Heilongjiang is one of China's water-rich provinces. Its numerous rivers form five water systems, including that of the Heilong River, Wusuli River, Songhua River, Nenjiang River and Suifeng River. Presently, there are about 6,000 lakes and reservoirs, covering a surface area of more than 800,000 hectares. About 70% of its rainfall concentrates in the warm season, providing an ideal environment for all the plants and crops to grow.