黄河流域降雨时空分布特征

Precipitation variations in the Yellow River Basin of China

对于黄河流域降雨时空分布规律的探究，有助于从细部区分不同区域和时段的降雨变化对黄河干支流产流产沙的影响，对于黄河水循环的科学研究和治黄工程措施均有重要意义。利用黄河流域内分布的67座气象站点，使用多种时间序列分析方法，对过去59年（1959-2017年）的黄河流域降雨序列的时空分布特征进行探究。结果表明：黄河流域具有7种典型的降雨空间分布类型；其中，源区（III区）全区域的年降雨量均有显著的增加趋势，是缓解黄河流域用水紧张的积极自然因素；多沙粗沙区（IV区）的年中大雨日数有显著的减少趋势，这可能是黄河下游近年来沙量锐减的原因之一。进一步的降雨序列频谱分析结果，一方面证实了2-4年的短周期是黄河流域多数站点降雨普遍最显著的周期，另一方面也部分佐证了分区的合理性。

The precipitation will change in the Yellow River Basin due to global climate changes. The flow in the Yellow River depends on the runoff from various regions and during different periods. Engineers need to predict these flow to make decisions about flood-control projects. The present study investigates the daily series of precipitation in the Yellow River Basin from 67 meteorological stations over the past 59 years （1959-2017） using multiple time-series analysis methods. The results show that the upper and middle parts can be divided into 7 regions. In the source region area of the Yellow River Basin （region lid, the annual precipitation has increased significantly which provides more water for use in the entire Yellow River Basin. However, in the middle reach （region IV）, annual number of days with medium or heavy rains in some areas have significantly decreased, which may be one reason for the reduced water flow and sediment load in recent years in the river. The precipitation frequency information shows the rainfall levels have periods of 2 - 4 years in the Yellow River Basin. These results give evidence for identifying critical areas that impact the runoff in the Lower Yellow River.