Research Frontier of Street Spatial Form

In order to comprehensively and objectively understand the research status of street form at home and abroad,WOS and CNKI database are as the source,and 176 street form papers retrieved from 2010 to 2021 are as samples to conduct statistical analysis of the data.The main research hotspots are reviewed systematically,and the research trends in the field of planning and architecture are pointed out.The hot topics of street form research in the past ten years are summarized,such as street spatial form characteristics,street form and thermal environment,air quality correlation,street form and walking,safety,vitality,health and other perceived correlations.The research methods are summarized from two levels of street form data collection and analysis.Finally,the current research trend characteristics and future trends are summarized and prospected to provide reference for the current research of street form.

基于多源数据的地表覆盖制图与分析——以广东省广州市为例

地表覆盖数据是关于土地利用信息的重要来源,在地理国情监测、气候变化研究、生态环境评估等方面发挥着重要的作用。本文以广东省广州市作为研究区域,利用OSM数据结合FROM-GLC数据和Landsat-8遥感影像数据,对研究区域地表覆盖进行分类并完成地表覆盖制图。实验结果表明,利用OSM数据进行地表覆盖制图结果总体精度较高,具有可用性,但是OSM数据空白区域占比较大,有数据区域个别要素数量较少,在参考选取样本时,样本代表性不够高,部分类型的地表覆盖分类精度较低。

Updating Traditional 1/50,000 Topographic Maps Using Crowd-Sourced Geodata and Free Sources Satellite Images

This paper addresses how open geodata and crowd-sourced geodata, and the open geoportals might be integrated with the mainstream surveying and mapping practices to update traditional topomaps quickly and inexpensively, that might be otherwise impossible to do it due to economic and logistic situations. The abundant geographic data on the internet could be used to update topographic maps while avoiding the time-consuming nature of the traditional method. To be able to use them, it is necessary to measure and quantify the quality of these data, as well as to verify their credibility, in order to incorporate them into official topographic maps. The proposed approach takes advantage of neocartography, and it’s not about further developing a new approaches, but looking differently at how data is collected, assembled controlled and been used for updating topomaps. At the beginning, the methodology used about how open geodata and crowd-sourced geodata involved in collecting, simplifying, generalizing, controlling and generating useful cartographic information that complement traditional and conventional counterparts is presented. This methodology was applied on a 1/50,000 topomap located in the north of Jeddah city (western region of Saudi Arabia), and we have demonstrated that by using this type of data, it is possible to update topographic maps quickly and at a lower cost while maintaining cartographic precision and accuracy standards.

Estimation of PM_(10) in the trafc-related atmosphere for three road types in Beijing and Guangzhou, China

The levels of roadside PM10 in Beijing, China, were investigated in 2011 and 2012 on a seasonal basis to estimate the population exposure to particulates for three road types. The measurements of PM10 were also conducted in the southern Chinese megacity of Guangzhou for comparison purposes. The results showed that roadside PMlo in Beijing correlated strongly with the PM10 background in the urban atmosphere. The levels of PM10 in street canyons were markedly higher than those along the open roads and in crossroad areas because of limited ventilation. An elevation of PM10 was observed in April, which was possibly due to the sand storms that frequently occur in the spring. Based on these observations, roadside PM10 in Beijing could have multiple origins and was to some extent dispersion- governed. In Guangzhou, the roadside PM10 did not closely relate to the background values. The PM10 pollution was greatly affected by local traffic conditions. The simulation of PM10 for different road types was completed during the study period using the Motor Vehicle Emissions Factor Model （MOBILE6.2） as an emission model and the California Line Source Dispersion Model （CALINE4） and Operational Street Pollution Model （OSPM） as dispersion models. The MOBILE6.2/CALINE4 software package was demonstrated to be sufficient for the simulation of PM10 in the open roads and crossroad areas in both Beijing and Guangzhou, and the simulation results of roadside PM10 in the street canyons by the MOBILE6.2/OSPM package were in close agreement with those of the measurements.

An efficient method of evaluating large scale urban residential skylight environment and an empirical study of Beijing main area

A good skylight environment in urban residential areas is an important component of a healthy city,and has always been highly valued.With the rapid development of new-type urbanization,the density of buildings continues to increase,and megacities have entered the stage of stock transformation.An effective method for evaluating the skylight environment of large-scale urban residential areas is urgently needed.However,there is still a lack of empirical research methods and cases of large-scale residential skylight environment.In this regard,this article takes the megacity Beijing as the research object,and proposes an efficient analysis method of residential skylight environment that integrates multiple real-world data at city scale.In terms of data,it collects and integrates 3D data of urban-scale building space and residential boundary data;in terms of algorithm,Sky View Factor(SVF)is used as the evaluation index of residential skylight environment,and an efficient analysis method of urban-scale skylight environment based on cloud parallel simulation is realized.Through analysis,it is found that:(1)the average SVF value of Beijing residential area is 61%,which means that its skylight quality is in general level;(2)the skylight environment of Beijing residential area is distributed in a circle,and there are 4 types of skylight environment quality residential areas;(3)The skylight environment of Beijing residential area is relatively weakly related to the distance from the residential area to the city center and the average height of the residential buildings,and is closely related to the plot volume ratio,the residential building density and the shading from surrounding buildings.The highlight of this study lies in the empirical research on the skylight environment of mega-city residential areas that incorporates multiple real data for the first time,which can promote the study of skylight environment on a city scale and provide a reference for the updating of Beijing’s residential daylight environment.