Analysis Of Thermal Conditions And Climatic Regionalization Of Grape Planting In China Based On Km Grid

China’s grape planting area continues to expand,the planting area and yield increase rapidly,grape varieties and their cultivation and management mode become more diversified,and the grape and wine industry develops rapidly.As a fruit tree with temperature tolerance and drought tolerance,the change of heat conditions will bring significant uncertainties to the layout,production and benefits of grape industry.In order to find out the influence of heat conditions on the distribution of grape cultivation and to define the suitable regions for grape cultivation based on heat conditions in China,the meteorological data of 370210 5 km×5 km space resolution and 3 hour time resolution near ground grid points and provincial total yield and planting area data in China from 1981 to 2010 are used in this study.Analyzing the cultivation situation and yield loss of grape in China;the heat conditions that affect grape cultivation based on the statistical methods of climate trend analysis and climate variability,combined with ArcGIS software;and carry out the heat regionalization of grape planting in China based on 90% guarantee rate.The main results are as follows:(1)From 1981-2010,the yield,area and per unit area yield of grape planting in China showed an upward trend.Before 1986,the increase was slow,and then the increase became larger.In the 1980 s,most provinces in China had planted grapes.In the 1990 s,some provinces,such as Guangxi,Jiangxi,Sichuan and Chongqing,began to grow grapes.In the 21 st century,Qinghai and Tibet,although they produced very little and planted very small areas,became one of the provinces where grapes were grown.Only Guangdong and Hainan were the provinces where grapes were not planted in China.The high value areas of per unit area yield are mainly in Anhui,Zhejiang,Liaoning province and Tianjin city.The high value areas of yield and area are Xinjiang,Shandong,Hebei and Henan province,which are the the main planting areas.(2)The year in which the relative meteorological yield fluctuated greatly in China was mainly concentrated in 1980 s.Meanwhile,the increase of per unit area yield in most provinces was relatively slow during that period.The annual variation of per unit area yield in Hunan,Inner Mongolia and Ningxia province is not obvious and low.The annual variation of per unit area yield in Anhui,Hubei,Liaoning,Shandong,Shanxi Province and Tianjin City is obvious and the increase is large.In the high value area of annual average per unit area yield,the annual variation of relative meteorological yield in Anhui and Liaoning provinces is small.In the main planting areas,Xinjiang Uygur Autonomous Region is the province with the smallest interannual variation of relative meteorological yield,which is a relatively safe planting area in-18.71%-10.17%,and Hebei is the smallest,which is-14.36%-34.3%.(3)In terms of spatial distribution,the first frost day series distribution is divided into nine time intervals,the last frost day series distribution is divided into eight time intervals,and the frost free period series is divided into five regions.In terms of Interdecadal change,The interdecadal change of the first frost day is obvious,which mainly shows the trend of advancing first and then postponeing;the interdecadal change of the last frost day is not obvious,and the proportion of the last frost day ahead is similar to that of the last frost day delayed;the interdecadal change of the frost free period is obvious,which mainly shows the trend of shortening first and then prolonging,which corresponds to the trend of the first frost day.(4)The fluctuation of the first frost day is small and the stability is very good.The negative climatic tendency rate is mainly distributed in the southwest to the northeast;the positive values are distributed in the southeast and scattered areas of northwest.In Fujian,Jiangxi,Hubei,Hunan,Guizhou,Yunnan,Chongqing,northern Guangxi,northern Guangdong and Eastern Sichuan,the last frost day fluctuates greatly and its stability is poor.It has good stability in areas without the last frost day,and in northern Tibet and southern Qinghai;the positive and negative distribution of climate tendency rate is obvious and the distribution is contrary to that of the first frost day.The frost free period is characterized by great fluctuation and poor stability in Tibet,southern Qinghai and the regions bordering Gansu,western Sichuan,Mohe and Xinjiang,and good stability in southern Hebei,northern Henan,Shandong(except for a few areas in northwest),Jiangsu,central Anhui,areas bordering Henan and Hubei,western Tarim Basin and areas along Kunlun Mountains;the rate is related to the distribution of climatic tendency on the first frost day and the last frost day.The region with shorter frost free period has earlier first frost day and later last frost day.The region with longer frost free period has later first frost day and earlier last frost day.(5)Based on the 90% guarantee rate,the frost free period is used as the index of heat regionalization of Chinese grapes.Meanwhile,the active accumulated temperature of growing season is introduced as an additional index.Divide China into five regions,and the buried and non-buried regions of Eurasian species,European and American hybrids and mountain grapes were divided.The results of heat regionalization matched well with the situation of grape cultivation in China.Based on the frost free period and active accumulated temperature during growing season as the index of heat regionalization,the northern boundary of grape cultivation and the suitable area of heat conditions in China can be well defined.Compared with previous studies,the accuracy of the results of grid meteorological data regionalization is higher.In the future,it can be further used to divide water conditions and define the southern boundary of grape cultivation in China.