Typhoon-induced slope failure is one of the most important geological hazards in coastal areas. However, the specific influence of typhoons on the stability of residual soil slopes still remains an open issue. In this study, the Feiyunjiang catchment in Zhejiang Province of SE China was chosen as the study area, and a downscaling physical model of residual soil slopes in the region was used to carry out the wind tunnel test. Our aim was to answer the question, How does the vegetation on the slope and slope stability respond during a typhoon event? For this purpose, multiple aspects were monitored and observed under four different wind speeds (8.3 m/s, 10.3 m/s, 13.3 m/s, and 17 m/s), including vegetation damage on the slope, macrocracks on the slope surface, wind pressure, wind load, permeability coefficient of the soil layer, and slope stability. The results showed that the plants on the slope could restore to their original states when the wind speeds ranged from 8.3 m/s to 13.3 m/s, but were damaged to the point of toppling when the wind speed increased to 17 m/s. Meanwhile, evident cracks were observed on the ground under this condition, which caused a sharp increase in the soil permeability coefficient, from 1.06 x 10-5 m/s to 6.06 x 10-4 m/s. The monitored wind pressures were larger at the canopy than that at the trunk for most of the trees, and generally larger at the crown of the slope compared with the toe of the slope. Regarding the wind load to the slope ground, the total value increased significantly, from 35.4 N under a wind speed of 8.3 m/s to 166.5 N under a wind speed of 17 m/s. However, the wind load presented different vector directions at different sections of the slope. The quantitative assessment of slope stability considering the wind load effect revealed that the safety factor decreased by 0.123 and 0.1 under the natural state and saturated state, respectively, from no wind to a 17 m/s strong wind. Overall, the present results explained the mechanism of slope failure during typhoon events, which provided theoretical reference for revealing the characteristics of residual soil slope stability under typhoon conditions.

Dust weather, a prevalent disaster in the arid and semi-arid areas of northern China, poses significant risks to both socioeconomic stability and public health. This meteorological phenomenon, characterized by strong winds sweeping sand particles across vast distances, frequently occurs in these regions. It inflicts considerable damage to infrastructure and environment, while also exposing human populations to an array of respiratory issues and diseases. However, despite the wide range of detrimental effects, the mechanics and influencing factors behind dust weather events remain laden with uncertainties. This lack of clear understanding impairs our ability to implement efficient prevention and control strategies, thereby necessitating in-depth exploration and research into the subject matter. Our quest to unravel the inherent dynamics of dust weather events led us to employ a multivariate analysis approach, combining ground meteorological observation data, satellite remote sensing data, and reanalysis data. Ground meteorological data, collected from weather stations scattered across the affected regions, provides accurate and precise measurements of local conditions such as wind speed, precipitation, temperature, and humidity. On the other hand, satellite remote sensing data opens up a bird's eye view of the situation, enabling us to monitor vast areas simultaneously. Furthermore, it can also reveal changes in land cover and vegetation, providing insights into the potential natural barriers to dust movement. Reanalysis data is a climate or weather model simulation of the past that includes data assimilation. This type of data combines model data with observational data to provide a consistent long-term view of the weather. This unique dataset, spanning a broad time series from 1973 to 2023-Affords us the opportunity to precisely track the shifting characteristics of dust events, thereby laying the groundwork for the identification of potential correlations. Our research primarily seeks to comprehend the relationship between dust events and a selection of environmental parameters. We specifically zeroed in on three factors: Wind speed, precipitation, and vegetation. The selection of these variables is predicated on their considerable influence over atmospheric conditions and soil stability, both of which directly impact the magnitude and frequency of dust events. A salient conclusion from our study asserts that wind speed plays a pivotal role in the occurrence of dust events. There exists a substantial positive correlation between the annual average number of dust days and wind speed, with a correlation coefficient of 0.89 and a significance level of less than 0.01. This underscores that an uptick in wind speed parallels an increase in dust days. Data accumulated since 2013 reveal an upward trend in wind speeds, thereby leading to a surge in dust days. It suggests that if wind speeds continue their upward trajectory, northern China may experience more frequent and severe dust events. Our second conclusion proposes a relatively weak and arguably insignificant correlation between the number of dust days and both precipitation and vegetation indices. Yet, it is critical to note that these factors should not be entirely dismissed. Precipitation and vegetation cover potentially play a moderating role in the transportation process of dust particles. Rainfall can enhance soil stability, reducing the potential for sand particle dispersion, while vegetation establishes a natural windbreak, helping to curb the spread of dust particles. Lastly, we noted an overall upward trend in the springtime vegetation cover of northern China over the last 20 years. This indicates progress in China's afforestation and desertification control efforts. Nonetheless, given the cross-border distribution of sand sources, solutions relying solely on one country's actions may fall short of fully addressing the dust issue. Therefore, we underscore the urgent need for heightened international collaboration and coordination to tackle such cross-border environmental and ecological challenges. Pursuing sustainable development mandates our collective effort to combat the trials posed by dust events. In framing these solutions, we must account for a broader geopolitical context, encouraging global unity to mitigate the adverse impacts of dust events.

The atmospheric boundary layer (ABL) is one of the most fundamental yet complex components of the Earth's atmosphere. Hence, studying the ABL has important theoretical value and practical significance. In this paper, the structural characteristics and heating (cooling) rate of the ABL in summer over the Northern Tibetan Plateau (NTP) were analysed using radiosonde observation data from the Amdo and Nagqu regions. The results indicate that the summertime ABL height over the NTP exhibited obvious diurnal variations, with the ABL height during the dry season being greater than that during the rainy season. The maximum convective boundary layer (CBL) height during the daytime reached 3200 m and 2500 m in the dry and rainy seasons, respectively, and the mean maximum CBL height was approximately 2500 m; the maximum stable boundary layer (SBL) height at night reached 900 m, and the mean maximum SBL height was approximately 500 m. The wind speed dominated by westerly wind in the dry season was greater than that dominated by easterly wind in the rainy season, and the zonal (meridional) wind speed (shear) on sunny days was greater than that on cloudy days. The inverse humidity phenomenon occurred in both Amdo and Nagqu, and the strong humidity inversion occurred mainly at midnight on sunny days and at noon on cloudy days. The heating (cooling) rate of the ABL displayed obvious diurnal variations, with the rates being greater on sunny days and lower on cloudy and rainy days. Furthermore, the mean values of the daytime heating rate and nighttime cooling rate of the ABL were relatively equal, indicating that the atmospheric energy budget was, for the most part, balanced.