2000—2018年青海湖流域气温和降水量变化趋势空间分布特征

青藏高原是全球气候变化的敏感区,气温和降水量的空间分布及变化趋势是气候变化研究的核心和基础,为开展生态环境变化评估提供基础资料。基于2000—2018年青海湖流域及其周边气象站观测数据,以高程为协变量,结合专业气象插值软件ANUSPLIN对气温和降水量进行空间插值。利用线性回归法分析了青海湖流域2000—2018年气温和降水量的变化趋势;利用双变量空间自相关分析法分析了青海湖流域气温和降水量空间匹配关系。结果表明：（1） 2000—2018年青海湖流域年平均气温呈显著增加趋势,平均增速为0.30 ℃·（10a）^-1,春季增温显著。（2） 降水量呈显著增加趋势,平均增速为73.20 mm·（10a）^-1,春夏季增速显著、秋季变化不明显、冬季趋于变干。（3） 青海湖流域气温和降水量空间匹配差异显著。从年尺度来看,气温和降水量莫兰指数（Moran’s I）为-0.66,表现为显著的负相关,面积比为67.56%,水热组合空间匹配不佳。从季节尺度来看,青海湖流域春季、夏季、秋季和冬季的气温和降水量Moran’s I分别为-0.49、-0.80、-0.32和-0.14,均为空间负相关。春夏季,流域低海拔区域气温逐渐升高,高海拔区域降水量逐渐增多,气温和降水量空间负相关面积逐渐增大,水热组合空间匹配不佳。值得强调的是青海湖巨大水体对环湖区局地气温的调节作用明显,是青海湖流域的“气候调节器”。

Spatial distribution characteristics of temperature and precipitation trend in Qinghai Lake Basin from 2000 to 2018

The Qinghai-Tibet Plateau, China is a sensitive area for global climate change. The spatial distribution and change trend of temperature and precipitation are the core and foundation of climate change research and provide basic data for developing ecological environment change assessment. This paper is based on the observation data of meteorological stations in the Qinghai Lake Basin and its surroundings during 2000—2018 using elevation as a covariate combined with the professional meteorological interpolation software ANUSPLIN to perform spatial interpolation of temperature and precipitation. The linear regression method was used to analyze the variation in the temperature and precipitation in the Qinghai Lake Basin. Furthermore, bivariate spatial autocorrelation analysis was used to analyze the spatial coupling relationship of temperature and precipitation in the basin. The research results show the following: (1) The temperature in the Qinghai Lake Basin from 2000 to 2018 showed an increasing, with an average growth rate of 0.30 ℃·(10a)^-1, and increased significantly in spring. (2) Precipitation showed a significant increasing trend, with an average growth rate of 73.20 mm·(10a)^-1; the growth rate is significant in spring and summer, the change is not obvious in autumn, and the winter tends to become dry. (3) The spatial matching of temperature and precipitation in the Qinghai Lake Basin is significantly different. On the interannual scale, the Moran’s I of temperature and precipitation is -0.66, showing a significantly negative correlation, with an area ratio of 67.56% and poor spatial matching of water and heat combinations. On a seasonal scale, the Moran’s I of temperature and precipitation in the Qinghai Lake Basin in spring, summer, autumn, and winter are -0.49, -0.80, -0.32, and -0.14, respectively, which are all negatively correlated in space. In spring and summer, the temperature in the low-altitude areas of the basin gradually increases, the precipitation in the high-altitude areas gradually increases, the area of negative correlation between temperature and precipitation gradually increases, and the spatial matching of water and heat is poor. Notably, the large water body of Qinghai Lake has an obvious regulating effect on the local temperature in the area surrounding the lake and serves as the climate regulator of the Qinghai Lake Basin.