| Based on data collected by water quality auto monitoring stations (Heyuan Linjiang and Huizhou Jiantan stations) located at the middle section of Dongjiang river from 2009—2012,the spatial and temporal variation and influential factors were evaluated by multi variate statistical models.The results reveal that water quality of both stations has been maintained betweenⅠ～Ⅲ level for the last few years.Spatial temperature and turbidity differences are insignificant while pH,EC,DO,I Mn,NH3N and TP show a significant difference.Pollutants concentration differences of Heyuan linjiang station were temporally in significant except for DO.Differences at Huizhou jiangtan station are temporally significant except for NH3N.Through Pearson correlation analysis,water temperature is closely related to DO but not with entropic species.DO at Huizhou Jiantan station is intimately related to water temperature,TP and IMn .Finally,through factor analysis,three major factors are extracted to reflect water physical chemical characteristics,surface runoff and human effects on water quality. |
