Methodology模型方法学

MEIC is a comprehensive model for emission inventory development, including source categorization, emission factor database, technology based method and high-resolution emission processing system on the cloud computing platform. The MEIC model integrates the whole process from basic data to model-ready 3-D emission files required for air quality models. Users can easily customize for different resolutions, scales, pollutants and years. The model-ready emission products can be accessed and downloaded online.

MEIC是一个完整的排放清单模型框架,包括了源分类分级体系、排放因子数据库、动态排放清单方法、多尺度高分辨率排放源模式、清单云计算平台等多个组成部分,实现了从建立排放清单所需的基础数据开始,到生成空气质量模型需要的排放数据立方体这一完整过程的动态连续处理,可完成多年度、不同空间尺度、多化学组分的排放清单开发以及与空气质量模型之间的无缝对接。

Source categorization源分类分级体系

The MEIC model is developed under six anthropogenic emission categories, including stationary combustion, industrial processes, mobile sources, solvent utilization, agricultural sources and waste disposal. For each source category, the emissions can further be divided by different sectors, fuel types/products, combustion/production technology, and end-pipe control devices. The latest version of MEIC covers more than 700 anthropogenic emission sources.

MEIC模型涵盖了固定燃烧源、工艺过程源、移动源、溶剂使用源、农业源和废弃物处理源等六大类人为排放源。每类排放源按照部门/行业、燃料/产品、燃烧/工艺技术以及末端控制技术分为四级,自第一级至第四级逐级建立完整的排放源分类分级体系,以第四级作为排放清单的基本计算单元。目前的模型版本包括了700多种人为排放源。

Dynamic methodology 动态排放清单方法

The MEIC model is developed using technology and process based methods, which resolves the quantitative relationship between emissions and technology turnover. Energy consumption, combustion/industrial/control technologies and emission factor database are fully coupled to estimate emissions accurately. Each calculation unit is mapped to activity database, technology turnover model, and emission factor database, which enable MEIC to update quickly by capturing the technology and activity levels changes.

针对我国污染源技术水平跨度大、构成复杂且更替速度快的特点,MEIC模型建立了基于技术和动态过程的排放清单方法,定量解析了主要大气污染物排放与燃烧技术、工艺技术和污染控制技术更替之间的多维响应关系,构建了能源消耗-工艺过程-排放特征之间的动态耦合模型,建立了第四级排放源与活动水平、工艺技术和排放因子数据库的完整映射,通过捕捉活动水平的变化和工艺技术的演变,实现排放清单的动态计算和快速更新。

For power, cement and steel industries, MEIC uses process based method to develop unit-based emission inventories. For each equipment, MEIC tracks its technology evolution to dynamically represent the emission variation induced by technical progress and more stringent emission standard.

对于电力、水泥、钢铁等主要工业排放源,MEIC模型采用基于工艺过程的排放清单计算方法,按逐个排污设备计算大气污染物的排放量。对于同一个排污设备,模型追踪了其全生命周期中的工艺技术的演变过程,从而能够动态表征由于活动水平变化、技术进步、排放标准加严等因素引起的排放变化。

For highway vehicles, MEIC develops a high resolution and comprehensive emission inventory based on county activity database, meteorological model, emission factor model, and traffic flow survey, which improve the spatial and temporal resolutions from province to county and from annual to hourly, respectively.

对于道路机动车排放源,MEIC采用了包括气温、湿度、海拔、工况等参数的排放表征模型,结合逐时气象场、机动车排放因子模型、路网信息和交通流数据,构建了高分辨率机动车动态排放清单,将机动车排放清单的时空分辨率分别从年提高到小时、从省提高到县。

Multi-scale high resolution emission processing system多尺度高分辨率排放源模式

MEIC developed a multi-dimensional high-resolution emission processing system to generate model-ready gridded emission input for air quality models. The emission processing system composes three modules for temporal allocation, spatial allocation, and speciation. The temporal module allocates annual emissions to hourly emissions based on the monthly, weekly and daily profiles. The spatial module allocates point and area sources to 3-D grids by using spatial and vertical distributions. The speciation module is developed using the profile-assignment approach. Emissions of total NMVOC and PM are firstly split into individual species, and then mapped into various chemical mechanisms that are configured in chemical transport models, such as SAPRC99, SAPRC07, CBIV, CB05, CBMZ, RADM2, RACM, GEOS-Chem, and MOZART.

MEIC模型通过自主研发的多尺度高分辨率排放源模式完成网格化排放清单的开发以及与空气质量模型的无缝对接。MEIC排放源模式包括时间分配、空间分配、化学成分分解三个模块。时间分配模块在第三级排放源层面建立排放月变化系数、周变化系数和日变化系数,将年排放量分配到小时。空间分配模块在第三级排放源层面上分点源和面源建立水平和垂直方向上的排放分配方法,将排放量分配到与空气质量模型对应的三维网格。化学成分分解模块基于源特征谱-化学机制映射关系开发,将NMVOC和颗粒物排放分配到单个组分并映射到化学机制物种,得到SAPRC99、SAPRC07、CBIV、CB05、CBMZ、RADM2、RACM、GEOS-Chem、MOZART等9种常见大气化学模型机制所需的排放物种。

Cloud computing platform排放清单云计算平台

The MEIC model allows online calculation and download of gridded emission inventories by using efficient algorithms for big data and cloud-computing technologies. The MEIC model provides high-resolution and model-ready emission inventories for several air quality and forecasting models. Users can require, customize, and access demanded data on-line through the cloud-computing platform.

MEIC模型采用海量排放数据高速处理算法和云计算技术,实现了网格化排放清单的实时动态在线计算和下载,可为主流空气质量模型、预测预警模型提供高分辨率的排放清单产品,并且使得用户能够通过在线平台按需定制排放清单数据。