ABSTRACT

Traditional hydrological routing schemes are structured in reference to a pre-assumed time-invariant inflow–storage–outflow function. In light of this, potential systemic changes arising from river regulation cannot be accommodated in such a static model structure. As such, a diagnostic methodology is developed in this study to examine the presence of potential systemic changes and recognize time spans in which the adopted inflow–storage–outflow function is inadequate to represent the functional behaviour of the system. This is done objectively by developing a two-step change-point detection algorithm based on the whiteness property of the innovation sequence. Using four carefully designed numerical experiments, our findings reveal that the proposed methodology (a) objectively detects the non-stationary behaviour in streamflow time series associated with systemic changes, (b) properly tracks the pathway of structural evolution of a hydrological routing model, and (c) automatically identifies time periods wherein a river routing model structure needs to be updated.

摘要

传统的水文选路方案是参考预先假设的时间不变的流入-储存-流出函数来构建的。有鉴于此，由河流调节引起的潜在系统性变化无法适应这种静态模型结构。因此，本研究开发了一种诊断方法来检查潜在的系统变化的存在，并识别所采用的流入-存储-流出函数不足以代表系统的功能行为的时间跨度。这是通过开发基于创新序列的白度属性的两步变化点检测算法客观地完成的。使用四个精心设计的数值实验，