Comparative Analysis of Different Remote Sensing Techniques for Mapping of Supraglacial Lakes on Hispar Glacier

The glacier changes are very significant in quantifying the direct effects of climate change. The glaciers inthe northern Pakistan especially in the Karakoram pose a large change in relief and are difficult to access due tocomplex topography. The global WOS (Web of Science) database indicate only a few studies conducted so far in thisregion in the domain of climate and cryosphere. The studies relating to glacial hazards in this region are even less. Thisstudy involves the mapping of supraglacial lakes on Hispar glacier using multiple remote sensing methods. Theaccuracy of results from those methods is discussed. Remote Sensing and GIS techniques have been applied to timeseries of Landsat images of years 2017, 2016, 2010, 2000 and 1990 (in the descending order) to quantify thesupraglacial lakes on the Hispar glacier. The remote sensing techniques include Band Rationing, Normalized WaterIndex (NDWI), Classification i.e. Unsupervised and Panchromatic Sharpening Image Enhancement Technique for theyears of 2017 and 2016 imageries. After defining the Hunza basin (involving of high resolution DEMs), all the satellitederived imageries have been preprocessed and processed. GIS tools have been used to calculate the areal extents ofyearly obtained supraglacial lakes and compare temporally with passing years, which in turn gave an accuratecomparative analysis among different remote sensing techniques. The satellite derived time series map layouts of eachtechnique have been formulated. The vulnerable supraglacial lakes on Hispar glacier of areal sizes ≤ 0.05 sq.km havealso been identified and delineate

Seasonal and spatial patterns of SST in the northern Arabian Sea during 2001–2012

Ocean–atmosphere interactions have been increasingly acknowledged to play an important role in climate change. It is necessary to understand ocean behavior, including the sea surface temperature (SST) that is a basis for initiating atmospheric models and climate change studies. In this paper, we analyze the spatial and temporal patterns of SST using monthly MODIS data of 2001–2012 from north Arabian Sea (11.9–25.68 °N, 56.7–75.03 °E). Seasonally, four phases of SST have been observed namely warming, cooling, warming and again cooling. Further, an empirical statistical model was fitted to the observed data that describes the annual SST pattern with significant accuracy