Atmospheric dustfall is solid air pollutant, has a major impact on the environment and human health. The objective of this study was to investigate the microscopic characteristics and sources of atmospheric dustfall in open-pit mining coal resource-based city in the arid desert area of Northwest China. The characteristics of size and shape factors, variation of shape factors with size distribution, types of individual particles, and sources of atmospheric dustfall, which were collected in the open-pit mining area and surrounding areas, were analyzed by X-ray diffraction (XRD) and scanning electron microscopy coupled with an energy dispersive spectrometer (SEM–EDS) combined with graphical method and shape factors. The results showed that the atmospheric dustfall in all functional areas was dominated by coarse-grained particles. The shape of the atmospheric dustfall deviated from spherical shape, and with decreasing particle size, the difference in shape factors increased in each functional area. The EDS and XRD analyses indicated the presence of 13 types of particles. The sources were mainly local and included soil dust from each functional area; industrial dust, construction dust, biogenic impurities, fossil fuel combustion, wear products of motor vehicle parts, motor vehicle exhaust emissions, and emission and excreta from biological activities in each functional area except the desert area; emissions from a steel plant in the industrial area; coal-associated ore, coal dust, coal gangue emissions, and emissions from the spontaneous combustion of coal gangue in the open-pit mining area; secondary chemical crystallization products in the industrial area and the open-pit mining area; dust generated by vehicles abrading the surface of the off-mine coal road and in the open-pit mining area.

Canopy interception is an important part of forest ecosystem hydrological processes. It is the first stage of water distribution when rainfall reaches the canopy and has an important impact on nutrient inputs and water exchange. Pinus tabulaeformis is a main tree species in the rocky mountain areas of Northern China, and it is also a primary species for artificial afforestation. In previous studies of canopy interception, applications of the revised Gash model did not take rainfall characteristics into account. Therefore, in this study, rainfall patterns were divided according to the local rainfall characteristics in the rocky mountainous areas of Northern China. Rainfall was divided into three patterns. Rain pattern A was the main rainfall type. Rainfall patterns B and C were two types of rainstorms. Next, the revised Gash model was used to simulate Pinus tabulaeformis plantations under different rainfall patterns. The results showed that the canopy interception rate of Pinus tabulaeformis plantations in this area ranged from 14.7% to 17.9%. The revised Gash model can be used to simulate Pinus tabulaeformis plantations in the rocky mountainous areas of Northern China, with good simulation results for more than 80% of the conventional rainfall patterns. Furthermore, the canopy interception effect of simulated cumulative rainfall events was better than the individual rainfall event. The simulation effect for special rainfall patterns was not good, so it is necessary to improve the model parameters or collect more rainfall samples. These results can be used to explore the applicability of the revised Gash model in Pinus tabulaeformis plantations in the rocky mountain areas of Northern China. They also demonstrate different applicability of the model under different rainfall characteristics.

During ecological restoration, it is necessary to comprehensively consider the state of vegetation in climate–soil–vegetation systems. The theory of ecohydrological optimality assumes that this state tends to reach long-term dynamic equilibrium between the available water supply of the system and the water demand of vegetation, which is driven by the maximization of productivity. This study aimed to understand the factors that affect the spatial distribution of vegetation and simulate the ideal vegetation coverage (M₀) that a specific climate and soil can maintain under an equilibrium state. The ecohydrological optimality model was applied based on meteorological, soil, and vegetation data during the 2000–2018 growing seasons, and the sensitivity of the simulated results to input data under distinct vegetation and soil conditions was also considered in the Yongding River watershed, China. The results revealed that the average observed vegetation coverage (M) was affected by precipitation characteristic factors, followed by wind speed and relative humidity. The M, as a whole, exhibited horizontal zonal changes from a spatial perspective, with an average value of 0.502, whereas the average M₀ was 0.475. The ecohydrological optimality theory ignores the drought resistance measures evolved by vegetation in high vegetation coverage areas and is applicable to simulate the long-term average vegetation coverage that minimizes water stress and maximizes productivity. The differences between M and M₀ increased from the northwest to the southeast of this area, with a maximum value exceeding 0.3. Meteorological factors were the most sensitive factors of this model, and the M₀ of the steppe was most sensitive to the stem fraction, mean storm depth, and air temperature. Whether soil factors are sensitive depends on soil texture. Overall, the study of the carrying capacity of vegetation in the natural environment contributes to providing new insights into vegetation restoration and the conservation of water resources.

Atmospheric dustfall is solid air pollutant, which is mainly influenced by local sources, so it has a major impact on the local environment and the health of local residents. The objective of this study was to investigate the distribution characteristics of dustfall fluxes and particle size, and the meteorological factors affected them. Atmospheric dustfall was collected in an open-pit coal mining area and surrounding areas in the arid desert area of Northwest China from March to December 2018. Dustfall fluxes was measured, particle size was measured by using graphical methods and grain-size characteristic parameters, the meteorological factors were measured by using Spearman’s Correlation Coefficient (SCC) and Stepwise Linear Regression (SLR), the correlations of dustfall fluxes, mean diameter, the content of particles at different grain-sizes were measured by using SCC. The results showed that dustfall fluxes were larger in open-pit mining area and desert area, and in spring and summer. The frequency of particle size distribution showed unimodal distribution, with the peak and the mean diameter in desert area being the largest, and being larger in spring and summer. The main meteorological factor affecting dustfall fluxes was wind speed and affecting particle size was relative humidity. There was no significant correlation between dustfall fluxes with mean diameter and the content of particles at different grain-sizes. The results of this study can provide areas and times where atmospheric dustfall control should be reinforced, and provide strong scientific support for regulatory policies.

In order to study the counterpoint configuration about the types of mining sites and ecological restoration technologies, open-pit coal mine dumps that had been ecologically restored, since many years, in the grassland mining area in western Inner Mongolia, were selected. A comprehensive evaluation of slope protection effect, vegetation restoration effect, soil improvement effect and engineering technology cost was carried out in order to classify the types of sites for open-pit coal mine dumps and to determine their counterpoint ecological restoration technology, so as to provide theoretical guidance and technical support for ecological restoration of the grassland mining area in western Inner Mongolia. The research results are as follows: (1) Soil thickness, slope gradient and slope aspect are the dominant factors affecting the site conditions of the dump site. Base on this, the dump site of the open-pit coal mine in the grassland mining area of western Inner Mongolia was divided into 9 types of sites. (2) For half-shade and half-sunny to thick soil gentle slope, we primarily recommend plant grid slope protection + planting + sowing + sprinkler irrigation, and the second recommendation is hexagonal brick slope protection + mortar masonry ditch + sowing + sprinkler irrigation; for half-shade and half-sunny to medium-thick soil gentle slope, we primarily recommend masonry skeleton slope protection + mortar masonry ditch + sowing + sprinkler irrigation, and the second recommendation is sowing + vegetation blanket coverage + sprinkler irrigation; for half-shade and half-sunny to thin soil gentle slope, it is recommended to use gravel capping + mortar masonry ditch. For sunny thick soil gentle slope, we primarily recommend eco bag blocking + planting + sowing + vegetation blanket coverage + sprinkler irrigation, and the second recommendation is eco bag blocking + sowing + grass curtain coverage grass curtain coverage + sprinkler irrigation; for sunny thick soil steep slope, it is recommended to use plant grid slope protection + mortar masonry retaining wall + sowing + sprinkler irrigation. For shade thick soil gentle slope, we primarily recommend eco bag blocking + planting + sowing + vegetation blanket coverage + sprinkler irrigation is preferred, and the second recommendation is planting bag stacking + mortar masonry retaining wall + sprinkler irrigation; for shade medium-thick soil gentle slope, it is recommended to use eco bag blocking + corrugated pipe drainage + sowing + vegetation blanket coverage + sprinkler irrigation; for the shade medium-thick soil steep slope, we primarily recommend eco bag blocking +sowing + grass curtain coverage + sprinkler irrigation, and the second recommendation is eco bag blocking + corrugated pipe drainage + sowing + vegetation blanket coverage + sprinkler irrigation. For thick soil platform, use of planting + sowing + sprinkler irrigation is recommended. The research results provide a scientific basis for selection of ecological restoration technologies in the grassland coal mining area in western Inner Mongolia. At the same time, with respect to the semi-arid grassland mining area with relatively fragile habitats, this research be of great significance to improve the greening benefits of the mining area and for improving the mining area and surrounding ecological environment.

The red soil region in southern China is an ecologically fragile area. Although ecological engineering construction has achieved phased results, there are still obvious gaps in research on the mechanisms underlying vegetation dynamics in response to natural and anthropogenic variables. Changting County (CTC) serves as a typical case of vegetation degradation and restoration in the region. We examined the vegetation dynamics in CTC with the fraction vegetation cover (FVC) based on kernel normalized difference vegetation index-based dimidiate pixel model (kNDVI-DPM) and employed the optimal parameter-based geographical detector (OPGD), multiscale geographically weighted regression (MGWR), and partial least square structural equation modeling (PLS-SEM) to analyze interaction mechanisms between vegetation dynamics and underlying factors. The FVC showed a fluctuating upward trend at a rate of 0.0065 yr⁻¹ (p < 0.001) from 2000 to 2020. The spatial distribution pattern was high in the west and low in the east. Soil and terrain factors were the primary factors dominating the spatial heterogeneity of FVC, soil organic matter and elevation showing the most significant influence, with annual mean q-values of 0.4 and 0.3, respectively. Climate, terrain, and soil properties positively and anthropogenic activities negatively impacted vegetation. From 2000 to 2020, the path coefficient of anthropogenic activities to FVC decreases from −0.152 to −0.045, the adverse effects of human activities are diminishing with ongoing ecological construction efforts. Climate and anthropogenic activities act indirectly on vegetation through negative effects on soils and terrain. The impact of climate on soils and terrain is gradually lessening, whilst the influence of anthropogenic activities continues to grow. This study provides an analytical framework for understanding the complex interrelationships between vegetation changes and the underlying factors.