Temporal And Spatial Evolution Characteristics Analysis Of The North Of Anhui Province

Precipitation is a key index to describe the change of regional and global climate system,and it was also the natural factor for human survival.The change of precipitation was closely related to people's production and life,which directly affects the development of industrial and agricultural production and national economy.The rule of temporal variation and spatial distribution on precipitation was studied,based on the analysis of precipitation data over the years.The results provide reference basis for the prediction of climate change,the prevention of meteorological disasters,the rational allocation of water resources and the development of agriculture and industry.In this paper,the spatial-temporal variation characteristics of precipitation are studied by spatial interpolation,trend analysis,wavelet analysis and Mann-Kendall mutation verification in the north of Anhui Province and surrounding,based on the precipitation data from 1956 to 2012 on 21 meteorological stations.The change trend,oscillation cycles,spatial pattern of the precipitation in the past half century were revealed.The results showed that:Over the past 57 years,the multi-year average precipitation was 872mm in the north of Anhui Province,and showed a slight increase tendency on the whole.The precipitation tendency ratio of the north of Anhui Province was 6.4mm/10a.The annual difference of precipitation was observed obviously,and the change has obvious periodicity.The uneven seasonal distribution of precipitation was obvious,and the change trend of precipitation in spring,summer and autumn is not obvious.In winter,the precipitation increased significantly and there was a long period of abrupt change.The precision of ordinary Kriging interpolation was the highest in the average annual precipitation and annual precipitation,and the prediction results could better reflect the spatial distribution of precipitation in northern Anhui Province.There was a decrease trend from the south to the north.The precipitation in the south of the study area is increasing,and the precipitation in the north is decreasing year by year.The extreme precipitation events annual average occurred 4-5 times,the frequency changed little,but the intensity increased slightly.The thresholds and intensity of extreme precipitation in the northern region were higher than those in the southern region,and the climate was more unstable.In the past 57 years,there were 20 years in dry year,and 17 years belonged to humid year.The overall climate was dry during this period,but the climate gradually became moist in the 21st century.