A New Approach to the Landslide Early Warning using the Chemical Composition Fluctuation in the Leakage from Susceptible Slopes

Landslides are natural disasters that annually inflict great damages to public and private properties which may associate with loss of life. In recent decades, research on developing methods for predicting the time of landslide has been one of the significant attempts made by scientists. Since in some type of material, landslides are preceded by undetectable movements that cannot be recorded and revealed by conventional instruments, recording the chemical changes of the water flowing out from the toe of the slopes susceptible to sliding can provide important and reliable indicators of landslide activities and early warning. In this study, changes in the chemical composition of water seeping out from the toe of an active landslide were investigated. This process was studied in a laboratory physical model, in which a sliding surface was simulated and the changes in the ion concentration of potassium (K), sodium (Na), magnesium (Mg), calcium (Ca), sulfate (SO4), chlorine (Cl), and bicarbonate as well as EC and pH in both stable state and in the conditions of slight rupture along the sliding surface were investigated. The results indicated that the appreciable chemical changes in the outflowing water, particularly changes in the concentration of some ions, could be used as suitable indicators for early warning of the landslide occurrence.