The Heilongjiang River is an important international boundary river. It runs through China, the former Soviet Union and Mongolia. From the source of the Hailar River, the Heilongjiang River is 4,370 kilometers long and has a total drainage area of ​​1.843 million square kilometers; the length within my country is 3,474 kilometers and the drainage area is 887,000 square kilometers. The length of the Heilongjiang River ranks third in my country, after the Yangtze River and the Yellow River. The total annual runoff reaches 270 billion cubic meters, second only to the Yangtze River and the Pearl River, and also ranks third in the country.