Use of displacement as a proxy for dike safety

Abstract

Climatic conditions and vegetation cover influence water flux in a slope which affect the pore water pressure and self weight, hence its stability. High evapotranspiration and low precipitation rates during summer cause dry soil with low soil moisture (SM) that leads to soil shrinkage, which leads to cracking and reduced shear strength, which consequently decreases the stability of slopes. Soil re-wetting increases slope weight and exerts an additional driving force on the slope. Using Earth observation (EO) data facilitates frequent, large-scale monitoring to identify the vulnerable areas along the slopes to avoid instability. Here we study the displacement of a vegetated dike subject to SM variations under varying climatic conditions. Results show that the SM and magnitude of total displacement at a desired location are highly positively correlated without time lag. This proof-of-concept study shows that near surface displacement due to interaction with the atmosphere has a strong relation with the water availability in the slope and therefore the Factor of Safety (FoS).

A Data-Driven Surrogate Approach for the Temporal Stability Forecasting of Vegetation Covered Dikes

“…In those numerical studies, the meteorological data combined with soil parameters were used as input for the model to estimate the change in FoS and the non-linear hydro-mechanical behaviour of a dike under various weather and vegetation conditions. The results were qualitatively validated using in situ data from an instrumented dike [42]. The same temporal signature and strong correlation in key parameters were observed in the real dike.…”

“…An example dike geometry is used in the numerical study which, to a large extent, resembles a regional (secondary) dike in Amsterdam, the Netherlands [2]. The same example dike is also used in [36,41,42]. This dike ( Figure 4) has a relatively steep slope on the lefthand side and a gentle slope on the right-hand side and is permanently covered by grass.…”

“…The feature selection was based on the available EO data that have high spatial/temporal resolutions and relatively good precision, and a good correlation with the FoS. Soil moisture and ground water level influence dike safety strongly [41,42], but they are difficult to observe without ground-based monitoring. Therefore, the selected features for FoS prediction in this study are LAI, di f [LAI], displacement, daily rainfall, cumulative rainfall and temperature.…”