| Climatic Potential Productivity is an important basis for assessing the extent of regional climate resource utilization.By studying the regional climatic potential productivity,it can characterize the allocation of agroclimatic resources such as light,heat,and water in the region,and provide theoretical basis for the adjustment of crop production pattern distribution and improvement of planting zoning.This paper selected the Huangshui River Basin as study area,which is one of traditionally cultivated region in the Qinghai-Tibet plateau.Firstly,the ANUSPLIN model was used to interpolate the meteorological pattern in the study area from 1988 to 2010 based on recorded meteorological data,radiation data,digital elevation model?DEM?data,administrative division data and other basic data.The linear trend analysis,Mann-Kendall test and coefficient of variation were used to research the climatic characters.The climate resources in the Huangshui River Basin were analyzed,and its spatial and temporal variation and trends were discussed.Secondly,photosynthetic potential productivity,photosynthetic thermal potential productivity and climatic potential productivity of spring wheat,highland barley and spring rape and their spatial and temporal changes were simulated by the climatic potential productivity model with step-by-step adjustment.The main conclusions were listed as follows:?1?The annually average temperature of the Huangshui Basin was between 1.21and 5.23?and the average value was 4.07?.The annually average temperature generally showed an increasing trend,and the rate was 0.34?·10a-1 in this period.The spatial variation of annual average temperature decreased from southwest to northeast and the temperature in the central and southeastern regions of the basin,such as Huangzhong County,Ping'an County,and Ledu County was generally higher than other areas.The average annual temperature in the northwest region was below-8.5?due to altitude,lower than other regions.According to the Mann-Kendall trend and catastrophe test,the annually average temperature was increasing,which was consistent with the results of the linear analysis.The abrupt temperature change occurred around 1998.Taking 2000 as the cut-off point,it showed a trend of warmer at pro-phase and colder latterly.?2?In nearly 30 years,the annual precipitation in the Huangshui River Basin had a range from 109.65 to 451.75mm,with average value of 353.45mm.The annual precipitation had a decreasing trend with rate of 0.34?·10a-1.Except for the eastern part of Tianjun County,the distribution of precipitation decreased from northwest to southeast from 1988 to 2018.The annual precipitation in the upper and middle reaches of the Datong River and in the upper reaches of the Huangshui River was generally high,which had certain benefits for the growth of crops in arid and less rainy areas.The Mann-Kendall trend test and catastrophe test results of annual precipitation showed that the annual precipitation had a slightly decreasing trend,and the change was frequent.The general trend was to decrease first,then increase,and then decrease.?3?From 1993 to 2010,the estimated mean photosynthetic potential productivity of three crops in the Huangshui River Basin showed that the spring wheat was the highest,followed by highland barley,and then spring rape,with the averages of37152kg·hm-2,25543kg·hm-22 and 20445kg·hm-22 respectively.The respective decline rates were 390kg·hm-2·10a-1,465kg·hm-2·10a-11 and 372kg·hm-2·10a-1,and average coefficient of variation?CV?values of photosynthetic potential productivity of three crops were 0.028,0.024 and 0.024 respectively,which was a low-volatility variation and was in a relatively stable state.The spring wheat had highest photosynthetic thermal potential productivity,followed by spring rape and highland barley,with the average values of 29654kg·hm-2,20070kg·hm-22 and 19652kg·hm-22 respectively.Among them,highland barley and spring rape decreased by 727kg·hm-2·10a-11 and 129kg·hm-2·10a-1respectively,but spring wheat increased at a rate of 791kg·hm-2·10a-1.The mean CV values of photosynthetic thermal potential productivity of spring wheat,highland barley and spring rape were 0.030,0.069,and 0.012 respectively,in which the photosynthetic thermal potential productivity of spring wheat and highland barley existed in medium and high volatility areas respectively,and represented relatively unstable.The climatic potential productivity of highland barley,spring rape,spring wheat were 32025kg·hm-2,23981kg·hm-2 and 22946kg·hm-2 respectively.The climatic potential productivity ofhighland barley,spring rape,and spring wheat showed upward trend with the rate of1380kg·hm-210a-1,877kg·hm-2·10a-11 and 459kg·hm-2·10a-11 respectively.The mean CV values of climatic potential productivity of highland barley,spring rape and spring wheat were 0.102,0.051,and 0.020 respectively,indicating that highland barley climatic potential productivity had high fluctuations. |
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