The Characteristics And Analysis Of Surface Wind Speed Variation In Liaoning Province

Surface wind speed is the direct reflection of atmospheric motion state.The weather changes resulting from atmospheric movement affects the human production and livings.Liaoning Province is located in the transition zone from Mongolia plateau to Bohai Bay,which is affected by the sea warm current and often invaded by the cold air from the north.And this leads to windy and dry weather in spring,it affects crop sowing and leads to economic losses.Because of nowadays' increasingly serious environmental pollution and its clean and renewable characteristics,wind energy resources are highly valued.Since Liaoning Province is close to the source of cold air with rich wind energy resources,it is particularly urgent to study the changes and influencing factors of surface wind speed in Liaoning Province.Taking Liaoning Province as the research area,this paper analyzes the space-time variation characteristic soft he monthly average wind velocity data from 22 weather stations during year 1956 to 2014.Time variation characteristics include the long-term variation tendency,seasonal variation,sudden changes and their periods.The Spatial distribution characteristics include the present situation of spatial distribution and its variation characteristics.According to the characteristics of time-space distribution of surface wind speed and the analysis of possible affecting factors from the aspects of terrain and human activities,the result shows that:(1)During yearl 956 to 2014,the surface wind speed in Liaoning Province was decreasing obviously.Through the 0.05 level significance test,the maximum annual average wind speed within the study appears in 1969 which was 3.63 m/s.Since the 21st century,some areas' surface wind speed is stable and has shown a rising trend;The minimum surface wind speed in Liaoning province is in spring time,while the maximum is in summer time and the average wind speeds in autumn and winter time are almost the same.The seasonal differences of wind speed in coastal areas are more significant,namely significant monsoon climate;There are no sudden changes of surface wind speed in Liaoning Province from year 1956 to 2014;Most of the areas has cyclical swings which last for 38-40 years.(2)The long-time average surface wind speed from 1956 to 2014 in Liaoning Province decreases from midland to the east and west direction.Dalian's wind speed is the biggest,which is 4.16 m/s.The trend coefficient of surface wind speed from 1956 to 2014 in Liaoning Province appears is basically negative,which shows a decreasing trend.The most significant decreasing trend is Dalian,which is located in Liaodong Peninsula,and the minimum value is the Kuandian in Liaodong region.High wind speed appears around Bohai Gulf areas.But different times have different variation trends.Spatial differences of surface wind speeds decrease in Liaoning Province in recent 40 years.For recent 30 years,the surface wind speed changes from negative to positive in some parts of areas in Liaoning Province,namely the surface wind speed increases.And for recent 20 years,the surface wind speed rate has an obvious increase in Kuandian,Liaoning Province.The first model variance of EOF contributes 68.36%to the surface wind speed in Liaoning Province,which shows negative,reflects the surface wind speed in the whole province consistently decreases firstly from southwest to northeast,then increases.(3)The spatial distribution of annual average surface wind speed is greatly influenced by terrain in Liaoning Province.The higher surface wind speed is in the central plains,the lower surface wind speed appears in foothills of Liaodong Mountain and western Liaoning Mountain,which is also greatly influenced by the sea.Coastal areas have a high surface wind speed;the influential actors of the surface wind speed variation in Liaoning province mainly includes the adjustment of economic structure,the under laying surface modification and the change of population density.Urban development should be given the impact of climate environment to achieve sustainable development in the future.