PENG Xi1,2, WANG Baoli1*, LIU Congqiang1, LIU Xiaolong1,2, and WANG Fushun3
1 State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China
2 Graduate University of Chinese Academy of Sciences, Beijing 100049, China
3 Applied Radiation Institute, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200433, China
Abstract We have investigated the diurnal variations of the pCO2 and related environmental factors in the cascade reservoirs with different trophic levels along Wujiang River. In surface water the pCO2 was 357±11 μatm in Hongjiadu Reservoir, 338±48 μatm in Dongfeng Reservoir, 682±303 μatm in Wujiangdu Reservoir, and 1677±429 μatm in Liuguang, respectively. The results indicated that these cascade reservoirs had much lower pCO2 values in surface water than river did, and hypereutrophic reservoir showed larger diurnal variations of pCO2 than meso-eutrophic reservoir. In water column, pCO2 tended to increase with the depth. Phytoplankton and the environmental factors such as temperature and pH had different influences on pCO2 diurnal variations due to different trophic levels, and the effect of phytoplankton on pCO2 variation increased with the increase of trophic level in these reservoirs.
Key words diurnal variations; pCO2; environmental factor; cascade reservoirs
* Corresponding author, E-mail: baoliwang@163.com
CHINESE JOURNAL OF GEOCHEMISTRY Vol. 31, No. 1, 2012, page 41-48
© Science Press and Institute of Geochemistry, CAS and Springer-Verlag Berlin Heidelberg 2012
