Abstract:To explore the intrusion pattern of rainfall runoff and the corresponding water-quality response, vertical water-quality monitoring in Jin-pen Reservoir of Xi'an City in China was implemented daily in the flood season. The results show that the seasonal thermal stratification occurs in the reservoir due to the change of air temperature. Storm runoff events in flood season damaged the structure of thermocline in the lower layer and weakened the stability of thermal stratification. Rainfall runoff, containing a large amount of particulate nutrients and sediments, entered the reservoir in the form of density current, which changed from underflow to interflow between transition zones and lacustrine zones, and the thickness of interflow was 20m during the early period of current intrusion. The concentrations of TP, TN, TOC increased significantly due to the intrusion of density currents in the middle and lower of water, with the highest concentration of TN, TP, TOC and turbidity was 0.2, 2, 0.6 and 16times higher than that in normal condition, resulting in serious water body pollution in short time. The decomposition rate of particulate pollutants settled in sediments increased due to the intrusion of higher temperature water in bottom, leading to a continuous increase of the endogenous nutrient loads in the reservoir, i.e., the concentration of TN, TP, TOC in bottom water was up to 1.88mg/L, 0.05mg/L, 4.6mg/L, respectively. Managers can take water from different layers of the reservoir and discharge high-turbidity current to ensure drinking water quality in flood season.
曾康, 黄廷林, 马卫星, 周子振, 李扬. 金盆水库汛期高浊水径流的潜入及热分层水体水质响应[J]. 中国环境科学, 2015, 35(9): 2778-2786.
ZENG Kang, HUANG Ting-Lin, MA Wei-Xing, ZHOU Zi-Zhen, LI Yang. Water-quality responses of the intrusion of high-turbidity runoff to the thermal stratified Jin-pen Reservoir during flood season. CHINA ENVIRONMENTAL SCIENCECE, 2015, 35(9): 2778-2786.