Based on the cloud characteristic parameters retrieved by FY-2G satellite and hourly precipitation from July to September 2018, April to September 2019, and April to July 2020 in the eastern region of Qinghai Province, the indications of cloud top height, cloud top temperature, cloud optical thickness and cloud particle effective radius to precipitation frequency and precipitation intensity were analyzed. The results are as follows: (1) The cloud optical thickness was the strongest indicator of precipitation frequency for single cloud characteristic parameter. The frequency of moderate rain and heavy rain showed an obvious increasing trend with the decrease of cloud top temperature, increase of cloud top height and cloud optical thickness, while the frequency of light rain showed a decreasing trend. (2) The double cloud characteristic parameters (cloud optical thickness and cloud top temperature) were better indicators for precipitation frequency than single cloud characteristic parameter, the precipitation frequency increased with increase of cloud optical thickness and decrease of cloud top temperature. When cloud optical thickness was between 21 and 30 and cloud top temperature was greater than 0 ℃, the frequency of light rain was largest. When cloud optical thickness was greater than 40 and cloud top temperature was between -45 and -31 ℃, the frequency of moderate rain was largest. When cloud optical thickness was greater than 40 and cloud top temperature was less than -45 ℃, the frequency of heavy rain was largest. (3) The triple cloud characteristic parameters (cloud top temperature, cloud optical thickness and cloud particle effective radius) were more indicative for precipitation frequency than single cloud characteristic parameter and less indicative than double cloud characteristic parameters.

 Using monthly temperature and precipitation data from 39 meteorological stations in impermanent arid area of Qinghai Province from 1981 to 2017, this paper discussed the spatial and temporal evolution of drought frequency and drought stations proportion in spring in different climatic functional zones based on standardized precipitation index (SPI), and emphatically analyzed the atmospheric circulation anomaly characteristics affecting the distribution of drought and flood in spring. The results show that drought frequency in spring in Qinghai Province ranged from 18.9% to 40.5%, and the drought stations proportion decreased with the rate of 4.9%·(10 a)-1 in spring. It presented humidification phenomenon in spring in each climatic functional zone, and in the pastoral area in southern Qinghai humidification was most obvious with the linear tendency rate of 0.23·(10 a)-1 of SPI. The 500 hPa circulation configuration affecting drought and flood distribution in the southern and northern of Qinghai in spring was generally consistent, the middle and high latitudes over Eurasia showed a “+ - +” distribution pattern in more rainfall years, and a low-to-high distribution from west to east formed over China. In drought years it showed an opposite characteristic. However, the influence of polar vortex on drought and flood distribution was greater in northern region of Qinghai, and western Asia trough influenced the southern region more. The SPI in spring presented significant negative correlation with subtropical upper-level westerly jet position in previous winter, and the Middle East jet stream index had more significant correlation with SPI than the east Asian jet stream index, and their correlation coefficients were 0.514 and 0.332, respectively. When the subtropical upper-level jet position was farther south than usual in previous winter, there was a high probability of spring drought in the following year in Qinghai Province.