东莞市城区大气二氧化碳浓度模型及模拟

Modeling and Simulation of Atmospheric CO_2 Concentration in the Downtown of Dongguan City

基于GIS及CO2实测数据,根据系统动力学原理,运用STELLA软件,构建东莞市城区大气CO2浓度模型,对城区CO2浓度进行模拟,探索城区CO2浓度变化规律及影响因素,为改善城区大气质量提供科学依据。模型由3个模块构成:大气交换模块、人类活动模块和绿地植被模块。反馈环主要有3个:大气交换与大气CO2浓度的负反馈,植被光合作用与大气CO2浓度的负反馈,以及植被呼吸作用与大气CO2浓度的负反馈。模型模拟结果显示,东莞市城区大气CO2浓度日平均值为483.62μmol/mol,越靠近市中心,大气CO2浓度越高。城区大气CO2浓度晚上高、白天低。人口密度和汽车尾气排放是城市大气CO2浓度的主要影响因素。仅增加城区绿地面积对城区CO2浓度影响不大。降低城区大气CO2浓度的有效措施:目前重点应为推广公共交通,并应逐渐转向推广清洁能源汽车。

Based on GIS and CO2 data,Dongguan atmospheric CO2 model was established with STELLA software and the system dynamics theory. CO2 concentration was simulated to study the trends and influencing factors, which would provide a scientific basis for improvement of urban air quality. The model consists of three modules including air exchange, human activity and green vegetation. There are three main feedback loops such as the negative feedback of air exchange and atmospheric CO2, the negative feedback of plant photosynthesis and atmospheric CO2 and the negative feedback of plant respiration and atmospheric, CO2. The simulation showed that average concentration of CO2 in Dongguan downtown was 483.62 μmol/mol, and the concentration was higher in the inner ring. The diurnal trend of the concentration was high at night and low during the day. The population density and automobile exhaust emission are the key components of atmospheric CO2. CO2 concentration could not be decreased greatly only by increasing the green area in the downtown. Effective measures to reduce CO2 concentration are to promote public transport, and gradually move to extend the use of clean energy automobile.