Abstract This study assesses the temporal changes of Swetvarn and Thelu glaciers between 1968 and 2019 in Rakvarn glacial valley of Bhagirathi basin. Here we utilized high-resolution satellite images of CORONA KHA (1968), LISS IV (2012) and SENTINEL-2 MSI (2019), along with medium resolution images of LANDSAT TM (1990) and SRTM (2000) to carry out the research work. Analytical viewed strongly convinced that the selected glaciers receding continuously with non homogeneous retreat rate since 1968. During 1968 to 2019 the snout of the Swetvarn glacier lost ∼623m total length with 12.21ma−1 retreat rate, while the snout of Thelu glacier lost ∼590m total length (11.56ma−1). Results further confirmed that about 16.60% glaciated area of Swetvarn glacier and 24.50% glaciated area of Thelu glacier also vanished completely between 1968 and 2019. During this tenure the ablation zone shows 160m upward shift for Swetvarn glacier and 145m for Thelu glacier respectively. Overall analysis explains that three climatic trends of Garhwal Himalayan region; (1) catastrophic variation between rainfall and temperature during 1960–1990, (2) gradual increase in temperature and decrease in precipitation, (3) increased liquid precipitation and decreased solid precipitation highly influences the process of melting of the study region.

中文翻译：

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1968 年至 2019 年间，印度加瓦尔喜马拉雅山 Bhagirathi 盆地 Thelu 和 Swetvarn 冰川的衰退模式

摘要 本研究评估了 1968 年至 2019 年间在 Bhagirathi 盆地 Rakvarn 冰川谷的 Swetvarn 和 Thelu 冰川的时间变化。在这里，我们利用 CORONA KHA (1968)、LISS IV (2012) 和 SENTINEL-2 MSI (2019) 的高分辨率卫星图像，以及 LANDSAT TM (1990) 和 SRTM (2000) 的中等分辨率图像进行研究工作。分析认为，自1968年以来，选定的冰川以非均匀后退率持续后退。1968年至2019年，Swetvarn冰川口部总长度减少约623m，后退率为12.21ma-1，而Thelu冰川口部减少约590m总长度 (11.56ma−1)。结果进一步证实，1968年至2019年间，约16.60%的Swetvarn冰川冰川面积和24.50%的Thelu冰川冰川面积也完全消失。在此期间，消融带分别显示 Swetvarn 冰川和 Thelu 冰川向上移动 160m 和 145m。综合分析说明了加瓦尔喜马拉雅地区的三种气候趋势；(1) 1960-1990 年降水与温度的灾难性变化，(2) 温度逐渐升高和降水减少，(3) 液体降水增加和固体降水减少，对研究区的融化过程影响很大。