塘西河水体颗粒和溶解有机碳季节变化及其来源分析

Seasonal variations and sources of particulate and dissolved organic carbon in Tangxihe River

基于2014年7月至2015年6月对塘西河水体中颗粒有机碳(POC)和溶解有机碳(DOC)为期一年的调查数据,分析了塘西河水体中POC、DOC浓度时空分布特征,结合DOC、POC、总有机碳(TOC)及POC、C/N比值相关性分析和颗粒有机物C/N比值分布范围,探讨了水体中有机碳的来源。结果表明,塘西河水体中DOC质量浓度年平均值在2.53~3.91 mg/L之间,DOC占总有机碳60%以上,高于世界河流平均水平;POC质量浓度范围在1.62~2.53 mg/L之间,POC占总有机碳40%以下,低于世界河流平均水平;在空间分布上,由1#到5#采样点,DOC浓度年平均值逐渐上升,POC浓度年平均值在各采样点之间变化不大;在时间分布上,DOC、POC浓度均呈现夏季高于春、秋季,冬季最低的变化规律;在每一季节内,DOC、POC浓度均存在一定的变化,且POC季节变异系数大于DOC,说明塘西河POC来源要比DOC复杂;塘西河水体中POC、DOC主要来源于内源,即水藻生长代谢产物,但陆源输入对水体中POC浓度有一定的影响。

Based on the survey data of particulate organic carbon（ POC） and dissolved organic carbon（ DOC） concentration in Tangxi River from July 2014 to June 2015,its spatial and temporal distribution characteristics were studied,and the source of POC was analyzed combined with correlation of POC,DOC,TOC,POC and C/N. The results showed that DOC annual average mass concentration in Tangxi River water range was between 2. 53-3. 91 mg/L,DOC accounted for more than 60% of total organic carbon,POC mass concentration ranged from 1. 62 to 2. 53 mg/L. In the spatial distribution,the DOC concentration annual average value increased gradually from 1#to 5#sampling site,the POC concentration average value changed slightly at each sampling site. In the temporal distribution,DOC and POC concentrations were higher in summer than that in spring and autumn,and the lowest in winter. Result showed that the concentrations of DOC and POC changed in each season.