Evaluation of the risk of the breaking of check dam based on a scorecard model.

Check dam is a line of defense in the comprehensive watershed management system, but with the extended operation time, the operational risk of check dam increases, coupled with the frequent occurrence of sudden heavy rainfall under the influence of climate change in recent years, further increasing the risk of dam break.

In this study, to address the current problem of untimely detection of potential dam break risk of check dam in China, we use the common variable screening based on WoE (Weight of Evidence) and IV (Information Value), establish a score card model based on logistic regression method, use KS curves and statistics, and AUC values for model evaluation, and analyze the 2016 From 22:00 on August 16 to 12:00 noon on August 17, 2016, a dam break was formed by a large rainstorm in Dalat Banner.

The following conclusions were obtained: The IV values of each variable, such as control area, total storage capacity, siltation area, storage volume, and maximum rainfall, were all greater than 0.1, and each variable had more than moderate predictive power as a function of the breaking of check dam, that is, each factor had an effect on the breaking of check dam.The IV values of precipitation factors are higher than those of check dam factors. The influence probability of precipitation factors on the breaking of check dam is about 67%, and the influence probability of check dam factors on the breaking of check dam is about 33%.Precipitation is a direct factor affecting the breaking of check dam, and the maximum 6-hour precipitation has the most significant effect; among the check dam factors, the control area, storage volume, and flood storage capacity have a greater effect on the breaking of check dam, accounting for more than 10%, while the siltation volume and depth have a smaller effect on the breaking of check dam, accounting for 2.85% and 2.89% respectively.Very low risk which check dam with a score of 95 or higher account for about 43%, low risk for 28%, average risk for 15%, and higher risk for 7%. Very high risk accounted for 5% and there was only one dam with danger which is rated below 10.

This study aims to monitor and warn the operation of check dam to ensure the safe operation of the check dam system and maintain the ecological security of the Loess Plateau.