Study On The Distribution Characteristics Of Flood Disaster And Its Effect On Maize Yield In Heilongjiang Province

Flood disaster is one of the agricultural meteorological disasters in Heilongjiang Province and its effect on maize production greatly.This article based daily average precipitation data and monthly mean precipitation of the 63 meteorological stations in Heilongjiang province during 1965-2014,combined with the yield data of maize yield and 14 representative maize site,through screening measurement,sorting and calculation analysis,taking advantage of the Z index,the tendency regression analysis,Mann-Kendall text,wavelet analysis,inverse distance weighted method and correlation analysis method to study the distribution characteristics of flood disasters in Heilongjiang province(including severe flood,mild flood,moderate flood)and its effect on maize yield,in order to provide reference data for the Heilongjiang Province agricultural flood disaster response and come to adjust the layout and structure.The statistical results show that:(1)The precipitation of the near 50 years is 519.88mm in Heilongjiang Province,which shows a trend of increasing volatility,the rising rate is 8.643mm/10a.The average annual precipitation has obvious stage,the annual precipitation is less before 1980's,the precipitation is more in 1980's and 2010 after,and the precipitation changed litter.The average precipitation was abrupt change in 1973,1983,1995,1998 and 2012 years and its has 26 years,14 years and 3-4 years periodic oscillation.Seasonal distribution of precipitation is uneven,and the annual precipitation was mainly concentrated in summer,followed by autumn,the lowest in winter.In spring and summer,there is a large fluctuation of precipitation,a decreasing trend in autumn and a stable trend in winter.Overall,the precipitation in the near 50 years show that the central and the eastern high,and the westward low pattern.(2)The severe flood occurred 6 years,mild flood occurred 7 years and moderate flood occurred 7 year,the recovery period were respectively 8.3 years,7.1 years and 7.1 years of the near 50 years in Heilongjiang province.The flood index has three periodic oscillations,with 18,10 and 3-4years.Four seasons,in addition to winter,the floods occur in spring,summer and autumn.Severe flood occur only in summer,mild flood and moderate flood occur in spring,summer and autumn.In the seasons,the number of flood disaster stations accounted for respectively summer>autumn>spring>winter.(3)In the near 50 years of 13 regions of Heilongjiang province,severe flood occurred 28 times,frequency of the high concentration area in the southeastern part of Heilongjiang province,Mudanjiang area;mild flood occurred 74 times,frequency of the high region in Daqing region and Yichun region;moderate flood occurred 106 times,frequency of the high region in Qiqihar area,Heihe area and Hegang area.Overall,the water-logging disaster of Heilongjiang province occurred primarily in Hegang,Yichun,Mudanjiang and Heihe region.The secondary flood area occurred in Daxinganling area and Daqing area.(4)The yield of maize and annual output in Heilongjiang province showed an upward trend during 1965-2014.The per unit yield and annual output of maize was the highest(6145.9kg/hm2 and 33 million 434 thousand and 200 tons)in 2014.There is a significant negative correlation between the average precipitation and meteorological yield of maize during the maize growth period.And precipitation of each month also had significant correlation with the meteorological yield of maize.Compared with other growing season,in August,precipitation had the most significant effect on relative meteorological yield of maize.(5)The situation of flood disaster is severe in Heilongjiang province.In order to cope with the flood disaster,it is necessary to combine the disaster prevention and disaster forecasting system.The corn in the booting stage and flowering stage was the most vulnerable to the effects of waterlogging,in order to reduce the influence of flood disaster in this two periods.It can minimize the influence of flood disaster on maize yield,if the implementation of targeted measures such as waterlogging field drainage effectively.