With the escalating global climate change and frequent human activities, Inner Mongolia, as a crucial ecological barrier in the Beijing-Tianjin-Hebei region, Bohai Economic Rim, and even the whole country, confronts many ecosystem issues. To reveal the intricate interplay between natural processes, human activities, and policy interventions shaping the region’s ecological landscape, we provide a comprehensive analysis of ecological quality in Inner Mongolia from 2002 to 2021. Key findings include: (1) The research uncovers an overall improvement in ecological quality across Inner Mongolia, albeit with certain regions exhibiting a pattern of deterioration followed by improvement, particularly notable in the central part of the province. (2) Cropland, shrub, grassland, barren, wetland, and water are decreasing, while impervious, and forestland are increasing. (3) Precipitation, temperature, and elevation are significant drivers affecting the quality of the ecological environment. Interestingly, while human production and activities have altered ecological conditions, factors like GDP, population density, and night lighting index do not directly impact environmental quality significantly. This underscores the intricate interplay among various factors within the socioeconomic system, highlighting its complexity. (4) Based on these findings, our policy recommendations include strengthening ecological monitoring and management, promoting sustainable urban development, conducting public education and awareness campaigns, and fostering stakeholder collaboration for data sharing and collective understanding. Adopting sustainable management strategies is essential for promoting ecological resilience and mitigating environmental degradation in Inner Mongolia, not only benefiting the local ecosystem but also contributing to national and global environmental well-being.

The western margin of the Badain Jaran Desert is an important cross-section of sand transportation on the alluvial plain in the middle and lower reaches of the Heihe River. Five typical surfaces（playa, reed land, salt-alkali land, shifting sandy land, nabkha dune） were selected in this study. MWAC dust collectors were used to carry out field observation of near-surface sand-dust transport flux. The horizontal flux and distribution characteristics of sand-dust at different surface heights（10 cm, 25 cm, 50 cm, 85 cm） were observed and analyzed during the observation period. Results showed that the horizontal flux of sand-dust decreased with height following an exponential function. Within 0-85 cm height, the horizontal flux and distribution characteristics of sanddust on the five typical surfaces were significantly different and the horizontal flux of sand-dust in the 0-10 cm accounted for the largest proportion. The horizontal flux of sand-dust showed a trend that shifting sandy land＞playa＞reed land＞salt-alkali land＞nabkha dune. Shifting sandy land and playa are the main sediment transport sources in the western margin of the Badain Jaran Desert. The density of vegetation coverage, the area size of exposed space and the characteristics of soil gravel content directly affected the sand-dust flux that were transported on the surface. Variations of wind speed were likely to affect the distribution of horizontal flux. When wind speed was increased, both the initiated sand particle size and the sand-dust flux were increased. The results could help to understand the dust transport process in the western desert margin, as well as the regional sandstorm process.

The wind speed and wind direction data during 2017-2021 measured at the Ixiekpati protection station of the Altun National Nature Reserve were used to analyze the wind conditions and sand transport potential of the Altun National Nature Reserve. The results showed that the annual average wind speed of Altun Mountain National Nature Reserve was 3.10 m·s-1, the annual average wind speed was 7.67 m·s-1, and the annual average wind frequency was 8.57%, which showed a higher wind frequency in spring and summer than in autumn and winter. The seasonal variation of the wind direction of sandy wind is large, mainly concentrated in winter, spring and summer, and the main wind direction in spring and winter is W wind, SW wind and WSW wind, while the NE wind and E wind are the main wind direction in summer. The annual sand transport potential（DP） of Altun Mountain National Nature Reserve is 580.23 VU, which is a high wind energy environment（＞400VU）; the annual synthetic sand transport potential（RDP） is 266.69 VU, the synthetic sand transport direction（RDD） varies greatly seasonally, and the annual directional variability index（RDP/DP） of the sand transport potential is 0.36, which is a medium directional variability（0.3～0.8） of the sharp in the whole year, the sand transport potential is the largest in spring, followed by summer and winter, and the sand transport potential is smaller in autumn, and there are strong seasonal differences. In the winter, spring and summer when the sand transport potential is larger, the directional variability indices of sand transport potential are 0.90, 0.41 and 0.20, which belong to low, medium and high variability, respectively.

Salt minerals have profound influences on soil architecture and physical properties through efflorescence and subflorescence. However, there is a lack of data on identifying the role of salt mineral types in aeolian erosion. In this study, seven types of single salt including NaCl, KCl, MgCl2, Na2SO4, K2SO4, MgSO4, and Na2CO3 were examined to preliminarily explore the influencing mechanism of efflorescence and subflorescence by these salts on aeolian erosion. Soil samples treated by these salts were prepared under an environmental condition of summer in the semiarid region and wind tunnel tests were conducted subsequently under a strong wind of 18 m s(- 1). The results show that Na2SO4, MgSO4, and Na2CO3 generated highly emissive surfaces. Crystals of Na2SO4 and Na2CO3 occurring in an acicular form and arranging loosely induced crusts with weak strength. For MgSO4, the fluffy aggregates on the crust surface as a result of dehydration were the main dust source. MgSO4 crystals within the crust occurred in a prismatic form and were covered with fissures or cracks, inducing a salt crust with great strength, but having the tendency to dehydrate. The crystals of NaCl, KCl, and MgCl2 occurred in cubic or tabular form and in compact arrangement, forming crusts with great strength and inhibiting dust emission. K2SO(4) formed a thin crust peeling off from the soil which is susceptible to aeolian erosion. Under the influence of subflorescence, Na2SO4, MgSO4, and Na2CO3 attenuated the strength of the soil through salt heaving, which increased the potential of aeolian erosion. In contrast, NaCl, KCl, MgCl2, and K2SO4 played a role as bonding agent and reduced the potential of aeolian erosion. These results suggest that salts that could crystalize into hydrous and anhydrous minerals, such as Na2SO4, MgSO4 and Na2CO3, can remarkably enhance the potential of dust emission at the soil surface and subsurface.

沙粒的表面磨蚀效应是地表产尘、释尘的重要机制,针对干湖盆泥漠地表开展磨蚀释尘实验研究,对理解干湖盆地表风蚀过程及盐碱尘暴形成机理具有重要意义.对采自西居延海干涸湖盆泥漠地表土样进行室内磨蚀模拟实验,研究了不同粒级(细、中、粗)沙粒不同落沙角度(30°,45°,60°)的磨蚀效应.结果表明:(1)泥漠地表磨蚀实验中能够产生明显释尘效应的沙粒粒级阈值为中沙(0.25 mm＜Md＜0.50 mm);(2)磨蚀粒径粒级相同时,磨蚀角度会对泥漠地表磨蚀释尘速率产生影响,磨蚀量的角度排序为60°＞30°＞45°,但同一粒级3种角度下的磨蚀释尘率差异不显著.(3)磨蚀角度为45.时,计算了泥漠地表的质量磨蚀率与能量磨蚀率,其中中沙为0.04 g·kg-1、0.43g·J-1,粗沙为0.08 g·kg-1、0.74 g·J-1,极粗沙为0.26 g·kg-1、2.54 g·J-1;在磨蚀沙粒粒级倍增而磨蚀角度不变情况下,泥漠地表磨蚀释尘率与能量磨蚀率未发生正比例线性增长变化.

With the acceleration of urbanization in South China, rainstorms and floods are threatening the safety of people in urban areas. The 11 April 2019（4·11 hereafter）rainstorm in Shenzhen City was a typical pre-rainy season rainstorm that caused great damage, yet such pre-rainy season events have not attracted sufficient attention in research.Risk perception of the public may indirectly affect their disaster preparedness, which is important for disaster management. In this study, we conducted a questionnaire survey that considered demographic factors and the level of risk perception, knowledge of risk, impact of the 4·11 rainstorm event on public risk perception, and degree of trust in the government. We used a two-factor model of risk perception to evaluate the factors that influenced public risk perception of the 4·11 rainstorm in Shenzhen. The main conclusions are: The 4·11 rainstorm improved public awareness of both risk and impact through the medium term, but the public’s perceived low probability of disaster occurrence and lack of knowledge of the pre-rainy season rainstorm phenomenon led to serious losses during this event. Although the public has high trust in the Shenzhen government, the management of rainstorm disasters in the pre-rainy season needs to be further improved.