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1.
上海城市热岛的变化特征 总被引：5，自引：1，他引：5
利用上海77个区域站2011—2014年逐时气温资料,运用城乡对比法分析了城市热岛(UHI)的时空变化特征。其次利用长三角20个国家站1961—2013年逐年平均气温资料,运用空间滤波法研究了上海城市化进程对城市热岛强度(IUHI)的影响。结果表明:1961—2013年IUHI整体上呈缓慢上升的趋势,IUHI递增率达0.15~ 0.17 ℃/(10 a),年平均最大IUHI达1.10~1.33 ℃,出现在2006年。上海城市化进程的加快有利于IUHI的增大。21世纪以来IUHI呈现减缓特征与全球气候变暖减缓的趋势一致。近年来,上海城区集中在外环以内,三个城市内部区域(内环区、中环至内环区、外环至中环区)IUHI存在一致的日变化特征,但受到城区内部下垫面差异性影响,IUHI呈现从内环区往外环依次递减的特征,并在夜间强热岛阶段最为明显。冬季IUHI和IUHI日变化均最大,秋季与之相当,春季次之,夏季最小。从IUHI空间分布特征看,春夏季较为一致(即东部气温较低,西部气温较高,强热岛中心集中在西北部)、秋冬季较为一致(即东部气温较高,西部气温较低,强热岛中心稳定在城区附近),这可能与季风有关。 相似文献
2.
利用MODIS地表温度数据,计算城市热岛强度指数,分析近15年广州市城市热岛的时空分布特征及演变规律,并结合气象观测数据、社会统计数据定性分析其主要影响因素。结果表明:广州市城市热岛的空间分布受地形地貌影响明显,负热岛区主要分布于森林密集的北部山区,无热岛区主要分布于中部低山丘陵区域,热岛区主要分布于高度城市化的中南部平原区。关于城市热岛的日变化规律,白天热岛区、负热岛区面积均小于夜间,但白天热岛区强度、负热岛区强度大于夜间。关于城市热岛的季节变化规律,冬季热岛区面积最大,热岛强度最小,夏季热岛区面积最小,热岛强度最大;冬季负热岛区面积最小,负热岛强度最小,夏季负热岛区面积最大,负热岛强度最大。对于城市热岛的年际变化规律,近15年来广州市的热岛区、负热岛区占全市总面积的百分比呈上升趋势,无热岛区所占百分比呈下降趋势,人为热排放在城市中心区域的持续增长,加上区内建筑物密度大、植被覆盖度低,导致了热岛区的增加,而北部山区至中部丘陵山区的植被的持续好转,加上地理特征限制了该区域的城市化发展,导致了负热岛区的增加。 相似文献
3.
Based on an in-homogeneity adjusted dataset of the monthly mean temperature, minimum and maximum temperature, this paper analyzes the temporal characteristics of Urban Heat Island (UHI) intensity at Wuhan Station, and its impact on the long-term trend of surface air temperature change recorded during 1961–2015 by using an urban-rural method. Results show that UHI effect is obvious near Wuhan Station in the past 55 years, especially for minimum temperature. The strongest UHI intensity occurs in summer and the weakest in winter. For the period 1961–2004, UHI intensity undergoes a significant increase near the urban station, with the increase especially large for the period 1988–2004, but the last 10 years witness a significant decrease, with the decrease in minimum temperature being more significant than that of maximum temperature. The annual mean urban warming and its contribution to overall warming are 0.18?C/10yr and 48.8% respectively for the period 1961–2015, with a more significant and larger urbanization effect seen in Tmin than Tmax. Thus, a large proportion warming, about half of the overall increase in annual mean temperature, as observed at the urban station, can be attributed to the rapid urbanization in the past half a century. 相似文献
4.
人为热源对城市热岛效应影响的数值模拟试验 总被引：3，自引：0，他引：3
利用耦合了单层城市冠层模型UCM的中尺度模式WRF,研究了人为热源对上海区域城市气候的影响。冬季地表温度的模拟结果表明,使用新陆面资料的试验效果要好于使用旧的陆面资料,加入人为热源的试验效果要优于没有加入人为热源的试验,这些反映了热岛效应是不断增加的城市面积和人为热源共同决定的。不同试验模拟的2 m高度上气温的模拟情况时,使用新陆面资料并且加入合理人为热源的试验模拟值明显大于其他试验的模拟值。 相似文献
5.
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
6.
Although the urban heat island (UHI) is a well-documented phenomenon, relatively little information in the literature is available about its impact on summer extreme heat event (EHE). As UHI is characterized by increased temperature, it can potentially increase the magnitude and duration of EHEs within cities. Based on daily maximum temperature records from 62 observation stations in Zhejiang province from the period 1971-2011 and satellite-measured nighttime light imagery from the Defense Meteorological Satellite Program (DMSP) Operational Linescan System (OLS) during 1992-2010, we analyzed the long-term change of summer EHEs and its association with the rapid urbanization process. The results could be concluded as follows: (1) Zhejiang has experienced rapid urbanization and dramatic growth in urban areas in the past two decades, especially after 2000. (2) The summer mean maximum temperature and the 95th percentile of summer daily maximum temperature in most of its stations have increased, with the most significant increase occurring in the highly urbanized areas including the city belt around Hangzhou Bay, Taizhou–Wenzhou and Jinghua–Yiwu city belts. (3) The hot days and hot-day degrees, defined by both daily 95th percentile and the threshold of 35℃, show that the UHI effect causes additional hot days and heat stress in urban stations compared to rural stations. The results in this study suggest that the UHI effect should be determined and incorporated in preparing high temperature forecasts in cities. 相似文献
7.
Summary This study presents the results of a preliminary research that was conducted in the city of Eilat, located in an extreme hot
and arid zone on the northern coast of the Red Sea. The purpose was to analyse the characteristics of the local urban heat
island (UHI). Diurnal pre-dawn and early-afternoon measurements were taken in winter and summer weather conditions on three
separate occasions for two consecutive years. The results show the development of a moderate UHI located around the most intensive
area of human activity; the city business centre and dense hotel belt. The UHI is more significant at midday during the summer
period, while early morning inversions in winter have a weakening effect on the UHI intensity. It was found that the topography
and wind regime have a dominant effect on the location and intensity of the UHI, while the sea has a very marginal effect.
Due to the UHI influences on the spatial distribution of the heat stress in the city, it is suggested that further applied
UHI research should be focused on the summer period. 相似文献
8.
Urban-rural difference of land cover is the key determinant of urban heat island (UHI). In order to evaluate the impact of land cover data on the simulation of UHI, a comparative study between up-to-date CORINE land cover (CLC) and Urban Atlas (UA) with fine resolution (100 and 10 m) and old US Geological Survey (USGS) data with coarse resolution (30 s) was conducted using the Weather Research and Forecasting model (WRF) coupled with bulk approach of Noah-LSM for Berlin. The comparison between old data and new data partly reveals the effect of urbanization on UHI and the historical evolution of UHI, while the comparison between different resolution data reveals the impact of resolution of land cover on the simulation of UHI. Given the high heterogeneity of urban surface and the fine-resolution land cover data, the mosaic approach was implemented in this study to calculate the sub-grid variability in land cover compositions. Results showed that the simulations using UA and CLC data perform better than that using USGS data for both air and land surface temperatures. USGS-based simulation underestimates the temperature, especially in rural areas. The longitudinal variations of both temperature and land surface temperature show good agreement with urban fraction for all the three simulations. To better study the comprehensive characteristic of UHI over Berlin, the UHI curves (UHIC) are developed for all the three simulations based on the relationship between temperature and urban fraction. CLC- and UA-based simulations show smoother UHICs than USGS-based simulation. The simulation with old USGS data obviously underestimates the extent of UHI, while the up-to-date CLC and UA data better reflect the real urbanization and simulate the spatial distribution of UHI more accurately. However, the intensity of UHI simulated by CLC and UA data is not higher than that simulated by USGS data. The simulated air temperature is not dominated by the land cover as much as the land surface temperature, as air temperature is also affected by air advection. 相似文献
9.
上海城市热岛的小波特征 总被引：21，自引：2，他引：21
为研究城市热岛的时间尺度结构及其变化特征,利用Morlet小波变换对上海1999年冬、夏两季的城市热岛记录进行分析和计算,结果表明:(1) 上海城市热岛明显呈多时间尺度结构,是由各种尺度的热岛叠加而成.冬季的热岛尺度结构比较单一,夏季的热岛尺度结构比较复杂.(2) 上海城市热岛的日变化(16～32h)和周变化(128～256h)冬季比夏季明显.(3) 上海城市热岛的周变化的振荡波峰出现在周五和周六,而波谷恰好落在周一和周二.这可能是因为128～256h尺度的热岛受人为热和大气污染物的驱动,其影响滞后1～2天. 相似文献
10.
Analyzing the thermal distribution on plane conditions objectively is difficult due to lack of enough meteorological observation stations within urban residential areas. In this paper satellite observations synchronous or quasi-synchronous with ground observations are adopted, and a teleconnection model is built between the satellite spectral and surface temperature for quantitative retrieval of temperature. Furthermore, by combining the satellite data with other multiple factors, a GIS comprehensive analysis model and a functional evaluation method for urban residential districts are established, which are used to study the relation between the air temperature and media characteristics on ground as well as the greening cooling effect in recent years in Shanghai. The results show that the air temperature in greened urban residential districts is generally lower than the average temperature and much less than the highest one. In general, the average air temperature in the greened area is at most 1.19℃ lower than the maximum temperature in the districts, which is 0.67℃ and 0.55℃ lower than that of the highest for buildings and roads respectively. The temperature is inversely proportional with greening fraction but is directly proportional with the ratio of roads and buildings. The higher the greening fraction in internal residential districts, the lower the temperature, and the higher the ratio of road and building is, the higher the temperature. 相似文献
11.
利用2012~2013年北京中央商务区（Central Business District,CBD）加密观测资料,分析CBD区域城市热岛（Urban Heat Island,UHI）强度日变化和空间变化特征及其影响因子。研究发现,CBD区域气温高于周边自动站气温,平均偏高0.64℃;CBD区域城市热岛强度呈现夜间强、白天弱的现象,中午甚至存在“城市冷岛”现象。季节平均UHI日变化表现为:在夜间,秋季最强,冬季次之,春季和夏季较弱;在白天,夏季最强,冬季次之,春季和秋季较弱。相对于晴朗无风天气,雾、雨、大风等天气对城市热岛有抑制作用,并结合小波分析结果发现,秋季城市热岛强度强于冬季是由于冬季雾、雨、大风等天气过程发生比例较高的缘故。CBD区域城市热岛空间变化特征研究发现,花园、学校等绿地有助于缓解城市热岛效应。雾日、雨日和大风日的CBD区域城市热岛强度空间变化标准差比晴朗无风日小。 相似文献
12.
Summary This paper examines the characteristics of the morning Urban Heat Island (UHI) in Athens basin, Greece. The study is performed
by using and analyzing mesoscale and synoptic data covering the period 1990–2001. The UHI was estimated using the 0600 Local
Time (LT) minimum temperature differences between rural and urban areas of the city. The analysis results in 7 UHI classes.
A strong UHI was found for the 1/3 of days. The specific meteorological characteristics (surface and upper air, cooling rate)
of each UHI class were revealed and examined. The spatial and temporal characteristics of the UHI were also identified.
The UHI is largest on nights with clear skies and low relative humidity. In all seasons the UHI switches on rapidly in afternoon.
During spring and summer, sea breeze commonly reduces and delays the UHI. Cases documenting the sensitivity and rapidity of
changes of the UHI to changes in classes (cloud cover, wind) are also presented. The cooling rate is higher in the urban area
under negative and lower under positive UHI conditions.
Mesoscale and macroscale phenomena were examined during the different UHI classes through a weather type scheme. It was emerged
that high UHI classes are associated with anticyclonic conditions or advection in the lower troposphere, while low UHI classes
are associated with strong northeasterly winds. Anticyclonic conditions which frequently occur in spring and early summer,
reduce or reverse the UHI to Urban Cooling Island. 相似文献
13.
基于MODIS数据的城市热岛动态监测及时空变化分析 总被引：6，自引：1，他引：6
以人口密集、经济快速发展的福建省沿海地区为研究区,在遥感和地理信息系统技术支持下,采用经优选的MODIS遥感数据反演的地表温度,提取城市热岛和植被覆盖信息,对研究区城市热岛进行动态监测和时空变化分析,并对地表温度与植被覆盖的互动关系进行定性与定量分析。结果表明：福建沿海城市热岛面积整体上呈逐年增长趋势,福州和莆田更为明显;城市热岛主要集中在人口密集、工商业发达的区域,同时沿海平原的热岛效应比内陆山区更为显著;地表温度与植被覆盖呈负相关,并且相关系数逐年增长。 相似文献
14.
15.
ANNUAL VARIATIONS OF TEMPERATURE ON FOUR URBAN UNDERLYING SURFACES AND FITTING ANALYSIS 总被引：1，自引：1，他引：0
Based on the observed 2-year temperature data for four kinds of typical urban underlying surfaces, including asphalt, cement, bare land and grass land, the annual variations and influencing factors of land surface temperature are analyzed. Then fitting equations for surface temperature are established. It is shown that the annual variation of daily average, maximum and minimum temperature and daily temperature range on the four urban underlying surfaces is consistent with the change in air temperature. The difference of temperature on different underlying surfaces in the summer half year (May to October) is much more evident than that in the winter half year (December to the following April). The daily average and maximum temperatures of asphalt, cement, bare land and grass land are higher than air temperature due to the atmospheric heating in the daytime, with that of asphalt being the highest, followed in turn by cement, bare land and grass land. Moreover, the daily average, maximum and minimum temperature on the four urban underlying surfaces are strongly impacted by total cloud amount, daily average relative humidity and sunshine hours. The land surface can be cooled (warmed) by increased total cloud amount (relative humidity). The changes in temperature on bare land and grass land are influenced by both the total cloud amount and the daily average relative humidity. The temperature parameters of the four land surfaces are significantly correlated with daily average, maximum and minimum temperature, sunshine hours, daily average relative humidity and total cloud amount, respectively. The analysis also indicates that the range of fitting parameter of a linear regression equation between the surface temperature of the four kinds of typical land surface and the air temperature is from 0.809 to 0.971, passing the F-test with a confidence level of 0.99. 相似文献
16.
17.
Temporal characteristics of the Beijing urban heat island 总被引：4，自引：0，他引：4
Summary This paper describes the inter-annual trend, and the seasonal and hourly variation of the near surface urban heat island (UHI)
in Beijing. The surface air temperature data (mean, maximum, and minimum) from one urban (downtown Beijing) and one rural
(70 km from downtown Beijing) station were used for the period 1977 and 2000. It is found that the temperatures in both urban
and rural stations show an increasing tendency. Specifically, minimum temperature shows the greatest tendency at the urban
station whereas maximum temperature shows the greatest increase at the rural station. The UHI intensity obtained by calculating
the difference in temperatures between the two stations identifies that the intensity is greatest and has the greatest increasing
trend for minimum temperature, while the UHI intensity of maximum temperature shows a slow decrease over time. UHI intensity
for minimum temperature has a strong positive correlation with the increase in the urban population and the expansion of the
yearly construction area. Seasonal analyses showed the UHI intensity is strongest in winter. This seasonal UHI variation tends
to be negatively correlated with the seasonal variation of relative humidity and vapor pressure. Hourly variation reveals
that the strongest UHI intensity is observed in the late nighttime or evening, while the weakest is observed during the day. 相似文献
18.
本文利用冬季观测的兰州市区、邻近山顶以及郊区皋兰县的辐射资料和温度廓线资料,分析了兰州城市气溶胶对太阳辐射影响;并用二流近似累加法计算了低层大气吸收太阳辐射的加热率,其结果与低层大气上部的实际增温在数值上比较接近。分析了城市气溶胶短波辐射效应对边界层温度廓线分布的影响。表明城市烟雾层削弱了地面热通量但增加了低层大气中上部的增温,从而增加了城市低层大气的稳定度。 相似文献
19.
The study underlines the characteristics of the urban heat island of Ia?i (Ia?i’s UHI) on the basis of 3 years of air temperature measurements obtained by fixed-point observations. We focus on the identification of UHI development and intensity as it is expressed by the temperature differences between the city centre and the rural surroundings. Annual, seasonal and daily characteristics of Ia?i’s UHI are investigated at the level of the classical weather observation. In brief, an intensity of 0.8 °C of UHI and a spatial extension which corresponds to the densely built area of the city were delineated. The Ia?i UHI is stronger during summer calm nights—when the inner city is warmer with 2.5–3 °C than the surroundings—and is weaker during windy spring days. The specific features of Ia?i’s UHI bear a profound connection to the specificity of the urban structure, the high atmospheric stability in the region and the local topography. Also, the effects of Ia?i’s UHI upon some environmental aspects are presented as study cases. For instance, under the direct influence of UHI, we have observed that in the city centre, the apricot tree blossoms earlier (with up to 4 days) and the depth of the snow cover is significantly lower (with up to 10 cm for a rural snow depth of 30 cm) than in the surrounding areas. 相似文献
20.
Juan A. Acero Jon Arrizabalaga Sebastian Kupski Lutz Katzschner 《Theoretical and Applied Climatology》2013,113(1-2):137-154
This work examines the characteristics of the urban heat island (UHI) in a medium-sized city in northern Spain (Bilbao) using 5-year climate data (2005–2009) and the results of three specific measurement campaigns (2009–2010). Urban climate variables are not only compared with those in rural sites but also local climatic differences occurring inside the city are analysed. The findings presented in this paper show the influence of complex topography and sea/land breeze in the urban climate. Spatial characteristics and temporal evolution of UHI is presented. Hourly maximum temperature anomaly (ΔT u–r, max) occurs just after sunrise and an urban cold island (UCI) is developed after midday. Along the year, mean UHI intensity is highest in autumn and the UCI effect increases in spring and summer in relation with sea breeze cooling potential. Diurnal and seasonal variation of air flow patterns appear to influence significantly on UHI intensity. 相似文献