Sumdorong Chu


Sumdorong Chu, referred to as Sangduoluo He in the Chinese media, is a tributary of the Nyamjang Chu river that flows along the disputed Sino-Indian border between the Cona County of Tibet and the Tawang district of Arunachal Pradesh. It orignates in the Tokpo Shiri Glacier on top of the eastern watershed range of Nyamjang Chu, and flows down to join Nyamjang Chu after over a distance of 7–10 kilometres. Its junction with Nyamjang Chu is to the north of that of Namka Chu, another contested river valley, by about two kilometers.
The Sumdorong Chu valley was the site of another standoff between India and China in 1986–1987 which, despite giving rise to the fears of another war, was successfully deescalated. Subsequently, India and China formulated agreements for managing future border tensions.

Location

Sumdorong Chu flows in a disputed border region between Tibet's Cona County and Arunachal Pradesh's Tawang district. The dispute arises due to differing interpreations of where the McMahon Line lies.
China adheres to the 1914 map of the McMahon Line, which shows the border as a straight line at 27°44'30" N latitude till the range of "Menlakathong La". India believes that the true border lay along the highest watershed line in the region, which runs along the northern watersheds of Namka Chu and Sumdorong Chu streams.

1987 standoff