气候变化与人类活动影响下华北平原冬小麦干旱成害机理及其风险评价

Climate change has led to an aggravating trend of agricultural drought. It is of great significance to study the risk assessment of agricultural drought for climate change adaptation and risks prevention. In view of the important role of human activities in agricultural drought risk assessment, this project studies the scientific issues related to the comprehensive evaluation of winter wheat drought risk coupling climate change with human activities, by selecting winter wheat in the North China Plain as the research object, taking the field experiment and the crop model simulation as the main research methods using multi-source data, multi-model, mathematical statistics and GIS technology ensemble. The main contents and tasks are to reveal the mechanism of drought-damage of winter wheat by experiment of planting winter wheat under different water stress; to construct the farmland management parameter set of winter wheat production in North China Plain by excavating multi-source information; to quantify the drought intensity and corresponding yield loss of winter wheat in North China Plain under the influence of climate change and human activities by crop model simulation; to evaluate the drought probability and loss risk of winter wheat at recent, medium and long-term, and the end of this century in North China Plain under different climate change and socioeconomic scenarios; and to reveal the temporal and spatial pattern and evolution trend of winter wheat drought risk in North China Plain. The results of this project are hopeful be able to effectively reduce the uncertainty of winter wheat yield simulation, and therefore accurately reveal the future comprehensive risk pattern of winter wheat drought in North China Plain, so as to provide a strong scientific basis for the prevention of agricultural drought risk to adapt to climate change.

气候变化导致农业旱灾有加剧趋势，加强农业旱灾风险评估研究对气候变化适应和风险防范具有重要意义。针对农业旱灾风险评价中忽视人类活动重要作用的现状，选择华北平原冬小麦为研究对象，以田间试验和作物模型模拟为主要研究手段，运用多源数据融合、多模型组合、数理统计及GIS空间分析技术，研究耦合气候变化与人类活动的冬小麦旱灾风险综合评价方法构建的科学问题。开展不同水分胁迫下冬小麦种植试验，揭示冬小麦干旱-成害机理；挖掘多源信息，构建华北平原冬小麦生产农田管理参数集；模拟气候变化和人类活动影响下华北平原冬小麦干旱致灾强度与产量损失；评价不同气候变化和社会经济情景下华北平原近、中、远及本世纪末期冬小麦旱灾概率风险和损失风险；揭示华北平原冬小麦旱灾风险的时空格局与演变趋势。研究成果可有效降低冬小麦产量模拟的不确定性，精确揭示华北平原未来冬小麦旱灾综合风险格局，为制订适应气候变化的农业旱灾风险防范提供科学依据。

气候变化导致农业旱灾有加剧趋势，加强农业旱灾风险评估研究对气候变化适应和风险防范具有重要意义。针对农业旱灾风险评价中忽视人类活动重要作用的现状，选择华北平原冬小麦为研究对象，以作物模型模拟为主要研究手段，运用多源数据融合、多模型组合、数理统计及GIS空间分析技术，研究耦合气候变化与人类活动的冬小麦旱灾风险综合评价方法构建的科学问题。开展了不同气候情景和共享社会发展路径下冬小麦生长模拟；构建了华北平原冬小麦生产农田管理参数集；模拟了气候变化和人类活动影响下华北平原冬小麦干旱致灾强度与产量损失；评价了不同气候变化和社会经济情景下华北平原冬小麦旱灾风险；揭示了华北平原冬小麦旱灾风险的时空格局与演变趋势。研究取得的重要成果有：（1）构建了基于多源数据的华北平原冬小麦旱灾风险综合评价数据库；（2）形成了耦合气候变化与人类活动的冬小麦旱灾风险综合评价方法体系；（3）揭示了华北平原近、中、远及本世纪末期冬小麦旱灾风险格局演变规律。研究发现，在不同气候变化和人类活动情景下，气候变化对冬小麦产量的影响占据主导地位；冬小麦产量的主导影响因子在RCP2.6-SSP1、RCP4.5-SSP2和RCP8.5-SSP3情景下均存在逐渐向土地利用变化转移的趋势。气候变化情景下华北平原地区旱灾风险整体呈现出南部旱灾风险高、北部旱灾风险低的总体空间分布格局；其中，RCP2.6情景下的旱灾风险均值最低，为0.19，RCP8.5情景下和RCP4.5情景下的均值大致相同，为0.21。气候变化与经济发展情景下，华北平原地区冬小麦旱灾风险水平远低于同等气候变化情景下的冬小麦旱灾风险水平。其中，RCP8.5-SSP3组合情景下的小麦旱灾风险均值仅为0.04。由此可见，经济发展情景下的人类适应活动，对减轻华北平原地区冬小麦旱灾风险水平具有显著作用。研究揭示的气候变化和人类活动下华北平原冬小麦旱灾风险，对于深刻认识冬小麦旱灾成害机理以及定量风险评估具有重要的科学价值，可为制定区域农业气候变化适应对策提供科学依据。