武汉城市相对湿度气候学特征与长期变化趋势     

索南看卓  任国玉  贾文茜  孙秀宝 《气候与环境研究》2018,23(6):715-724

在对相对湿度(RH)序列进行均一性检验和订正的基础上,分析了武汉4个城市站RH的气候学特征和长期变化趋势。结果表明:(1)迁站对RH序列引起较大非均一性偏差,其中武汉站2010年迁站引起的偏差达到8%;(2)城区年平均RH较高,介于75%~85%,武汉站最高;(3)每年1~6月城区RH逐渐增加,6月达到峰值,之后缓慢减少,但季节内变化一般很小,月际间差异仅有0.1%~2.5%,存在夏季RH最高,春、秋次之,冬季最低的季节性特征;(4)武汉城市区域1961~2015年平均RH总体呈长期减少趋势,线性变化趋势-0.81%/10 a,20世纪90年代之后下降趋势加剧;(5)近55年城区春、秋、冬3个季节平均RH均呈不同程度的下降,以春季最为明显,夏季存在较为显著的上升趋势,但1991后年及四季均呈现显著的下降趋势。  相似文献   

河北城市化和观测环境改变对地面风速观测资料序列的影响   总被引：14，自引：2，他引：12       下载免费PDF全文

刘学锋  江滢  任国玉  梁秀慧  张成伟 《高原气象》2009,28(2):433-439

选用河北省143个气象台站1975-2004年10 m高年平均风速资料,以及1990年和2000年人口普查资料,根据人口增长、台站迁移、仪器高度变化、台站微观环境变化等影响地面风速变化的台站历史信息,把所有气象台站分为4类,并分别对其进行比较分析.结果表明:河北省绝大多数台站风速变化呈减小趋势;城市化进程、台站观测环境等因素均在不同程度上对地面平均风速变化趋势产生了影响,其中台站所在城镇城市化程度是风速减小趋势不可忽略的原因,其影响程度约在1/4左右;台站观测环境因素中观测场附近微观环境变化对风速减小趋势具有重要影响,超过了区域背景风速减小趋势.台站观测环境因素对风速资料序列均一性的影响也不容忽视,至少有1/3的平均风速序列非均一性断点是由观测环境变化产生的.  相似文献   

华南地区城市化对区域气候变化的影响   总被引：5，自引：2，他引：3  

吴婕  徐影  师宇 《气候与环境研究》2015,20(6):654-662

按照人口数将华南地区站点分为大城市站、一般城市站、郊区站,并利用华南地区1960~2011年的站点观测资料分别计算了3类站点年平均、季节平均的气温、高温日数、降水、相对湿度、风速、日照时数距平序列的变化,分析了城市化对华南地区区域气候的影响。结果表明:相较于背景场,大城市的平均气温有更明显的上升趋势;高温日数在3类站点中均有增加的趋势,在城市化的影响下,大城市的高温日数有明显的增加;平均气温日较差在整个华南地区均有下降趋势,特别是在大城市中。在3类站点中,降雨总量均有减少的趋势,且降雨更多的以中雨及以上的形式表现。该地区的相对湿度、风速、日照时数均呈现减少趋势,在城市化影响下,大城市的相对湿度、风速、日照时数均有明显的减少。华南地区处于我国最大的城市群之一——珠江三角洲地区,同时处于气候系统复杂的热带季风区,因此有必要研究城市化对该地区多个气象变量的可能影响。  相似文献   

京津冀地区气溶胶时空分布及与城市化关系的研究   总被引：2，自引：1，他引：1  

张西雅  扈海波 《大气科学》2017,41(4):797-810

利用AERONET（AErosol RObotic NETwork）数据对2008~2012年Terra MODIS（MOderate-resolutionImaging Spectroradiometer）C006 3 km卫星遥感气溶胶产品在京津冀地区的适用性进行了验证,分析京津冀地区3km分辨率气溶胶光学厚度（AOD）的时空分布和变化特征。利用DMSP（Defense Meteorological Satellite System）/OLS（Operational Linescan System）夜间灯光数据作为城市化评价手段,对京津冀地区城市化与AOD时空分布之间的关系进行了研究。结果表明:（1）MODIS 3 km气溶胶产品遥感反演数据和同期AERONET监测数据在研究区具有很好的一致性,相关系数达0.91,满足期望要求;（2）时间上,2008~2012年研究区年平均AOD值在0.361~0.453之间变化,年际间变化浮动大,总体呈下降趋势;AOD春季呈明显下降趋势,夏季总体呈微弱上升趋势,秋季和冬季呈明显上升趋势;（3）空间上,2008~2012年北京、天津和河北中南部的AOD值较高,河北北边AOD值较低;四季AOD空间分布呈现较强烈季节变化,夏季最高,冬季最低;（4）夜间灯光数据和AOD时空分布不仅在空间分布上呈现较好的一致性,且2008~2012年二者的地理权重回归（GWR）模型拟合度R2达0.8左右。研究区内AOD与夜间灯光数据二者相关性显著,城市化发展水平和人类活动对气溶胶的分布有着明显的影响。  相似文献   

Redevelopment and the urban forest: A study of tree removal and retention during demolition activities     

《Applied geography (Sevenoaks, England)》2017

Though relationships between urbanization and tree cover are generally well studied, the effect of redevelopment on urban trees, at the scale of the individual property, is not well understood. Developing knowledge in this area is important in order to limit tree loss during redevelopment and thus, ensure sustained ecosystem services. Here, we explore the removal or retention of trees adjacent to building demolition in Christchurch, New Zealand. We mapped the presence or absence of individual trees on 123 properties prior to, and following, building demolition. Using a classification tree (CT) analysis, the presence or absence of 1209 trees was modelled as a function of: tree-related variables, property-related variables, and economic variables. The CT model estimated tree presence/absence with overall accuracy of 80.4%. Results show that 21.6% of all trees were removed as a consequence of building demolition, resulting in a tree canopy cover reduction of 19.7% across all 123 properties. The CT showed that tree crown area was the most important variable for predicting the presence/absence of trees, whereby trees with small crown areas (<7.9 m²) were most frequently removed, especially if they were within 0.7 m of a demolished building. Land value was also an important determinant of tree presence/absence, such that tree removal was more prevalent on properties with higher land value ($/m²). The results provide important new insights into some of the reasons for tree removal or retention during redevelopment at the scale of the individual property where most tree-related decisions are made.  相似文献   

城镇化对湿地的影响研究进展     

王娇月  韩耀鹏  刘丽丽  王丽  邴龙飞  尹岩  郗凤明 《湿地科学与管理》2017,(3):61-65

湿地是人类生存和发展的主要环境之一,城镇化进程严重影响了湿地生态系统。从城镇化对湿地的景观格局、水文、生物多样性影响方面综述了城镇化对湿地生态系统影响的研究进展。研究发现城镇化改变了湿地的景观格局,使湿地面积不断减少,景观破碎化,湿地异质性增大,连通性降低。城镇化改变了湿地的水文条件,使天然调蓄能力减弱,径流系数增强,洪峰流量增大,水土流失加重,河网和水系结构特征改变,水质受到严重影响。城镇化降低了湿地生物多样性,使物种丰富度和分布降低,珍稀物种因丧失生境而灭绝,生物入侵增强,进而导致种群组成和生态系统的功能发生变化。最后提出了在全球变化背景下城镇化对湿地影响研究的新方向及其保护措施建议。  相似文献   

The Impact of Urbanization on Groundwater Quantity,Quality,Hydrothermal Changes and Its Countermeasures     

Wanbin Huang  Chunhua Yan  Xiaonan Zhang  Guoyu Qiu 《地球科学进展》2020,35(5):497-512

Groundwater, as a drinking water source for nearly one third of the world’s urban population, plays a strategic role in the development of urbanization. The object of this study is urban areas with the largest demand for water resources, the heaviest load of groundwater pollution and the most intense development of underground projects. This study sorted out the eco-hydrological problems such as the variation of the groundwater hydrological process, the groundwater pollution, and the urban heat island of groundwater in urban areas under the background of urbanization. Furthermore, the mechanism of changes in the quantity, quality and heat of groundwater was also systematically analyzed, and the intrinsic interaction among these three factors was revealed. The study showed that changes in land use and land cover caused by the urbanization are the main reasons for the variation of groundwater hydrological process. The pollution load of urbanization construction and domestic production waste has aggravated the deterioration of groundwater quality. The increase in vertical heat flux caused by urbanization gives rise to the warming of groundwater. By summarizing the eco-hydrological problems and causes of groundwater in urbanized areas, several suggestions were proposed: \mathrm{①} Establishing the evaluation method and system of urban groundwater resources; \mathrm{②} Speeding up the technological breakthroughs of groundwater pollution control; \mathrm{③} Improving the regional control strategies for groundwater pollution; \mathrm{④} Optimizing the allocation of groundwater resources. This study will provide the theoretical basis and technical support for ensuring urban water safety, building ecological civilized cities and further promoting the sustainable development of economy and society.  相似文献   

The degree of urbanization across the globe is not reflected in the δN of seagrass leaves     

Bart Christiaen  Rebecca J. Bernard  Behzad Mortazavi  Just Cebrian  Alice C. Ortmann 《Marine pollution bulletin》2014

Many studies show that seagrass δ¹⁵N ratios increase with the amount of urbanization in coastal watersheds. However, there is little information on the relationship between urbanization and seagrass δ¹⁵N ratios on a global scale. We performed a meta-analysis on seagrass samples from 79 independent locations to test if seagrass δ¹⁵N ratios correlate with patterns of population density and fertilizer use within a radius of 10–200 km around the sample locations. Our results show that seagrass δ¹⁵N ratios are more influenced by intergeneric and latitudinal differences than the degree of urbanization or the amount of fertilizer used in nearby watersheds. The positive correlation between seagrass δ¹⁵N ratios and latitude hints at an underlying pattern in discrimination or a latitudinal gradient in the ¹⁵N isotopic signature of nitrogen assimilated by the plants. The actual mechanisms responsible for the correlation between δ¹⁵N and latitude remain unknown.  相似文献   

山西省阳泉市城市热岛效应特征分析     

李润春  崔建国  牛俊玫  李兴  岳凯杰  王晓敏 《气象与环境学报》2014,30(2):74-80

利用1972－2011年阳泉市3个国家级气象站资料、2011年36个乡镇区域自动站气温资料,分析了阳泉市城市热岛效应的年际变化、季节变化、月变化和日变化特征。结果表明：阳泉市存在弱的城市热岛效应,1972－2011年平均热岛强度0.554 ℃。阳泉市城市热岛强度整体呈显著上升趋势,热岛强度的增加主要是由于夏季热岛强度的增强;热岛强度冬、秋季强,春、夏季弱;12月最强,5月最弱;热岛强度日变化表现为12时最小,从傍晚开始随降温逐渐增大,到早晨气温降到最低时最大,日出之后迅速减小;2008－2011年最强热岛强度出现在2010年1月14日08时,达7.9 ℃。阳泉在升温天气热岛强度变幅增大,易在早晨形成较强城市热岛,下午形成城市冷岛;降温天气热岛强度变幅减小;温度变化较小时则易维持弱的城市热岛。阳泉市主要城市发展因子与霾日数、气温呈显著正相关,在目前的经济发展水平条件下,阳泉市城市化发展可能使城市温度增高,城市绿地面积的增加可能对热岛效应有缓解作用。  相似文献   

当代非洲城市化的动因与困境   总被引：1，自引：0，他引：1  

丁金宏 《世界地理研究》2008,17(2):47-55

非洲的城市人口已经正在以年均超过4%的增长率增长,居世界首位,其中个别城市甚至还要高。对文献的回顾显示,贫困、非正规经济或类似经济的增长与发展已经成为撒哈拉以南非洲国家城市化的一个不可分割的部分。结论是快速城市化是非洲政府所面临的最紧迫的管理挑战。并且,要在致力于解决当前问题的同时,创造使城市成为经济增长和发展的更有效中心的政策环境。城市必须是可控制的、适于居住的、以及经济上可望成功的。  相似文献