Optical Properties of Water Body in Xiaojiang River Backwater Area, Three Gorges Reservoir, 2008

摘要

To discuss optical properties of water body in Xiaojiang river backwater area after the early impounding stage of the Three Gorges Reservoir (TGR), the correlations between visible light attenuation coefficients (Kd(PAR)) and Secchi Disc transparency (SD), total particulate matters (TPM), dissolved organic carbon (DOC) and chlorophyll-a (Chla) were investigated, and spatiotemporal variations of Kd(PAR) and its influencing factors were analyzed. In the study area, there are no significant spatial variations of Kd(PAR), but the seasonal changes are obvious, with the highest value in winter and the lowest value in summer. Statistics analysis suggests that there are strong correlations between Kd(PAR) and SD, TPM, TIM, the value of R~2 are 0.7791, 0.7285, and 0.7637, respectively. The relationship between Kd(PAR) and DOC is less significant(R~2=0.1289). However, the correlation between Kd(PAR) and Chla was weak (R~2=0.006). Further study shows that, the impact of total particulate matters on the optical properties of water body is as a result of both seasonal impoundment of the TGR and particular hydrological condition of Xiaojiang river basin.