Predicting When Peak Discharge Occurs for Ephemeral Flow at McMurdo Station Watershed

摘要

McMurdo Station watershed in Antarctica is one of the southernmost basins that annually experiences active water flow during the austral summer. This runoff, primarily from snowmelt, has daily and seasonal fluctuations. The flow fluctuation and variation depend on the air temperature and on many other factors. At times, extreme runoff has occurred at McMurdo Station such that water overflows across the roads and bypasses the culverts, creating disruption and massive erosion. Knowing when the peak runoff occurs is critical for operation and maintenance of the channels. We conducted an analysis of indicators relating the air temperature and cloud cover to flow rate to quantify when significant flow occurred. Flow data taken during austral summers 2009-2010 and 2010-2011 were used in the analysis. Based on the correlation between the change in accumulated thawing degree-days and cloudiness expressed as clearness, the time delay in the peak discharge can occur between 4 and 14 days after a peak temperature. Relating temporal indicators and flow records, a relationship between real time data and the need for maintenance personnel to implement mitigation factors could be achieved.