摘要
为了研究河流筑坝对河流氮生物地球化学循环的影响,在夏季水体分层期间对猫跳河梯级水库坝前分层采集水样进行了相关地球化学分析。结果显示,在上游的两座水库存在2个明显的温度分层现象,并影响到了水体N2O的产生和分布。红枫水库整个剖面的氮分布主要受硝化作用控制,而百花湖、修文及红岩水库则表现为上层水体为硝化作用,中层为硝化反硝化共同作用。所有水库表层水和下泄水高饱和度的N2O含量表明这些水体为大气N2O的源。百花湖底层反硝化作用强烈,中间产物N2O大量消耗。底层泄水的方式对于温室气体释放影响重大,因此不同水库下泄水的N2O含量在时间和空间上的变化与水库运行和调蓄模式有关。研究结果表明,梯级水库过程对N2O的排放影响很大,在水电开发的环境保护中应当引起重视。
In order to make clear that what kind of impacts the cascade reservoirs play on the nitrogen biogeochemistry circle in the river, we sampled water by different layers in front of the each dam and outflow water in the cascade reservoirs of Maotiao River, Guizhou Province, Southwest China. The water chemistry of the cascade reservoirs is discussed in terms of the physical and chemical parameters, together with N2O distribution in summer. The results indicate that discontinuity layers of temperature plays an important role in production and distribution of N2O in reservoirs of Maotiao River. The N2O distribution in the layer above the SDL （secondary discontinuity layer） in the four cascade reservoirs is dominated by nitrification, while between the SDL and PDL （primary discontinuity layer） is controlled by both of nitrification and denitrification. As two main processes that affect the production of the N2O, nitrification and denitrification change the distribution of N2O in cascade reservoirs. The contents of N2O in reservoirs are higher than that in the atmospheres. This suggests that high contents of the N2O in the reservoir are the N2O source of the atmosphere. However, N2O contents decrease at depth below 15 m with low contents of DO indicates that denitrification produced N2 by consuming a large part of N2O. The water discharge from bottom of cascade reservoirs along Maotiao River released large amount of N2 O into atmosphere, which should be taken into account for improving environmental protection of waters in cascade reservoirs when hydroelectric power will be developed.
出处
《长江流域资源与环境》
CAS
CSSCI
CSCD
北大核心
2009年第4期373-378,共6页
Resources and Environment in the Yangtze Basin
基金
国家自然科学基金(90610037和40603005)
国家重点基础发展研究计划(2006CB403205)
中国科学院创新团队国际合作伙伴计划联合资助
关键词
氧化亚氮
富营养化
源汇效应
梯级水库
nitrous oxide
eutrophication
source-sink effects
cascade reservoirs
