Influence of DEM resolution on landslide simulation performance based on the Scoops3D model

Because of the physical character of soil from granite weathering and the typhoon rains in South China, the model for early warnings of existing shallow landslides cannot be well applied in that area. This study developed a new shallow landslide model based on the effect of soil macropores for determining the rainfall threshold to post an early warning of the possibility of a shallow landslide in South China. We studied the hydrological effects of macropore flow and proposed a mechanistic model of the formation of shallow landslides by introducing the macropore coefficient of granite residual soil. The rainfall threshold of each slope unit was calculated by combining the hydrological model with the proposed shallow landslide model. Lastly, we tested the calculated result in the Maguihe watershed, Guangdong province, South China, which experienced a group of massive shallow landslides on 21 September 2010. The study results showed that the macropores of vegetation roots had a significant effect by increasing the permeability of granite residual soil. Coniferous forest land has the highest initial infiltration rate and stable infiltration rate, followed by shrub forest land, and then bare land. Statistical verification showed that the accurate prediction rate of the proposed model was 80.65%, which is adequate for early warning of shallow landslides in South China. We discuss the application conditions and parameter calibrations of the proposed model, and offer recommendations for future research.

Section: Introductionmentioning

confidence: 99%

Combining soil macropore flow with formation mechanism to the development of shallow landslide warning threshold in South China

Wang

Gong²,

Shang³

2023

“…Diatomite was usually studied as a material for industrial applications in building, bleaching, filtering, and so on (Stoemer and Smoll, 2001;Fragoulis et al, 2005;Van Garderen et al, 2011). In recent decade, with the continuous development of foundation engineering, civil engineering construction is developing towards various complex geological conditions (Yang et al, 2022;Ma et al, 2021;Zhou et al, 2022;Liu et al, 2022;Qiu et al, 2022;Wang et al, 2022). In the construction of railways and highways, diatomite areas are often encountered along the route and the engineering characteristics of diatomite is also beginning to attract researchers' attention (Koizumi et al, 2009;Calvo et al, 2012).…”

Section: Introductionmentioning

confidence: 99%

Engineering properties and microcosmic mechanism of cement stabilized diatomite

Cui

Tao²,

Zhang³

et al. 2022

In this study, the engineering properties of remolded diatomite and the effects of cement on the compression characteristic, strength properties and microstructures of cement-stabilized diatomite were investigated. Samples were prepared and stabilized with different cement content ratios, ranging from 0% to 15% by dry mass. Results show that compared with undisturbed diatomite, the compressibility of the remolded diatomite increases while the strength characteristics decrease. With the increase of cement content, the compressibility of cement-stabilized diatomite is significantly reduced and the strength characteristics are improved. Adding cement to diatomite changes the structure of pure diatomite and forms more tiny pores between cement and diatomite, while curing reduces the porosity ratio of samples and enhance the strength of cement-stabilized diatomite, especially for diatomite with higher cement content. The physical-chemical reactions including hydrolysis and hydration between cement and diatomite increase the content of sodium aluminosilicate, calcium aluminosilicate and other minerals in the soil.

“…Ground penetrating radar (GPR), time domain reflectometry (TDR) and frequency domain reflectometry (FDR) techniques based on soil dielectric properties were widely applied to estimate surface soil water content (Luo et al, 2019;Liu et al, 2022). In practical engineering applications, the soil dielectric constant could be quickly and accurately measured by the above nondestructive techniques to indirectly predict the spatial and temporal distribution of surface soil moisture (Wu et al, 2019;Qiu et al, 2022). Therefore, the laterite dielectric constant model has very important applications in the irrigation automatic control of regional agricultural, protection of soil ecological environment, geological disasters monitoring, evaluation of soil and water conservation, etc.…”

Section: Introductionmentioning

confidence: 99%

Study on the dielectric properties and dielectric constant model of laterite

Wang

et al. 2022

The soil dielectric constant model reflects the relationship between the volumetric water content and the dielectric constant. The ground penetrating radar (GPR) could quickly, precisely and non-destructively obtain the water state of the soil layers. A reasonable and reliable dielectric constant model is of great significance for predicting, monitoring and exploring water migration in soils. Taking Yunnan laterite as an example, this study comprehensively considered the key physical factors (dry density, water content, temperature) of the in situ laterite dielectric properties. The dielectric properties and the influencing factors of laterite has been discussed with the laboratory tests by reshaping laterite, and the dielectric constant model was finally proposed to evaluate the natural water state of the laterite. The results show that the relative dielectric constant of laterite increases gradually with the increasing volumetric water content, dry density and temperature respectively. The water content is the most important influencing factor, secondly followed by temperature and dry density. The dielectric constant model of laterite was built based on the influence of dry density and temperature on the relationship between the relative dielectric constant and volumetric water content. The proposed multivariate model has a good prediction effect on the water content of laterite, and the prediction effects compared with other existing models are as follows: Multivariate model, Zhao model, Malicki model, Zhou model, Topp model, Liao mode and Herkelrath model. This model could be applied to evaluate the plastic limit index and the liquid limit index using the relative dielectric constant, and then finally estimate the soft and hard state grades of laterite. This study could provide a reference for the construction of laterite dielectric constant models in different regions, and a convenient way for the estimation of the laterite water content state and engineering categories.