It is located on the river of the same name (Nen River), which also forms part of the provincial border with Inner Mongolia, more than 200 kilometres (120 mi) southwest of the urban area of Heihe.Land area 15,360 square kilometres (5,930 sq mi), population 500,000.Under the name Mergen or Merghen (墨爾根, Mò'ěrgēn), Nenjiang was the provincial capital and seat of the military governor of Heilongjiang Province in 1690–1699.[1] Nenjiang has a monsoon-influenced humid continental climate (Köppen Dwb), with long, harsh, but dry winters, and short, very warm summers.[5] 2 Formally part of Oroqen Banner in Inner Mongolia but administered de facto by Daxing'anling Prefecture in Heilongjiang.