【作者】 胡亚南；

【导师】 许吟隆；

【作者基本信息】 中国农业科学院 ， 农业气象与气候变化， 2013， 博士

【摘要】 华北平原是中国农业主产区和粮食生产基地，冬小麦-夏玉米轮作是该地区主要的种植模式。本研究综合气象学、农学、灾害学等多学科的理论和方法，以华北地区京津冀鲁豫5省市冬小麦-夏玉米轮作种植制度为研究对象，基于该地区1981~2009年的农业气象站点资料，综合利用区域气候模式、作物模型等工具，采用月、周尺度的帕默尔干旱指数来衡量作物生育阶段的农业干旱，评估A1B情景1961~1990年和2011~2050年两个时段下，基于当前生产水平条件的新旧轮作区内干旱时空分布及干旱灾害风险。本研究主要的成果和结论如下：（1）A1B情景2011~2050年，华北地区冬小麦适种北界、夏玉米潜在种植区北移，冬小麦-夏玉米轮作区范围向东向北扩张；轮作区降水适宜度显著提高，未来降水条件将更有利于小麦、玉米的生长。（2）过去50年内（1961~2010年）华北区的年尺度干湿状况具有三类分布型，即全区干湿一致型、南北反向型和东西反向型；从时间系数上看，自80年代后期全区性的干旱程度加重。A1B情景下1961~1990年基准时段，华北轮作区的夏玉米、冬小麦全生育期干旱分布分别具有全区一致、南北反向、中部与南北反向的三类分布型；在80年代之前，全区一致分布型的典型性较高；80年代，后两种分布型较为典型。A1B情景下未来40a（2011~2050年），华北轮作区夏玉米、冬小麦全生育期的干旱分布特征，具有典型的全区一致性，并且在20年代~40年代初两种作物均呈现典型的连续20年的全区性的干旱。（3）A1B情景下1961~1990年（基准时段）和2011~2050年两个时段的玉米干旱发生频率差异较冬小麦大。未来40a冬小麦和夏玉米干旱发生频率增加，其中夏玉米大于0.45高发频率范围增加最为显著，冬小麦干旱发生频率介于0.35~0.45之间的范围增加最为显著。未来40a冬小麦和夏玉米的干旱年发生频率小于0.35的地区较基准时段的覆盖面积明显缩小，分布范围向北缩减。夏玉米在同一时段、同一干旱等级下各轮作区域内干旱发生频率均高于冬小麦的干旱发生频率，且地区之间的干旱频率的差异大于冬小麦。（4）未来40a内气候变化对华北轮作区限灌冬小麦影响表现为正效应，全区96%地区均表现为干旱年平均产量增加。轮作区内，未来和基准时段的冬小麦干旱年平均产量相比，表现为南部和北部产量水平变化不大，中部明显增加的格局；干旱年冬小麦的产量综合潜在损失呈下降趋势的地区占95.1%，山东省产量综合潜在损失降低幅度最大；冬小麦的潜在减产率小于基准时段的值的地区占原有轮作区的97.2%。2011~2050年间，华北轮作区雨养玉米的干旱年平均产量水平大部分地区表现为低于基准时段产量值；未来雨养夏玉米干旱年产量综合潜在损失量较基准时段以增加为主，与冬小麦以减少为主的趋势正好相反，河南洛阳、山东淄博潍坊一带为产量潜在损失值升高的高值中心；潜在减产率大于基准时段的值的区域占原有轮作区内的92.4%，该变化趋势与冬小麦正好相反。（5）未来40a的冬小麦干旱风险和基准时段相比，整体上轮作区内冬小麦干旱风险呈降低趋势，其中轮作区内低风险、较低风险和中等风险区域增加，较高和高风险区域减少。未来40a华北轮作区内夏玉米干旱风险与基准时段相比，主要呈增大趋势，其中较高和高风险区大幅增加、低风险区域锐减、新增轮作区内夏玉米干旱风险均呈较高和高风险等级。对冬小麦-夏玉米轮作体系来说，两个时段均以中等干旱风险为主，但未来40a中等干旱风险分布范围增加显著。更多还原

【Abstract】 North China plain is the main producing areas of agriculture and food production base in China.Winter wheat and summer maize rotation is major cropping pattern in the region. Combined withtheories and methods in meteorology, agriculture, disaster sciences in this study, it was designed forevaluate the agricultural drought disaster risk at1961~1990and2011~2050under A1B climaticscenario, taken the winter wheat summer maize rotation cropping pattern as the research object, andbased on the the agro-meteorological station data for1981to2009. It was also comprehensivelyutilizing the regional climate model and crop models as tools. The Palmer Drought Severity Index wasconducted for reflect the agricultural drought status at monthly and weekly scale in crop growth periods.Based on the results above, the risk assessment results reflected the drought disaster temporal andspatial distribution, and its changes, for the current yield level of winter wheat and summer maize. Themain results and conclusions of this study are as follows:(1) The northern boundary of winter wheat planting and summer maize potential growing areaswould be moving northward. The area of winter wheat summer and maize rotation planting patternwould be expanded at eastward and northward. Precipitation suitability in North China was significantlyimproved in2011~2050compared with1961~1990. Its precipitation condition would be moreconducive to the cultivation of wheat and maize.(2) For the past50years (1961~2010), the condition for wet or dry in North China has3-type ofdistribution patterns, which were―all consistency‖,―north-south reverse‖and―east-west reverse‖pattern. The analysis of time coefficients of three spatial distribution patterns showed that droughtdegree had an increasing trend since1980s.There had three distribution modes of drought for summer maize and winter wheat in1961~1990under A1B, which were―all consistency‖,―north-south reverse‖and―central reverse with north andsouth‖patterns. And its time coefficient showed that the―all consistency‖pattern was very typicalbefore1980s and the other two distribution modes were typical in1980s. For the next40years from2011~2050, the―all consistency‖drought distribution style would be mostly typical for both winterwheat and summer maize. And there would have a20consecutive years drought period at the overallrotation region for summer maize and winter wheat from2020s to the early of2040s.(3) The differences of maize drought occurrence frequency between1961~1990and2011~2050under A1B scenario, is larger than wheat. For the next40years, the frequency of drought will be bothincreasing for winter wheat and summer maize. The most significant increase in frequency range ofdrought occurrence area is larger than0.45for summer maize, but range from0.35to0.45for winterwheat. The area covered with drought frequency less than0.35will be significantly decreasednorthward in the next40years than baseline period for winter wheat and summer maize. It is larger ofsummer maize compared with winter wheat for the drought frequency at same time and same droughtdegree.(4) The effect of climate change on limited irrigating winter wheat would be positive, and96% area of the rotation planting region showed an increase in the average yield of in drought years. Theaverage yield of winter wheat in drought years in2011~2050, compared with the baseline period,showed that there’s little changes in production levels at the northern and southern, while had asignificantly increase in central region.95.1%of the region, the yield potential loss of winter wheatshowed downward trend in drought years, where the largest range of yield potential losses reductionwas located at Shandong Province. For the original rotation district,97.2%area of winter wheatpotential yield reduction was less than the value of the baseline period.In most part of the original rotation region, the average yield of rainfed summer maize in droughtyears in2011~2050would be lower than the values in baseline period. For the next40years, the yieldpotential losses of rainfed summer maize in drought years were higher than the baseline period, whichwas opposite to the decrease trend of winter wheat and the highest central region of yield potentiallosses were around Luoyang in Henan Province, Zibo and Weifang in Shandong Province. The ratio ofpotential yield reduction was greater than the value of the baseline period, in the92.4%of originalcropping rotation region, and the trend of winter wheat is just the opposite(5) Compared with baseline period, winter wheat drought risk overall rotation cropping area wasdecreasing in2011~2050. However, the very low risk, low risk and medium risk area of winter wheatwould be increase, while the high and very high risk area will be decrease. Drought risk for summermaize would mainly trend to increase in the next40years compared with the risk level for baselineperiod, especially that its high and very high risk area would be substantial increase, the low risk regionwould decrease sharply, and the risk of summer maize in new rotation region showed a high or veryhigh degree. Considering the whole rotation pattern, it was mainly midium drought risk both inreference prieod and future, but with a larger area in future than1961~1990.更多还原