渭河流域冬小麦旱灾风险及其对气候变化的响应研究

Along with the intensification of global climate change, world food production and security would be threatened by drought much more obvious than ever. Crop drought risk assessment which be carried out is a key precondition to prevent and alleviate drought impact, and is also significant to food security of world, country and region. The winter wheat in the Wei River Basin is intended to be chosen as the object in this project. Firstly, the temporal and spatial variation law of regional drought under the background of climate change will be analyzed by using SPEI (Standardized Precipitation Evapotranspiration Index), and then the drought hazard assessment model of disaster-inducing factor will be set up by coupling drought cumulative effect. Secondly, the CFI (Crop Failure Index) driven by crop growth model will be established to effectively separate and quantify the impact of physical and socioeconomic factors, and then a drought vulnerability assessment system with CDF (Cumulative Distribution Function) at the core will be built. Finally, the project revolves round the hazard and vulnerability of drought risk formation process to quantitatively assess the drought risk of winter wheat in the Wei River Basin, and the drought risk distribution characteristics as well as their variations which response to climate change will be revealed, and then effective measures to alleviate regional drought risk will be suggested. The results of this study could provide scientific basis for optimizing water resources allocation and carrying out agricultural drought risk management reasonably in the Wei River Basin.

随着全球气候变化的加剧，干旱对世界粮食生产和安全的威胁愈发明显，科学开展作物旱灾风险评估是预防和减轻干旱灾害影响的重要前提，对世界、国家和地区粮食安全均具有重要意义。项目以渭河流域冬小麦为研究对象，利用SPEI解析气候变化下区域干旱时空变化规律，建立耦合干旱累积效应的致灾因子危险性评估模型；构建作物生长模型驱动的作物减产指数，以有效分离及量化承灾体所受自然和社会经济因素的影响，并以此为基础建立累积分布函数为核心的承灾体脆弱性评估体系；围绕旱灾风险形成过程中的危险性和脆弱性，定量评估渭河流域冬小麦旱灾风险，揭示区域冬小麦旱灾风险分布特征及其对气候变化的响应差异，并提出减轻区域风险的有效措施。研究成果可为渭河流域优化水资源配置及合理开展农业旱灾风险管理提供科学依据。

科学开展作物旱灾风险评估是预防和减轻干旱灾害影响的重要前提，对维护区域粮食稳定和安全具有重要意义。本项目以渭河流域冬小麦为研究对象，利用多尺度干旱指数SPEI分析了历史时期和未来情景下渭河流域干旱时空变化特征，基于干旱累积效应评估了冬小麦干旱致灾危险性，利用作物减产指数分离并量化冬小麦自然和社会经济脆弱性，基于自然灾害风险分析原理定量评估了历史时期和未来情景渭河流域冬小麦旱灾风险水平。结果表明：1980−2018年渭河流域整体上干旱趋于严重，尤其是中北部地区干旱呈显著增强趋势，2021-2050年RCP2.6模式下流域未来干旱可能会加剧，而RCP6.0模式下流域未来有湿润化趋势；高和极高危险性面积比例超过了60%，危险性整体处于较高水平，未来气候情景下渭河流域旱灾危险性比历史时期更高；干旱暴露度指数DEI9和作物减产指数CFIphy有极显著的正相关关系，渭河流域社会经济脆弱性整体高于自然脆弱性，未来情景自然脆弱性指数DVIphy显著高于历史时期；渭河流域冬小麦旱灾风险呈现北高南低的分布格局，流域整体以中等和高风险为主，高和极高风险面积之和接近45%，未来情景下风险有进一步增加的态势，需要采取积极措施减轻区域旱灾风险水平，适应气候变化。