| 摘要: |
| 水体溶解性有机物（DOM）是湖泊生态系统中碳循环的重要组成部分；为了解城市化建设对湖泊DOM特征的影响，本文以目前国内最大城市人工湖——上海滴水湖为例，利用紫外-可见吸收光谱和三维荧光光谱技术，探讨了冬季到夏季（1月、3月和7月）过程中，滴水湖及周围水系中有色可溶性有机物（CDOM）组成的时空变化特征，初步探究了上海临港新城城市化建设对水体CDOM组成和来源的影响。结果表明：①平行因子分析法（PARAFAC）解析CDOM三维荧光图谱发现，滴水湖及相连河道水体主要有类酪氨酸C1、类色氨酸C2和陆源类腐殖质C3三类CDOM物质，其中类蛋白质组分（C1和C2）的荧光强度贡献占比降低，C3的贡献占比升高；②自生源指数（BIX）绝大多数位点都>1.0或接近1，荧光指数（FI）均值在1.4-1.9之间，说明从冬季到夏季过程中受到内源和外源输入的双重影响，以生物活动产生（微生物源）为主，且具较强的自生源特征；春、夏季受到降雨量/地表径流的外源输入影响，CDOM相对浓度被稀释降低，1月a(254)显著高于3月和7月（P<0.01），且CDOM分子量较小；③滴水湖周围河道的用地类型以居民区和新建公园为主，以及建设中的建筑工地，0.8
|
| 关键词: 滴水湖 有色可溶性有机物 城市建设 用地类型 大型人工湖泊 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金项目（面上项目，重点项目，重大项目） |
|
| A preliminary study on the source and composition characteristics of chromophoric dissolved organic matter in Dishui Lake, a large urban artificial lake* |
|
Qu Yeling1, Min Chuntian2, Xu Junjie2, Wang Ting3, Zhang Wei1, Xu Houtao4, Wang Liqing1
|
|
1.Engineering Research Center of Environmental DNA and Ecological Water Health Assessment,Shanghai Ocean University;2.Shanghai Chengtou Xinggang Municipal Management Co,Ltd;3.Shanghai Aquatic Wildlife Conservation Research Center;4.Shanghai Aquatic Science and Technology Co.,Ltd.
|
| Abstract: |
| Dissolved organic matter (DOM) in the water columns constitutes a vital component of the carbon cycle within lake ecosystems. To investigate the impact of urbanization on DOM characteristics of urban lakes, we took Dishui Lake, the largest urban artificial lake in China, as a case study. We examined the temporal and spatial variation characteristics of chromophoric dissolved organic matter (CDOM) in Dishui Lake and its surrounding water system from winter to summer (January, March, and July) using ultraviolet-visible absorption spectroscopy and three-dimensional fluorescence spectroscopy. The influence of the urban construction, Lingang New City, Shanghai, on the composition and source of CDOM in water was preliminarily explored. The results are as follows: ①Tyrosine-like C1, tryptophan-like C2 and terrestrial humic-like C3 were identified through parallel factor analysis (PARAFAC). The contribution of protein-like (C1 and C2) components to fluorescence intensity decreased, while the contribution of C3 increased. ②Most values of the autogenetic index (BIX) is >1.0 or close to 1, and the fluorescence index (FI) ranged from 1.4 to 1.9, indicating that the characteristics of CDOM during the temperature rising (from winter to summer) is influenced by both endogenous and exogenous inputs, and biological activity (microbial source) is the main source and has strong autogenetic characteristics. Influenced by exogenous input from rainfall or surface runoff, the relative concentration of CDOM was diluted and decreased in the spring and summer seasons. In January, a (254) was significantly higher than that in March and July (P<0.01), and the molecular weight of CDOM was low. ③The land use types of river channels around the lake are primarily residential areas and newly built parks, and building site under construction with 0.8 1, high biological metabolic activity in the water body and significant impact of CDOM on human activities. The C3 fluorescence intensity gradually decreased from the river channels to the lake district, indicating that terrestrial humic-like substances mainly entered Dishui Lake through river channel. ④The fluorescence parameters BIX and FI were significantly correlated with protein-like components and nitrogen concentrations (P<0.05), can serve as potential indicators for future water quality monitoring of Dishui Lake. Our study suggests that rainfall, runoff input, land use type, and rapid urbanization collectively affect the CDOM characteristics of the lake, and the relevant results can provide a basis for further understanding the composition characteristics and water environment management of dissolved organic matter in urban water bodies under the background of urban development. |
| Key words: Dishui Lake CDOM urban construction land use type large urban artificial lake |
