分层型水库夏季水质对极端厄尔尼诺事件的响应  

Response of the Water Quality of a Stratified Reservoir to an Extreme El Nio Event During Summer

作　　者：邱晓鹏[1] 黄廷林[1] 曾明正[1] 史建超[1] 曹占辉[1] 

机构地区：[1]西安建筑科技大学环境与市政工程学院,西安710055

出　　处：《环境科学》2017年第2期547-554,共8页Environmental Science

基　　金：国家科技支撑计划项目(2012BAC04B02)

摘　　要：为探究极端厄尔尼诺事件对分层型水库夏季水质的影响,分别于正常年(2012年)和厄尔尼诺年(2015年)的5~8月对枣庄周村水库主库区和入库径流的物理和化学指标进行了监测.结果表明,周村水库正常年夏季降雨量明显高于厄尔尼诺年夏季;正常年夏季水位由124.26 m上升至127.14 m,恒温层厚度增加3.1 m;而厄尔尼诺年夏季水位由121.65 m下降至119.46 m,恒温层厚度减少3.2 m.周村水库入库径流属表层流,其营养盐浓度明显高于库区变温层.正常年夏季外源营养盐的汇入导致库区变温层总氮由1.00 mg·L^(-1)升至2.60 mg·L^(-1),硝态氮由0.19 mg·L^(-1)升至1.28 mg·L^(-1),总磷由0.023mg·L^(-1)升至0.088 mg·L^(-1),而厄尔尼诺年夏季库区变温层营养盐浓度变化不大.厄尔尼诺年夏季恒温层水体还原性污染物浓度明显高于正常年同期水平,其中铁、锰、氨氮和硫化物浓度的最大值分别为0.38、1.36、2.36和1.67 mg·L^(-1),均超过地表水Ⅲ类水质标准.极端厄尔尼诺事件对周村水库夏季变温层水体营养盐浓度和恒温层水体污染物浓度均有较大的影响.Global warming can intensify the El Nino phenomenon that recurs every 2-7 years, which will lead to a great interannual variability of climate and may induce the deterioration of the water quality of reservoirs. To study the influence of the extreme El Nino events on the water quality of stratified reservoirs during summer, field surveys were conducted in Zhoucun Reservoir and its inflow rivers from May to August in a normal year （2012） and a strong El Nino year （2015）. Temporal variations of physical and chemical index were investigated during monitoring. The results showed that the Zhoucun Reservoir was stratified during the study period. The precipitation in the summer of the normal year was significantly higher than that in the El Nino year at the same period. In the summer of the normal year, the water level increased from 124. 26 m to 127. 14 m and the hypolimnion thickness increased by 3. 1 m. However, in 2015, the rapid decrease of the water level from May to August （from 121. 65 m to 119. 46 m） led to the decrease of the hypolimnion thickness （by 3. 2 m）. The inflow rivers belonged to surface current and its nutrients concentrations were obviously higher than those in the epilimnion. The inflow nutrients loads increased significantly in the summer of the normal year, as a result, total nitrogen increased from 1. 00 mg·L ^- 1 to 2. 06 mg·L ^- 1 , nitrate increased from 0. 19 mg·L ^- 1 to 1. 28 mg·L ^- 1 , and total phosphorus increased from 0. 023 mg·L ^- 1 to 0. 088 mg·L^ - 1 in the lacustrine zone of the reservoir. In contrast, the nutrients concentrations changed little in the summer of the El Ni·o year due to the decrease in runoff. Nonetheless, the reducing pollutants concentrations of the hypolimnion in the El Nino year were significantly higher than those in the normal year, which may be due to the temporal variations of hypolimnion thicknesses. The maximum concentrations of iron, manganese, ammonium and sulfide in the summer of the El Nino year were 0. 38, 1. 36, 2. 36 and 1

关 键 词：分层 厄尔尼诺 营养盐 恒温层 温跃层 

分 类 号：X524[环境科学与工程—环境工程]