当前位置: X-MOL 学术Environ. Earth Sci. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Gully slope distribution characteristics and stability analysis for soil erosion risk ranking in parts of southeastern Nigeria: a case study
Environmental Earth Sciences ( IF 2.8 ) Pub Date : 2021-03-31 , DOI: 10.1007/s12665-021-09605-7
Johnbosco C. Egbueri , Ogbonnaya Igwe , Chinanu O. Unigwe

Critical slope stability analysis has proven to be a reliable technique which could be used in gully erosion risk assessments. The integration of experimental and stability modelling has assisted extensively in the analysis of natural slopes. In the current paper, several geotechnical properties and slope parameters were studied in an attempt to characterize gullying processes and risk in southern Anambra State, Nigeria. Field mapping, geotechnical analyses, geostatistical analyses, and limit equilibrium simulations were integrated to achieve the research objectives. The field measurements showed that most of the gullies are characterized by high slope angles ranging between 18° and 85°. Based on the geotechnical analysis, the soil slopes were observed to be highly vulnerable to landsliding. Principal component and regression analyses efficiently captured the interrelationships between the analyzed erosion gully parameters. Several slope stability models were used to estimate the factor of safety (FS) of the slope materials. It was revealed that most of the slopes are unstable and vulnerable whereas others are critically to moderately stable. Furthermore, while the slopes recorded FS in the range of 0.82–1.72 in unsaturated condition, FS of 0.70–1.33 was observed for saturated condition. This result indicated that the gully slopes are more vulnerable to failure by erosive forces in wet season, due to rainwater infiltration and pore-water pressure buildup. Gully slopes within the Nanka Formation showed higher failure vulnerability than those in Ogwashi and Benin formations. The details of this study would be helpful towards the mitigation of landslide hazards in the study area.



中文翻译:

尼日利亚东南部部分地区水土流失风险等级的沟壑分布特征和稳定性分析:一个案例研究

临界边坡稳定性分析已被证明是一种可靠的技术,可以用于沟壑侵蚀风险评估中。实验模型和稳定性模型的集成为自然斜坡的分析提供了广泛的帮助。在当前的论文中,研究了几种岩土属性和坡度参数,以试图描述尼日利亚南部阿南布拉州的流沙过程和风险。现场制图,岩土分析,地统计分析和极限平衡模拟相结合以达到研究目的。现场测量表明,大多数沟壑的特征是在18°至85°之间的高倾斜角。根据岩土工程分析,观察到土质边坡极易发生滑坡。主成分和回归分析有效地捕获了所分析的侵蚀沟参数之间的相互关系。使用了几种边坡稳定性模型来估算边坡材料的安全系数(FS)。据透露,大多数斜坡是不稳定的和易受伤害的,而其他的则是至中等程度的稳定。此外,尽管在非饱和条件下斜坡记录的FS在0.82-1.72的范围内,但在饱和条件下观察到的FS在0.70-1.33的范围内。该结果表明,由于雨水的渗透和孔隙水压力的增加,在雨季,沟壑边坡更容易受到侵蚀力的破坏。Nanka组内的沟壑坡度比Ogwashi组和贝宁组的崩塌脆弱性更高。

更新日期:2021-03-31
down
wechat
bug