Chinese History and Statistics -- Page 10
Temperatures also vary considerably from north to south and between summer and winter. In winter the isotherms, or lines connecting points of equal temperature, are remarkably regular in their east-west alignment. Average January temperatures are below freezing throughout the north and west, but they rise steadily southward to an average of 9 deg C (40 deg F) at Wuhan to 16 deg C (60 deg F) at Guangzhou. China's summer temperatures are more uniform, with isotherms running in a north-south direction. Average July temperatures are above 20 deg C (70 deg F) in most of China and decrease toward the western highlands. The annual temperature range between summer and winter increases from 9 deg C (15 deg F) in Hainan, an island province in the extreme south, to more than 27 deg C (80 deg F) in northern Manchuria.
Drainage (Part 1)
China's rivers carry about 2,800 cu km (670 cu mi.) of water to the sea every year, amounting to 40% of Asia's total annual runoff. By far the largest system is the Pacific Ocean drainage basin, which covers about 5,400,000 sq. km (2,100,000 sq. mi.). Five major river systems lie within this basin, the Amur, Huang He, Huai He, Chang Jiang, and Zhu Jiang. The Amur has a total length of 4,700 km (2,900 mi.) and is joined by the Songhua and the Wusuli rivers. The Huang He is 4,800 km (2,980 mi.) long and has a basin area of 772,000 sq. km (298,000 sq. mi.). It rises from the Tibetan highlands and eventually enters the North China plain, where its bed is enclosed on both sides by dikes. The Huai He is 1,100 km (680 mi.) long and drains a basin area of 210,000 sq. km (81,000 sq. mi.). The Chang Jiang, China's principal river, is 5,990 km (3,720 mi.) long and drains a basin of 1,800,000 sq. km (700,000 sq. mi.). The Zhu Jiang, the most southerly of the five rivers in the Pacific drainage basin, is a composite river consisting of Xi Jiang, Bei Jiang, and Tung Jiang, which converge close to the outlet into the sea. The Zhu Jiang drainage basin covers 448,000 sq. km (173,000 sq. mi.).