Huang Tinglin

Summer absorption characteristics, spatial distribution and source analysis of CDOM in Zhoucun Reservoir in Huaihe Catchment

Based on the data of the absorption coefficient of colored dissolved organic matter (CDOM) from 24 surface water sam⁃ ples collected from Zhoucun Reservoir in Huaihe Catchment, we analyzed the spatial distribution characteristics of CDOM absorp⁃ tion coefficient, investigated the correlation between CDOM absorption coefficient and environmental parameters, and explored the possible source of CDOM in the reservoir. The samples collected from the reservoir were categorized into three different groups (storage port, transition region and main reservoir area), the absorption coefficients ( a(355) and a∗(355)) had a decrease process from the storage port to main reservoir area, while the S value exhibited an increased trend. Meanwhile, significantly nega⁃ tive correlations of the value of S240-500 were found with a(355) and a∗(355), respectively, which may have implications for the remote sensing estimation of CDOM in this study. A significantly negative correlation between a(355) and dissolved organic carbon (DOC) concentration was conducive to the establishment of DOC remote sensing inversion model, and relationships between a (355) and aph(440) implied the potential contribution of phytoplankton metabolism and degradation products to the CDOM pool in the Zhoucun Reservoir. These results on the CDOM analysis made a significant contribution to the management of the Reservoir in the future.

Numerical simulation and verifications on thermal stratification in a stratified reservoir

Taking Jinpen Reservoir in Xian as a study case,a numerical simulation method for thermal structure of a stratified reservoir was developed and validated against the field data. The development and characteristics of the thermocline under various conditions of short wave radiation and bulk extinction coefficient for short wave radiation was numerically investigated by using a commercially-available software of Fluent. The net total surface heat transfer is positive in spring and summer,while negative in autumn and winter. The long wave radiation mainly contributes to the net total surface heat transfer,while the short one controls the development of the thermocline. The depth of the thermocline increased and the temperature gradient over the thermocline decreased as the bulk extinction coefficient decreased,and the bulk extinction coefficient is positively related to the algae concentration. There was a maximum value of the surface short wave radiation for a certain reservoir,the temperature difference between the top and bottom of the thermocline increased when the short wave radiation was below the maximum radiation,but it decreased when the short wave radiation was beyond the maximum radiation. Moreover,a heat balance and a stable thermocline cant be easily developed under higher short wave radiation.