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Reservoir-induced earthquakes (RIEs) occur frequently in the Three Gorges Reservoir Area (TGRA) and the rock mass strength of the hydro-fluctuation belt (HFB) deteriorates severely due to the reservoir-induced seismic loads. Three models of typical bedded rock slopes (BRSs), i.e. gently (GIS), moderately (MIS), and steeply (SIS) inclined slopes, were proposed according to field investigations. The dynamic response mechanism and stability of the BRSs, affected by the rock mass deterioration of the HFB, were investigated by the shaking table test and the universal distinct element code (UDEC) simulation. Specifically, the amplification coefficient of the peak ground acceleration (PGA) of the slope was gradually attenuated under multiple seismic loads, and the acceleration response showed obvious surface effect and elevation effect in the horizontal and vertical directions, respectively. The S-type cubic function and steep-rise type exponential function were used to characterize the cumulative damage evolution of the slope caused by microseismic waves (low seismic waves) and high seismic waves, respectively. According to the dynamic responses of the acceleration, cumulative displacement, rock pressure, pore water pressure, damping ratio, natural frequency, stability coefficient, and sliding velocity of the slope, the typical evolution processes of the dynamic cumulative damage and instability failure of the slope were generalized, and the numerical and experimental results were compared. Considering the dynamic effects of the slope height (SH), slope angle (SA), bedding plane thickness (BPT), dip angle of the bedding plane (DABP), dynamic load amplitude (DLA), dynamic load frequency (DLF), height of water level of the hydro-fluctuation belt (HWLHFB), degradation range of the hydro-fluctuation belt (DRHFB), and degradation shape of the hydro-fluctuation belt (DSHFB), the sensitivity of factors influencing the slope dynamic stability using the orthogonal analysis method (OAM) was DLA > DRHFB > SA > SH > DLF > HWLHFB > DSHFB > DABP > BPT. (c) 2024 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/ licenses/by-nc-nd/4.0/).

期刊论文 2024-08-01 DOI: 10.1016/j.jrmge.2023.09.0431674-7755 ISSN: 1674-7755

Hydro-Fluctuation Belt (HFB), a periodically exposed bank area formed by changes in water level fluctuations, is critical for damaging the reservoir wetland landscape and ecological balance. Thus, it is important to explore the mechanism of hydrological conditions on the plant-soil system of the HFB for protection of the reservoir wetland and landscape restoration. Here, we investigated the response of plant community characteristics and soil environment of the HFB of Tonghui River National Wetland Park (China), is a typical reservoir wetland, to the duration of inundation, as well as the correlation between the distribution of dominant plants and soil pH, nutrient contents, and enzyme activity by linear regression and canonical correlation analyses. The results show that as the duration of inundation decreases, the vegetation within the HFB is successional from annual or biennial herbs to perennial herbs and shrubs, with dominant plant species prominent and uneven distribution of species. Soil nutrient contents and enzyme activities of HFB decreased with increasing inundation duration. Dominant species of HFB plant community are related to soil environment, with water content, pH, urease, and available potassium being principle soil environmental factors affecting their distribution. When HFB was inundated for 0-30 days, soil pH was strongly acidic, with available potassium content above 150 mg kg(-1) and higher urease activity, distributed with Arundo donax L., Polygonum perfoliatum L., Alternanthera philoxeroides (Mart.) Griseb., and Daucus carota L. communities. When inundated for 30-80 days, soil pH was acidic, with lower available potassium content (50-150 mg kg(-1)) and urease activity, distributed with Beckmannia syzigachne (Steud.) Fern.+ Polygonum lapathifolium L., Polygonum lapathifolium L., Medicago lupulina L. + Dysphania ambrosioides L. and Leptochloa panicea (Retz.) Ohwi communities. Using the constructed HFB plant-soil correlation model, changes in the wetland soil environment can be quickly judged by the succession of plant dominant species, which provides a simpler method for the monitoring of the soil environment in the reservoir wetland, and is of great significance for the scientific management and reasonable protection of the reservoir-type wetland ecosystem.

期刊论文 2024-04-01 DOI: 10.1016/j.jenvman.2024.120776 ISSN: 0301-4797

The reservoir coastal zone is the transitional zone between the terrestrial ecosystem and the aquatic ecosystem. Soil is an essential part of the terrestrial ecosystem and vital for life on Earth. To understand the composition and diversity of the soil eukaryotic microbial community under the background of artificial planting of Chrysopogon zizanioides in various habitats after reservoir construction, including the original habitat (OH), the hydro-fluctuation belt (HB), and the road slope (RS), and to analyze the interaction between the main groups of eukaryotic microorganisms, this study conducted 18S rDNA amplification high-throughput sequencing of the soil eukaryotic microbial community. The study found that the dominant phylum of eukaryotic microorganisms in the three habitats was consistent, but there were significant differences in the community and diversity of eukaryotic microorganisms in the three habitats. The differences in fungal communities between sample sites were greater than those of soil microfauna. Correlation analysis showed that nitrogen, phosphorus, and organic matter were significantly correlated with eukaryotic microbial diversity, with alkaline-hydrolyzed nitrogen and total phosphorus significantly correlated with fungal communities and pH and water content correlated with soil microfauna. Co-occurrence network analysis found that the interactions between fungi and the correlation between fungi and soil microfauna dominated the eukaryotic microbial community, and the interactions between eukaryotic microbes in different habitats were dominated by positive correlations. After the construction of the reservoir, the newly formed hydro-fluctuation belt reduced the types of interrelationships between fungi and microfauna compared to the original habitat. The road slope provided protection of the supporting project for the reservoir construction, although there was also planted vegetation. Eukaryotic microbes declined significantly due to the damage to and loss of the organic layer, and the decline in microfauna was the most significant, resulting in a simple structure of the soil food web, which affects the function and stability of the soil ecosystem.

期刊论文 2024-02-01 DOI: 10.3390/plants13030393 ISSN: 2223-7747
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