青藏高原土壤湿度及其与中国东部夏季降水的关系

Soil Moisture in the Tibetan Plateau and Its Relationship with Summer Precipitation in Eastern China

摘要: 本文利用GLDAS数据集中的土壤湿度资料，采用经验正交函数(EOF)和相关的方法对青藏高原地区土壤湿度的时空分布特征进行了分析，并进一步研究了高原春季土壤湿度与中国东部夏季降水的联系。结果表明：1981~2016年青藏高原不同季节的土壤湿度在空间分布特征上相一致，呈现出由东南部向西北部递减的分布特征，并且土壤湿度会随着土壤深度的加深而增加。青藏高原春季各层次土壤湿度与中国东部地区夏季降水有良好的相关性，具体表现为：高原春季土壤湿度与中国东部夏季降水量呈负相关。从通过信度检验的典型区域来看，高原春季土壤湿度与夏季东南沿海地区降水量呈负相关，在6、7月与长江中下游地区的降水呈负相关，在7、8月东北地区降水呈负相关；还在8月与长江中下游地区降水呈正相关，在6月与东北地区降水量呈正相关。

Abstract: In this paper, using the soil moisture data in the GLDAS dataset, the temporal and spatial distribution characteristics of soil moisture in the Qinghai-Tibet Plateau were analyzed by empirical orthogonal function (EOF) and related methods, and the soil moisture in the spring of the plateau and the summer precipitation in eastern China were further studied. The results show that the soil moisture in the different seasons of the Qinghai-Tibet Plateau is consistent in spatial distribution from 1981 to 2016, showing a decreasing distribution from the southeast to the northwest, and the soil moisture will increase with the depth of the soil. The soil moisture at all levels in the Qinghai-Tibet Plateau has a good correlation with the summer precipitation in eastern China. The specific performance is that the soil moisture in the spring plateau is negatively correlated with the summer precipitation in eastern China. From the typical area through the reliability test, the spring soil moisture in the plateau is negatively correlated with the precipitation in the southeast coastal areas in summer, and negatively correlated with the precipitation in the middle and lower reaches of the Yangtze River in June and July, and precipitation in the northeastern region in July and August. It was negatively correlated; it was also positively correlated with precipitation in the middle and lower reaches of the Yangtze River in August, and positively correlated with precipitation in Northeast China in June.