Publications

Mir, Riyaz Ahmad; Jain, Sanjay K.; Saraf, Arun K.; Goswami, Ajanta (2015). Accuracy assessment and trend analysis of MODIS-derived data on snow-covered areas in the Sutlej basin, Western Himalayas. INTERNATIONAL JOURNAL OF REMOTE SENSING, 36(15), 3837-3858.

Abstract
Snow is important for hydrological studies and is a variable very sensitive to climatic variations. In the present study, the variability of snow-covered areas (SCAs) obtained through Moderate Resolution Imaging Spectroradiometer (MODIS) snow data products was analysed using the Mann-Kendall test and Sen's slope estimator in the Sutlej basin, Western Himalayas, India. However, due to the limitations of long time-series snow cover data, the study has been carried out for a time period from 2000 to 2009. Before trend analysis, the estimated SCA was validated using the ground-based snowfall data. A simple linear regression test was applied to analyse the relationship between the variation in SCA and snowfall. The relationship between the mean annual snowfall and SCA indicated a highly significant correlation (R-2 = 0.95). In order to have a better insight into the relationship, the regression test was also carried out for six elevation zones. The coefficient of determination (R-2) varied from 0.78 at the 1500-2000 m asl zone to 0.96 at the 3000-3500 m asl zone. The trend analysis indicated reduction in SCA with significant negative behaviour for annual, winter, and post-monsoon seasons and for November and December months. The negative trend was observed for an elevation of <2500 m asl in the basin. Moreover, during the same period (2000-2009), the temperature (T-max and T-min) increased while there was a decrease in snowfall. The trend analysis of temperature from 1984 to 2009 revealed positive trends with significant trend in T-min as determined by using the Mann-Kendall statistical test. The reduction in SCA was, therefore, attributed to the increasing trends in temperature, particularly T-min, associated with reduction in snowfall. These SCA variations have significant implications for water resources managers in the area as some of these observed trends, if continue, may result in changes in hydrological/ecological balance of the Sutlej basin.

DOI:
10.1080/01431161.2015.1070320

ISSN:
0143-1161