There are three major trunk railway lines connecting the province with other parts of China. Main roads in service cover more than 46,000 kilometres. The province has nine civil airports and air services link the province to Beijing, Shanghai, Guangzhou and other cities. The international airport offers direct flights to Hong Kong, Japan, Bangkok, Singapore, Rangoon, and Chiang Mai. There are also regular flights to Hong Kong. There are more than 600 rivers, with total water power resources of up to 104 million kilowatts, ranking the province second in the country.