Climatic rivers in the southeast coastal hills

This area belongs to subtropical humid monsoon climate. It is characterized by maritime climate. Average annual temperature in most areas15 ~ 24℃; 1 The monthly average temperature is 3 ~ 18℃, and the July average temperature is 24 ~ 29℃. The active accumulated temperature above 10℃ is 4700 ~ 8000℃, and the duration is more than 170 days, reaching 300 days in the south. Crops can be harvested twice to three times a year, and double-cropping rice can be planted in most areas. The annual precipitation 1200 ~ 2000 mm, and the precipitation distribution increases from southeast to northwest. Due to the influence of topography, there is more rain on windward slope and less rain on leeward slope.

The source of the river is short and urgent, and it flows into the sea, forming a pluralistic water system. The density of water network is high, with an average of 0. 1 km per square kilometer; Abundant runoff, with an annual runoff of 62.366 billion cubic meters, much larger than the Yellow River.

Cold wave and typhoon rainstorm are the main disastrous weather in this area. In normal years, there is only frost and snow in the north of this area, but if there is a strong cold wave, the temperature will be below zero. This area is the most frequently and strongly affected by typhoons. The typhoon came, followed by strong winds and heavy rain. The rainstorm intensity is high, with the daily precipitation in Puning, Guangdong reaching 619 mm (196010/0/0/7), and Fuqing, Fujian, with an even greater daily precipitation of 737 mm (122 June 974).