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泥河水库水—气界面CO2通量研究

Study on Carbon Dioxide Fluxes Across Water-air Interface in Nihe Reservoir

【作者】 吕东珂

【导师】 于洪贤;

【作者基本信息】 东北林业大学 , 水生生物学, 2009, 硕士

【摘要】 本文以哈尔滨泥河水库为研究对象,利用静态箱-气相色谱法首次对我国水库生态系统水-气界面CO2通量进行观测。本文选择泥河水库春、夏、秋三季无冰期对CO2通量进行观测以研究其日变化及季节变化特征,同时对泥河水库碳的源/汇情况做出初步的判断。通过大量的数据分析,我们发现:1.从季节上看,泥河水库春、夏、秋季均表现为大气CO2的源。平均CO2通量为690.42±15.18(mg m-2 d-1)。CO2通量季节变化明显,其基本变化趋势为:夏季756.42±54.58(mg m-2 d-1)>春季714.16±83.45(mg m-2 d-1)>秋季600.67±77.14(mg m-2d-1)。2.从日变化上看,泥河水库全天表现为CO2的源。春、夏、秋三季日平均碳通量分别为26.43±2.52(mg m-2 h-1),35.44±4.09(mg m-2 h-1),24.52(mg m-2 h-1)。CO2通量日变化规律为:日间随着太阳辐射的增强,CO2排放量减少,一般在13:00前后CO2通量达到全天极小值。随后CO2通量开始逐渐增加,在22:00~1:00之间达到全天源的极大值。除秋季日变化规律以双峰型变化趋势为主,春、夏两季均表现为单峰型递增趋势。3.影响水—气界面CO2通量变化的要素在日变化和季节变化上有所不同。影响CO2通量日变化的主要因子有:温度、风速、碱度和叶绿素,碳通量与温度、叶绿素呈负相关,与风速和碱度呈正相关。影响CO2季节变化的主要因素有:温度、水生植物、水位以及天气情况。4.泥河水库全年碳排放为1.01 Gt C a-1(G=1×109g)。通过与已有研究结果对比发现,泥河水库CO2总体排放量比热带及亚热带水体低,比高寒地区以及贫营养型水体要高,总体上属于中等偏下水平。其通量值与自然湖泊CO2排放量相近,与已有研究结果基本一致。

【Abstract】 The static chamber/gas chromatograph techniques was used the first time in China to measure CO2 fluxes across water-air interface in Nihe reservoir in Harbin.In this paper, observations were conducted to study the character of diurnal variation and seasonal variation of CO2 fluxes in ice-free seasons including spring,summer and autumn.And meanwhile,the preliminary assessment was given on the situation of carbon source/sink in Nihe reservoir. Through the amount of data analysis,we found that:1.From the seasonal variation view,Nihe reservoir was the source of atmospheric CO2 in three seasons with the average CO2 fluxes of 690.42±15.18(mg m-2 d-1).The character of seasonal variation was obvious and their basic trends were:summer>spring>autumn with the average fluxes of 756.42±54.58(mg m-2 d-1),714.16±83.45(mg m-2 d-1) and 600.67±77.14(mg m-2 d-1),respectively.2.From the point view of diurnal variation,all-day performance was source for CO2 in Nihe reservoir.The average carbon flux in three seasons were 26.43±2.52(mg m-2 h-1), 35.44±4.09(mg m-2 h-1),24.52(mg m-2 h-1),respectively.The rules of diurnal variation of CO2 fluxes were:Day With the solar radiation enhanced in daytime,CO2 emission reductions, CO2 flux to reach the minimum at about13:00,and thereafter CO2 flux increased gradually affected by aquatic organisms’ respiration and reached source maximum between 22:00~1:00. Besides the autumn with the diurnal variation trend of bimodal,the spring and summer are reflected in increasing trend of single-peak type.3.The factors that effected variation of c across water-air interface were a little differed between variation of diurnal and seasonal.The main factors impacted on diurnal variation of CO2 fluxes are:temperature,wind speed,alkalinity and chlorophyll.There was negative relationship between carbon flux and temperature,chlorophyll,and positively correlated with wind speed and alkalinity.While the main factors affected seasonal variation are:temperature, aquatic plants,and water level and weather conditions,respectively.4.The carbon emissions of all-year in Nihe reservoir is 1.01Gt a-1(G=1×109g). Compared with previous studies we found that total emissions of CO2 in Nihe reservoir located at lower-middle level on the whole which is much less than the water bodies in tropical and subtropical but higher than the ones in cold areas as well as oligotrophic water body.In addition,CO2 emissions of reservoir are similar to nature lakes.This result is basically corresponded to previous study.

【关键词】 泥河水库水-气界面CO2通量
【Key words】 Nihe reservoirwater-air interfaceCO2 fluxes
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