气候变化非稳态下的区域农业干旱模拟与作物产量影响评估

Drought monitoring is the difficulty of the current drought research under climate change and non-stationarity. The simulation and prediction of drought trend is the forefront of the current drought research, which is of great strategic significance to China's food security. As our country’s major grain producing areas, Songnen plain has happened many agricultural drought events in recent decades, and regional drought events aggravated gradually. There is still needs a clear and effective drought monitoring theory and method system for regional agricultural drought process under the climate change and non-stationnarity effect. Songnen plain will be selected as the study area in this project. The standardized precipitation index(SPI) was improved by introducing the extreme value probability distributions in order to adapt to the impact of precipitation non-stationarity. The according to the improved SPI index, crop water deficit index which is established by the experiment of water use efficiency and remote sensing soil water index for factor representation of atmosphere, crop and soil. Then a climate change and non-stationarity-based monitoring model (agricultural drought comprehensive monitoring model) will be established. Based on the methods of calibration this model parameters, analysis the uncertainty and combination with experimental data to verify the model of the applicability of the study area. Finally, the model will be used to reveal the agricultural drought spatio-temporal characteristic and the impact of future climate change on agricultural drought and crop yield will be discussed. This study will provide a guiding role in agricultural development, enrich the drought knowledge system, and promote the effective implementation for agricultural water conservation.

气候变化非稳态下的农业干旱趋势模拟与预估是当前农业水管理研究的前沿与难点，对我国的粮食安全有重要的战略意义。中国松嫩平原作为全国重要的粮食主产区，近几十年发生多次农业干旱事件，且有区域干旱加重趋势，目前尚缺乏一种有效监测气候变化非稳态下的区域农业干旱发生过程的理论和方法体系。本项目拟以松嫩平原为研究区，通过引入极值概率分布函数改进标准降水指数，以适应降水非稳态带来的影响；通过结合农田试验获得作物水分亏缺指数以及遥感土壤水指标建立基于气候变化非稳态条件下的农业干旱综合监测模型，对模型进行不确定性分析和优化，同时结合实验数据评价模型在研究区的适用性；根据模型揭示研究区内农业干旱在气候变化非稳态下的时空演变特征，并探讨未来气候变化对农业干旱的趋势以及对作物产量的影响。该研究将对农业可持续发展提供科学指导，并且丰富农业水管里知识体系，推进农业节水措施的有效实施。

干旱成灾机理十分复杂，在气候变化非稳态背景下，干旱监测与风险趋势预估是防旱抗旱亟需关注的难点问题。松嫩平原作为我国重要的粮食产区，干旱风险严重威胁着粮食安全。在此背景下，本项目考虑土壤水、降水、潜在蒸散等与干旱有显著关系的变量，通过构建修正土壤水分亏缺指数、非平稳标准降水蒸散指数，以适应气候非稳态带来的影响。借助Copula联合分布函数探究了松嫩平原气象干旱多维特征重现期特征，基于EEMD-HHT方法分析了农业干旱周期，深入探索了研究区在气候变化背景下的干旱演变特点。此外，项目探究了气候变化对气象干旱的定量影响以及人类活动对不同干旱特征变化的定量性作用，基于气候模式模拟数据分析了未来气候变化对农业干旱的趋势影响。研究结果可为松嫩平原防旱抗旱和农业可持续发展提供科学指导。