黄河小浪底水库水沙调控对DOC输送的影响

Effect of the Runoff-sediment Control of the Xiaolangdi Reservoir on DOC Transport

于2011年11月至2012年10月在黄河中游的三门峡、小浪底和花园口3个水文站进行每月1次的周期性采样观测以及在调水调沙期间进行连续采样观测，分析了小浪底水库水沙调控对溶解有机碳（DOC）输送的影响．结果表明，在小浪底水库和三门峡水库正常调度期间，三门峡站、小浪底站和花园1：3站的DOC含量分别为1．97～2．71mg·L^-1、1．87～2．76mg·L^-1和2．07～2．93mg·L^-1，并且均有明显的季节变化；在调水调沙期间，三门峡站、小浪底站和花园口站的DOC含量分别为2．14～3．32mg·L^-1、2．21～2．84mg·L^-1和2．11～2．84mg·L^-1，并且水库排沙阶段的DOC含量明显高于水库泄水阶段的DOC含量．无论是在水库正常调度期间还是在调水调沙期间，DOC含量与TSS含量及流量均没有表现出显著的相关性，而在水库正常调度期间DOC含量与水温呈现显著的正相关关系．11月一次年3月三门峡站和小浪底站的DOC输送量比较接近，4～7月三门峡的DOC输送量明显低于小浪底站，而8～10月三门峡站的DOC输送量又明显高于小浪底站，表明小浪底水库在8～10月大量拦蓄DOC，而在4～7月又将拦蓄下来的DOC排出水库．三门峡站、小浪底站和花园口站DOC年输送量分别为8．6×10^10、9．0×10^10和9．7×10^10g，其中三门峡站9月DOC输送量最多，约占全年DOC输送量的22．0％，小浪底站6月DOC输送量最多，约占全年DOC输送量的17．6％，花园口站7月DOC输送量最多，约占全年DOC输送量的16．7％．在2012年调水调沙期间小浪底站和花园口站的DOC输送量占全年DOC输送量的比例分别为14．7％和13．8％，而三门峡站DOC输送量仅占全年DOC输送量的3．6％．

The sampling was carried out in Sanmenxia hydrological station, Xiaolangdi hydrological station and Huayuankou hydrological station from November 2011 to October 2012. The impact of the runoff-sediment control of the Xiaolangdi reservoir on DOC transport was analyzed. The results were as follows. DOC contents in Sanmenxia station, Xiaolangdi station and Huayuankou station were 1.97-2.71 mg·L^-1 , 1.87-2.76 mg·L^-1 and 2.07-2.93 mg·L^-1 , respectively, during the normal operation period of Xiaolangdi Reservoir and Sanmenxia reservoir, and the DOC content in the three reservoirs had obvious seasonal change. DOC contents in the three stations were 2. 14-3.32 mg·L^-1 , 2.21-2.84 mg·L^-1 and 2.11-2.84 mg·L^-1, respectively, during the runoff-sediment control, and the DOC content in the sediment-releasing period of reservoir was higher than that in the water-releasing period of reservoir. DOC content had no significant correlation with TSS and flow either during the normal operation or during the water-sediment regulation of the reservoir. But the DOC content had significant correlation with water temperature during the normal operation of the reservoir. DOC flux in Sanmenxia station was similar to that in Xiaolangdi station from November to March. DOC flux in Sanmenxia station was obviously less than that in Xiaolangdi station from April to July. And the DOC flux in Sanmenxia station was much higher than that in Xiaolangdi station from August to October. The result showed that DOC was retained from August to October by Xiaolangdi reservoir and discharged from Xiaolangdi reservoir from April to July. The yearly DOC fluxes were 8.6 ×10^10, 9.0 ×10^10 and 9.7 ×10^10 g respectively in Sanmeuxia station, Xiaolangdi station and Huayuankou station. The DOC flux of Sanmenxia station was the highest in September, which accounted for 22.0% of the yearly DOC flux, and the DOC flux of Xiaolangdi station was the highest in June, which accounted for 17.6% of the yearly DOC flux. The DOC flux of Huayuankou station was the highest in July, which accounted for 16.7% of the yearly DOC flux. DOC fluxes during the runoff-sediment regulation accounted for 14.7% and 13.8% of the yearly DOC flux respectively in Xiaolangdi station and Huayuankou station, but the DOC fluxes during the runoff-sediment regulation accounted for only 3.6% of the yearly DOC flux in Sanmenxia station.