1961 - 2018年青海高原昼夜雨量时空变化特征分析

基于青海高原1961 - 2018年47个气象站昼夜雨量数据， 分析了青海高原及各生态功能区的昼夜雨量及雨日的时空变化特征。结果表明： 近58年来， 青海高原昼夜雨量空间分布基本一致， 总体表现为东南向西北减少， 夜雨日多于昼雨日分布。青海高原昼夜雨量总体均呈增多趋势， 昼雨量的增加速率大于夜雨量； 从空间分布来看， 柴达木盆地西部、 东部农业区大部及青南牧区南部少数地区昼夜雨量呈减少趋势， 而柴达木盆地东部、 环青海湖地区、 青南牧区大部昼夜雨量均呈增多趋势。青海高原昼雨日略有增加， 夜雨日有减少趋势； 在地域上， 柴达木盆地昼夜雨日增多趋势明显， 而东部农业区昼夜雨日减少趋势明显。青海高原昼夜雨量分别呈2 a、 3 a的周期。近58年来， 青海高原、 东部农业区、 环青海湖地区、 柴达木地区昼雨量均无明显的突变现象， 仅青南牧区昼雨量在2003年前后存在明显突变现象； 青海高原、 东部农业区、 青南牧区夜雨量无明显突变现象， 环青海湖地区、 柴达木盆地夜雨量分别在1979年、 2003年出现了突变现象。

Research of the spatio-temporal variation characteristics of daytime and nighttime precipitation in the Qinghai Plateau from 1961 to 2018

The spatial and temporal variations of daytime precipitation and nighttime precipitation were analyzed based on observed data from 47 meteorological stations from 1961 to 2018. The resulted indicated that： （1） The spatial distribution of daytime and nighttime precipitation were basically consistent， in the 58 years， with a decreasing trend from southeast to northwest， precipitation in daytime less than that in nighttime； （2） Spatially， there was an obvious decreasing tendency of precipitation in daytime and nighttime in the Qinghai Plateau， but in the eastern agriculture area， the western Qaidam and the Qingnan pastoral there was an increasing trend， and others areas showed an obviously increasing tendency； （3） There was a few increasing days of daytime precipitation but a decreasing days of nighttime precipitation， it had an decreasing tendency of daytime and nighttime precipitation in the eastern agriculture， but an increasing trend in Qaidam region； （4） There were quasi-periodic variations of 2 years in daytime rainfall and 3 years in nighttime rainfall in the plateau； （5） There was no clear abrupt variation of nighttime rainfall in the Qinghai Plateau， the eastern agriculture， the Qinghai Lake area and Qaidam basin， except for a jumping in 2003， but nighttime rainfall had an abrupt in Qinghai lake area in 1979 and 2003， respectively.