Variation And Application Of Hydrothermal Condition In Liaoning Province Under Future Climate Scenarios

The rational allocation of heat and water provides favorable climatic conditions for agricultural production.It is important to make clear the matching and variation rule of heat and water for guiding agricultural production.Based on the data of daily precipitation and temperature under historical data(from 1961 to 2014)and CMIP5 data(from 2011 to 2090),the variation of precipitation and temperature,and applied to the analysis of heat and water of spring corn of Tieling in Liaoning Province.The results show that:1.On the whole,the variation law of inner-annual inhomogeneous distribution of precipitation(?DP)showed the characteristics of increasing from east to west in Liaoning Province.The precipitation in Liaoning Province is mainly concentrated between July 20 and July 28.The lower the latitude is,the later the precipitation concentration period(PCP)is.Liaoning Province can be divided into 4 types of divisions according to the ?DP:region ?(Southern Liaoning),region ?(Central Liaoning),region ?(Eastern Liaoning)and region ?(Northwest Liaoning).The most important characteristics are the decrease of IIDP,the increase of ?DP's interannual variations and the advance of PCP.The main low-frequency oscillation periods of precipitation concentration degree(PCD)and PCP are both between 2.0 and 4.0 years,which is basically consistent with the oscillation period of annual total precipitation in each divisions of Liaoning Province.The ?DP depended on air temperature strongly,which showed difference on different period.Temperature concentration period(TCP)and PCP obey normal distribution.The peak matching degree of heat and water is lowest in region ?,highest in region ? and ?,unstable in region ?.2.The study found that the spatial distribution of PCD in the three future periods is the same as the historical period,which IIDP is increasing from east to west,and the three periods of precipitation mainly concentrated between late July and early August in Liaoning Province.The rising rate of PCD in each division is in the order of region ?>?>?>? shows a distribution pattern of high in the east and low in the west.Except for region IV,PCP also shows a downward trend.The main low-frequency oscillation periods of PCD and PCP are between 2.0 and 6.0 years in each division.From 2011 to 2090,the climatic tendency rate of Liaoning Province is between 0.22 to 0.3?/10a(P<0.05).PCD is increasing and PCP is decreasing.The IIDP also depended on air temperature strongly,the peak matching degree of heat and water showed first decrease and then increase in each division,lower in region ?,?and IV,higher in region ?.3.It is theoretically feasible to advance the sowing date because of onset day of accumulated temperature of ?10? is advanced and the corn maturity that meets the mechanical grain harvest is postponed in Tieling,but the degree of advancement in different periods is different.The study found that the corn yield had a significant downward trend under the four sowing dates(P<0.01)in Tieling.When the sowing in the current period advances 10 days,the corn yield reduction in Tieling area is smaller,and the 50 mm irrigation at grain filling stage(August 7)can reduce the yield reduction trend;When the sowing date advances 5 days in the middle of the 21st century,the corn yield in Tieling increased slightly,and the 25mm irrigation at heading-blooming stage(August 2)can further increase the yield increase trend;When the sowing date advances 5 days of the 21st century,the corn yield reduction in Tieling was the smallest,and the 75mm irrigation at heading-blooming stage(August 2)can curb the yield reduction trend.