项目以源于历史文献的中国东部旱涝等级数据为基础，并补充源于自然证据的干湿/降水变化代用数据；利用时空统计数据插补和尺度转换技术，建立一套过去千年中国东部干湿变化2.5°×2.5°格点数据集（时间分辨率为年）；同时结合海—气涛动模态和CMIP多模式千年模拟数据集，共同揭示中世纪暖期、小冰期与1750年以来中国东部年代际干湿格局差异；辨识在20世纪增暖过程中，中国东部极端降水事件发生频率、强度与中世纪暖期和小冰期的异同；阐明冷、暖气候背景下中国东部年代际干湿格局变化与海—气涛动模态的遥相关机制及其对外强迫（太阳、火山和人类活动）阶段性变化响应机制的可能区别；为全球变化背景下的亚洲气候多尺度变化与海气相互机制研究，提供季风降水格局年代际变化复杂特征与机制等方面的深入认识和基础数据；提升对东亚季风区全球变化响应规律的理解，为未来数十年降水格局变化趋向预估提供自然变率背景。

This project will construct a 2.5° × 2.5° gridded dataset of yearly hydroclimatic variation over Eastern China during the past 1000 years by interpolation and temporal-spatial scale transformation to statistical data, based on the grades of dryness/wetness derived from historical documents and natural proxy data related to precipitation variations. Combined with atmosphere-ocean oscillation modes and the simulations from multi-models in CMIP, the similarities and differences of hydroclimatic patterns in East China among the Medieval Warm Period, the Little Ice Age and after 1750, including the frequency and intensity of extreme precipitation, will be revealed. Furthermore, how the interdecadal hydroclimate pattern and its correlation to atmosphere-ocean modes, as well as their responses to external forcings (such as solar, volcanic and anthropogenic activities) will be illustrated under the background of cold or warm climate changing. This project will also provide insights into complex decadal variations of monsoon precipitation patterns for studies on multi-scale climate changes in Asia and the mechanism of atmosphere-ocean interactions in the context of global changes, promote the understanding of East Asian monsoon region’s responses to global changes, and contribute a scientific basis for the estimation of precipitation patterns in this area in the following decades.