Exploring the quantitative impact of short-term weather variability intensity (SWVI) on influenza incidence in Hubei Prov⁃ ince is of significant importance for conducting early risk warning and formulating prevention policies. Based on the influenza inci⁃ dence data and meteorological station observation, an index of SWVI has been built, which can measure the cumulative changes over a short-term in minimum temperature between two consecutive weeks. Based on the Distributed Lag Nonlinear Model (DLNM), the rela⁃ tion between SWVI index and influenza incidence risk was evaluated and a set of method for level classification of influenza incidence risk was developed. The results show that the intra-annual variation of number of Influenza-Like Illnesses (ILI) exhibited bimodal struc⁃ ture, with the first peak occurring in autumn and winter, and the second peak appearing in early summer months. The SWVI index also exhibited a bimodal distribution, but the peak occurring earlier than the peak of ILI. From November to March of the following year, SWVI index had a strong indicative significance for the change of ILI morbidity. In this period, when SWVI reaches 8.0 ℃, the cumula tive relative risk (RR) of ILI incidence at the same period and the next week was 1.16 (95% confidence interval: 1.087-1.250). In addition, SWVI index also had an indirect effect on the risk of ILI with a lag of 4-9 weeks, which was less affected than the immediate effect, but lasted longer. Using the percentile method and the relationship model between the SWVI index and the ILI incidence risk, a set of influenza risk early warning method was established. When the SWVI index was greater than or equal to 8.0 ℃, the influenza incidence reached high risk level

Under the background of global warming, studying the characteristics of dry-wet climate changes in the Shiyang Rive Basin and their influence on vegetation coverage has significant importance for the ecological environment construction of the basin. Based on the precipitation temperature homogenization index (S) in the Shiyang River Basin from 1971 to 2020, the spatial-temporal changes of the dry-wet climate in the basin were analyzed from the aspects of drought station frequency ratio, drought frequency, and more. Combined with the Normalized Differential Vegetation Index (NDVI) remote sensing data, the influence of dry-wet change on NDVI was analyzed. The results showed that the inter-annual and seasonal S indices showed an increasing trend in the Shiyang River Basin over the past 50 years, with the most pronounced increase in summer. The drought degree and drought occurrence area have shown a decreasing trend in the basin. The intensity of drought in the midstream and downstream were more severe compared to the upstream, with higher drought frequencies in the downstream. The annual NDVI increased with the alleviation of drought, the increase of precipitation and decrease of temperature. The precipitation in the early and middle period of growth, as well as the temperature in the middle period had a great influence on the annual NDVI. In February, May and July, the NDVI had a lag effect in response to drought.

Based on MODIS-NDVI (normalized difference vegetation index) datasets, the vegetation coverage was calculated in Liaoning Province from 2001 to 2019. Combined with land cover products of MODIS and air temperature and precipitation data at 61 meteorological observation stations in Liaoning Province, the spatio-temporal variation characteristics of vegetation coverage of five main types of vegetation were analyzed emphatically, and their responses to temperature and precipitation changes were discussed. The results are as follows: (1) The multi-year mean vegetation coverage was 0.48, and it was high in the east and low in the west of Liaoning Province from 2001 to 2019. The annual vegetation coverage increased in most areas of Liaoning Province in the past 19 years, and it presented an obvious increasing trend with the rate of 0.036 per 10-year as a whole. In additional, the vegetation coverage of five main vegetation types including crop, grassland, deciduous broadleaf forest, woody savanna and savanna increased significantly in Liaoning Province in the past 19 years, and the increasing rate of grassland vegetation coverage was the largest, while for crop vegetation coverage it was the smallest. (2) The vegetation coverage of crop was positively correlated with precipitation and negatively correlated with temperature in semi-arid areas of warm temperate zone in Liaoning Province, while it was positively correlated with precipitation and temperature in semi-humid areas of warm temperate zone. The response of grassland vegetation coverage to precipitation was stronger than temperature, while deciduous broadleaf forest, woody savanna and savanna were more sensitive to temperature. (3) The time lag responses of vegetation coverage with five main vegetation types to temperature and precipitation were different. The response of crop and grassland to precipitation in last month was sensitive during the growth season, while the responses of deciduous broadleaf forest, woody savanna and savanna to previous month’s temperature and precipitation were sensitive at the end stage of growth season.

In order to reveal the influence of climate change and human activity on runoff in the Taizihe basin, based on conventional observation data including temperature and precipitation at five meteorological stations and runoff at a hydrological station of Liaoning Province during 1961-2018, the trend and mutation characteristics of runoff, areal precipitation and potential evapotranspiration were analyzed statistically by using linear regression analysis and cumulative anomaly methods, etc. And on this basis, the contributions of climate change and human activity to runoff change were estimated quantitatively by using slope change ratio of cumulative quantity (SCRCQ). The results show that the runoff and areal precipitation, potential evapotranspiration decreased slightly in the Taizihe basin during 1961-2018 as a whole, and the significant mutation of runoff and areal precipitation occurred in 1975, 1984, 1996 and 2009, while that of areal potential evapotranspiration occurred in 1983. The correlations of runoff with areal precipitation, potential evapotranspiration were extremely significant, and the runoff increased with increase of precipitation and decrease of potential evapotranspiration. The study period was divided into five stages according to the abrupt point of runoff. Compared with the base period (1961-1975), the contribution rates of climate change to runoff decrease were 23.24%, -0.08%, 18.57% and 28.45% during 1976-1984, 1985-1996, 1997-2009 and 2010-2018,  respectively, while for human activities they were 76.76%, 100.08%, 81.43% and 71.55%, respectively, which indicated that the human activities played an dominant role in decreasing of runoff in the Taizihe basin.