典型流域水文极端事件模拟及对外界胁迫响应对比分析研究

In recent years, flood and drought events happen frequently and have influence on water safety in the basin. Identifying hydrological extreme events in the basin is the key of water resourses management. Therefore, the project is proposed in the Dongting Lake basin and The Tarim river basin . The purpose is to analysis the threshedhold characters of hydrologic extreme events and simulating its relative sensitivity. At the same time ,by using the weather generator auxiliary, critical areas is corresponded to meteorological conditions (such as precipitation, lasting drought, etc.) of the reverse transformation, and change traditional climate impacts by top-down GCM application simulation results and downscaling are analyzed.Based on this, according to the space and time variation parameter extension method, hydrological extreme events in different periods of random distribution characteristics and evolution process will be studied in the condition of current and future climate situations. The random distribution character and mankind activity's contribution in different period will be achieved. The research results of the projects can provide scientific basis for risk management and water resources utilization and protection in similar watershed.

近年来，频繁发生的洪旱事件对流域水安全影响巨大，有效地识别自然变异和人为胁迫影响下的流域水文灾害与极端事件的时空响应特性是流域水资源管理的关键。本项目拟选择具有不同区域特征的典型流域，对比研究变化环境下的洞庭湖流域和具有显著干旱特征的塔河流域的水文响应特征,模拟流域的水文极端事件的阈值特性及对外界胁迫的敏感性；利用天气生成器辅助进行不同流域关键源区水文过程向相应的临界气象条件（如降水、持久干旱等）的转化，改进传统气候变化影响研究采用自上而下应用GCM模拟结果及降尺度等带来的精度与不确定性问题；以此为基础，模拟分析当前和未来气候情景下的极端水文事件在不同时期的随机分布特征、演变过程、关键诱因及其贡献程度,从而揭示不同流域水文态势与外界变化条件胁迫的响应过程，从而推求有限资料条件下特定或极端情景的水文特征和技术参数，为类似流域水资源利用与保护提供参考。

本项目拟在以往研究成果和资料基础上，选择典型的对比流域洞庭湖流域和塔河流域，分别研究确立不同流域水文极端事件风险及其敏感性模拟分析机制；利用天气生成器辅助进行不同流域关键源区水文过程向相应的临界气象条件（如降水、持久干旱等）的转化，克服传统气候变化影响研究采用自上而下应用GCM模拟结果及降尺度等带来的精度与不确定性问题；以此为基础，建立贝叶斯多变量条件概率和信息转换函数，模拟当前和未来气候情景下的极端水文事件在不同时期的随机分布特征、演变过程、关键诱因及贡献程度；从而揭示不同流域水文态势与外界变化条件胁迫的互响应机理，推求有限资料条件下特定或极端情景的水文风险特征，为类似流域水资源风险管理。