5. Severity Level of N-flow Events in the Yellow River

Using the measured data on no-flow events in the Lower Yellow River since 1972, this paper presents an approach to describe the no-flow status in terms of a comprehensive indicator. The severity level of no-flow events are identified by cluster analysis. Furthermore, the relation between severity level and incoming water from upstream and its variance is well established with a BP-typed Artificial Neutral Network (ANN), which is helpful to identify the complex response of the severity level to flow characteristics. The availabitlity of the approach for quantitative description and prediction of no-flow events is discussed through comparisons between predicted and measured results in the Lower Yellow River.