All chapters:

Introduction

Climate

Waters and water management

Ecosystems and ecoregions

Species diversity and use of biological resources

Nature conservation: econet and protected areas

Countries & cultures

Economy

Land use

International policy

Waters and water management

Amur is one of largest rivers of the world some 4,5 thousand kilometers long. At approximately two million square kilometers, it is also the world's eleventh largest watershed. (see comparative table)

The Upper Amur-Heilong Basin includes the Mongolian headwaters and Argun/Erguna River basin, the main stem of which flows for more than 900 kilometers and forms the China-Russia border. Western part of the basin has thousands shallow steppe lakes, which fill and dry in the course of drought cycle.
The main stem of the Amur-Heilong River proper that flows to the east from Great Hinggan Mountains is often referred to as a river of three reaches, Upper, Middle, and Lower. The Upper and Middle Amur are shared by Russia and China. The Lower Amur lies completely within Russia and stretches 947 km from the mouth of the Ussuri River to the estuary of the Amur-Heilong River emptying into Tartar Straits. The largest tributaries of the Amur-Heilong River are the Zeya (Russia), Bureya (Russia), Amgun (Russia), Songhua (China), and Ussuri/Wusuli (China, Russia). The Upper and Middle Amur and lower reaches of all tributaries have wide well-developed floodplains with numerous floodplain lakes connected to main river channels.
Main channel of the Amur River proper so far has no dams and reservoirs, among main tributaries only Zeya, Bureya and Songhua rivers are obstructed by dams.

The Amur River average annual discharge into the Pacific is 364 km³ (Makhinov 2005) and this enormous flow (equal to 77% of the Mekong River and 7 times greater than the Yellow River) carries 15-24 million tons of sediments, for an average of 55 g of sediment per m³ of water. On first impression the Amur-Heilong seems quite clear, despite considerable water pollution and other human impacts. The average sediment load in the Amur-Heilong is similar to that of the Congo (heavily forested) or the Columbia River (intensively dammed), but is only 0.15% of the average sediment load in the world's most sediment-laden river, China's Yellow River (36 kg/m³).

Despite large discharge at the river mouth, many parts of Amur River basin are water-deficient drought-prone areas, and southern part of the basin is subject to very intensive water management and water infrastructure development. Water resources are limited and their sustainable use depends on cooperation between three basin countries.

Since basin is divided between countries this river system is not sufficiently studied even by hydrologists. No agreement is reached among experts regarding the exact size of the Amur basin. The western and southwestern reaches of the basin in China and Mongolia have numerous endorheic rivers, rivers that drain into closed inland wetlands or lakes, rather than into the main river system. Other partly endorheic basins drain into the Amur-Heilong only in wet years and some have stopped flowing entirely due to human water consumption. For these reasons, authors estimate the total watershed area differently. The most common estimates of the basin's area are 1.86 million km² in official Russian sources (Surface water resources of the USSR. Hydrology. 1966), and 1.93 million in many international sources (IUCN/WRI World Watersheds eAtlas 2005). We consider Kherlen, Khalkh, and Uldz Rivers and some other closed basins to be important intrinsic components of the Amur-Heilong basin ecosystem(see map). When considering these headwaters, the estimated basin area is at least 2,129,700 km².