Improvement Of China's Nearly 500 Years Of Grid-point Precipitation Anomaly Field Recovery Methods, Analysis And Western Alternative Records Discussion

The 500-year grid precipitation anomaly series of the east of China has been achieved by evaluating and interpolating the precipitation data, which combined the precipitation information (1501-1911) originated from historical documentary records using text identification automatically software written in Visual Basic language and instrumental precipitation data (1912-2000). But the former method is not very perfect.In this study, the former method of 500-year grid precipitation anomaly series of China has been checked carefully and some incompletion in the method has been analyzed and improved. The 500-year 1 X 1 grid precipitation anomaly series in the east of China has been obtained by new improved method.The rationality of the improved method and the reliability of the new grid precipitation anomaly series have been tested and validated. The result shows that the improved method is feasible and the 500-year grid precipitation anomaly series in the east of China is also exact.The varying characteristics of dryness and wetness area of different regions and the dryness and wetness distribution patterns in the east of China during 500 years have been analyzed by 500-year grid precipitation anomaly series in the east of China.Finally, the main research achievements on precipitation reconstruction of substitutable data during the recent 2000 years in the west of China are summarized and discussed. The precipitation series of several spots in the west of China has been compared with the dryness and wetness area of different regions and the dryness and wetness spatial patterns in the east of China during recently 500 years. The result shows that the some precipitation variation in the west of China is in good according with the dryness and wetness area and in the east of China, but others do not have this obvious corresponding relationship.