A GIS-Enabled Approach for Assessing Damage Potential of Levee Systems Based on Underlying Geology and River Morphology

Flood protection levee systems are complex, interconnected systems, where failure at one location means failure of the entire system. Levees are formed through various geologic processes and human activities over time and information regarding soil properties is collected only at limited point locations and varies significantly both laterally and with depth. Prediction of levee performance in locations where no soil data is available becomes a limitation for system risk assessment studies. Geographic Information Systems (GIS) are particularly suitable for the complex and efficient management of spatial information, georeferencing capabilities, and geostatistical analysis. A GIS enabled approach for assessing damage potential of levees systems is presented. Spatial variability of soil properties is correlated with regional variables such as distance from nearest river segment, river meandering sinuosity index, and surface geology. A geostatistical ordinary kriging approach is used for developing these correlations. Soil strength parameters of identified levee stratigraphy layers were statistically analyzed using a geostatistical ordinary kriging approach and correlated with preselected regional variables. A levee system in Northern California is used as a pilot study for the proposed approach. Excessive underseepage and loss of freeboard due to soil liquefaction are evaluated as the two damage indices for earthen levees.