The Temporal And Spatial Symmetry And Trend Judgment Of Landing Typhoons In The Southeast Coastal Land Area

Typhoon is one of the most common natural disasters in southeast coastal region of China,every summer typhoon hit the southeast coastal region.Typhoon has brought huge losses to the local people's life and property safety.Industrial,agriculture and transportation have been attacked by typhoon.Thus,it is important to research the spatial and temporal variations of landing typhoon in southeast coastal area and symmetry statistical in order to better plan for a sustainable future.This paper used climate tendency rate method,correlation coefficient method,multiple linear fitting,abnormal degree calculation and Kriging difference method,analyses the spatial-temporal variations of climate background during 1960-2016 in southeast coastal area and the spatial-temporal variations of landing typhoon.Used the trend from symmetry method to explore the future trends and symmetry rules of landing typhoon in southeast coast area.Combined with ENSO events and the eastern Pacific SST in the equatorial and climate change background to explore their influence on landing typhoon.The main conclusions are as follows:(1)The annual temperature change have three mainly stages:1960-1984 for low volatility period;For the rapidly rising stage in 1985-1998;In 1999-2016 for high lag phase,the four seasons temperature regardless of the district and the partitions are on the rise.Spatial distribution characteristics appear latitude variation characteristics,high latitude's temperature is low,low latitude's temperature is higher.In same latitude,temperature in the east is higher than western.The annual average temperature trend rate showed rising,present latitude zonal distribution.Four seasons temperature trend rate space distribution characteristics is differfnt,spring and autumn present the characteristics is in the south high and north low,temperature in summer is on the rise,only a handful of areas showed a trend of decline,the winter temperature spatial distribution tendency rate presents the north low and south high.(2)Southeast coastal area of district,north district and the central annual precipitation were showing two paragraphs,the first paragraph for stable fluctuations in 1960-2007 period,the second phase of 2008-2016 rise quickly.The southern district of precipitation in the whole time is no obvious trend of rising and falling,so the southern precipitation changes steadily.Precipitation is an obvious difference present in four seasons:summer>spring>autumn>winter.In space precipitation presents the southeast more and northwest less;off shore more and opean sea less.Annual precipitation trend rate have regional difference,present "two head up,and middle drop"distribution pattern.The four seasons tended of precipitation rate are different,the spring precipitation rate from north to south present" down-up-down-up".Summer precipitation tendency rate is rising in the northern,southern is decling.Autumn precipitation tendency rate presents in Fujian province and Zhejiang province precipitation is on the rise,Guangdong and Hainan precipitation showed a trend of decline.Most of winter precipitation tendency rate rise,only in the center of the Fujian province is showed decline.(3)In 1960-2016 the number of landing typhoon is rise,number of landing typhoon in north area is stable after down frist wave and then the trend is rapidly rising.The middle region numbers of typhoon change trend show the "drop-rise-drop-rise-drop" ccharacteristics.The southern district of typhoon landing time trends present "-down-litres" trends.7,8,9 for the typhoon season.In July,north and south of the typhoon landing number increases obviously,and in the central typhoon frequency shows no significant decline;August landing typhoon numbers in any district or partitions are on the rise,the southern district of rising trend is not obvious,the rise of the most obvious for the district and the north;September of landing typhoons in the south and central have no obvious change,the district and north region typhoons shows slightly upward trend.Typhoon intensity show the different characteristics in the different periods,roughly 10-13 level typhoon is given priority,in the space,different grades of typhoon landing site in the area is relatively uniform.(4)Typhoon land southeast coastal areas in 1960-2016 intensity of symmetry is superior to the typhoon anomaly frequency.The central typhoon has logged an abnormal number of years and north anomaly intensity in the the symmetry is the best.In southeast coastal area the judgment of the trend of the anomaly number and intensity year were 2017.In north typhoon abnormal results of the trend in frequency is 2018 or 2019,abnormal results of the trend of judgment in series 2019 or 2020.The central typhoon abnormal results of the trend in frequency in 2017,abnormal results of the trend of judgment in series is 2019.Results of the trend in the southern district of typhoon abnormal frequency 2017 or 2019,abnormal results of the trend of judgment in series in 2017.(5)Southeast coastal region of landing typhoon and ENSO events have strong correlation,on the landing frequency:La Nina years>normal years>El Nino years;on the landing intensity:El Nino years>normal years>La Nina years.Number of typhoon and the SST anomaly of monitoring area have a negative correlation;The north and SST present no significant positive correlation;Central and monitoring sea SST showed significant negative correlation;Southern district present no significant negative correlation between SST changes.Typhoon number southeast coastal land area in any district,north district,the central or southern district,was associated with a negative temperature relationship,present positive correlation with precipitation.Look from the intensity of land of the rising temperature log in southeast coastal land typhoon level has a rising trend;Precipitation period more concentrated in the high-grade typhoon level.This reasch analyzed the statistical law of landing typhoon in southeast coastal region,and connecting whit the background of climate change durning 1960-2016 to explore the typhoon abnormal landing number and intensity in symmetry and trend of changes in southeast coastal areas.In order to prevent and mitigat the disaster,and formulate relevant policies to provide beneficial reference for the government.