| This paper will take Songnen Plain as object of study, with the annual temperature and monthly precipitation data of 16 meteorological stations selected from 1961 to 2013 along with almanac data, combined with Thornthwaite Memorial empirical model to calculate the value of the crop climatic productivity in Songnen Plain. Temperature and precipitation of the annual and seasons change as well as the growing season of the temporal and spatial characteristics in Songnen Plain has been studied, besides the trends and influence suffer from temperature and precipitation of crop productivity has also analyzed; Crop productivity value between actual crop output and the model results in Songnen Plain were compared and analyzed, based on these prediction of future change trends of climate productivity has been made in order to be better analyze crop yields in the Songnen Plain, especially in the context of global warming, relationship between crop yields and climate productivity. By predicting future trends of climate crop productivity a lot of measures may be adopt to prevent crop losses in the study area. The main conclusions are as follows:(1) In the last nearly 53 years, although temperatures vary largely at different times in the annual, spring, summer, autumn, winter and growing season in the Songnen Plain, temperature showed a tendency to increase in general in the entire time. These trend of temperature become more apparent after 1990 years. The annual trend rate of temperature variation between year and four seasons tends to be greater than zero, indicating that temperature is rising. Since 21 century, warming trend is more evident and wave of cool and warm occurs repeatedly. Temperature in annual, spring, winter and the growing show mutation in 1972 in the Songnen Plain, temperature in summer show mutation in 1993 to 1995 respectively. There is no real mutation point of temperature in autumn. The average annual temperature of space distribution in the Songnen Plain increase from the central region to the south, the west and the eastern region, in contract decreasing to the north. It is found that the temperature was significant increasing by linear trend in the last nearly 53 from value of the time factor variation analysis, average annual temperature of first eigenvectors corresponding to, which is consistent with the previous annual trend analysis.(2) Precipitation variation trend is basically same in annual, spring, summer and growing season in the Songnen Plain, which all show wave trend from reduction to increase and reduction again from 1960 s to 1990 s. Compared to descend trend amount of precipitation in annual, summer, autumn and growing season, precipitation between the autumn and winter show the opposite since 1990 interannual variation trend of precipitation between spring and winter showed an upward trend, and the rate of annual variation tendency was 2.6 mm/10 a, 4.1 mm/10 a and 1.2mm/10 a respectively. Precipitation among summer, autumn and growing season fluctuated downward, with the rate of annual variation tendency was-1.5 mm/10 a,-1.1 mm/10 a,-2.2 mm/10 a. The precipitation in the annual, spring and summer does not mutated, but precipitation in autumn, winter and the growing show mutation in 1972. The spatial distribution of annual precipitation Songnen Plain is regular, but there are regional differences that the magnitude of the change gradually decreasing from north to south, increasing from the central region to the east and the west. These maybe have a great relationship with the terrain, geographic latitude and longitude.(3) Climate productivity in the annual, summer, autumn and growing season in 1961~2013 reached a maximum in the 1980 s in Songnen Plain, the slow decline from 1960 s to 1970 s and an increasing trend from 1970 s to 1980 s. Climate productivity value again gradually reduced after 1980 s. Annual climatic productivity tended to increase and reach the maximum in 1998, which is higher than the average years by 1399.6 kg/(hm2·a). Climate productivity in summer, autumn and growing season all has declined, and the rate of annual variation tendency were-3.003 kg/(hm2·a),-3.397 kg/(hm2·a) and-3.302 kg/(hm2·a) respectively. The each component value of first characteristic vector of climate productivity space distribution is all greater than 0, which indicate that space distribution variation of the climate productivity is same in the Songnen Plain from 1961 to 2013, amplitude decreasing from the Northeast to southwest region, and the time factor corresponding to was a linear slow increasing trend, significantly increasing trend since 2001. Climate productivity of northeast region stations is rising whereas declining in southwest region.(4) Analysis of correlation between climate productivity and temperature as well as precipitation in annual summer, autumn and growing season in the Songnen Plain showed that the impact of precipitation change on the climate productivity dominates over the impact of temperature on climate productivity, and correlation coefficients between climatic productivity and precipitation in the summer, autumn and growing season were 0.911, 0.998, 0.999 and 0.998 respectively, whereas the correlation coefficient between temperature and climatic productivity are lower than 0.5. climatic productivity increased by 7.5%, when climate is "warm and wet". Value of the climatic productivity decreased 7.6%, when climate is the "cold and dry". The climate productivity decrease by 1%, when climate is "warm dry". Climatic productivity decrease by 0.7%, when climate is the "cold wet". Climate is prone to "warm dry" in the Songnen Plain in future, which is not beneficial to improve the climate productivity and crop yields.(5) Comparative analysis between climatic productivity and the actual single yield selected in four stations in heilongjiang province in songnen Plain shows that actual single yield is less than climate productivity in Anda, BeiLin, Qiqihar and Harbin from 2006 to 2010. But as time goes, the gap between the two is smaller. In 2011 and 2012, the actual single output is higher than climate productivity values in anda, BeiLin and Harbin.(6) By binary linear regression equation to predict Climate Crop productivity increases or decreases by 6.448 kg/(hm2·a), when the Songnen Plain temperatures every increase or decrease by 1 ℃. With the annual precipitation increase or decrease by 1 mm, crop productivity will increase or decrease by 208.766 kg/(hm2·a). Combined annual average temperature and annual precipitation change in trend analysis in the Songnen Plain, average annual temperatures increases 0.32 ℃ and precipitation increases 2.67 mm every 10 years in the Songnen Plain, which the dualistic regression equation can predict based on that climate crop productivity increases by 559.469 kg/(hm2·a) every 10 years. |
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