Urban expansion of oasis cities between 1990 and 2007 in Xinjiang,China

An oasis is not only the most concentrated area of human activity in an arid area but also the largest area where artificial disturbances occur at a regional scale. The study of oasis urban expansion and related factors is important to understand the development of cities in arid areas, guide the evolution of rational urban expansion and promote sustainable development of oasis cities. Although there have been several studies on urban expansion in Xinjiang over past decades, a lack of quantitative data and methods impedes further research. In this paper, urban expansion of the studied area in 1990, 2000 and 2007 is evaluated using 39 Landsat satellite images, a geographical information system (GIS) and remote sensing (RS). We also analyse the related factors of urban expansion using quantitative and qualitative methods. We found that economic development and the area of the urban administrative region greatly effect urban expansion. Too rapid growth and outward urbanized expansion paradigms should not be applied blindly in arid areas from the point of view of sustainability. Historic–geographic features of oases and urban planning influence oasis urban morphology. Compact urban morphology is relatively better for protecting precious water and arable resources, and reducing ecology damage to the surrounding oasis. The relationship between urban expansion and population growth was not coordinate before 2000, and effectively only improved after that date. City growth should be moderated, with lower elastic coefficients, slower expansion and higher elasticity coefficients. Oasis cities in Xinjiang are expanding under the combined effects of urbanization, economic development, transportation, environment, resources, policy and planning.     

Urban development and landscape change in the Yangtze River Delta region in China

The impact of large-scale urban development on land resources has long been debated by urban planners and designers. This study investigated the extent to which different urban characteristics are associated with land-cover change. The Yangtze River Delta region in China, forming one of the largest sprawling urban landscapes among the regions around the world, was chosen for the study area. Spatial analysis and multiple regression methods were applied to empirically investigate the pattern of resource sites lost to urban development in the area between the 1950s and 2017. The results showed that contrary to the widespread notion that large-sized cities are predominantly responsible for a region’s environmental degradation, city size was not a significant factor in determining the rate of resource loss. Large-sized cities gained their populations with far lesser impacts on land than small-sized cities and towns if normalized to the same number of populations. One explanation for the diminishing effect of city size on land-cover change relates to the degree of spatial dispersion of urban development and local differences in social valuation of diversified lands by cities.     

干旱区的城市生境特征与绿洲化对策

干旱地区的城市亦被称为绿洲。从其发生与生境状况分析,注意到近期城市的扩展已脱离绿洲型的发展轨道,而与全球城市模式类同,亦具城市化的共有弊病。又因所处区位受到荒漠气候的强烈影响,较其它地带的城市,其生境更加恶劣。干旱区居民长期凭借绿洲生境而生息劳动,早期出现的城市亦脱胎于绿洲。目前仍沿用绿洲以称城市,但与绿洲的生境相比较已面目全非,实质是以现代设施在荒漠中建立的水泥荒漠。目前全球范围正展开以改善城市生境为目标的生态城市建设,位处干旱区的城市应从其所在区位出发,以绿洲化作为生态城市建设目标,切实改善居民生存环境质量。应仿照绿洲,在外围营造阻隔荒漠气候侵袭的防护林,在市区通过营造片林与行道树,形成类似条田林网格局,以一定植被规模重构绿洲化城市,形成绿洲生境以改善城市居民生存条件,回归干旱区居民世世代代依存的绿洲空间。     

城市雨水口垃圾污染调查与研究

雨水口既是城市排水管系汇集雨水径流的瓶颈，又是城市非点源污染物进入水环境的首要通道，一旦被垃圾充塞，不仅导致排水不畅甚至水涝，还会对城市水体造成严重的污染。从对北京城区雨水口垃圾的抽样调查分析，和对雨水口垃圾产生的污染模拟实验和量化计算，讨论了我国城市雨水口垃圾问题的严重性和实施有效控制的重要性。     

中国城市建成区绿化覆盖率变化特征及影响因素分析

城市建成区绿地建设有利于改善城市环境,提高人居适宜度,优化城市生态系统服务功能。基于2002—2018年建成区绿化覆盖率及影响因子数据分析了中国城市建成区绿化覆盖率变化特征及其主要影响因素,结果表明,(1)中国建成区绿化覆盖率在2018年达到了41.11%,相比2002年增加了11.36%,2018年绿化覆盖率达到了35.0%以上的城市占全国城市的93.55%。(2)中国建成区绿化覆盖率存在明显的区域差异。按照华北、东北、华东、中南、西南和西北六个地区划分中国城市区域,华东地区的城市建成区绿化覆盖率最高,中南地区次之,其余四个地区为华北地区>东北地区>西北地区>西南地区;各地区建成区绿化覆盖率随时间发生显著变化(P<0.05),华北地区绿化覆盖率发生显著变化的城市占比最高达94.60%,中南地区最低为65.88%。(3)建成区绿化覆盖率与城市化指标(地区生产总值GDP、地区人均生产总值PGDP、绿化投入LP、建成区面积BUA、城区面积百分比UAP、建成区面积百分比BUAP、总人口TP、城市人口密度UPD、城区人口UP、建成区人口BUP、城区人口百分比UPP、建成区人口百分比BUPP)和气候因子(年平均温度YT、年平均湿度YH和年降雨量YW)均呈极显著正相关关系(P<0.01),其中PGDP、LI、BUAP、UAP、UPD、BUPP和YT、YW、YH是影响建成区绿化覆盖率的最主要因子。本研究结果可为中国未来城市绿地建设均衡发展提供重要的理论参考依据。     

The widening urbanization gap between the Three Northeast Provinces and the Yangtze River Delta under China’s economic reform from 1984 to 2014

Urbanization has created a significant gap between the Three Northeast Provinces (TNP) and the Yangtze River Delta (YRD) since China’s reform and opening-up. In this study, we explain this problem by employing an urban expansion index, spatial hierarchical clustering, the Zipf-PLE model, fractal theory, and time-series analysis. Statistical data on the built-up area, population, and gross domestic product were downloaded from the National Bureau of Statistics of China. The results revealed the following. (1) During the stage of the planned economy, as a result of the significant government investment in development, the urban built-up areas in the TNP and the YRD reached 1867 and 757 km², respectively, in 1984. (2) During the stage of the socialist market economy, the urban built-up area of the YRD experienced rapid growth over the 30 years from 1984 to 2014 with a rate of increase of 668.8%, which was higher than that of the TNP (139.9%). In 2014, the urban built-up areas of the TNP and the YRD were 4479 and 5820 km², respectively. (3) Locational advantages had significant effects on urban development after China’s economic reform. The coastal cities of the YRD had higher rates of increase of the built-up areas. By contrast, the border cities of the TNP had lower rates of increase. Finally, this paper finds that the socialist market economy exhibited more efficiency in promoting urban expansion and economic development. The results are significant for generating balanced and sustainable regional development strategies in the future.     

Understanding the major drivers for implementation of municipal sustainable policies in underground space

Because of the expanding population in our cities with its demands for more diversified services, we cannot afford a piecemeal type of urban underground growth. Utilization of the urban street system for buried utilities has a serious adverse effect on other street functions because of the continuing necessity to perform excavations for the repair of existing lines and the installation of new ones. The excavations not only are a serious cause of traffic delay and congestion but also create noise and aesthetic disturbances, and result in excessive street maintenance requirements and in shortened overall street life. Consider the enhancing effects in quietness on abutting properties and users of the street, and the benefits become very great. Unfortunately, the lack of data and the difficulty in quantifying the intangibles have made it impossible to arrive at a reasonably accurate figure of overall negative impact on the urban environment of street cuts. However, if drivers are sufficiently strong to merit the use of utility tunnels, then sustainable municipal policies improving living quality will be implemented.     

哈尔滨市城市用地扩展时空特征及驱动机制分析

在RS和GIS的支持下集成多源数据,提取哈尔滨市1989—2008年城市土地利用扩张信息。利用单一土地利用动态度和弹性系数模型分析了近20年城市用地扩展时空特征。结果表明：1）近20年城市用地面积增加了123.93km2,其中1996—2002年和2002—2008年增长较快,年均增长率分别为3.24%和3.52%。2）1989—1996年城市扩展规模在合理的范围内上下波动;1996—2002年城市用地扩展速度过快,高于城市人口增长速度;2002—2008年城市用地仍在持续扩展,但扩展速度小于人口增长速度。3）1989—1996年西南南方向上扩展面积较大,为3.61 km2;1996—2002年西北北和西南西方向扩展程度较大,分别为18.37 km2和8.78 km2;2002—2008年西北西方向扩展较为集中,面积为20.45 km2,主要表现在松北区大规模开发建设。4）从经济增长、人口数量、交通牵引和政策与城市规划等因素探讨了哈尔滨市城市用地扩展驱动机制,对指导城市合理规划和促进城市理性发展具有一定理论参考价值。     

广东省城市体系生态环境类型

城市生态环境类型是随城市和区域不断发展而分化的产物，根据广东省城市体系格局，选取主要的十九个城市，确定适当的生态环境参数，对广东省城市生态环境的区域差异和主要类型进行多元统计复合分析，根据生态环境的相似性和相异性将广东省城市体系划分为四个类型，为区域规划和城市管理决策提供依据。     

城市工业化灾害及其综合减灾设计对策──兼论北京城市防灾减灾的规划编研思路

文章从城市减灾问题研究的实际出发 ,认为城市灾害系统中对于城市威胁最大的城市工业化灾害至今重视不够 ,甚至缺少必要评估。无论是大中城市发展 ,还是大力倡导的中国小城镇建设 ,城市工业化防灾应引起关注。因此提出不仅应研究城市减灾中的工业化致灾问题 ,还必须关注工业建筑及建设中的防灾规划及布局 ,这是一项极为重要的可持续发展战略。     

生态位理论及其在城市竞争研究中的作用——以中原城市群为例

城市生态位作为生态学重要理论之一,可用于分析城市群内部不同城市间竞争、演化等现象。以中原城市群9个省辖市为基本单元,运用生态位理论模型,进行多指标的综合加权和聚类分析,得出如下结论:(1)就中原城市群整体而言,城市生态位偏低且呈现明显的层次分异;(2)中原城市群城市生态位空间分异表现复杂。综合城市生态位、自然生态位及人口生态位空间分异并不明显,而经济生态位和社会生态位空间分异却十分显著,其中经济生态位最为显著;(3)中原城市群缺少4个子系统都具有优势特征的城市,只有郑州独具2项优势特征,但其自然生态位较低,自然生态位是郑州城市生态位的限制性因子。     

Urban planning and sustainable development under transitional economy: a case study of Guangzhou

There are always conflicts between the need for conservation and economic growth in the developing countries. Planning plays a primary role in balancing these conflicts. This is particularly obvious in Chinese cities since China adopted its open door policy in 1978. Foreign investment has been a major driving force for rapid growth of the Chinese economy. Planners in China have been facing the dilemma of protecting the natural environment on the one hand while, on the other hand, supporting the overall national goal of attracting foreign investment to maintain continuous economic growth. The planning system in China, which has been largely based on a planned economy, soon found itself handicapped in safeguarding the environment from rapid industrialization and urbanization fostered by market forces. This paper takes Guangzhou as an example to study challenges to the planning system in Chinese cities in the past two decades of rapid economic growth and urbanization. By means of a case study on an industrial development within a protected orchard area in Guangzhou, this study illustrates the conflict between the need for rural conservation and the pressure for economic development in the Chinese cities. In particular, it analyzes the pressures on the present urban planning system in China in terms of the following categories: the emergence of private investors in urban development; the goal of pursuing a high economic growth rate; the implications of a transitional economy for urban planning; and the weakness of the present urban planning system. It concludes that the role of urban planning in China should change from simply providing guidelines on board land-use strategy, to a combination of a strategic plan with specific development control laws at the operational level. Finally, some recommendations are suggested as to how to improve the planning system in China.     

热岛效应季节动态随城市化进程演变的遥感监测

作为城市特有的一种环境问题,热岛效应动态发展变化的规律是城市热岛研究的基础工作.遥感技术在城市热岛动态变化监测方面的有用性已经得到了证实.然而当前城市热岛遥感研究基本都取少数几景进行对比分析,这使得遥感在城市热岛时空动态监测方面不能充分发挥作用.采用50景长时间序列Landsat TM和ETM+SLC-on/off影像,采取定性和定量分析相结合的方法,使用热岛强度、热岛范围等指标和热岛显著区的概念对厦门市1987-2008年20年间热岛季节动态随城市化进程演变的趋势进行分析,结果表明:厦门城市热岛在2003、2004年之后已由春夏秋扩展到冬季,且冬季热岛的高等级斑块在数量、个体面积和总面积上均有明显增长趋势.引起这种变化的原因还需要进一步研究和分析.     

中国省域城市生态适宜度综合评价

依据城市生态系统原理,从生产位、生活位、环境位3方面构建了综合衡量城市生态适宜度的指标体系和数学方法,以各个省区地级以上城市作为分析样本,通过对评价区的各领域以及生态适宜度水平综合评价,结果表明:中国省域城市生态适宜度具有的明显区域性差异,城市生态适宜度大致呈现:东部高、中西部低,南方高、北方低的格局,既与区域自然生态条件有关,也同地方社会经济发展、城市建设与管理水平相关。     

我国城市土壤重金属的污染格局分析

收集了国内43个大中城市的3688个城区土壤重金属数据,通过描述性分析、评价分析、聚类分析等,初步确定了我国城市土壤重金属的污染格局.结果表明,我国城市土壤As、Cd、Cr、Cu、Hg、Ni、Pb、Zn的平均赋存量分别为13.39、0.68、63.04、38.17、0.31、26.18、47.34、137.72 mg·kg-1.Nemerrow指数、地质累积指数和潜在生态危害指数评价表明,污染最严重的城市是太原、南京、开封,主要污染重金属是Hg、Cd、Pb.43个城市中,上海、武汉、淄博、昆明、抚顺、昌吉、郑州、贵阳、成都、攀枝花、天津、珠海、大庆、北京、南宁、广州、香港、长春、太原等19个城市属于Cd强度污染;徐州、长沙、开封、重庆、乌鲁木齐、沈阳、西安、杭州、南京、兰州、洛阳等11个城市属于Hg-Cd强度污染、Pb中度污染;其余13个城市属一般轻度污染.长江以南城市土壤重金属污染比长江以北城市严重,中小城市土壤重金属污染低于特大城市.     

基于新加坡模式推进中国低碳生态城市发展的思考

通过回顾新加坡城市发展过程,分析了新加坡城市规划、建设、管理、发展四位一体的低碳生态化发展模式。在此基础上,对中国城市发展提出了以低碳生态为规划导向、以增强城市载体功能和绿色发展为建设目的、以完备立法、严格执法、全民参与为管理手段,以＂两型社会＂为发展目标的建议,推进低碳生态城市发展。     

津河水系的修复对天津城市生态环境的影响

针对天津城市生态环境特点和背方城市大气污染现状，探讨了津河水系的修复对改善城市环境质量，丰富城市景观以及修复城市生态环境的重要意义。     

长株潭城市群静脉产业的一体化发展

作为全国性的两个＂两型社会＂综合改革实验区之一,长株潭城市群发展面临着经济增长、资源短缺、环境保护之间相互制约的困境,是湖南省城市化发展中急需解决的问题。通过分析长株潭城市群发展现状,认为做大做强静脉产业是建立资源节约型和环境友好型社会的重要保障,并从发展体系、经营模式、物流体系、教育体系等几个方面对长株潭城市群静脉产业一体化发展进行了探讨。     

苏南快速城市化地区森林生物量时空变化及影响分析

随着我国城镇化进程的快速推进,城镇密集区城市扩张带来的负面生态环境问题得到广泛关注。森林生态系统具有固碳释氧等多种生态服务功能,对减小城市化的负面效应、改善生态环境具有积极作用。近年来我国植树造林成效明显,森林资源总量和质量持续提升,科学评估森林生物量动态对理解碳源汇变化及制定森林保护政策具有重要的意义,但当前对快速城市化地区长时期生物量变化及影响因素研究较少。苏南地区处于我国最大的城镇密集区长江三角洲的中心,近年来该地区森林面积和质量不断增加,而受中低卫星遥感数据分辨率影响,以往对该地区生态系统生物量研究未探测到这种变化。利用1990、2005年江苏省森林资源调查数据及2010年江苏省森林覆盖监测数据,采用换算因子连续函数法和平均生物量法等计算苏南地区三个时期森林生物量,研究20年来苏南快速城市化地区森林植被生物量的时空变化,并结合社会经济数据探讨了生物量变化与经济人口的关联。结果表明：20年来,苏南地区森林植被面积、生物量和生物量密度总体呈显著增加趋势,生物量从7.15 Tg增长到16.72 Tg,乔木林的生物量密度由29.32 t＆#183;hm-2上升至39.82 t＆#183;hm-2,但远低于同期全国的均值;各市生物量分布不均匀,2010年生物量总量从大到小依次是南京、无锡、镇江、常州和苏州;各市森林生物量总量主要由森林面积和地形决定,森林面积增加是生物量增加的主要因素,阔叶林比例和林龄的增长也促进了生物量增加,随着区域森林林龄不断增长,森林生物量仍将不断增加;政府政策和经济利益等影响下的森林建设是区域森林生物量增加的主要原因,较高的经济发展水平促进了各市森林资源数量增长,而高人口密度未对森林面积和生物量未产生显著负面?     

北京城市温室气体排放清单基础研究

回顾中国城市,主要是北京温室气体排放研究和排放状况,结合目前国际上主要采用的城市清单方法,梳理北京温室气体排放清单,并利用收集的北京市基本资料进行相关分析,作为北京和洛杉矶温室气体清单比较研究的基础.通过分析可以看出,中国城市温室气体清单的编制需要大量精确的数据作为支撑,但目前由于在统计口径上与国际上通用的排放清单有差...