气候变暖背景下西北农牧交错带气象干旱演变规律及其影响机制

The ecotone between agriculture and animal husbandry in Northwest China is a sensitive area of the effects of climate change, and is the most serious area in China. Climate change in the ecotone between agriculture and animal husbandry in Northwest China is directly related to the food security in arid and semiarid area. It’s the key to scientifically plan the production of agriculture and ensure the farmers and herdsmen production efficiency in terms of climate change, especially the change of drought in the ecotone between agriculture and animal husbandry in Northwest China under the climate warming. In this project, the ecotone between agriculture and animal husbandry in Northwest China is taken as the research area, the meteorological drought as the research object, and the climate warming as the entry point. The characteristics of spatial-temporal variations of the climate and climate mean states in the ecotone between agriculture and animal husbandry in Northwest China are expounded. It’s reveal the influence of meteorological drought in the ecotone between agriculture and animal husbandry in Northwest China. To analysis the climate state change on the influence of the meteorological drought. Consequently, the mechanism of climate warming and the East Asian summer monsoon effect on meteorological drought has been revealed. To explore the mechanism of meteorological drought in the ecotone between agriculture and animal husbandry in Northwest China affected by climate warming and the East Asian summer monsoon. The relationship between meteorological drought and climate change in the ecotone between agriculture and animal husbandry in Northwest China is discussed. To build the dynamic relationships of meteorological drought, climate change and the East Asian summer monsoon in the ecotone between agriculture and animal husbandry in Northwest China, which provide theoretical support for formulate and implement measures that meteorological drought to adapt to climate change. The research for the development of the regional meteorological drought warning and disaster prevention and reduction to provide theoretical support, and provide reliable basis for scientific planning, faming and animal husbandry production.

西北农牧交错带是气候变化影响的敏感区域，是我国旱灾最严重的地带，西北农牧交错带的气候变化直接关系到干旱半干旱区粮食安全。准确预估气候变暖背景下西北农牧交错带的气候变化，尤其是干旱的变化，是科学规划农牧业生产、确保农牧民丰产增效的关键。本项目以西北农牧交错带为研究区域，以气象干旱为研究对象，以气候变暖为切入口，阐明西北农牧交错带气候和气候态的时空演变特征；揭示西北农牧交错带气象干旱的年代际演变规律；分析气候态改变对气象干旱的影响，揭示气候变暖和东亚夏季风对西北农牧交错带气象干旱的影响，探讨在气候变暖背景下，西北农牧交错带气象干旱受气候变化和东亚夏季风的影响机制；建立西北农牧交错带气象干旱、气候变暖与东亚夏季风的动态关系，为制定与落实西北农牧交错带气象干旱适应气候变化的对策措施，以及更好地发展该区域的气象干旱预警和防灾减灾提供理论支撑，为科学规划农牧业生产提供可靠依据。

西北农牧交错带受东亚季风环流、西风环流和高原季风的共同影响，加之脆弱敏感的生态系统以及过度的人类活动影响等因素，干旱气象灾害具有十分明显的区域性和复杂性，是主要干旱气候区之一，更是我国旱灾最严重的地带。本项目围绕西北农牧交错带气象干旱受气候变暖和东亚夏季风的影响这一关键科学问题，主要开展了以下4个方面的研究，即西北农牧交错带气候和气候态的时空演变特征及其主要影响系统、区域气象干旱的年代际演变规律及气候态的改变对气象干旱监测的影响、气候变暖和东亚夏季风对气象干旱的影响、以及气候变暖背景下气象干旱受气候变暖和东亚夏季风的影响机制及其动态关系。通过项目的实施，阐明了近半个世纪以来西北农牧交错带气候的明显变化特征，尤其是气温显著升高和降水量明显减少的时空分异性。指出了区域气象干旱的年代际演变规律，明确了区域性干旱强度、次数、频率和范围的变化特征，以及气候态的改变对区域性干旱强度和范围的影响。明确了气候变暖背景下区域蒸散量变化特征、不同植被受升温影响的蒸散量的年内变化特征，以及夏季风对降水特征量的影响，指出区域蒸散量对秋旱的影响较明显，这种影响主要存在与年代际尺度。通过建立耦合协调度模型，阐明了在气象干旱、气候变暖与东亚夏季风之间的动态的协调发展关系，虽有波动，但总体上在协调范围内。项目研究结果可为客观辨识、监测和应对未来气候变暖背景下西北农牧交错带的干旱发生发展提供科技支撑。