Observation of Snow Cover Variations at Mt. Kilimanjaro Using Landsat TM and ETM+ Images

Since the industrial revolution began, CO2 levels have been increasing with climate change. The objectives of this study are to quantitatively analyze snow cover area and distribution according to height changes with respect to time and to statistically predict the date of snow cover disappearance using remote sensing data over Mt. Kilimanjaro, Tanzania. Total numbers of 23 Landsat-5 TM and Landsat-7 ETM+ images are used for observing the snow cover variation, spanning the 27 years from June 1984 to July 2011. For this observation of snow cover variations, the following steps are applied: 1) atmospheric correction is performed on each image using the cosine approximation (COST) atmospheric correction algorithm, 2) the snow cover area is extracted from the normalized difference snow index (NDSI) algorithm, 3) the minimum height is determined using SRTM DEM and extracted snow cover area, and 4) the date of snow cover disappearance is predicted using a linear regression model. Among 23 images, seventeen images of the dry season are used for analyzing snow cover changes. Results show that snow cover area for about 30 years are largely changed from 9.01 km2 to 2.54 km2, equivalent to a 73% reduction. The minimum height of snow cover increased by approximately 290 m, from 4,603 m to 4,893 m. Linear regression model result shows that the snow cover area decreased by about 0.34 km2/yr and the minimum height of snow cover increased by about 9.85 m/yr. Moreover, L-band synthetic aperture radar (SAR) images are used to analyze seasonal variation of snow cover from 2006 to 2011. The results indicate that snow cover area of Mt. Kilimanjaro has fast decreased according to global warming. *This work was researched by the supporting project to educate GIS experts; Distribution of elevations for snow-covered area: (a) 24 Jun. 1984 and (b) 21 Jul. 2011 ; Changes of snow-covered area with respect to surface elevation: (a) 24 Jun. 1984 and (b) 21 Jul. 2011