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1.
京津唐城市群土地利用变化的区域增温效应模拟 总被引:4,自引:0,他引:4
土地利用变化与大气相互作用,影响区域气候,而城市及其周边地区受人类活动影响很大,成为土地利用变化最为强烈的区域。利用耦合了城市冠层模型的中尺度大气模式(WRF/UCM),在2008年的初始大气条件和边界条件下,用20世纪70年代后期和2008年两期京津唐地区土地利用资料替换WRF/UCM模式推荐的地表覆盖数据,模拟分析不同土地利用类型及其变化对应的气候差异情况。在此过程中,利用插值方法(ANUSPLIN)得到京津唐及其周边26个气象站点观测气温的插值数据,并以此在时空尺度上对比验证了模式的模拟结果。结果表明:WRF/UCM较好地模拟出了近地表2 m的气温,无论在空间上还是在时间上都表现良好;由城市扩展主导的土地利用变化导致研究区大部分区域的增温幅度大于0.05℃,且最大的增温区域出现在城市扩展区,可达1.31℃。此外本研究初步探讨了土地利用变化的增温贡献率,结果显示研究区土地利用变化导致增温0.08℃,整体贡献率为9.88%,城市扩展区增温0.29℃,表示出了城市扩展导致的增温贡献率达到32.75%。 相似文献
2.
东北地区城市针叶树冬季滞尘效应研究 总被引:62,自引:4,他引:58
对不同种针叶树同一降尘条件及同种针叶树不同降尘条件的滞尘能力进行研究,结果表明,针叶树在东北的冬季有很强的滞尘作用,不同的针叶树滞尘能力排序为沙松冷杉>沙地云杉>红皮云杉>东北红豆杉>白皮松>华山松>油松,不同针叶树叶表面结构不同,滞尘量较小的白皮松、华山松和油松表面平滑,细胞与气孔排列整齐,而滞尘量较大的红皮云杉、沙松冷杉、东北红豆杉的针叶表皮平滑程度较差,细胞与气孔排列较前3种植物差,在红皮云杉叶表面上有大小不等的瘤状物,不同针叶树叶断面形状与滞尘量相关,白皮松和油松叶片的上表面呈弧形,不易附着灰尘;华山松叶片呈三棱形,上表面较窄,附着灰尘的量较小;两种云杉的叶片呈四棱形,上表面较3种松属植物的叶片要宽与平展,因此相对滞尘量要大;沙松冷杉和东北红豆杉的叶断面形状都较扁、平,这种断面正是构成其滞尘量大于3种松属和两种云杉属植物的主要因素。 相似文献
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城市绿化树种的滞尘效应——以哈尔滨市为例 总被引:115,自引:10,他引:115
提出以植物材料的滞尘功能作为城市绿地设计中重要依据 ,对哈尔滨市 2 8个树种进行滞尘测定和叶表电镜扫描 ,结果表明 ,不同的树种滞尘量差异显著 ,树种之间的滞尘能力可相差 2~ 3倍以上 .常绿针叶树种中 ,红皮云杉、杜松是优良的滞尘树种 ,4周后滞尘分别达到 5 .7和 4.4g·m-2 .落叶阔叶树种中 ,银中杨、金银忍冬、山桃稠李是优良的阔叶滞尘树种 ,两周后滞尘分别达到 1.9、2 .0和 2 .45 g·m-2 .电镜观察发现 ,叶表皮具沟状组织、密集纤毛的树种滞尘能力强 ,叶表皮具瘤状或疣状突起的树种滞尘能力差 ,并结合滞尘测定对滞尘方式进行了讨论 . 相似文献
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随着我国城市化进程的不断深入,建筑消费大量的材料和能源,如何计算建筑碳足迹具有重要意义.本文应用碳足迹的方法,结合地理信息系统和高分遥感手段对辽宁中部城市群进行碳足迹评估.结果表明: 辽宁中部城市群的建筑相关碳足迹系数为269.16 kg·m-2.基于遥感影像提取建筑面积的方法能够有效提取建筑面积总量和空间分布,提取精度达到89%,对累积碳足迹计算和空间分布评估起到重要作用.辽宁中部7个城市建筑面积和累积碳足迹由高到低依次为沈阳、鞍山、抚顺、辽阳、营口、铁岭和本溪;2011—2013年,年均碳足迹增长由高到低依次为沈阳、本溪、抚顺、鞍山、铁岭、营口和辽阳.准确计算建筑碳足迹总量并分析其空间分布,对于碳减排和空间格局优化或规划具有重要意义. 相似文献
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Polybrominated diphenyl ethers (PBDEs) are toxic contaminants with a persistent character and adverse effects on humans and wildlife. Therefore, the deposition of these chemicals in vegetation must be carefully controlled. Our objective was to determine PBDE concentrations (BDEs 28, 47, 66, 85, 99, 100, 153, 154, 183 and 209) in Pleurozium schreberi collected in a heavily industrialized urban agglomeration. High PBDE concentrations in the moss confirm the presence of active sources of atmospheric pollution in an area tested. The distribution of these xenobiotics was related to the vegetation cover being lower in sites surrounded by forests which indicates that PBDEs may have a tendency to be trapped from the air by tree leaves and needles. Congener profiles in P. schreberi were dominated by BDE 209 which was for 79% (in case of the coke smelter) to 95% (in case of the chemical plant) part of the total PBDE burden in this moss. The principal component and classification analysis classifying the concentration of PBDEs in P. schreberi allowed us to distinguish the pattern of these compounds characteristic for the origin of pollution. P. schreberi may be used as a bioindicator for PBDEs in areas contaminated with these chemicals. 相似文献
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高质量发展与生态环境交互作用的研究是实现可持续发展和建设美丽中国的关键议题。选取成渝地区36个市县为研究单元,以2005年、2010年、2015年和2018年为主要研究时间节点。基于可持续发展和美丽中国理念构建成渝城市群高质量发展评价指标体系,借鉴压力-状态-响应模型构建生态环境质量评价指标体系,应用熵权法测度城市高质量发展水平和生态环境质量水平;运用耦合协调度模型测度二者的耦合协调关系;利用地理探测器和社会网络分析法分析各因子交互作用类型及强度。结果表明:(1)成渝城市群城市高质量发展与生态环境耦合度高,交互影响作用显著;耦合协调水平较低,以低水平耦合协调为主,呈现明显的双核心空间结构。(2)城镇化与生态环境两系统间的因子交互作用强于各系统内部因子交互作用,系统间的因子交互作用呈现显著的非线性增强,系统内因子以双因子增强为主,系统间存在较强交互协同效应,各子系统交互作用存在明显的"涌现现象"和"蝴蝶效应"。(3)生态环境系统在与城镇系统的交互作用中发挥主导作用,生态环境水平、生态环境压力为关键交互因子;资源禀赋、生态保护、资源消耗、环境水平、创新力量、文化传承等为主要子因子。研究深刻解析成渝城市群城镇化与生态环境的交互协同模式,以期为成渝城市群的高质量发展提供科学参考。 相似文献
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珠三角城市群生态空间分区方法与管控对策 总被引:2,自引:0,他引:2
生态空间管控是维护区域生态安全,解决区域生态供需矛盾的重要手段。生态空间分区一直是生态管控的热点问题,对促进城市群可持续发展具有重要意义。以珠三角城市群为例,基于政策目标、民众需求、专家知识等方面综合构建评价体系,开展了基于生态空间质量和生态系统健康评价的生态空间分区的探索研究。结果表明:珠三角城市群生态空间约占城市群面积的82.8%,生态空间质量好,但生态系统健康水平低。城市尺度肇庆市、深圳市生态空间质量较高,珠海市、中山市生态空间质量较低;惠州市、肇庆市生态系统健康水平较高,佛山市、中山市生态系统健康水平较低。综合生态空间质量和生态系统健康,区域尺度将城市群生态空间分为重点保护区、重点修复区、潜在修复区和生态保育区。重点保护区占生态空间总面积的10.1%,是区域生态源地,应实行最严格的环境保护制度,划定生态保护红线和自然保护地,加强生态建设和生物多样性保护,并加强生态连通性建设,提升区域整体生态系统服务;重点修复区占生态空间总面积的21.6%,以生态修复,实施生态治理工程,推进生态产业为主;潜在修复区占生态空间总面积的13.1%,以保护优先、自然恢复为主,对生态空间进行全面的养护,保护和提升品质,重点提升生态系统服务;生态保育区占生态空间总面积的55.2%,重点实施生态廊道建设,同时加强区域高标准农田建设,在保护生态空间的基础上合理开展生产建设活动。对生态空间分区管控的研究可方便决策者对生态修复空间和生态保护空间进行识别和分类管理,有效指导国土空间规划和区域生态环境管理体系的完善。 相似文献
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Chukwujindu M. A. Iwegbue Francis O. Arimoro Godwin E. Nwajei Osayonmo I. Eguavoen 《Soil & Sediment Contamination》2012,21(3):382-406
The distribution of Cd, Pb, Ni, Cr, Cu, Mn, Fe, and Zn in sediment and surface water, and some physico-chemical characteristics of Orogodo river sediments, were evaluated. The sediment pH ranged from 5.1–7.3; conductivity values ranged from 34.5 to 389.0 μScm?1. Total nitrogen values ranged from 0.06–0.10%, NH3-N values ranged from 0.25–0.44 mgkg?1, percent total organic carbon ranged from 0.21–1.68%, and total phosphorus values ranged from 0.004–0.02% for dry and wet seasons. The sand fraction consists of 87–95%, silt fractions ranged from 0–2%, and clay fraction between 4–13%. The mean concentrations of metals (dry weight basis) in the streambed sediments ranged from 1.92–17.37 mgkg?1 for Cu, 0.98–4.78 mgkg?1 for Ni, 0.01–32.98 mgkg?1 for Mn, 353.22–2045.64 mgkg?1 for Fe, 69.96–100.16 mgkg?1 for Zn, 0.21–1.32 mgkg?1 for Cr, and Cd was less than 0.001 mgkg?1 for wet and dry seasons. The mean concentrations of metals in the surface water ranged between 0.01–0.05–0.05 mg/L for Cu, nd-0.11 mg/L for Ni, 0.001–0.31 mg/L for Pb, 0.001–1.82 mg/L Mn, 0.01–3.52 mg/L for Fe, 0.16–0.61 mg/L for Zn, nd-0.007 mg/L for Cr, and <0.001 mg/L for Cd. Based on principal component analysis, two main sources of metals in the Orogodo River can be identified: (i) Cr, Cu, Pb, and Fe are mainly derived from industrial sources; (ii) Mn, Zn, and Ni associated with traffic activities. No element examined had a contamination/pollution index value greater than unity (pollution ranges). This implies that the multiple pollution indices obtained from the analysis showed that Orogodo River sediments were not polluted with heavy metals. 相似文献
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我国城市群快速发育与增长的同时也伴随着巨大的生态代价。基于生态约束视角提出城市群可持续发展的"供需-效率-结构"三维测度模型,以闽三角城市群为实证,综合运用生态足迹、生态承载力与信息熵模型,从资源供需关系、发展生态效率与生态本底结构三个方面评价其2018年区域城镇可持续发展空间分异规律,并进一步探究其影响因素与转型发展路径。研究发现:(1)闽三角区域城镇发展空间分异明显,具体表现为南北差异与海陆差异,空间集聚效应正在形成。(2)城镇可持续发展潜力与能源消耗和经济发展水平呈显著负相关,而人口、城镇化、经济、能源消耗等影响因素对资源供需关系、发展生态效率与生态本底结构三个子系统的影响机制存在差异。(3)鉴于影响机制差异,采用系统聚类法将闽三角城镇划分为赤字型、失衡型、粗放型与可持续型四类,针对不同类型城镇的主要发展制约因素提出相应的转型发展路径。研究希望为城市群可持续发展研究提供新的思路,为闽三角区域城镇转型发展提供参考与借鉴。 相似文献
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夏季南京市中心-郊区-城市森林梯度上的近地层大气特征 总被引:1,自引:0,他引:1
运用定点观测法和车载传感器的流动观测法,研究了夏季沿南京市市中心-郊区-城市森林梯度的近地层大气温度(T_(N-S))、CO_2浓度(p_(N-S)(CO_2))、湿度和污染气体浓度的变化规律.结果表明,沿市中心-郊区-城市森林梯度,T_(N-S)、p_(N-S)(CO_2)、相对湿度(RH_(N-S))和污染物浓度(p_(N-S)(SO_2)和p_(N-S)(NO_2))均表现为规律性的变化,与观测点距市中心的距离间的关系可用logistic方程进行较好的拟合(R~2在0.71~0.90之间).与城市森林(S9)相比,市中心(S1)的T_(N-S)和p_(N-S)(CO_2)在一天中的任何时段均有不同程度的升高,其中,T_(N-S)升高幅度在5:00~6:00时段最小,而在17:00~18:00时段最大,分别为1.3℃和4.7℃,白天和夜间平均分别升高了3.7℃和2.1℃;而p_(N-S)(CO_2)升高幅度在1:00~2:00时段最小,在13:00~14:00时段最大,分别为7.0μmol/mol和66μmol/mol,白天和夜间平均分别升高了55μmol/mol和20μmol/mol.S1和S9点间,绝对湿度(AH_(N-S))的全天平均值无显著差异;而RH_(N-S)除了5:00~6:00时段两点均接近饱和外,一天中S9点均高于S1点,两点最大差值出现在13:00~14:00时段,S1和S9分别为37.4%和52.9%,全天平均升高了7.0%.与S9点相比,S1点的p_(N-S)(SO_2)和p_(N-S)(NO_2)在上午10:00~11:40间分别升高了0.88倍和2.1倍.表明,当前城市的一些环境因子如T_(N-S)和p_(N-S)(CO_2)相当于全球数十年或更久以后的水平. 相似文献
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Air pollution is one of the top environmental concerns and causes of deaths and various diseases worldwide. An important question for sustainable development is to what extent urban design can improve or degrade urban air quality. In this article, we explored the relationship between ground-based observations of air pollution and urban form in the Yangtze River Delta (YRD), the largest metropolitan region in China. We analyzed six criteria pollutants (SO2, NO2, PM10, PM2.5, CO, O3) and summarized metric (air quality index, AQI) from 129 ambient air quality monitoring stations during 2015. Urban form was characterized using six spatial metrics, including the size, shape, regularity, fragmentation and traffic coupling factor of urban patches, based on satellite-derived land cover data. The results indicated that: (1) PM2.5, PM10 and O3 were three primary pollutants in the YRD. The annual average AQI was 79, and the air quality was “moderate” for human health, with the highest and lowest AQI appeared in winter (107) and summer (60). Moreover, the air quality of the southern areas (Zhejiang province, AQI: 68) was generally better than the northern parts (Jiangsu province, AQI: 86). (2) Through the size and shape of urban patches, urban form had a significant effect on urban air quality in the YRD. PARA_MN (Mean Perimeter-area ratio), ENN_MN (Mean Euclidean Nearest Neighbor Distance), CA (Total Urban Area) and NP (Number of urban patches) had the most significant impacts on air quality. PM10 and PM2.5 were two important pollutants highly positively related to CA and NP, while negatively related to PARA_MN and ENN_MN. In addition, the polycentric urban form was associated with high air quality. (3) Land use configuration was an important indicator to describe the urban air quality. When buffer distance of spatial scale was 25 km, air quality showed the highest correlation with forest coverage. A high forest coverage rate contributed to the better air quality, increasing or preserving the forested areas would help mitigate the air pollution. 相似文献
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1980-2015年珠三角城市群城市扩张的时空特征分析 总被引:1,自引:0,他引:1
以珠三角城市群9座城市为研究对象,基于1980-2015年3期遥感影像提取的土地利用数据,通过扩张强度、扩张速率以及景观格局指数定量分析珠三角城市群尺度上城市扩张的时空变化特征。结果表明:(1)城市群扩张数量特征:1980-2015年珠三角城市群建设用地面积扩张约3倍,1980-2000和2000-2015期间分别扩张1513.1、3043.8 km2;扩张强度不断增强,扩张速率明显加快。(2)城市群扩张空间特征:珠三角城市群中扩张迅速的城市主要分布在研究区中部的城镇密集带及沿海地区;扩张较慢的城市主要分布在靠内陆的周边地带。(3)基于时间尺度发现珠三角城市群结构的演变呈现出由单核模式(广州,1980年)-双核模式(广州、深圳,2000年)-多中心、网络化模式演化的特征(东莞、中山等相邻城市,2015年)。(4)基于景观格局特征,珠三角区域扩张快速的城市形状复杂,结构趋于分散;扩张较慢的城市形状更规则,分布更聚集。(5)天然的人文联系与优越的地理位置、社会经济、政府政策以及基础设施的建设等因素共同驱动珠三角城市群的发展。该研究对提高城市群规划管理水平具有参考价值。 相似文献
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Effect of an urban park on air temperature differences in a central business district area 总被引:1,自引:0,他引:1
Sang-Hwa Lee Kyoo-Seock Lee Wen-Cheng Jin Ho-Kyung Song 《Landscape and Ecological Engineering》2009,5(2):183-191
Urban open spaces such as parks can act as urban cool islands. For example, in Seoul, Korea, the many Lee Dynasty royal palaces
and tombs act as urban cool islands that reduce the temperature of the park compared with the surrounding urban areas. In
order to determine the effect of air temperature differences because of the urban royal tomb park, Seolleung Royal Tomb Park
(SPK) and the nearby Seolleung subway station (SLS), air temperatures were recorded at 10 min intervals from November 9th,
2007 to November 8th, 2008. The data were analyzed and examined to illustrate air temperature-reducing effects during the
day and over the year. Results of the investigation show that the average air temperature differences due to SPK in the nearby
SLS was 1.76°C, and the maximum air temperature-reducing effects due to SPK occur in September, not during the winter. The
air temperature-reducing effect due to SPK decreases rapidly from the park boundary, because of the urban morphology and land
use. 相似文献
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This paper examines the long-term influence on pine (Pinus sylvestris L.) wood properties of alkaline dust pollution (pH 12.3–12.7) emitted over 135 years from a cement plant in Estonia. A study
of stemwood physical and mechanical properties in 70–80-year-old Scots pines growing in three zones of different air pollution
levels showed serious deviations in comparison with a relatively healthy forest in an unpolluted area. Specimens from polluted
trees evidenced smaller sapwood annual ring widths than those from the control trees. At the same time, the number of growth
rings in sapwood at breast height increased under pollution. In the polluted areas, percentage of latewood in the annual ring
widths was higher than in the unpolluted area. Small amounts of cement dust, which contains elements essential for the mineral
nutrition of the trees, might have acted as fertilizer. Pine wood in the polluted stands exhibited increased density, bending
strength across the grain, compression strength along the grain and, in some instances, hardness along the grain. 相似文献
18.
ABSTRACTIntroduction. A well-supported pattern among dioicous bryophytes is male rarity. However, few assessments of bryophyte sex ratios have been made across environmental gradients to assess the role of environment in shaping population sex ratios.Methods. We systematically surveyed 200 shoots from a 20?m2 urban population of Bryum argenteum, and regenerated each shoot apex until sex expression occurred (up to 315 days).Key results. Female shoots outnumbered male shoots 132 to 68, giving a sex ratio of 1.94♀: 1♂. The female bias was found in two transects in higher light environments but not in the third transect, which had a lower light level and an equal sex ratio. Female shoots took longer than male shoots to reach gametangial induction (122 vs. 60 days) and longer to produce 5 inflorescences (120 vs. 80 days). Male shoots produced an average of 10× the total number of inflorescences compared to female shoots (34 vs. 3.5 inflorescences). Despite producing more inflorescences, male plants also produced more regenerant shoots, thus contradicting the prediction that a higher prefertilisation reproductive effort in males trades off with vegetative proliferation. Female plants harboured significantly more associated microbes than male plants.Conclusions. Our results support the role of light in influencing sex ratios in this species, suggest that trade-offs between reproduction and vegetative growth may not be strong for males, and indicate a potential role of a sex-specific microbiome in influencing sex ratios. 相似文献
19.
《农业工程》2014,34(1):44-52
In urbanized areas, habitat loss and fragmentation resulting from urban growth and human activities may threaten the biological diversity. It is essential to maintain the connectivity in some isolated and fragmented habitat patches. In 2005, the orchard-based conservation with the legal binding was implemented in Shenzhen to mitigate the ecological threats from forest destruction and to protect the ecological diversity. It is critical to evaluate the efficiency of orchard habitat from the species’ perspective for providing the reference for the habitat management. Based on graph-theoretic methods, we compared the habitats with or without orchards and evaluated the contribution of orchards to the whole network connectivity and its three fractions (intra, flux and connector), and then analyzed the species that could benefit the most from the habitat supplement. We identified the important landscape elements for serving the prioritized conservation. The results showed that orchard-based conservation was an efficient way in maintaining the functional connectivity, which mainly contributed to the intrapatch connectivity and species dispersal flux. The value of orchard incorporation was strongly related with the dispersal ability of threatened species. Our findings indicated that the orchard conservation would be more valuable for species with relatively weak dispersal abilities. We showed the key patches and links that most contribute to uphold functional connectivity in the reserve network. We believe that the assessment based on habitat functional connectivity can effectively serve the practical guidelines of habitat conservation and management in urban areas. 相似文献
20.
过去几十年我国经历了快速城市化过程,这使得不透水面大幅度增加,导致地表径流和洪峰流量增加,进入水体的污染物增多。城市非点源污染已成为河流水体恶化、生态系统退化的重要原因。在快速城市化过程中,城市群已成为城市化发展的新阶段。位于同一流域的各城市所产生的城市非点源污染导致城市群流域水环境问题越来越突出,成为制约城市群流域可持续发展的关键因素之一。现有的关于城市非点源的研究多集中于城市内部小尺度,对城市群大尺度的研究亟需发展。以位于浑河太子河流域的辽宁中部城市群为例,在沈阳市不同功能区和不同下垫面进行降雨径流采样,基于事件平均浓度(EMC)法和SWMM(Storm Water Management Model)模型相结合的方式,定量评估城市群流域城市非点源污染负荷。研究结果表明:路面径流中城市非点源污染物浓度、负荷量及其单位面积负荷要高于屋面径流和透水面径流。辽宁中部城市群TP、TN、COD、TSS的年均城市非点源污染负荷分别为265.52、852.89、2249.71、192496.74 t/a,重金属Cd、Ni、Pb、Cr、Cu、Zn的年均城市非点源污染负荷分别为347.99、9932.... 相似文献