上海市主要河流水-气界面温室气体通量及影响因素研究

发布时间：2018-04-04 00:06

本文选题：河流　切入点：温室气体　出处：《华东师范大学》2017年硕士论文

【摘要】：大气中温室气体浓度的增加导致出现以变暖为特征的全球气候变化引起了人们的广泛关注。人为活动导致的河流生态系统中碳氮负荷增加,成为了大气温室气体的重要来源。本文以上海市为例,选取一些代表性河流,通过野外采样调查,分析上海市河流水体CO_2、CH_4和N_20溶存浓度,进而计算河流水-气界面CO_2、CH_4和N_20通量大小并分析控制因子,在此基础上估算上海市河流温室气体增温潜势(GWP)及排放潜力,为河流生态系统温室气体排放估算及对全球温室气体贡献提供一定的参考。本文主要结果如下:(1)冬季上海市河流水体CO_2、CH_4和N_20浓度范围分别是116.28±7.94～325.91±19.7lμmol·L-1、0.65±0.17～10.94±2.15μmol·L-1和 322.87±40.61～918.778±101.55nmol·L-1;夏季河流水体CO_2、CH_4和N_2O浓度范围分别是13.66±1.61～196.75±4.22μmol·L、0.06±0.00～17.50±0.87 μmol·L-1 和97.19±8.22～1476.53±109.1 5nmol·L-1。河流水体中CO_2溶存浓度有着较明显的时间变化,即冬季高、夏季低,CH_4和N_2O浓度无明显时间变化特征。水体C02和CH_4浓度在空间分布上表现为中心城区大于郊区。(2)上海市河流水体温室气体浓度受空气湿度、水温、NO3-和NH_4+浓度、Eh、pH和DO影响。空气相对湿度在冬季与水体N_20浓度、夏季与水体CO_2浓度极显著负相关。水温在夏季与水体N_2O浓度负相关性显著。水质因因子中,水体中NO3-浓度在冬季与CH_4浓度呈极显著正相关性,NH_4+浓度在冬季与水体CO_2、夏季与水体C02和CH_4浓度分别呈显著、极显著正相关关系。Eh在冬季与水体CO_2浓度呈极显著负相关关系。pH值与水体CO_2浓度相关性显著。DO仅在冬季与水体CO_2浓度显著负相关。(3)冬季上海市河流水-气界面CO_2、CH_4和N_20平均通量范围分别是21.24±0.24～144.73±17.83 mmol.m-2·h-1、10.33±41～94±14.06μmol·m-2·h-1 和 6.54±1.42～41.93±1.30μmol·m-2·h-1;夏季河流水-气界面CO_2、CH_4和N_2O通量范围分别是2.06±0.93～134.61±1.63 mmol·m-2·h-1、0.30±0.01～111.23±5.56μmol·m-2-h·1-和7.42±0.63～77.28±5.71μmol·m-2·h-1。河流总体上是大气温室气体的源。时间变化上,河流水-气界面CO_2通量表现为冬季高夏季低,CH_4通量无显著季节变化,N_2O通量夏季高于冬季。空间分布特征表现为:①冬季河流水-气界面CO_2通量在宝山区、中心城区以及浦东新区北相对较低,松江区和闵行区相对较高;夏季河流水-气界面CO_2通量总体上呈现为中心城区、宝山区较高,其余各地区水-气界面CO_2通量处于中低水平。②水-气界面CH_4通量仅在夏季中心城区和宝山区处出现最大值,其余各处冬夏季CH_4通量均处于低水平。③水-气界面N_2O通量冬季在松江、闵行、金山和奉贤处较高,夏季在金山区较高。(4)上海市河流水-气界面CO_2、CH_4和N_2O排放通量受风速、空气湿度和温度、水体气温、水温、NOO3-、NH_4+、Eh和pH影响。不同季节主要的影响因子不同。气象因子中,风速在冬季与河流水-气界面CO_2、CH_4和N_2O排放通量均呈极显著正相关性,夏季与水-气界面CH_4和N_2O通量分别呈显著、极显著正相关关系。空气相对湿度在夏季与水-气界面CO_2通量呈极显著负相关关系。气温在冬季与水-气界面CO_2和N_2O通量相关性显著。水温在冬季与河流水-气界面CO_2通量呈极显著负相关。水质因子中,冬季水体NO3-浓度和Eh与水-气界面CO排放通量相关性显著。夏季水体NH_4+浓度和pH与水-气界面C02通量显著相关性;水体NH_4+浓度和水-气界面间CH_4通量正相关性显著。(5)河道等级对水-气界面CO_2、CH_4和N_2O通量没有明显的影响。河道水质污染状况对河流水-气界面CO_2、CH_4和N_2O通量具有明显的影响,劣于V类河流水-气界面温室气体通量值大于Ⅲ类河流,总体上说明河流污染程度越严重,水体温室气体排放越大。(6)以100年时间尺度为计,上海市河流温室气体增温潜势为18738.92 gCO_2·m-2·a-1,其中CO_2增温潜势贡献最大;上海市河流水体N_2O排放系数为0.0373。水-气界面C02和CH_4通量呈现河流水库湖泊,N_2O通量河流湖泊。河流、湖泊和水库水-气界面总碳通量呈现出河流水库湖泊,总氮通量河流湖泊,3种水体中碳的输出均以CO_2形态为主。
[Abstract]:To increase the concentration of greenhouse gases in the atmosphere caused has aroused extensive attention to warming as the characteristics of global climate change. The increase of carbon nitrogen load of river ecological system induced by human activities, has become an important source of atmospheric greenhouse gases. Taking Shanghai city as an example, selects some representative rivers, through field sampling survey analysis of Shanghai river water, CO_2, CH_4 and N_20 dissolved concentration, then calculate the river water air interface of CO_2, CH_4 and N_20 flux and control factor analysis, based on the estimation of the rivers in Shanghai city of greenhouse gas warming potential (GWP) potential and emissions, provide a reference for the estimation of greenhouse gas emissions in the river the ecological system and the contribution to global greenhouse gases. The main results of this paper are as follows: (1) the winter Shanghai river water CO_2, CH_4 and N_20 concentrations were 116.28 + 7.94 to 325.91 + 19.7l ~ mol ~ L-1,0.6 5 + 0.17 to 10.94 + 2.15 mol L-1 and 322.87 + 40.61 to 918.778 + 101.55nmol - L-1; summer river water CO_2, CH_4 and N_2O concentrations were 13.66 + 1.61 to 196.75 + 4.22 mol - L, 0.06 + 0 to 17.50 + 0.87 mol L-1 + 8.22 CO_2 and 97.19 ~ 1476.53 109.1 5nmol - L-1. river water dissolved concentration has obvious time variation, which is high in winter and low in summer, CH_4 and N_2O concentration had no obvious time variation. The water C02 and CH_4 concentration in spatial distribution as the center of the city. (2) higher than that in the suburbs of Shanghai city river water temperature chamber gas concentration the air humidity, temperature, NO3- and concentration of NH_4+, Eh, pH and DO. The influence of air relative humidity in winter and summer water N_20 concentration, CO_2 concentration and water temperature was significantly negatively correlated. In the summer with the concentration of N_2O in water. The water quality due to negative correlation factor, the concentration of NO3- in water and CH_4 in winter Significant positive correlation between concentration and NH_4+ concentration in the winter and summer water and water CO_2, C02 and CH_4 were significant and very significant positive correlation between.Eh and CO_2 concentrations in winter were significant negative correlation between.PH values and CO_2 concentrations significantly correlated only in winter.DO and water CO_2 concentration was negatively correlated. (3) the winter Shanghai river water air interface of CO_2, CH_4 and N_20 respectively the average flux range is 21.24 ~ 144.73 + 0.24 + 17.83 + 41~94 + 14.06 mmol.m-2 - h-1,10.33 mol - m-2 - H-1 and 6.54 + 1.42 to 41.93 + 1.30 mol - m-2 - H-1 - Xia Jihe; water gas interface CO_2, CH_4 N_2O and flux range were 2.06 + 0.93 to 134.61 + 1.63 mmol - m-2 - h-1,0.30 + 0.01 to 111.23 + 5.56 mol - m-2-h - 1- and 7.42 + 0.63 to 77.28 + overall 5.71 mol - m-2 - h-1. river is atmospheric greenhouse gas source. The change of time, the river water - Gas Field CO_2 flux is higher in winter and lower in summer and no significant seasonal variation of CH_4 flux and N_2O flux in summer than in winter. The spatial distribution features: the winter river water air interface of CO_2 flux in Baoshan District, the central city and the north of Pudong New Area is relatively low, Songjiang District and Minhang District is relatively high; the summer river water air interface of CO_2 flux show the whole city center, Baoshan District high, the rest of the area of the gas water interface CO_2 flux in the low level. The water air interface of CH_4 flux only had a maximum value in the summer and the city center of Baoshan District, where the rest of the summer and winter CH_4 fluxes were at a low level. The water air interface of N_2O flux in winter in Songjiang Minhang, Fengxian, Jinshan and high, the summer in Jinshan District is high. (4) Shanghai river water air interface of CO_2, CH_4 and N_2O fluxes by wind speed, air humidity and temperature, water temperature, water temperature, NOO3-, NH _4+, Eh and pH. The main influencing factors of different meteorological factors in different seasons. In winter, the wind speed and the river water air interface of CO_2, CH_4 and N_2O fluxes were significantly positive correlation between the summer and the water air interface of CH_4 and N_2O fluxes were significantly and very significantly correlated with air. The relative humidity in the summer and the water air interface of CO_2 flux was negatively related significantly. The temperature in winter and the water air interface of CO_2 and N_2O. The water flux correlation in winter and the river water air interface of CO_2 flux was negatively correlated. Water quality factors, significant winter water concentration of NO3- and Eh with water air interface of CO flux correlation. The summer water concentration of NH_4+ and pH and the water air interface of C02 flux was significantly correlated significantly; NH_4+ concentration and water - water gas interface between CH_4 flux and positive correlation. (5) the river level of the water air interface of CO_2, CH_4 and N_2O fluxes were not significantly The effect of water pollution on the river. The river water air interface of CO_2, has obvious effects of CH_4 and N_2O flux, inferior to V river water air interface of greenhouse gas flux is greater than the class III River, general description of river pollution is more serious, water more greenhouse gas emissions (6) in 100 years. Time scale, the rivers in Shanghai city of greenhouse gas warming potential is 18738.92 gCO_2 - m-2 - A-1, the CO_2 warming potential contribution; Shanghai river water N_2O emission coefficient of 0.0373. gas water interface C02 and CH_4 fluxes showed River reservoirs and lakes, rivers and lakes. The river N_2O fluxes, the total carbon flux Lake and reservoir water air interface shows the river water reservoir lakes, the total nitrogen flux of rivers and lakes, 3 water carbon output were dominated by CO_2 form.

【学位授予单位】：华东师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X16;X143

【参考文献】