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Abstract
Snow cover area (SCA) is an important component of the solid water reservoir in the catchment. The study of snow trends is essential for managing water resources and for understanding regional climate change. Changes in the snow budget have socioeconomic and environmental implications for agriculture, water-based industries, environment, land management, water supplies; and many other areas related with snow melt water resources. To date, however, only a few scientific studies are available to analyze the Upper Indus Basin (UIB). The basic objective of this study was to map the change assessment of SCA of UIB in 2003 and 2013. Moderate Resolution Imaging Spectroradiometer (MODIS) satellite data were retrieved for the period of 2003 and 2013. Three different digital image processing techniques, including normalized difference snow index (NDSI), satellite image classification and band threshold values were applied to assess the SCA. The results show that snow accumulation typically starts from the beginning of October and continues up to mid of March. From end March, the snow starts melting until it is reduced to a minimum in September. A comparison of snow cover of 2003 and 2013 clearly indicates that the snow accumulation period has shifted and anomaly was observed in the start of November. In 2013, snow cover decreases by almost 49% area during the period 30 Sep to 15 Oct, whereas it increases by 133% area in the first sixteen days of November i.e. 1-16 Nov, as compared to the year 2003. Overall, the correlation between the year 2003 and 2013 SCA is found to be 0.87, which is highly positive correlation.
Keywords: Snow cover; MODIS data; NDSI; Upper Indus Basin; Climate change.
1. Introduction
Seasonal snow cover is a main water resource in arid and semi-arid regions (Gurung et al., 2011). Over one-sixth of world population depends on seasonal snow and glacier melt water for water supply (Barnett et al., 2005). Pakistan is an agriculture based country and its economy is mainly dependent on its agriculture. The agriculture of Pakistan is highly dependent on the Indus irrigation system. The Indus River is one of the major water carriers of South Asia emerging from the Tibetan Plateau and the Himalayas. Tarbela is the first major structure on the Indus River for storage...