基于碳密度情景模拟的小城镇绿地微气候效应及空间优化研究

Green land systems has the role of carbon absorption, cooling, and humidification to improve the urban ecological environment. Green space carbon sinks and green space microclimate effects are complex systems. Based on the analysis of the suitability of Greenfield carbon sequestration, this paper combines spatial planning technology with hydrodynamics simulation technology, explores the simulation theory and method of carbon dioxide distribution law and Greenfield microclimate effect in the planning and design, and puts forward green space indicators and space layout methods suitable for small towns. Mainly, the research content involves four parts：(1)According to the new classification system of urban and rural green spaces, select the type of green space with representative characteristics, determine the observation time and observation location, and establish a green space database to collate observation data. (2)To establish a three-dimensional model of urban elements such as architecture, green space, and roads, and to divide the grid and set the parameters. (3)With reference to the existing green space carbon sequestration model, the capacity and reserve distribution of urban Greenbelt vegetation are evaluated, the spatial distribution of carbon density is revealed, and the optimal layout of urban Greenbelt system is established. (4)Using the three-dimensional microclimate software ENVI-met to simulate the microclimate effects under different green space layout scenarios, the synergy effect and mechanism of "carbon density-microclimate" in the space layout of green space were explored. (5)Further determine the technical parameter system of climate impact of green space layout in small towns and feed it back into the planning layout of green space.

绿地具有吸碳、降温、增湿等改善城市生态环境的作用。课题基于绿地固碳适宜性分析，将空间规划技术与流体力学模拟技术相结合，探索二氧化碳分布规律和绿地微气候效应在规划设计中协同发展的模拟理论与方法，提出适合小城镇的绿地指标及空间布局方式。具体内容包括：①按照新的城乡绿地分类体系，选择具有代表特点的绿地类型，确定观测时间和观测地点，建立绿地数据库整理观测数据；②建立城市要素如建筑、绿地、道路等的三维模型，并进行网格划分和参数设置；③借鉴已有绿地固碳测算模型，评价城镇绿地植被的碳汇能力和储量分布，揭示碳密度空间分布规律与特征，建立城市绿地系统优化布局情景；④运用三维微气候软件ENVI-met对不同绿地布局情景下的微气候效应进行模拟，探究绿地空间布局的“碳密度—微气候”的协同效应及其作用机制；⑤进一步确定小城镇绿地布局气候影响技术参数体系，并将其反馈于绿地规划布局。

绿地具有吸碳、降温、增湿等改善城市生态环境的作用。本课题项目基于绿地固碳以及绿地改善风热环境效益两个方面的主要作用，结合CFD流体力学及ENVI-met微气候模拟软件，一方面探索城市二氧化碳计算方法及其空间分布规律，另一方面，探索绿地微气候效应在城市绿地系统规划当中的作用，并提出适合小城镇的绿地空间布局方案。具体研究内容如下：①按照新的城乡绿地分类（GB/T51346-2019）体系，选择具有代表特点的104个样本点，确定观测时间和观测地点，建立绿地数据库以及CO2、温度、湿度、风速等观测数据；②建立城市要素如建筑、绿地、道路等的三维模型，并进行网格划分和参数设置；③借鉴已有绿地固碳测算模型，评价城镇绿地植被的碳汇能力和储量分布，揭示碳密度空间分布规律与特征，建立城市绿地系统优化布局情景；④运用CFD模拟软件对不同绿地布局情景下的微气候效应进行模拟，探究绿地空间布局改善方案。