Based on the observation of rail temperature and meteorological measurements under four different underlying surfaces of water,forest,urban and cultivated land in Guangxi,the characteristics of the rail temperature on different underlying surfaces and its relationship with meteorological conditions are analyzed,and then the multiple regression fitting equations under different conditions are established.The results show that the value of difference between the daily maximum(minimum)of rail temperature and the daily maximum(minimum)of the air temperature is 0-18 ℃(0-5 ℃).There is a significant positive correlation between daily rail temperature extremum and air temperature extremum in different underlying surfaces,indicating that air temperature is one of the decisive factors affecting the change of rail tempera-ture.In typical high temperature and low temperature processes,there is a good synchronization between the extremum of rail temperature and air temperature.Compared to not distinguishing between sky types,the correlation between rail temperature extremum and air temperature extremum is improved under three different sky types:foggy day,cloudy to overcast day and sunny to less cloudy day.Under these three con-ditions,the four meteorological elements(air temperature,precipitation,relative humidity and wind speed)are used to carry out multiple regression for the rail temperature of the four underlying surfaces.It is found that the correlation coefficients between the calculated and the observed rail temperature all surpass 0.90 and the mean absolute error(MAE)is between 0.42 and 3.33 ℃.Except for the sunny to less cloudy type,the correlation coefficients of the other types are in the range of 0.94-0.99,and the MAE is less than 2.58 ℃,which implies that the fitting prediction effect of rail temperature is reliable.
维普
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