Abstract

The Lower Red River in Manitoba regularly experiences springtime ice jam flooding, with the most severe events occurring between Lockport and Netley Lake. A database of ice jam events was developed through newspaper archives and historical stage data. Each event was given a severity rating from 1-5, based on the resulting ice jam flood. This facilitated an investigation of ice jam timing and frequency on this section of the Lower Red River and the development of a threshold-based ice jam prediction tool. Out of 54 ice jam events from 1962-2017, all ice jam events occurred when the peak spring flow exceeded 1000 cms and all severe events (severity 3+) occurred when peak spring flows exceeded 1500 cms. The threshold ice jam prediction model was developed using five meteorological and hydrometric parameters including accumulated degree day of thaw, accumulated degree day of freezing, freeze-up water level, snow on ground, and rain equivalence. The model was able to differentiate all severe event years from non-event years with only one false positive result. By gaining a better understanding of ice jamming in the area, this research provides an accessible prediction method that can help guide decisions related to the risk and severity of spring ice jamming.

摘要

曼尼托巴省的红河下游经常出现春季冰塞洪水，其中最严重的事件发生在洛克波特和奈特利湖之间。通过报纸档案和历史舞台数据开发了一个冰果事件数据库。根据由此产生的冰塞洪水，每个事件的严重性等级为 1-5。这促进了对红河下游这一部分冰塞时间和频率的调查以及基于阈值的冰塞预测工具的开发。在 1962-2017 年的 54 次冰塞事件中，所有冰塞事件都发生在春季峰值流量超过 1000 cms 时，所有严重事件（严重性 3+）发生在峰值春季流量超过 1500 cms 时。阈值冰塞预测模型是使用五个气象和水文参数开发的，包括解冻累积度数、累计结冰度日、结冰水位、地面积雪和降雨当量。该模型能够区分所有严重事件年份和非事件年份，只有一个假阳性结果。通过更好地了解该地区的冰堵塞，这项研究提供了一种可访问的预测方法，可以帮助指导与春季冰堵塞的风险和严重程度相关的决策。