The storm is heavily influenced by the monsoon, it has obvious seasonal variations. The torrential rains in the northeast of China are concentrated in July and August. The heavy rain most occurs in July and August in Liaoning, Heilongjiang and Liaoning provinces. The ratio of regional rainstorms in three provinces is 82%, 88% and 93 %. Local rainfall concentration is relatively small, 68%, 74% and 75% are respectively in three provinces. From the above proportion, the concentration of rainstorm has a tendency to focus to north. In addition, the local rainstorm in July is more than in August, but regional rainstorm and extra-large rainstorms in August are more than in July.
The starting time of the rainstorm in Lvshun station was occured by rainfall in March 24th in 1918. In general, Liaoning province mostly began in April. Jilin province mostly began in the first-June and mid-June. Heilongjiang province mostly began in mid-June and late-June .
The termination of rain is usually occurred in late-August in the middle of Heilongjiang province. Northeast and west always occurred in the early and mid September. The end time of individual stations can be delayed until October. Heavy rains in most parts of Jilin province ended in early and mid September. A few stations in the western plains and the eastern mountain ended in late August. Parts of the border with Liaoning province and the upper reaches of the Tumen River ended in early October. Individual years are even postponed until mid November. Heavy rains in most parts of Liaoning province ended in mid September to late October. Torrential rain in the northeast region has been terminated in Yanji and Hunchun areas in Jilin province, there was a local rainstorm on November 12, 1964. The earliest period of the storm was July 6, 1978, at Heihe station in Heilongjiang province. About the rainstorm, the northwestern region of Heilongjiang province began in July , ended in August , with minimum rainfall period . Tumen river, yalu river, middle and lower reaches of Liaohe River, the storm began in April and ended in October and November , the rainstorm lasts between 180 and 200 days .
The annual changes of heavy rainfall
According to the strategic to the data of heavy rainfall in Heilongjiang and Liaoning province , paint the the annual changes of heavy rainfall curve in the north of the northeast (represented by Heilongjiang province) and southern (represented by Liaoning province) , and make variance analysis , we got that there are five, seven, two and 11 years of heavy rainfall cycle in the northeast region.
The Heilongjiang province in the north , there were heavy rainfall in the 1960s and early 1970s . There was less rain in the middle and late period of 70s , and became more in 80s . Liaoning province in south had more rain in the late 1950s and early 60s , the heavy rain became less in the late 60s to the early 70s , and there is an increasing trend in late 70s . According to previous information , for the occurrence of heavy rain , the south is a few years ahead of the north . The middle and lower reaches of Liao river , Hun river , Taizi river in Liaoning province and the second Songhua river and Huifa river in Jilin province has occurred torrential rain in 1995 . Three years later, in 1998 the heavy downpours in the Nenjiang river basin in the north of the northeast also reflect this feature .
The information is provided from Disaster Risk Reduction Knowledge Service.
Comment list ( 0 )
