June 3, 2013
The headwaters of the Zayul Chu River is a series of glaciers. This river becomes the Lohit River as it enters India. The impact of glaciers is visible just from the color of the water, the greenish tone being generated from glacier flour. The Lohit River is also the focus on a hydropower development plan that proposes six dams that would generate 7450 MW.
Glaciers at the Headwater of Zayul Chu noted by red, yellow and purple arrows.
Here we examine three glaciers that have seen lake expansion at the terminus in the last 25 years using satellite imagery from 1987, 1996, 2009 and 2011. In 1987 there was no lake at the end of the glacier ending at the purple arrow. In 1987 the glacier ending at the red arrow, ended in a narrow lake. At the yellow arrow the glacier ended in a small round lake in 1987. By 1996 the glacier at the red arrow has retreated leading to a lake that is 100 m longer than a decade before. The glacier at the yellow arrow has pulled from the lake it had ended in. In 2009 a small lake has formed at the end of the glacier with the purple arrow, a distance of 200 m. The glacier at the red arrow has retreated from the lake it had formerly ended in, a distance of 400 m. The glacier at the yellow arrow has retreated 200 m from the lake it had ended in. Each of these glaciers ends between 4200 and 4600 m and begins above 5300 m. The glaciers retain snowpack on the upper reaches each summer and will continue to retreat but can survive current climate. The retreat of the Zayul Chu headwaters glaciers parallels those of the Bode Zangbo Headwaters a short distance to the north and the Hkakabo Razi Glaciers a short distance south.
1987 Landsat image