The Spatial Distribution Pattern Analysis of City Infrastructure Cases of Urban Management

The effective disposal of daily city infrastructure cases is an important issue for urban management. To more effectively utilize a large amount of historical cases data collected and accumulated in the urban grid management system, and to analyze their spatial distribution pattern information for city managers, this study used the comparative kernel density analysis method in two types of cases (i.e. power facilities and traffic guardrail) in Xicheng District, Beijing for the year 2016 and 2017. This research analyzes them at different scales (300 m, 600 m, 1,200 m), and the experiment results show that the method of comparative kernel density analysis is able to provide an intuitively spatial visualization distribution analysis of city infrastructure related cases. The quantitative information of spatial agglomeration degree is helpful for city managers making decision.

Study of Urban and Rural Construction Land Change Based on Small Scale in Dafang

This paper is to examine the urban and rural construction land data of Dafang between basic year and final year based on country scale and spatial econometrics,and analyze its spatial pattern and change feature. According to the results,the construction lands in all the villages of Dafang County showed strong spatial autocorrelation and significant spatial cluster. After the analysis of local Moran's I,the construction lands in 381 villages of 36 counties presented strong activity. The original small-scale villages were gradually enlarging,which will not only gradually benefit local development,but also be in accordance with the strategy of " one city,one district,eight parks".

Relative Contributions of Spatial and Environmental Processes and Biotic Interactions in a Soil Collembolan Community

Understanding the underlying processes of how communities are structured remains a central question in community ecology. However, the mechanisms of the soil animal community are still unclear, especially for communities on a small scale. To evaluate the relative roles of biotic interactions and environmental and spatial processes in a soil collembolan community, a field experiment was carried out on a small scale(50 m) in the farmland ecosystem of the Sanjiang Plain, Northeast China. In August and October, 2011, we took 100 samples each month in a 50 m × 50 m plot using a spatially delimited sampling design. Variation partitioning was used to quantify the relative contributions of the spatial and environmental variables. A null model was selected to test for the non-randomness pattern of species co-occurrence and body size in assemblages of collembolans and to test whether the pattern observed was the result of environmental or biotic processes that structured the community on a small scale. The results showed that large variance was accounted for by spatial variables(18.99% in August and 21.83% in October, both were significant). There were relatively lower effects of environmental variation(3.56% in August and 1.45% in October, neither was significant), while the soil water content, soil p H and soybean height explained a significant portion of the variance that was observed in the spatial pattern of the collembolan community. Furthermore, the null model revealed more co-occurrence than expected by chance, suggesting that collembolan communities had a non-random co-occurrence pattern in both August and October. Additionally, environmental niche overlap and the body size ratio of co-occurrence showed that interspecific competition was not influential in collembolan community structuring. Considering all of the results together, the contributions of spatial and environmental processes were stronger than biotic interactions in the small-scale structuring of a soil collembolan community.

Issues with Spatial Scale in Urban Research

Scale is the range or measurement unit of the characteristics of natural or human ontology in the temporal or spatial dimension and is widely used in daily life and the study of various disciplines.Scale effect pertains to certain laws and characteristics that can only be reflected on a specific scale,so choosing the appropriate scale remains the basic premise of scientific research.The concept of the urban spatial system is complex and has the characteristics of scale dependence,and the selection of an appropriate spatial scale is important for the accurate estimation and description of urban issues.In this paper,we discuss spatial scale in urban research using cases that primarily come from the Chinese experience,provide some examples that demonstrate the importance of appropriate scale in urban research,including urban shrinkage,and highlight problems in spatial research.Ultimately,we suggest that scale consciousness should be the basic consciousness required in empirical research.

乌鲁木齐市物流企业区位时空演化、影响因素和发展策略研究

物流企业的空间布局不仅可以改变现有的物流组织形式,对重塑地区的产业空间格局也会产生重大影响。基于2006—2022年乌鲁木齐市物流企业空间数据,在对乌鲁木齐市物流企业区位时空演变分析的基础上,运用地理探测器和多尺度地理加权回归进一步探究物流企业区位选择的影响因素及其空间异质性,并提出优化物流企业空间布局的发展策略。结果表明:(1)乌鲁木齐市物流企业存在集聚分布特征,呈现出由“一主轴、一核心”向“三主核、两副核”演变的空间格局。(2)乌鲁木齐市地区间物流企业发展存在显著的正向溢出效应。(3)物流企业区位选择的影响因素中,物流企业数解释力度的均值为66%、地区GDP为48%、人口密度为49%、物流园区距离为28%;其中物流企业数和物流园区距离是空间异质性因素且其系数在空间上变化较大,地区GDP是具有正向影响的全局变量,人口密度是具有负向影响的全局变量。研究结果不仅拓展了企业区位理论的研究,而且丰富了研究案例,同时可以为乌鲁木齐市进行物流产业规划和高质量建设丝绸之路经济带商贸物流中心提供理论依据和实践参考。

尺度重构视角下经济技术开发区向综合功能新区转型的空间应对——以烟台黄渤海新区为例

鼓励和促进经济技术开发区向综合功能新区转型发展,是经开区空间生产转型的内在需求,也是响应国家对经开区发展定位的重要举措。本文基于尺度重构理论视角,以烟台黄渤海新区为例,总结分析经开区向综合功能新区尺度重构的基本逻辑。研究认为,经开区向综合功能新区转型发展的过程,是一次“尺度上移”的过程,通过赋予更高层级的管理权限,重构区域生产关系、社会关系以及治理关系,形成产业协作有序的功能板块、更高标准的产城格局以及更加扁平化的治理结构。研究发现,烟台黄渤海新区在建设过程中,面临多空间主体及多政策制度并存的治理难题,其空间呈松散发展状态,以及低水平的产城融合特征。据此,文章提出整合港产功能板块、调整产城关系以及实施渐进性治理机制的治理策略,推动新区高质量发展,打造带动区域经济高质量发展的重要增长极。

A research into the large-scaled spatial forms of cities based on urban design

In the process of unprecedented urbanization in contemporary China, a great many of Chinese cities have witnessed a rapid expansion of urban scale to different degrees. With the continuous compilation, amendment and enforcement of urban planning, the functional structure, spatial environment, street patterns and textures and even the social aspect of cities have changed conspicuously, all of which have directly happened to the spatial forms of the dimension, or even the multi-dimension of a certain city. By describing and analyzing the structure, evolution and explicit tokens of the spatial forms of cities, this thesis attempts to set up a model of factors that affect urban forms, as well as discuss the attributes, protection, adjustment and development-potential of urban land closely associated with forms. In addition, on the basis of the professional features for urban design to participate in the modeling and construction-management of desirable spatial forms of cities, the author has put forward technical measures for quantitatively appraising and analyzing the large-scaled spatial forms of cities, thus offering technical support to municipal governments and management departments of planned construction.

基于多尺度地理加权回归模型的城市住宅价格影响因素空间异质性——以桂林市主城区为例

基于桂林市2022年10月二手房价格数据,结合多尺度地理加权回归(multi-scale geographically weighted regression,MGWR)模型,分析不同尺度下城市住宅价格影响因素的空间异质性。结果表明:(1)桂林市住宅价格呈显著空间自相关,局部空间自相关结果表明,桂林市住宅价格空间呈显著的集聚分布,以“高-高”和“低-低”集聚为主,“高-低”和“低-高”集聚范围较小;(2)相较于普通最小二乘法(ordinary least squares,OLS)和地理加权回归(geographically weighted regression,GWR)模型,MGWR模型的R2更高,能更准确地测度变量对住宅价格的影响程度和空间差异性;(3)住宅房龄、教育医疗和商务设施为全局变量,绿化率、公共交通设施、铁路设施配套、生活配套和旅游景点的空间异质性处于中等水平,对外交通设施的空间异质性较大,在局部范围内对住宅价格有显著影响且差异明显;(4)住宅房龄、生活配套和旅游景点对住宅价格具有负向影响,教育医疗和商务配套对住宅价格具有正向影响,其余变量在不同空间区位上对住宅价格表现出抑制或增值作用。

基于MobileNetV2的小肠溃疡病灶图像识别

小肠镜下的溃疡病变形态复杂,鉴别诊断困难。为实现小肠溃疡病变的人工智能辅助识别,提高诊断效率和准确度,构建了一种基于MobileNetV2网络的小肠溃疡性病灶识别算法。以MobileNetV2为主干特征提取网络,将输出特征图进行空间上的多尺度提取后输入至通道注意力模块中进行特征重标定,并将多个尺度上的特征进行融合后输出分类。为了缓解数据集不均衡所带来的影响,提出了一种改进的损失函数。所用数据集来自上海长海医院282位患者的共2124张小肠镜临床图像。采用所提方法对该数据集测试的识别准确率为87.86%,5折交叉验证平均准确率为87.27%。使用梯度加权类激活图进行了可视化验证,同时将所提模块应用在不同主干网络架构上,均具有良好的通用性。研究表明,该网络模型能够更加注重病灶信息,加强病灶特征判别指向,对于小肠溃疡图像具有较高的识别准确率,可初步实现小肠溃疡病灶的自动识别。

河谷城市“三生”空间冲突演化与分异机制——以兰州市为例

文章以河谷城市甘肃省兰州市为例,在测度“三生”空间冲突强度并揭示多尺度分异机制的基础上提出冲突协调策略。结果显示:①“三生”空间格局演化与地域分异显著。生活空间的增加主要源于对生态空间和生产空间的侵占。②兰州市“三生”空间冲突时空演化与地类分异显著。时序上,“三生”空间冲突强度呈持续上升态势,整体处于基本可控级别;空间上,形成了“一心、两翼、多轴带”的空间冲突格局;就地类而言,城镇的生活空间与生产空间冲突水平较高。③兰州市“三生”空间冲突影响因素尺度效应和异质性明显。高程、坡度、地形起伏度等对“三生”空间冲突具有抑制作用;人口密度、人均G D P、夜间灯光指数等因素加剧了区域“三生”空间冲突程度。

最优尺度下新安江流域景观生态安全格局及其影响因素

新安江流域作为首个跨省生态补偿政策试点,其政策实施对于地区城市整体生态治理具有正向促进作用,分析新安江流域城市政策实施前、中、后期的景观生态风险时空演变趋势及驱动因素,可为该地区及同类区域生态治理及风险防范提供科学支撑。基于2000、2010、2020年三期土地利用遥感数据,寻求评价景观生态风险的最优尺度,分析其时空演变趋势,并借助地理探测器计算空间因子的影响程度。研究表明:研究区最优研究尺度为粒度70 m、幅度11 km;2000—2020年,研究区景观生态风险显著降低,较高以上风险区面积大幅缩减,生态风险呈显著的空间正相关性,且相关程度不断减弱,高值聚集区逐渐减少;研究区内土地利用强度与坡度对景观生态风险驱动效应最强,各因子交互探测时可显著提高解释能力。研究区各市景观生态风险空间差异显著,需加强对草地、水域景观整体性的维护,进一步加强新安江流域城市生态稳定性,同时应考虑地区用地结构及风险状况,针对性采取风险治理措施。

多尺度可玩城市空间的塑造与发展——以哥本哈根为例

城市居民的心理健康问题普遍存于各年龄层中。作为公共生活的载体,城市环境与居民的日常行为联系紧密,对其身心健康有着重要影响。玩耍可有效预防和缓解心理健康疾病,尤其在后疫情时代,可玩城市空间塑造的意义更加深远。从建筑到街区,从街区到城市,居民可玩的城市空间应随着空间尺度的进阶而丰富。哥本哈根从20世纪初开始建设小型儿童游戏场,如今发展到综合性的超级公园,对可玩城市空间的探索有着丰厚的经验。基于空间理论,梳理哥本哈根可玩城市空间的发展脉络,以尺度进阶的视角归纳不同空间尺度上可玩城市空间的设计要点,从不同维度分析其营造案例,为我国可玩城市空间的发展提供一些参考和研究的基础。

基于拓扑优化和缩尺试验的小宽厚比独柱式桥墩帽梁力学性能研究

由于小宽厚比独柱墩帽梁属于典型的应力扰动区构件,内部受力较为复杂,普通独柱墩帽梁的设计方法可能对其不适用。对小宽厚比独柱墩帽梁模型进行拓扑优化,分析小宽厚比独柱墩帽梁的空间受力特征,根据拓扑优化结果建立小宽厚比独柱墩帽梁的空间拉压杆模型基本构形,并根据最小应变能准则提出了确定其最优构型的方法。针对目前对小宽厚比独柱墩帽梁试验研究较少的现状,进行缩尺模型试验,研究其竖向静载作用下的受力特性。结果表明:在横桥向,帽梁顶部在双支座荷载下具有最大拉应力;在顺桥向,帽梁中间位置拉应力最大,帽梁的顶部拉应力低于中部,帽梁底部则表现出受压的趋势。由于未考虑顺桥向的力流扩散,根据相关规范中拉压杆模型设计方法计算得到的内力值与试验结果相差较大,说明规范法不适用于小宽厚比独柱墩帽梁的设计。试验结果的应力分布情况与根据拓扑优化结果提出的空间拉压杆模型一致,并且采用空间拉压杆模型计算得到的拉杆应力值相比规范法更加合理,证明本研究所提的空间拉压杆模型基本构形以及确定最优构型方法的合理性。

萍乡市路网形态对住宅用地价格空间的多尺度影响——基于sDNA与MGWR模型的研究

为了探究萍乡市路网形态对住宅用地价格的影响,以2011-2020年萍乡市中心城区出让住宅地价样点为例,基于空间设计网络分析(sDNA)模型和多尺度地理加权回归(MGWR)模型探究路网形态对住宅用地价格的多尺度关系。结果表明,2011年以来,萍乡市住宅空间分布呈现轴向发展、向内填充与向外扩散并进、多中心圈层结构相融合的演化趋势;路网形态总体呈现块状聚集,轴向延伸的空间格局;路网接近度对住宅用地价格呈现出正向的城区边缘高,中心区低的空间格局,密度、穿行度与之相反,同时出现跨尺度相似性。研究成果可为市政完善土地市场价格管理体系提供科学的决策依据,同时为城市交通规划以及房地产选址布局提供相关建议。

农村建设用地多维结构特征分析——以凯里市为例

科学、严谨地对农村建设用地规模进行测算,是划定农村建设用地边界的前置条件,也是进行村庄规划的必要前提,更是乡村振兴需要重点考虑的因素之一。本文根据第三次全国国土调查数据和农业农村遥感监测数据库,应用空间特征法和景观指数法对凯里市农村建设用地的规模结构特征、空间分布特征和景观特征进行多维度量化分析,梳理凯里市农村建设用地存在的主要问题,并提出相应建议,以全面厘清凯里市农村建设用地布局特征,提高土地资源利用效率和管理水平,推进国土空间提质增效。

轻小型无人机在中心城区大比例尺地形图测绘中的应用

随着空间信息技术的不断发展,轻小型无人机在大比例尺地形图测绘中的应用也日渐广泛。针对传统测绘手段生产大比例尺地形图的局限性,以中心城区1∶500比例尺地形图测绘项目为对象,研究了基于轻小型无人机生产大比例尺地形图的作业流程,分别从像控点布设与测量、影像数据采集及数据处理等方面开展研究,构建出场景的三维实景模型,将三维模型导入EPS三维测图平台进行地物采集,辅以外业调绘和补测数据,完成了大比例尺地形图的生产,最后利用外业采集数据,从平面、高程和间距对成果精度进行分析,经精度评定成果质量符合规范要求。研究结果表明轻小型无人机可满足中心城区1∶500比例尺地形图的测绘要求,并可提升测绘效率,降低生产成本。

国土空间规划背景下连江县综合立体交通网规划研究

我国经济已由高速增长转向高质量发展阶段,交通成为中国现代化的开路先锋,城市交通系统将面临新一轮的契机与挑战,综合交通体系将更加注重对国土开发、区域协调、产业布局的先导作用。以连江县综合立体交通网规划为例,以城市国土空间总体规划提出的城市性质为依据,结合上位规划和城市特点,研究并提出交通发展战略,从而确定综合立体交通网的规划方案,以期为国土空间规划背景下中小城市的综合立体交通网规划提供参考思据。

山西晋中地区地下水取水井空间分布特征分析

为实现水资源统一管理、合理开发利用地下水资源,对晋中地区地下水取水井进行了调查研究,并通过规模、用途、密度、地形地貌、地下水类型、行政区划、水资源分区七大类分类分析了空间分布特征。结果表明,晋中取水井以规模以上机电井为主,开采深度以100(含)~200m为主,成井时间以1991—2022年为主,整体属低密度区,但平川区规模以上机电井密度较高,存在取水井空间分布不平衡、开采深度较深、平川区超采、超采和潜力并存等特征。

Factors that affect the assembly of ground-dwelling beetles at small scales in primary mixed broadleaved-Korean pine forests in north-east China

Disentangling the relative roles of environmental and spatial processes in community assembly is a major task of community ecology.It is necessary to uncover this question at multiple spatial scales;however,the relative importance of spatial and environmental processes on ground-dwelling beetle assembly at a small scale is still unclear.Based on two permanent plots(each 300 m)located in primary mixed broadleaved-Korean pine forests,the topographic,soil,and plant factors were collected,and the spatial variables(MEMs,distancebased Moran’s eigenvector maps)were calculated.A redundancy analysis(RDA)was used to evaluate the influence of topographic,soil,and plant variables on ground-dwelling beetle compositions.A variation partitioning analysis was used to quantify the relative contributions of environmental and spatial processes on the assembly of ground-dwelling beetles.The results of the RDA reported that the soil,plant,and topographic variables affected Staphylinidae and Silphidae beetle compositions in both plots.According to the results of variation partitioning,pure soil and plant variables were important for the assembly of Silphidae beetles in the LS plot.The contributions of pure topographic,soil,and plant variables were significantly lower than those of pure spatial variables.The contributions of pure spatial variables were significant for the assembly of Staphylinidae and Silphidae beetles in both plots.In addition,the relative importance of environmental and spatial processes was not significantly changed after including more environmental variables and the unexplained variations.Finally,this study suggests that both spatial and environmental variables are important for the assembly of ground-dwelling beetle communities,while pure spatial variables are more important than pure environmental variables at a small scale(300 m).

Impact of City Scale and Regional Difference on Small & Medium-Sized Cities' Development and Its Implication

By studying the relationship between urban development performance and city scale and regional difference, this paper aims at revealing the real challenges faced by small and medium-sized cities(referred to as SMSC hereafter) in China. It analyzes the growth of different-sized cities, their positions in China's overall urban system, the influence of city scale on their capability in migrant absorption, economic development, public service, and environmental remediation, as well as the capability difference among SMSCs. Results show that city scale is less a determinant in economic development capability and per capita ownership of public service than in economic performance, quality of public service, and environmental remediation capabilities. Besides, there are many other factors determined by regional differences instead of city scale. Therefore, in the context when SMSC plays an increasingly important role in the process of urbanization, relevant parties should avoid the "trap of scale," and re-position urbanization within the framework of sustainable development.