Wintertime characteristic variability of ice distribution and water transfer efficiency improvement in Central Route of South-to-North Water Diversion Project in China
The efficiency and safety management of the Central Route of the South-to-North Water Diversion Pro-ject(CRSNWD)during winter are significantly impacted by ice.To improve its performance,it is crucial to gain a better understanding of water temperature and ice distribution within the system.This paper compiles 11 winters'field observations,including meteorological data,hydraulic characteristics,and ice distributions from 2011 to 2022.The study aims to illustrate the spatial and temporal variability of water temperature and ice distribution,un-derstand the driving factors behind ice propagation in the system,and propose ice-prevention plans for wintertime water transfer.The results of field observations reveal that the ice-affected region is smaller and has a shorter dura-tion than anticipated.The area within the CRSNWD affected by ice lies between the Qilihe siphon and Beijumahe culverts,while the ice jam-affected region is situated between the Hutuohe siphon and Beijumahe culverts.The average ice thickness over multiple years is 15 cm,with an extreme value of 2.9 m,and the historical water level rise due to ice jams is 0.73 m.Water temperature during winter decreases from south to north in the CRSNWD,ex-hibiting a negative correlation with flow discharge and air temperature.The critical cross-sectional average water temperatures for border ice,ice floes,and ice cover are 3.5 ℃,1.5 ℃ and 0.25 ℃,respectively.The study i-dentified air temperature,water diversion discharge,solar radiation,and wind speed as the most dominant factors influencing ice processes in the system.Severe ice jams that occurred in January 2016 resulted from a combination of lower accumulated freezing degree days,larger flow discharge,and a short-term cold wave.A high wind speed in the Caohe duct causes a rapid decrease in water temperature and significant ice formation.Based on these find-ings,the study proposes shortening operation periods,reducing ice-affected regions,optimizing hydraulic control parameters,and developing ice-prevention techniques to enhance the wintertime operation of the CRSNWD.
water temperature and ice distributionspatial and temporal variabilitySouth-to-North Water Di-versionwintertime safetywater transfer efficiency
万方数据
维普
