes rate. Assessment of Glaciers retreat and expansion of Glacial Lakes are being determined by using AcrGIS 9.3. The land use of whole watershed delineation area has been done using ERDAS imagine by observing the changes of glaciers and glacial lakes with time. Here the data were of four different years of Landsat images of 1990, 2001, 2007 and2009 and also the spot images of 2009 of which they are from almost the same months.