!Lower Dibang Valley Lower Dibang Valley is a district in Arunachal Pradesh in India. It is bounded on the north by the Dibang Valley district, on the East by the Lohit district and Mc Mohan Line, on the west by the eastern and Upper Siang districts of Arunachal Pradesh and on the south by the Tinsukia district of Assam. The headquarters town of this district is Roing. The district was carved out of the un-divided Dibang Valley district at its headquarter at Roing with effect from 16th December 2001. The district is named after the River Dibang. Area of this district is about 3900 sq km. Population of the district as per census 2011 was 53,986. There are three sub-divisions, three community blocks and 127 villages in the district.