Gao Feng, Shao Mei-Ling, Tang Jian-Feng, Cao Chang-Li, Yi Hui
Key Laboratory of Biotic Environment and Ecological Safety in Anhui Province, College of Life Sciences, Anhui Normal University, Wuhu 241000, China.
Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
Huan Jing Ke Xue. 2019 Sep 8;40(9):4009-4017. doi: 10.13227/j.hjkx.201902118.
Rapid urbanization has a significant impact on dissolved organic matter (DOM) in water and sediment; thus, it is important to explore the distribution characteristics and influencing factors of DOM in watersheds. Xiaojia River is a typical urban area in Beilun District of Ningbo City, Yangtze River Delta. The spectral characteristics of DOM in the water and sediment in this river were studied to examine their sources and characteristics. The DOM was analyzed by three-dimensional fluorescence spectroscopy (EEM) coupled with the parallel factor analysis (PARAFAC) model. The following results were noted. ① Four fluorescence DOM components were derived by EEM-PARAFAC:C1 represents terrestrial humus with a high molecular weight; C2 represents terrestrial humus with a low molecular weight, which was produced by biodegradation; C3 represents protein-like substances that were sensitive in a microenvironment; and C4 is terrestrial humus. ② Both new-born endogenous and terrestrial sources have large impacts on DOM components. The humification degree was very weak with a low concentration of humus. The DOM in the sediments was derived mainly from terrestrial or soil sources with small endogenous contribution with high humification. The concentration of humus in the sediments was significantly higher than that in water. ③ Redundancy analysis (RDA) showed that farmland and urban land use were the dominant environmental factors and had relatively high correlation with the water indicators. Construction land, farmland, and wetland land use positively correlated with the sediment components. Among them, urban land use had the greatest influence on the concentration parameter Fn(355) of humus-like substance C4 and the humus-like substance in sediments.
快速城市化对水体和沉积物中的溶解有机物（DOM）有重大影响；因此，探索流域内DOM的分布特征和影响因素很重要。小浃江是长江三角洲地区宁波市北仑区的一个典型城区。研究了该河流中水体和沉积物中DOM的光谱特征，以考察其来源和特性。采用三维荧光光谱（EEM）结合平行因子分析（PARAFAC）模型对DOM进行分析。结果如下：① 通过EEM-PARAFAC得到四个荧光DOM组分：C1代表高分子量的陆地腐殖质；C2代表经生物降解产生的低分子量陆地腐殖质；C3代表在微环境中敏感的类蛋白质物质；C4是陆地腐殖质。② 新生内源和陆源对DOM组分均有较大影响。腐殖化程度很弱，腐殖质浓度较低。沉积物中的DOM主要来源于陆地或土壤，内源贡献小，腐殖化程度高。沉积物中腐殖质的浓度明显高于水体中的浓度。③ 冗余分析（RDA）表明，农田和城市土地利用是主要的环境因素，与水体指标相关性较高。建设用地、农田和湿地土地利用与沉积物组分呈正相关。其中，城市土地利用对腐殖质类物质C4的浓度参数Fn(355)和沉积物中腐殖质类物质影响最大。
