Double-index model of landslide meteorological warning based on the I-D threshold

Abstract

Objective Determining the rainfall threshold is of great significance in controlling the risk of rainfall-induced landslides. Methods A total of 98 rainfall-induced landslides in Quzhou, Zhejiang Province, were used to study the rainfall threshold. Based on the statistical analysis of the rainfall data from 1970 to 2019, the rainfall threshold models established by the I-D, E-D and E-I curves are compared and analyzed. Subsequently, a landslide meteorological warning double-index model with daily rainfall R0 and 5-day effective rainfall R5 as warning indices was established based on the I-D model. Finally, the rationality and reliability of the model were confirmed using historical rainfall and landslide data. Results The results show that: (1) I-D is better than E-D and E-I in predicting rainfall-induced landslides; (2) The double-index model reasonably forecasts the average annual warning times of red, orange and yellow landslides in Quzhou, which are 1.5, 3.2 and 9.3, respectively; 20 landslides can be accurately predicted by the double-index model, of which 15 landslides are red and orange, and the model has successfully predicted all eight landslides in 2014; (3) The 7 hysteretic landslides used to test the prediction ability of the model all fell into the warning area, including 3 orange, 3 yellow and 1 blue events. Conclusion The results proposed in this paper are helpful for the meteorological warning of landslides in Quzhou and provide new methods for government risk assessment and management.

Keywords

• rainfall-induced landslide
• effective rainfall
• rainfall threshold
• double-index model
• landslide meteorological warning