Understanding the variation characteristics and possible causes of lake-land breeze speed in Dongting Lake under large-scale climate background is of reference significance for the development and utilization of wind energy resources，water transportation and disaster prevention and reduction. The hourly wind direction and wind speed data at Yueyang Station from 1954 to 2021 are used to analyze the wind speed characteristics and long-term trends of the shoreline and lake-land wind by using the linear tendency estimation，Mann-Kendall mutation detection and sliding t-test methods. The results show that about the wind direction and wind speed characteristics of the four times，02：00，08：00 and 20：00 （Beijing time，the same as below） were almost the same，and the easterly wind and land breeze were dominant，while the westerly wind and lake breeze prevailed at 14：00，and the wind speed at 14：00 was significantly higher than other times. At the inter-annual scale，the variation trend of lakeshore and lake-land wind speed was consistent at four times，both the wind speeds at four times and the land breezes at 02：00，08：00 and 20：00 all showed an obvious decreasing trend，while the change of the lake breeze at 14：00 was not significant. For monthly scale，the wind speed peaks at 02：00，08：00 and 14：00 were all in July，and at 14：00 in winter months land breezes were dominated，and in other months it was dominated by lake breezes. It was dominated by land breezes at 02：00，08：00 and 20：00 in each month，and lake breeze speed was the highest in flood season throughout the year. On the hourly scale，the variation trend of hourly wind speed from 2004 to 2021 was basically the same as that of the lake-land breezes. The frequency of the land breezes was higher than that of the lake breezes，and the wind speed was larger and lake breeze was dominated from 10：00 to 17：00，and the lake breezes with a duration of 3 to 10 hours occurred from 09：00 to 18：00 in each month. The mutation tests find that the wind speed at four times decreased significantly from the 1970s，but only at 14：00 it changed abruptly around 1970，and the abrupt changes of the lake-land breeze speeds at four times occurred in 2002 or 2003. The increase of lake breeze speed and short-term wind speed caused by the change of detection environment can not change the long-term decrease trend of wind speed，and the change of instruments has little effect on wind speed and lake-land wind speed.

Based on long-term remote sensing products, this paper constructs evaluation indicators for surface high temperatures and analyzes the distribution characteristics of surface high temperatures in Hunan Province over the past 20 years, aiming to provide technical references for agricultural production, disaster prevention and mitigation. Firstly, the daily surface high temperature dataset are calculated using long-term data regression of MYD11A1, MYD13A1 and MYD09GA from 2002 to 2021. The percentage method, percentile method and trend ratio method are used to construct remote sensing evaluation indicators for surface high temperatures, then the spatial and temporal distribution characteristics of surface high temperatures are analyzed. The results indicate that when using the proportion of areas with daily surface temperatures greater than or equal to 45 ℃ as the threshold for classifying surface high temperature levels on a daily scale, it aligns best with meteorological warning indicators. The annual maximum surface high temperature in Hunan Province showed a significant increase with 2013 as a turning point. The extreme threshold for annual surface high temperatures in Hunan Province (ranging from 40.2 to 64.1 ℃), determined using the percentile method, can serve as an evaluation metric for high temperature intensity. Additionally, using the trend rate of surface high temperatures in Hunan Province to evaluate the increase or decrease trends of annual surface high temperatures has good application value. Rapid warming in the Changsha-Zhuzhou-Xiangtan urban agglomeration and the Dongting Lake area, as well as extreme high temperatures in the Hengshao drought corridor, require special attention in the future.

Based on ERAinterim reanalysis data from 2009 to 2018, the spatial and temporal distribution characteristics of cloud liquid water content and cloud ice water content in Qinghai were analyzed. The results show that both cloud liquid water content and cloud ice water content increased from northwest to southeast. Cloud water resources were concentrated in the southern part of Yushu, southeastern part of Guoluo and Qilian mountain areas, where they were highest in summer and autumn and could reach 60～70 g·m-2. Cloud liquid water content and cloud ice water content increased firstly and then decreased with increasing altitude. Cloud liquid water content was concentrated at a height of 4 to 6 km, and cloud ice water content was concentrated at a height of 7 to 8 km. The altitude with the maximum cloud ice water content was higher than that with the maximum cloud liquid water content. In summer and autumn, the amplitudes of vertical variation of cloud liquid water content and cloud ice water content were biggest in Qinghai southern plateau, while they were smallest in Qaidam Basin. Cloud liquid water content and cloud ice water content in most parts of Qinghai increased from 2009 to 2018 and the increasing trend in autumn was most obvious. Cloud liquid water content and cloud ice water content was highest in September and lowest in January. The differences in monthly variations of cloud liquid water content and cloud ice water content in Qaidam Basin were smallest. The difference in monthly variations of cloud liquid water content in eastern agricultural region was biggest, while the difference in monthly variations of cloud ice water content in Qinghai southern plateau was biggest.

Based on hourly precipitation data from 96 meteorological stations during the flood season from 1980 to 2018 in Hunan Province, the occurrence frequency and contribution rate to the total precipitation amount were used as important indicators, and the spatialtemporal evolution characteristics of precipitation structure in Hunan Province during the flood season were analyzed. The results are as follows: (1) The occurrence frequency of rainfall events decreased by power function with increasing durations, while its contribution rate to the total precipitation amount of rainfall events increased linearly with increasing duration. The occurrence frequency of short duration rainfall event was high, while its contribution rate to the total precipitation amount was low. The occurrence frequency of long duration rainfall event was low, but contribution rate to the total precipitation amount was high and long duration rainfall event was the main body of precipitation in flood seasons. Both the occurrence frequency and contribution rate to the total precipitation amount of short duration rainfall events  were higher in southern Hunan than in northern Hunan, while the occurrence frequency and contribution rate to the total precipitation amount of long duration rainfall events were higher in northern Hunan than in southern Hunan. (2) In the past 10 years, both the occurrence frequency and contribution rate to the total precipitation amount of short duration rainfall events increased linearly, while the occurrence frequency and contribution rate to the total precipitation amount of long duration rainfall events decreased linearly. (3) Occurrence frequency of all rainfall events decreased by power function with increasing precipitation levels, while contribution rate to the total precipitation amount increased linearly with increasing precipitation levels. Although the occurrence frequency of torrential rainfall event was low, while it was the main contributor to precipitation during the flood season. The occurrence frequency and contribution rate to the total precipitation amount of light to moderate rainfall events were generally higher in southern Hunan than in northern Hunan, while the occurrence frequency and contribution rate to the total precipitation amount of heavy to torrential rainfall events were higher in northern Hunan than in southern Hunan.  (4) The interannual variation of occurrence frequency of light to heavy rainfall events was not significant, but the occurrence frequency of the torrential rain event increased significantly, while the interannual variation of contribution rate to the total precipitation amount of light rainfall events was not significant, but for moderate rain to heavy rainfall event it showed a significant downward trend, and contribution rate to the total precipitation amount of torrential rainfall events showed a significant upward trend.

Based on daily temperature, relative humidity, precipitation, wind speed, cloud coverage data in Lishui of Zhejiang Province during 1971-2018, according to the holiday climate index grading standard, this paper analyzed the spatial and temporal distribution characteristics of HCI and holiday climate suitability of Lishui by using mathematical statistics method in order to evaluate the holiday climate environment. The results show that the average HCI was 69.7 in Lishui, which belonged to the “appropriate” level. The holiday climate was favorable from April to May (HCI=72.2) and from September to November (HCI=76.1), and it was the best in October (HCI=80.6). The holiday climate “suitable and above” days were 258.1 d, “general and acceptable (HCI=40-59)” days were 83.2 d, all showed a slow decreasing trend. The “unsuitable and below” days were 24.0 d, showing a significant increasing trend. The holiday climate environment was superior in the northeast Jinyun from April to May, and it was the best in the southwest Qingyuan from September to November.

In recent years, the rainstorm occurred frequently in Zhuzhou of Hunan Province, which caused increasingly serious urban water-logging, and the rainstorm parameters of drain and flood control design had changed obviously. Based on minutely precipitation from 1963 to 2017 at Zhuzhou weather station, the samples of annual maximum precipitation with sixteen durations were selected by using the moving average method, and the variation characteristics of designed rainstorm intensity and pattern before and after climate abrupt change in Zhuzhou were discussed. The results show that rainstorm days and annual maximum precipitation had an obvious abrupt change in 1983 in Zhuzhou of Hunan Province. After the mutation, rainstorm days increased and rainstorm intensity strengthened, which caused the increase of extreme precipitation events in Zhuzhou. Before the mutation, the change trends of annual maximum precipitation with different durations were inconsistent and non-significant, while they showed obvious increasing tendency after the mutation, and the precipitation with duration 120 minutes and above passed the significance test. The precipitation of rainstorm with different durations increased under different recurrence periods after the mutation, and the difference of precipitation before and after the mutation increased with increase of recurrence period and extension of duration. The position and precipitation of rain peak for short-time and long-time rainstorm pattern moved forward and increased after the mutation, respectively, which partly explained why the water-logging was frequent in Zhuzhou in recent years.