Middle Amur Lowland

(also Amur-Sungari Lowland), a low-lying region in the southern part of Khabarovsk Krai, USSR, and in northeastern China, where it is known as the Sanchiang Plain (seeSANCHIANG PLAIN). The lowland, which is 670 km long and 100–200 km wide, occupies the depression between the Si-khote-Alin’ Mountains in the east, the Khingan-Bureia Mountains in the northwest, and the East Manchuria Mountains in the south. It is drained by the middle course of the Amur River and the lower courses of the Sungari and Ussuri rivers. The land is flat and marshy with occasional low insular ridges (Khekhtsir, elevations to 949 m). The region has a monsoonal climate, with a warm, rainy summer and a severe, relatively snow-free winter. The summer monsoon and autumn typhoon rains cause vast flooding. Sparse Darhurian larch taiga alternates with swamps; in the south there are Manchurian-type coniferous-broadleaf forests. The city of Khabarovsk is located in the center of the lowland.