[Pollution Characteristics of Snowmelt Runoff on Different Underlying Surface in Main Urban Area of Harbin]

Snowmelt runoff is the main non-point pollution source of receiving water in the high latitude cities of north China in Spring. In order to control the pollution of surface water body by the snowmelt runoff, the pollution characteristics of 6 kinds of underlying surfaces and 18 sampling points in the main urban area of Harbin were analyzed from late March to early April 2015. Through software SPSS 22.0 and its principal component analysis method, BOD₅, COD, ammonia nitrogen, TP (total phosphorus), petroleum and TN (total nitrogen) were identified as the significant pollution indexes of the snowmelt runoff in the main urban area of Harbin. Single factor ANOVA (Analysis of Variance) and its LSD (Least Significant Difference) multiple comparisons method were adopted to analyze the pollution difference among underlying surface groups and between two kinds of underlying surfaces. The results of AVOVA analysis showed that the difference of TP in all kinds of underlying surface was the largest and that of BOD₅ was the least, and the significant levels (Sig.) were 0.342 and 0.631, respectively. The results of multiple comparisons showed that the MeanDiffs (Mean Difference) between two underlying surfaces of different pollutants were different, and the contribution rates of different pollution index were different too. Meanwhile, due to the influence of geographical position, for the same pollutant, there were differences in different sampling points of the same underlying surface, especially in city road and pavement. Pollution characteristics of snowmelt runoff on different underlying surface showed that the snowmelt runoff pollution in the main urban area of Harbin was mainly affected by the traffic flow, human activities, coal fired heating in winter and industrial emissions.