【作者】 何华；

【导师】 龙天渝；

【作者基本信息】 重庆大学 ， 城市环境与生态工程， 2010， 博士

【摘要】 纵观当今世界,全球变暖已日益引起广泛的重视,因而促进了低碳经济的迅猛发展,低碳研究开始成为目前的研究热点。在建筑领域,与建筑节能、绿色建筑和生态建筑相关的科研工作取得了显著的成效,但是低碳建筑、低碳居住区和低碳城市的研究则刚刚起步。低碳研究包括碳源和碳汇两个方面的内容,建筑可归属于碳源,居住区和城市则同时包含这两个方面的内容。作者选择了居住区这个中观尺度进行研究,就是希望能够承上启下上,即用低碳居住区的研究成果指导低碳建筑的研究,同时为低碳城市的研究奠定基础。居住区的碳源主要包括建筑碳源和社会碳源,碳汇则主要来自居住区绿地。建筑碳源和社会碳源目前有大量的基础数据可供参考,而居住区绿地碳汇基础数据却相对缺乏,因而本文将进行以绿地碳汇为重点的居住区低碳研究。研究人员很早就开始了关于植物光合、植物呼吸和土壤呼吸的微观机理研究,已经取得了非常丰硕的研究成果,而从应用角度出发的绿地碳汇计算研究则近些年才兴起。其中,生物量法和植物光合速率法是比较典型的绿地碳汇计算方法:生物量法进行计算时主要考虑首尾时间点,忽略中间状态的研究;光合速率法进行计算时尽管考虑了中间状态,但由于取点受限导致不能准确地描述中间各点的状态,因此它们都不能实现对绿地碳汇实时和连续的精细描述。本文的研究目的就是要实现居住区绿地碳排放和碳吸收的逐时描述,因此提出了建立基于典型气象年的全年逐时绿地碳汇数学模型的目标,它由逐时植物呼吸碳排放方程、逐时土壤呼吸碳排放方程和逐时植物光合碳吸收方程组成。为此,必须建立逐时植物光合速率方程、逐时植物呼吸速率方程、逐时植物叶面积方程和逐时土壤呼吸方程。水、光和热是影响植物生长的重要环境因子,这些环境因子的变化会引起绿地碳汇作用的变化。本文选取了光强、温度和湿度三个主要环境因子作为变量,通过试验研究它们与绿地碳汇之间的关系,然后对试验结果进行回归分析以建立绿地碳汇的数学模型。由于自然状态下全年逐时数据的获取工作量非常巨大,以现有资源投入的水平很难完成这项工作,因而本文提出了基于典型气象年数据的模拟测试的新方法。本文提出的模拟测试的新方法,就是在人工模拟环境因素的条件下测试植物的光合速率和呼吸速率,建立逐时的环境因素与植物光合速率和呼吸速率之间的量化关系。这种试验方法很好地解决了在自然状态下测试时环境因素不可控的弊端。本文进行模拟测试时,通过均匀设计的方法进行环境因素组合,从而极大地减少了测试工作量。为验证模拟测试的有效性,作者还提出了植物光合和植物呼吸的对比测试方法,即设定相同的环境因素,对比实际测试与模拟测试条件下植物的光合速率和呼吸速率,然后分析这些数据以确定模拟测试是否能够代替实际测试。植物叶面积和土壤呼吸测试虽然受测试条件限制采用常规方法,但仍是为绿地碳汇逐时模型服务的,这两个测试的目的是要建立基于典型气象年的逐时植物叶面积方程和逐时土壤呼吸方程。对试验数据的分析结果表明作者实现了预期的目标。经过对荔枝公园6种植物光合对比测试数据、居住区8种植物光合对比测试数据和梅林公园78种植物光合对比测试数据的分析,发现模拟测试条件下的植物光合速率与实际测试条件下的植物光合速率具有很好的拟合性,因此证明了植物光合模拟测试的可行性。在此基础上进行了梅林公园78种植物的植物光合模拟测试,得到了拟合度极高的78种植物的冬季逐时光合速率方程。经过对荔枝公园6种植物呼吸对比测试数据和居住区8种植物呼吸对比测试数据的分析,发现模拟测试条件下的植物呼吸速率与实际测试条件下的植物呼吸速率具有很好的拟合性,从而证明了植物呼吸模拟测试的可行性。在此基础上,进行了梅林公园78种植物的呼吸模拟测试,得到了拟合度极高的78种植物的冬季逐时呼吸速率方程。通过对叶面积测试和土壤呼吸测试数据的分析,本文还建立了78种植物的年度叶面积方程和78种植物下覆土壤的逐时呼吸速率方程。本文提出了基于建筑系统、社会系统和绿地系统的居住区全生命周期碳收支计算框架,然后以绿地碳汇研究成果(即绿地碳汇逐时数学模型)为基础,提出了居住区全生命周期碳收支的具体计算方法。该计算方法体现了“全员”、“全程”、“动态”和“精确”四大原则,即内容涵盖了所有的碳行为主体,时间覆盖了整个居住区的全生命周期,考虑了各碳行为主体在全生命同期中的动态变化,通过逐时的计算力求精细。在实例计算中本文给出了碳收支计算的具体操作方法,深圳市某小区的碳收支计算结果表明:碳源与碳汇的数量比例为29:1,在居住区全生命周期中碳源和碳汇严重失衡;在碳源构成中,社会碳源与建筑碳源的比例为4.6:1,社会碳源成为影响碳收支平衡的重要因素。最后本文对“零碳”、“低碳”居住区的建设进行了探讨。结果表明通过减少人口和增加绿地,可以实现“零碳”的目标,但是此时用地非常不经济,人均用地指标是规范规定的13倍或17倍,绿地率高达97%或75%。与目前提倡的“节地”显然是相悖的,可见在人口高度聚集的城市建设“零碳”并不现实。本文还进行了“低碳”居住区的计算,提出了“低碳”居住区的数量标准。但是,由于目前支撑低碳评价的相关基础性标准缺失,因此加强这些标准的建设是完善“低碳”居住区评价体系的重点和难点,也是该领域下一步需要研究的内容。更多还原

【Abstract】 In today’s world, people pay great attention to global warming gradually, which promotes rapid development of low carbon economy, and low carbon research has become focus at present. In architectural field, research on building energy efficiency, green building and ecological building has made great progress but that on low carbon building, residential area and city has developed just in recent years. Low carbon comprises two factors which are carbon sink and carbon source, and building could fall into the factor of carbon source but residential area and city included two of them. Residential area with middle scale was selected as research object by the author so that research finds in the dissertation could give some guides to low carbon building and lay a foundation for low carbon city. Carbon sources in residential area include building and society carbon source,and green space is the main carbon sink on the other side. In residential area, there are much basic data for carbon sources calculation but little for green space sink calculation. Therefore, low carbon research on residential area in the dissertation was mainly based on green space sink.Research on microscopic mechanism for plant photosynthesis, plant respiration and soil respiration begun many years ago so a great deal of relevant finds have been obtained but that on calculation methods of green space sink started just decades of years ago. Among those methods, the quantitative biomass examinations and plant photosynthesis examinations could be representatives. In the quantitative biomass examinations,calculation is made only considering start point and end point with intermediate state ignored,and on the contrary,intermediate state is taken into account for plant photosynthesis examinations which could not precisely depict all the intermediate points either because it is difficult to get data of all intermediate points. Then it could be concluded that neither of them could precisely depict green space carbon sink instantaneously and continuously. Thus, the purpose of the dissertation is to describe carbon emission and absorption of green space hourly in residential area,so that hourly mathematic model of green space all year round in typical meteorological year becomes the specific goal. This model consists of hourly carbon emission equations for plant respiration and soil respiration and hourly carbon absorption equations for plant photosynthesis. Moreover, equations of hourly plant photosynthesis rate, hourly plant respiration rate, hourly soil respiration rate and hourly leaf area are the basis for them. Water, Sunshine and temperature are the key environmental factors for plant growth and those factors would also affect green space carbon sink. Consequently, three key environmental factors of light intensity, temperature and humidity are chosen to be variables for those equations. Examinations were taken to build those equations so as to establish green space mathematical model based on regression analysis on those experimental data. Because it will spend too many resources for people to acquire datum of the whole year hourly in natural state, the writer advanced a new method to solve this problem based on the datum of typical meteorological year.The new method is simulation experiment, which is applied for equation establishment of hourly plant photosynthesis and hourly plant respiration. This method means to acquire test data in artificially simulated environment in order to build quantitative relations between environmental factors and plant photosynthesis and respiration rate. If taking experiments in natural situation, those environmental factors should not be adjusted freely. In the plan of simulation experiment, uniformity design was introduced for variable design so lots of experiment works were reduced. Contrast experiments of plant photosynthesis and plant respiration were taken to prove the validity of the simulation experiment. It means to compare plant photosynthesis and respiration rate in natural environment with that in artificial simulated environment and the result would show whether it is rational to replace actual experiment with simulation experiment. Ordinary experimental measures were taken for plant leaf area and actual experiment for soil respiration due to limitation of actual equipments. These two experiments are used to build plant leaf area and soil respiration equation hourly in order to establish green space mathematical model based on the datum of typical meteorological year.Analysis on the experimental data shows that all the expected aims have been achieved. According to analysis on data of contrast experiment for plant photosynthesis, it verified the feasible of simulation experiment for plant photosynthesis that data of plant photosynthesis in simulation experiment could match that in actual experiment very well. Those data involve six different kinds of plants in Litchi Park, eight different kinds of plants in a residential area and seventy-eight different kinds of plants in Meilin Park. Having verified the validity of simulation experiment, simulation experiment for seventy-eight different kinds plants was taken and finally obtained equations of hourly photosynthesis rate for those plants with high fitness. According to analysis on data of contrast experiment for plant respiration, it also verified the feasible of simulation experiment for plant respiration that data of plant respiration in simulation experiment could match that in actual experiment very well. Those data involve six different kinds of plants in Litchi Park and eight different kinds of plants in a residential area. Having finished the verification, simulation experiment for seventy-eight different kinds plants was taken and finally obtained equations of hourly respiration rate for those plants with high fitness. Based on analysis on data of leaf area and soil respiration experiments, leaf area equations for seven-eight different kinds of plants and respiration equations for seven-eight different kinds of soils were built also.Having presenting calculation framework for whole life circle carbon budget in residential area based on building system, social system and green space system, this dissertation detailed the calculation method with research finds on green space carbon sink above. This calculation method illustrates four basic principles which are all objects, whole procedure, dynamics and accuracy. It means that all objects of carbon behavior regarded, the whole life circle of residential area covered, dynamic change of objects included and hourly calculation introduced. The example demonstrates details of the calculation procedure whose results show ratio of carbon source to carbon sink is 29:1 and that of society source to building source is 4.6:1. So it can be concluded that serious imbalance exists between carbon sink and carbon source in residential area and society source is a key factor for carbon budget balance.Zero and low carbon residential area construction were discussed at last. It shows that by reducing population and increasing area of green space, zero carbon can be realized but in this situation it does not make full use of land because land per capita is 13/17 times of stipulated specifications and green space ratio even reaches 97/75 percent. It is obvious that this practice have contradicted the goal of land saving in city. Thus, the conclusion could be made that zero carbon is not practicable in city with so large population. Also, calculation of low carbon residential area was made to establish a low carbon standard for this residential area. With the absence of relevant codes to support low carbon appraisal, it becomes the difficulty and emphasis to build those codes.This dissertation was subsidized by national 11th Five-Year Plan major scientific and technological project of No. 2006BAJ02A13-5.更多还原