Sanjiang or Three rivers plain in Heilongjiang, vast wetland watered by Heilongjiang 黑龍江|黑龙江[Hei1 long2 jiang1] or Amur, Songhua 松花江[Song1 hua1 jiang1], Ussuri 烏蘇裡江|乌苏里江[Wu1 su1 li3 jiang1]