喀斯特水库及入库河流TOC、TN的变化特征及影响机制  

Variation Characteristics and Influence Mechanisms of TOC and TN in Karst Reservoirs and Inlet Rivers

作　　者：邹艳 周忠发 孔杰 李永柳 王翠 温朝程 谢江婷 ZOU Yan;ZHOU Zhongfa;KONG Jie;LI Yongliu;WANG Cui;WEN Chaocheng;XIE Jiangting(College of Geography And Environmental Sciences/Karst Research Institute,Guizhou Normal University,Guiyang 550001,China;The State Key Laboratory Incubation Base for Karst Mountain Ecology Environment of Guizhou Province,Guiyang 550001,China)

机构地区：[1]贵州师范大学喀斯特研究院/地理与环境科学学院,贵阳550001 [2]贵州喀斯特山地生态环境国家重点实验室培育基地,贵阳550001

出　　处：《地球与环境》2023年第3期255-265,共11页Earth and Environment

基　　金：国家自然科学地区基金项目(42161048);贵州省科技计划(黔科合基础[2020]1Y154)。

摘　　要：为探究岩溶地区筑坝水库水体碳氮营养盐的分布特征及影响机制,以平寨水库为研究对象,于2020年1月、5月、7月和9月对水库及入库河流水体进行采样监测。采用数理统计、相关分析等方法对水体理化因子和总有机碳(Total Organic Carbon)、总氮(Total Nitrogen)的表层和剖面特征进行分析,结果表明:(1)各河流间水化学指标差异大,时间上TOC和TN浓度秋季最高,丰水期低于枯水期。空间上浓度特征为:河流上游<汇水区<库区;(2)垂直剖面上TOC和TN浓度受夏秋季水库热分层期影响,均在夏秋季有较大波动;(3)水体TOC、TN浓度及变化有不同的控制因素。稀释作用造成TOC浓度丰水期低于枯水期,秋季陆源物质累积使其9月浓度显著升高,而岩溶水库特殊地质背景和库区较缓的水动力条件形成的生物固碳是河流汇入库区后浓度增加的原因;TN浓度变化主要受外来输入的影响。因此对平寨水库的保护必须控制人类活动的外来输入,加强对流域周围工农业生产生活的管理。To investigate the distribution characteristics and influence mechanisms of carbon and nitrogen nutrients in water bodies of dammed reservoirs in karst areas,Pingzhai Reservoir was studied,with water bodies of reservoirs and inlet rivers been sampled and monitored in January,May,July and September of 2020.The surface and profile characteristics of hydrochemistry factors and total organic carbon(TOC)and total nitrogen(TN)in the water bodies were analyzed by using mathematical statistics and correlation analysis.The results show that:(1)The water chemistry indexes varied greatly among rivers,with the highest concentration of TOC and TN been observed in autumn,and lower values were found in wet seasons than that in dry seasons;the spatial distribution pattern were:upstream of rivers<catchment area<reservoir area.(2)TOC and TN concentrations in the vertical profile were influenced by the thermal stratification period of the reservoir in summer and autumn,and both had large fluctuations in summer and autumn.(3)There were different controlling factors for TOC and TN concentrations and changes in water bodies.The dilution effect causes the TOC concentration to be lower in the wet season than in the dry season period,and the accumulation of land-based materials in autumn resulted in its significantly increase in September,while the special geological background of karst reservoirs and the biological carbon sequestration formed by the slower hydrodynamic conditions in the reservoir area were the reasons for the increase in concentration after the river sinks into the reservoir area;the changes in TN concentration were mainly influenced by external input.Therefore,the protection of Pingzhai Reservoir must involve the controlling of the external input of human activities and strengthen the management of industrial and agricultural production and domestic activities around the watershed.

关 键 词：总有机碳 总氮 剖面特征 影响机制 喀斯特水库 

分 类 号：X524[环境科学与工程—环境工程]