2000-2019年西北地区云水资源时空特征研究

Spatial and temporal characteristics of cloud water resources in Northwest China from 2000 to 2019

中文关键词:  西北地区，云水资源，时空特征，季节特征，统计分析

英文关键词:Northwest  China, Cloud  water resources, Temporal  and spatial  characteristics, Seasonal  characteristics, Statistical  analysis

中文摘要:

      为认识西北地区的云水资源特征以及科学规划人工增雨开发空中水资源作业布局，利用2000-2019年中国地区1°×1°云水资源数据集，采用线性拟合和经验正交分解等方法，统计分析了西北地区云水资源(Cloud Water Resource，简称CWR)的分布及演变气候特征。结果表明：(1)从全区整体看，云水资源的相关物理量(包括：状态量、平流量、总量和降水效率)主要表现为夏季最高，春、秋季次之，冬季最低的季节特征。其中，春季云水资源总量约为1736亿吨(折合柱水量约为51.2mm)，仅次于夏季；春季水凝物降水效率为48.7%，相较于秋季，春季的云水资源开发潜力更大。(2)从区域内1°×1°网格的计算结果得到空间分布，受地势与环流的影响，近20年云水资源年总量及水汽年总量、水凝物年总量的多年平均空间分布呈“两高一低”的特征，高值位于西风急流区与季风影响区，低值区主要位于高原气候区。(3)近20年，西北区域格点的云水资源年总量平均以23.6 mm/a速率增加，其中春季的增加趋势最显著，增速为8.5 mm/a。季节分布上，CWR夏季最多，春、秋季次之，冬季最少；水凝物降水效率夏季高，秋、春季较低，冬季最低。(4)CWR年总量的EOF分解第一模态(EOF1)贡献率为78.2%，分布特征为区域东部较高，在2008年出现年际转折，开始转变为CWR量东部多西部少的分布格局。(5)在西北地区典型区域中，天山区域格点平均的CWR年总量以及水凝物降水效率均高于祁连山区，祁连山区的CWR在增加，天山区在减少。

英文摘要:

      In order to understand the characteristics of Cloud Water resources in Northwest China and scientifically plan the layout of air water resources for artificial rainfall development, the 1°×1° cloud water resources dataset in China from 2000 to 2019 was used to statistically analyze the distribution and evolution of cloud water resources (CWR) in Northwest China by using linear fitting and empirical orthogonal decomposition methods. The results show that: (1) From the whole area, the related physical quantities of cloud water resources (including state quantity, plain discharge, total amount and precipitation efficiency) are mainly the highest in summer, followed by spring and autumn, and the lowest in winter. Among them, the total cloud water resources in spring is about 173.6 billion tons (equivalent to about 51.2mm column water), which is approaching to that in summer; The precipitation efficiency of hydrometeors in spring is 48.7%, and the development potential of cloud water resources is greater than that in autumn. (2) From the calculation results of the 1°×1° grid in the region, the spatial distribution of annual total cloud water resources, annual total water vapor and annual total hydrometeors in the past 20 years is characterized by "two highs and one low" due to the influence of terrain and circulation. The high value is located in the westerly jet and monsoon affected regions, while the low value is mainly located in the plateau climate region. (3) In the past 20 years, the annual total cloud water resources at 1° grid point in the northwest region increased at an average rate of 23.6 mm/a, and the increase trend was the most significant in spring, with a growth rate of 8.5 mm/a. In terms of seasonal distribution, CWR was the highest in summer, followed by spring and autumn, and the least in winter. The precipitation efficiency of hydrometeors is high in summer, low in spring and autumn, and lowest in winter. (4) The contribution rate of the first mode of EOF decomposition (EOF1) of CWR is about 78.2%. The distribution feature is that the eastern part of the region is relatively high. In 2008, there was an interannual turning point, and the distribution pattern of more CWR in the east and less CWR in the west began to change. (5) In typical areas of Northwest China, the average annual total CWR and precipitation efficiency of hydrometeors in Tianshan Mountains are higher than those in Qilian Mountains, CWR increased in Qilian Mountain area and decreased in Tianshan Mountain area.