Analysis And Regionalization Of Apple Flowering Cold Injury Risk Based On GIS In Shanddong Province

With climate becoming warming, spring phenophases of apple has been getting earlier, and the risk of flowering cold injury has been increasing, thus it is necessary to understand the climate change rule and the relationship between climate factors and the flowering time, predict the flowering time, analyze and regionalize apple flowering cold injury risk, make full use of effective climate resources to draw on advantages and avoid disadvantages, so as to provide scientific basis for the safety production and sustainable development of apple industry in Shandong Province and even the whole country. In this paper, based on the winter and spring air temperature data at typical counties of apple producing areas in Shandong Province from1971to2012, the temperature change characteristics and the future trends were analyzed by using linear tendency estimate, Mann-Kendall method and R/S analysis. The change characteristics of extreme minimum temperature in April were studied at same time. Using the data of apple phenological period in Liaocheng from1971to2012, the change tendency of apple first flowering and its correlation with meteorological factors were analyzed, and the apple first flowering prediction model were established by using stepwise regression method. Apple flowering cold injury composite indicator were determined through extreme minimum temperature, the extreme minimum temperature day’s diurnal range temperature and apple orchard evapotranspiration in April by using index weighted summation method. Apple production areas in Shandong Province were regionalized for apple flowering cold injury risk by using GIS. The main results were as follows:1. Winter and spring climate change scenarios of three big apple production areas’ typical counties in Shandong province:Winter and spring average temperature of Qixia, Yiyuan and Guanxian as representative sites of three big apple production areas in Shandong Province (i.e. Ludong coasts, Luzhong coteau and Luxi plain) from1971to2012all presented an increasing trend, and the warming rate of average temperature in winter was higher than the temperature from March to April; Increasing linear trend rate of Yiyuan was the highest:winter average temperature’s value was0.552℃/10a, from March to April average temperature’s value was0.376℃/10a, Guanxian followed by rising0.473℃/10a in winter and0.359℃/10a from March to April, Qixia had the lowest warming rate of0.299℃ /10a in winter and0.292℃/10a from March to April. Winter and average temperature from March to April of Qixia, Yiyuan and Guanxian happened obvious mutation from low to high in the late1980s, the starting time of mutations for winter average temperature in Qixia, Yiyuan and GuanXian were1987,1987and1989, and for average temperature from March to April in Qixia, Yiyuan and GuanXian were1985,1989and1987,respectively.2. Winter and spring climate change trends of three big apple production areas’typical counties in Shandong Province:in winter and from March to April average temperature change trend in the future would be consistent with that in the past, still continuing to rise, and the warming rate of average temperature in winter will be higher than March to April. Winter average temperature warming trend of Yiyuan will be the highest, while March to April average temperature warming trend of Qixia will be the highest. Extreme minimum temperature in April is presenting a trend of increasing, warming trend rate of GuanXian may be highest, the value was0.682℃/10a, reaching extremely significant level; Qixia followed by0.44℃/10a, reaching significant level; Yiyuan may have the lowest warming rate of0.361℃/10a, the range of temperature raising not significant. The emergence of extreme temperature date in April will be random, and obviously different annually. Extreme minimum temperature below5℃days in April may show a trend of decline. Linear trend rate of Guanxian will be the highest, the value being1.23d/10a, Qixia followed by1.036d/10a, and Yiyuan will be the lowest,0.912d/10a.3. Apple flowering prediction numerical model of Shandong Province:Apple first-flowering dates in Liaocheng from1970to2012presented a significantly advancing trend. Linear trend rate was1.956d/10a Meteorological factors of February and March influenced had a bigger effect on apple first-flowering dates, the influence of previous meteorological factors were relatively smaller. The temperature factors had a great effect, and the correlation between temperature factors and apple first-flowering dates reached extremely significant level; sunshine time factors took second place, and the correlation between sunshine time factors and apple first flowering reached significant level; and precipitation factors had a smaller effect on apple first-flowering dates, not reaching significant level. Using the highest temperature of late February to march, the number of days whose temperature was higher than0℃of mid to late March, sunshine time of January, sunshine time of late February and average temperatures from late February to March, it was established apple first flowering prediction model by correlation analysis and stepwise regression method. The prediction effect of the model application in Liaocheng was preferably, but the model had poor stability when it was applied in other areas of Shandong Province through the model test.4. Climatological equations of apple flowering cold injury index:it was established Climatological equations of apple flowering cold injury indexes with extreme minimum temperature in April, the extreme minimum temperature day’s diurnal range temperature and apple orchard evapotranspiration in April by the method of stepwise regression analysis. Analytic hierarchy process was applied to determine these indexes’ weights, and the values of indexes’weights were0.7396,0.0938and0.1666, respectively.5. Analysis and regionalization of apple flowering cold injury risk based on GIS in Shandong Province:Based on GIS platform, apple flowering cold injury risk was regionalized in Shandong Province into "no freezing injury","mild cold injury","partial mild cold injury","moderate cold injury"," partial severe cold injury " and "severe cold injury" six grades by weighted summation method. The regionalization results were that "no freezing injury","mild cold injury" and "severe cold injury" areas did not appear in apple production areas of Shandong Province;"Partial mild cold "areas accounted for a larger area of apple production areas in Shandong Province, which were mainly distributed in southern of Luxi plains region and central and southern of Luzhong coteau region."Moderate cold injury" areas were mainly distributed in north of luxi plains region, northwest of Luzhong coteau region and southern of Ludong coasts region;"partial severe cold injury" areas were mainly distributed in Ludong coasts region and northeast of Luzhong coteau region, and didn’t appeared in Luxi plains region.