Modeling the effects of green alternative on heat island mitigation of a meso level town,West Bengal,India

Urban heat island (UHI) is emerged as a ubiquitous phenomenon that affects the outdoor thermal comfort. Hence urban microclimatic studies using numeric simulation software to find out adaption strategies are attracting the great attention of researchers and policymaker. Number of scientists carried out their research on this topic using different tools and technique whereas ENVI-met model is the most widely used simulation tools. The present study intended to examine the implication of green infrastructure of the town on enhanced microclimatic condition and to evaluate the best suitable mitigation strategy modelling cool city with ENVI-met software (V4). Five greening condition such as existing UHI condition (C1), 100% greening of roof (C2), 100% greening of roof and walls (C3), 50% greening of roof and walls (C4) and: Plantation at suitable area with 50% greening of roof and walls (C5) have been taken into consideration for the microclimate simulation for all three selected sites. Among these five conditions, C3 for the open mid-rise and compact low-rise, C5 for the open low-rise are identified as one of the most suitable strategies which can reduce the air temperature of peak hours by 2.6 °C, 1.33 °C and 1.87 °C respectively. These models are validated by simple linear regression between simulated and existing air temperature in case of existing UHI condition (C1) and in all the cases coefficient of determination value is high such as for open mid-rise, compact low-rise and open low-rise, it is 0.92, 0.92 and 0.75 respectively. Therefore it can be concluded that the application of those strategies can improve the urban thermal environment as well as the outdoor thermal comfort of English bazaar Town and its surroundings.     

街道峡谷湍流流动的风洞试验与数值计算

在１：２５０的风洞模型上,测量街道峡谷的平均流速,湍流度等参数,分析了街道峡谷内的湍流流动状态,探讨了屋顶来流风在街道峡谷内产生复杂流场的主要特征,并用三维湍流流模型对风洞试验模型进行了数值计算,试验和计算结果为研究街道峡谷风环境以及街道峡谷的传热传质过程提供了基础。     

异构无人系统协同作战关键技术综述

针对异构无人系统的规模、异构性强弱,对异构无人系统进行了分类,引入了异构无人系统协同作战班组的概念以及应用设想,并通过城市环境中异构无人系统协同作战问题为牵引,提出了异构无人系统协同作战面临的挑战与解决思路,在此基础之上,从异构无人系统协同控制架构、协同任务规划、智能交互、目标感知、环境感知等主要方面对异构无人系统协同作战的关键技术进行了分析,最后对异构无人系统协同作战目前的研究进展与挑战进行了总结。     

典型城市街道内汽车排放污染物扩散规律的模拟研究

采用自主开发的街道峡谷内污染物扩散模式,对城市中几种典型的街道峡谷内流场和污染物的浓度场进行了模拟研究。模拟结果表明:在一定气象条件下,街道中机动车排放污染物的扩散受街道宽高比、街道两侧建筑物对称性、街道两侧建筑物高度分布及街道两侧的建筑物形状等因素的影响;街道峡谷宽高比接近1时、递升型峡谷以及宽阔街道有利于污染物的扩散。     

Modeling urban heat islands in heterogeneous land surface and its correlation with impervious surface area by using night-time ASTER satellite data in highly urbanizing city,Delhi-India

The present study is an assessment and identification of urban heat island (UHI) in the environment of one of the fastest urbanizing city of India, Delhi Metropolis, employing satellite image of ASTER and Landsat 7 ETM+ in the thermal infrared region 3–14 μm. Temporal (2001 and 2005) ASTER datasets were used to analyze the spatial structure of the thermal urban environment subsequently urban heat island (UHI) in relation to the urban surface characteristics and land use/land cover (LULC). The study involves derivation of parameters governing the surface heat fluxes, constructing statistics of ASTER thermal infrared images along with validation through intensive in situ measurements. The average images reveal spatial and temporal variations of land surface temperature (LST) of night-time and distinct microclimatic patterns. Central Business District (CBD) of Delhi, (Connaught Place, a high density built up area), and commercial/industrial areas display heat islands condition with a temperature greater than 4 °C compared to the suburbs. The small increase in surface temperature at city level is mainly attributed to cumulative impact of human activities, changes in LULC pattern and vegetation density. In this study the methodology takes into account spatially-relative surface temperatures and impervious surface fraction value to measure surface UHI intensity between the urban land cover and rural surroundings. Both the spatial and temporal variation in surface temperature associated with impervious surface area (ISA) has been evaluated to assess the effect of urbanization on the local climate.     

谈浐灞半岛迎水面景观建设

随着社会现代化进程的加快,人们对水域空间的景观和休闲娱乐功能的要求也不断提高,论述了浐灞半岛迎水面景观建设的总体需求,要把握的基本原则和景观设计要注意的事项,以期改善水域空间景观,为居民提供安全舒适的休闲娱乐空间,进而提升地区形象,美化地区环境。     

Urban growth assessment around Winam Gulf of Kenya based on satellite imagery

Urban growth and population dynamics are among the most critical information needed for future economic development planning, natural resources allocation and environmental management. In the present work, two methods, the first based on night-time images produced by NOAA and population maps provided by Oak Ridge National Laboratory's (ORNL) LandScan, and the second one on SAR imagery, were used in order to assess the expansion of urban areas surrounding the Winam Gulf (Lake Victoria, Kenya) at different scales. In the time covered by night-time lights imagery, the study highlighted a period of constant growth rate between 2002 and 2006 and a negative trend after 2006 and 2008. This decrease may be related to two main events occurring in the study area between 2006 and 2007: the decline of the Lake Victoria level and the abnormal proliferation of the floating weeds within the Winam Gulf. Meanwhile, the urban feature extraction obtained at a different scale within a particular district from 1997 up to 2008 results in a constant growth rate. Population movements around this zone explain different dynamics that should be studied in detail in order to understand their particular roots.     

西部城市住宅开发与可持续发展战略研究

目前的城市开发，各地政府只顾近期效益，大搞政绩工程，各市不断地采用“模仿”、“克隆”的方式，使“千城一面”，使城市原有风格特征逐渐褪去。西部城市住宅开发决不能以牺牲生态环境为代价谋取经济的短期增长，而必须走“环境”与“经济”双赢的可持续发展道路。城市住宅开发必须符合地域特点，遵循地理的差异性，要有鲜明的个性特征；开发建设时使用环保、节能建筑材料，推进资源回收与开发的应用力度；必须尊重历史，保护文物、古迹，建设特色城市。     

未来城市空中交通管理研究综述

随着垂直起降（VTOL）航空器快速发展,城市空中交通（UAM）的概念逐渐引发了人们的关注。城市空中交通作为一种新型交通运输模式,将给未来城市发展带来无尽的活力。然而,现有空中交通管理系统不能满足未来城市空中交通按需运行的发展要求,必须针对城市空中交通运行特点,构建未来城市空中交通管理体系。首先,从城市空中交通发展概况与发展历程,简要概述了城市空中交通的由来、兴起与发展前景;其次,设计了城市空中交通管理的运行概念,并结合中国空管的现状特点,提出了中国未来城市空中交通管理体系架构;然后,分别从空域规划、流量控制、交通服务与基础设施建设等方面系统论述城市空中交通管理的研究现状。最后,结合未来城市空中交通发展需求,提出了城市空中交通管理所面临的问题挑战,给出了中国城市空中交通管理的发展建议,以期为城市空中交通管理深入研究与快速发展提供参考借鉴。     

廊坊市城市无形资产经营的问题研究

随着我国城市化程度的进一步提高，城市无形资产在城市发展中的地位和作用愈发凸显。本文从城市经营的角度出发，探讨了城市无形资产经营的内容和重要意义，对廊坊市城市无形资产经营进行了分析，并提出了提升城市无形资产经营的相应建议。