| Chinese drowsiness harm damaged countries,censorship drought disasters habitual reproductive practice,erratic harm Injury Prevention Important significance.In this study,the Jitai Basin was selected as the study area,and the drought and flood disaster grade sequences in the area were established based on the data of drought and flood in 1403-1911.This paper analyzes the frequency,intensity,period and sudden change point of drought and flood disaster by means of mathematical statistics,wavelet analysis and sliding t test,and expounds the local impact and post-disaster response measures after drought and flood disaster.The main draw the following conclusions:(1)The data of this paper are derived from the historical data of drought and flood disaster in 8 counties and 1 city of Jitai Basin.Combined with the actual situation of Jitai Basin,the drought and flood disaster is divided into five grades,and then the text description is parameterized,and the sequence of drought and flood disaster grade in 1403-1911 of Jitai Basin is reconstructed.(2)Number and frequency of droughts and floods Jitai Basin show: During the period from 1403 to 1911,a total of 315 floods occurred in the Jitai Basin,and the frequency of flooding occurred more than that of drought.Drought and Flood levels low appearance frequency order: 5 waterlogging> drought bias stage 2> class 4 partial flooding> 1 dry stage.According to the statistics of the century,the frequency of flooding in the 15 th century,18 th century and 19 th century was higher than that of drought.The frequency of drought in the 16 th century,17 th century and 20 th century was higher than that of waterlogging.From the dynasty,the frequency of drought and flood disaster in the Qing Dynasty was higher than that in the Ming Dynasty,and the frequency of flooding in each dynasty was higher than that in drought.(3)The analysis of the intensity of drought and flood disaster in Jitai Basin shows that:By calculating the average index of drought and flood disaster,it is found that the intensity of drought and flood disaster in the region from 1403 to 1911 is higher than that of drought,and the intensity of drought is greater than that of waterlogging in individual time.From the dynasties,the Ming Dynasty drought and water,the Qing Dynasty floods serious,the whole period of flood intensity is greater than the drought.(4)The period analysis of drought and flood disaster in Jitai Basin shows that: The 509 years drought and flood disaster grade sequences were analyzed by wavelet analysis.In the 500 years and 100 years to distinguish the scale of a total of eight cycles,namely 54-58 years,5-8 years,13 years,31-33 years,23 years,115 years,180 years,275 years.Which 54-58 a cycle occurs the most,as the main oscillation cycle.(5)Mutation analysis of drought and flood disaster in Jitai Basin shows that: The tide test of drought and flood in the area was simulated by 500 years and 100 years respectively,and the sudden change of the drought and flood disaster in the area was obtained.as followed: 1452 by the floods turn drought,in 1468 transferred floods by the drought in 1485 by the floods turn drought,in 1574 transferred floods by the drought in 1662 by the floods turn drought,in 1683 transferred from drought waterlogging,1801 by the floods turn drought,1826 Year drought transfer,in 1866 by flooding drought.(6)The influence of drought and flood disaster and its social response in Jitai Basin shows that: Drought and flood disasters have a serious impact on social development,mainly for the destruction of agricultural production,resulting in population reduction,affecting social stability.In order to mitigate the effects of drought and flood disaster,the government and the people have taken a lot of prevention and control measures,mainly to build water conservancy facilities,to build warehouses and to implement social relief. |
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