青藏高原典型河流与湖泊表层水体碳时空变化特征初步分析

为了研究青藏高原典型河流与湖泊水体碳时空变化特征,采集了典型河流、湖泊、冰川等水体样品,通过实验室测试分析获取了总碳、无机碳和有机碳观测数据。结果表明青藏高原典型河流与湖泊水体碳以无机碳为主、有机碳为辅。其中,长江、黄河和澜沧江源区典型河流与湖泊水体总碳平均含量分别为62.46,32.88,17.70 mg/L,长江南源当曲源、正源沱沱河源和北源楚玛尔河源水体总碳含量分别为32.90,36.56,32.90 mg/L;青藏高原封闭性湖泊水体碳含量比河流水体较高,封闭性湖泊水体总碳、总无机碳和总有机碳平均含量分别为403.82,398.35,1.24 mg/L,而河流水体则分别为17.03,14.56,2.46 mg/L,河流水体有机碳含量比封闭性湖泊水体较高。该成果可为我国青藏高原水域碳循环研究提供基础数据,对高海拔区域气候变化研究具有参考价值。

Temporal and Spatial Changes of Carbon in Water from Typical Rivers and Lakes over the Tibetan Plateau

Consecutive field investigations and observations were carried out over the Tibetan Plateau from 2014 to 2016 in order to obtain the temporal and spatial distribution of carbon in water from typical high-altitude rivers and lakes. Water from typical rivers, lakes and ice points were sampled to be analyzed using the vario TOC analyzer from German Elementar corporation in our laboratory. The total carbon concentration, total inorganic carbon concentration and total dissolved organic carbon concentration were obtained. Preliminary results show that inorganic carbon is the major form whereas organic carbon is the auxiliary form of carbon in water from typical rivers and lakes in the Tibetan Plateau and source region of three rivers, namely the Changjiang River, the Yellow River, and the Lancang River. The averaged concentration of total carbon in water from typical rivers and lakes over the source region of Changjiang River, Yellow River and Lancang River source area was 62.46 mg/L, 32.88 mg/L, and 17.70 mg/L, respectively; while the total carbon concentration in the Dangqu River source (southern source), the Tuotuo River source (main source) and the Qumar River (northern source) was 32.90 mg/L, 36.56 mg/L, and 32.90 mg/L, respectively. Over the Tibetan Plateau, the total carbon concentration and total inorganic carbon concentration in surface water from typical lakes (403.82 mg/L and 398.35 mg/L, respectively) were much higher than those from typical rivers (17.03 mg/L and 14.56 mg/L, respectively); however, total organic carbon concentration displayed an opposite trend, with 1.24 mg/L in lakes and 2.46 mg/L in rivers. The research results are of vital importance for the climate change and water resources and eco-environmental safety in the Tibetan Plateau and the source region of the three rivers.