长江源区近年水质时空分布特征探析

Discussion on Recent Spatial-temporal Distribution of Water Quality in Changjiang River Source Area

长江源区地处青藏高原,气候条件恶劣,受技术条件限制,有关源区特有的高原生态环境状况的调查和报道较少。根据2012,2014,2015年长江源区科学考察获取的水质监测资料,分析了长江源区常规监测指标、金属类及有机物等水质指标,探析了近几年长江源区水质时空分布特征。结果表明:长江源区河流水质良好,大多数区域的水质指标达到Ⅰ—Ⅱ类水标准;受水体含沙量和区域地质条件的影响,源区不同区域河流水质有一定差异;源区水质年际间差异不大,基本在相同的范围内波动;与国内外河流背景值相比,源区水质基本处于河流背景值范围内;源区有邻苯二甲酸酯类有机污染物检出。该结果对于进一步开展长江源区水生态环境研究具有重要意义。

Source area of Changjiang River is located at Qinghai-Tibet Plateau with severe climates. Due to technicallimits,there are few investigation and reports about the unique ecological environment conditions in the source area.According to monitoring data of water quality obtained from scientific investigations in the source area in 2012,2014 and 2015,we analyze conventional monitoring indicators and water quality indexes such as organic and metal pollutants. On the basis of the analysis,we discuss the spatial-temporal distribution of water quality in the source area in recent years. Results show that firstly,water quality of rivers in the source area are good,and water quality belongs to I type or II type in most regions; secondly,influenced by sediment contents of water body and regional geological conditions,water quality indexes vary among rivers in different regions in the source area; furthermore,water quality shows a small inter-year variation with a similar fluctuation; in comparison with the background values of other rivers in China and abroad,values of water quality in the source area are basically within the range of background values of river; finally,organic pollutants such as phthalic acid esters are detected in surface water samples of the source area. The results are important for further study on the water ecology of Changjiang source area.