岩溶区峡谷型水库枯水期表层水体有机碳浓度分布特征

Distribution Characteristicsof Organic Carbon Concentrationsin Upper Layer of Canyon-type Reservoirsin Karst Areas During Dry Season

关键词:  总有机碳  溶解有机碳  峡谷型水库  岩溶区

Key words:  total organic carbon  dissolved organic carbon  canyon-type reservoirs  karst areas

摘要:

为揭示岩溶区峡谷型水库碳循环规律，以岩溶区峡谷型水库万峰、董箐水库为研究区，通过现场监测和水体样品采集，分析水库枯水期理化指标、有机碳(Organic Carbon，OC)浓度的变化特征和分布规律。研究结果显示：万峰水库水体温度(Water Temperature，WT)、电导率(Conductivity，COND)、总溶解固体物(Total Dissolved Solids，TDS)含量、氧化还原电位(Oxidation-Reduction Potential，ORP)、总氮(Total Nitrogen，TN)浓度、总磷(Total Phosphorus，TP)浓度均比董箐水库高，且变化范围较大，万峰、董箐水库WT、COND、TDS、TP的空间差异较小，ORP和TN的变异系数较大，具有较高的空间变异性；万峰水库总有机碳(Total Organic Carbon，TOC)、溶解有机碳(Dissolved Organic Carbon，DOC)浓度分别为3.11-6.66、2.35-5.12 mg/L，呈干流高于马岭河支流的分布特征，董箐水库TOC、DOC浓度分别为3.07-4.75、2.87-3.99 mg/L，呈库湾(D1)>码头(D4)>坝前(D2)的分布特征，万峰水库TOC和DOC浓度均比董箐水库高，且变化范围较大；万峰、董箐水库有机碳均以DOC为主，颗粒有机碳(Particulate Organic Carbon，POC)含量较少但高于其他水库。本研究为岩溶区水生态系统碳循环研究提供数据支持及参考。

Abstract:

To reveal the carbon cycle patterns of canyon-type reservoirs in karst areas,this study took Wanfeng and Dongqing Reservoirs as the study areas.The variation characteristics and distribution patterns of physicochemical indicators and organic carbon concentrations during the dry season were analyzed by field monitoring and water sample collection.The results showed that the Water Temperature (WT),Conductivity (COND),Total Dissolved Solids (TDS),Oxidation-Reduction Potential (ORP),Total Nitrogen (TN) and Total Phosphorus(TP)in Wanfeng Reservoir were higher than those in Dongqing Reservoir and had large variation ranges.The spatial variations of WT,COND,TDS and TP in Wanfeng and Dongqing Reservoirs were small.The coefficients of variation of ORP and TN were large and had high spatial variability.The concentrations of Total Organic Carbon (TOC) and Dissolved Organic Carbon (DOC) in Wanfeng Reservoir ranged from 3.11 mg/L to 6.66 mg/L and 2.35 mg/L to 5.12 mg/L,respectively,being higher in the main stream than in the tributary Maling River.The TOC and DOC concentrations in Dongqing Reservoir ranged from 3.07 mg/L to 4.75 mg/L and 2.87 mg/L to 3.99 mg/L,respectively,showing the distribution pattern of reservoir bay (D1)>quay (D4)>pre-dam (D2).The TOC and DOC concentrations in Wanfeng Reservoir were both higher than those in Dongqing Reservoir and had large variation ranges.The organic carbon in both Wanfeng and Dongqing Reservoirs were dominated by DOC.The concentrations of Particulate Organic Carbon (POC) in the two reservoirs were low but higher than those in other reservoirs.The findings provide data support and reference for studying the carbon cycle in water ecosystems in karst areas.