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41.
社区尺度绿色基础设施暴雨径流消减模拟研究   总被引:8,自引:5,他引:3  
刘文  陈卫平  彭驰 《生态学报》2016,36(6):1686-1697
当前快速的城市化进程导致了城市地区内涝事件频繁发生。绿色基础设施是减轻城市洪涝的有效措施之一。SWMM(Storm Water Management Model)等模型的复杂性使得规划管理者对模型的操作和应用存在困难,而且缺乏对绿色基础设施径流消减机制的展现。目前的研究中,比较单个与综合绿色基础设施配置径流消减效果的研究相对较少。基于水量平衡和城市水文过程,开发了社区尺度绿色基础设施消减作用的暴雨径流模型,并以北京市一典型社区为例,模拟研究了一年一遇和五年一遇两种暴雨条件下不同绿色基础设施配置对暴雨径流流量和峰值的消减效率。结果表明:用两场野外监测的降雨和径流数据验证模型得到的决定系数分别为0.68和0.71,纳什效率系数分别达到0.99和0.96,表明模型是可靠的。在一年一遇和五年一遇两种暴雨条件下,将常规绿地改造成5 cm深度的下凹式绿地,径流量分别减少了8.23%和23.30%,径流峰值分别减少了20.31%和29.11%;在建造300 m3调蓄池的情景下,径流量分别减少了84.90%和20.97%,径流峰值分别减少了88.99%和0.10%;在50%的不透水地表铺装透水砖情景下,径流量分别减少了46.51%和38.52%,径流峰值分别减少了39.96%和35.48%。3种绿色基础设施都可以较好的消减社区暴雨径流,但是随着暴雨强度的增强,下凹式绿地的消减效果略增强,调蓄池的消减效果变差,透水砖铺装的消减效果较稳定。综合3种措施对暴雨径流具有显著消减效果,可以100%消减一年一遇暴雨产生的径流,在五年一遇设计暴雨条件下,分别消减75.47%的总径流量和64.52%的径流峰值。  相似文献   
42.
Understanding the processes driving seabirds'' reproductive performance through trophic interactions requires the identification of seasonal pulses in marine productivity. We investigated the sequence of environmental and biological processes driving the reproductive phenology and performance of the storm petrel (Hydrobates pelagicus) in the Western Mediterranean. The enhanced light and nutrient availability at the onset of water stratification (late winter/early spring) resulted in annual consecutive peaks in relative abundance of phytoplankton, zooplankton and ichthyoplankton. The high energy-demanding period of egg production and chick rearing coincided with these successive pulses in food availability, pointing to a phenological adjustment to such seasonal patterns with important fitness consequences. Indeed, delayed reproduction with respect to the onset of water stratification resulted in both hatching and breeding failure. This pattern was observed at the population level, but also when confounding factors such as individuals'' age or experience were also accounted for. We provide the first evidence of oceanographic drivers leading to the optimal time-window for reproduction in an inshore seabird at southern European latitudes, along with a suitable framework for assessing the impact of environmentally driven changes in marine productivity patterns in seabird performance.  相似文献   
43.
彭建  魏海  武文欢  刘焱序  王仰麟 《生态学报》2018,38(11):3741-3755
近年来频发的暴雨洪涝成为威胁城市可持续发展的主要灾害类型,而土地利用变化改变了区域原有的景观结构和水文过程,是城市暴雨洪涝灾害风险加剧的重要诱因,定量探讨土地利用变化对暴雨洪涝灾害及其风险影响具有重要意义。以深圳市茅洲河流域为例,基于CLUE-S模型、SCS模型及等体积淹没算法等,对12种暴雨洪涝致灾-土地利用承灾情景下的城市暴雨洪涝灾害风险进行定量模拟。研究结果显示,相同土地利用空间格局下城市暴雨洪涝灾害随暴雨致灾危险性增加风险加剧显著;在同等致灾危险性水平下随建设用地面积增加,中等风险和高风险区面积均呈现较为明显的增加趋势,中、高风险区面积与建设用地面积的增加率表现出较高的协同变化特征;以50年遇危险性水平为例,随着建设用地面积由基期的15368.85hm~2增加至近期16076.07hm~2和远期16750.89hm~2,高风险区面积由254.07hm~2增加至276.48hm~2和286.2hm~2。由此可见,尽管暴雨强度的增加是城市暴雨洪涝灾害风险加剧的根本诱因,但是以建设用地面积增加为表征的土地利用变化对暴雨洪涝灾害风险的影响不容忽视。  相似文献   
44.
The aim of this study is to survey the PM10, PM2.5, and PM1 concentrations in rural and urban areas in Tehran province during cold, warm and dust storm days from December 22, 2016 to June 5, 2017 using Grimm Model aerosol spectrometer. During the study period, daily PM10, PM2.5, and PM1 concentrations ranged from 27.2 to 244.96, 8.4 to 77.9, and 6.5 to 56.8 μg/m3 in urban sites, and 22.8 to 286.4, 6 to 41.1, and 2.1 to 20.2 μg/m3 in rural parts, respectively. Particularly, both daily WHO limits for outdoor PM10 (50.0 μg/m3) and PM2.5 (25.0 μg/m3) exceeded in 95% and 83% of the outdoor measurements in winter and 82% and 58% in total sampled days in urban site, respectively. The 24-h average PM10 and PM2.5 concentrations also exceeded by 59% and 18% in winter and by 36% and 14% of all sampling days in rural site, respectively. During the dust storm, the 24-h average PM10, PM2.5, and PM1 concentrations were, respectively 4.7, 2, and 1.96 times higher than those in urban site and 2, 1.7, and 1.3 times more than those in rural site in all sampled days.  相似文献   
45.
To test the hypothesis that sudden unexplained death (SUD) in some epileptic patients is related to geomagnetic activity we exposed rats in which limbic epilepsy had been induced to experimentally produced magnetic fields designed to simulate sudden storm commencements (SSCs). Prior studies with rats had shown that sudden death in groups of rats in which epilepsy had been induced months earlier was associated with the occurrence of SSCs and increased geomagnetic activity during the previous night. Schnabel et al. [(2000) Neurology 54:903–908) found no relationship between SUD in human patients and geomagnetic activity. A total of 96 rats were exposed to either 500, 50, 10–40 nT or sham (less than 10 nT) magnetic fields for 6 min every hour between midnight and 0800 hours (local time) for three successive nights. The shape of the complex, amplitude-modulated magnetic fields simulated the shape and structure of an average SSC. The rats were then seized with lithium and pilocarpine and the mortality was monitored. Whereas 10% of the rats that had been exposed to the sham field died within 24 h, 60% of the rats that had been exposed to the experimental magnetic fields simulating natural geomagnetic activity died (P<.001) during this period. These results suggest that correlational analyses between SUD in epileptic patients and increased geomagnetic activity can be simulated experimentally in epileptic rats and that potential mechanisms might be testable directly.  相似文献   
46.
对江苏沿海地区(强)热带风暴条件下农田林网防止水稻倒伏和减产效应的研究表明,有林网农田的水稻倒伏率为16.28%,无林网农田为49.73%;水稻在灌浆结实期倒伏以后,千粒重减少13.24%,产量减少14.32%,有林网农田的水稻倒伏减产率为无林网农田的1/3.主林带林木保存率大于90%的林网抗倒度最大,水稻倒伏减产率最小.  相似文献   
47.
基于对尖峰岭热带山地雨林集水流域的定位研究,分析了3年间该群落冠层对大雨、暴雨及大暴雨势能的消减、缓冲耗能效应以及年暴雨携带养分在系统中贮存效应,其冠层消减大雨、暴雨及大暴雨势能占年总消减势能在61.8%~71.8%之间,其中消减(≥200mm)大暴雨势能量占年总消减势能的43.9%;大雨、暴雨及大暴雨雨水的年均养分含量为55.122kg/hm2,其产流流失为42.917kg/hm2,年均净积累为12.205kg/hm2,除取Si外,年净积累量达32.674kg/hm2,充分体现出热带山地雨林生态系统具有的环境生态效应。  相似文献   
48.
Dissolved organic carbon (DOC) concentrations and export were studied in two small catchments in central Ontario to examine DOC sources and to assess the hypothesis that organic matter adjacent to the stream is a significant contributor of DOC during storms. Different DOC dynamics and exports were observed according to the depth of the riparian water table. In Harp 4-21, riparian flowpaths were predominantly through A and upper B soil horizons and riparian soils contributed between 73 and 84% of the stream DOC export during an autumn storm. In Harp 3A, riparian flowpaths were predominantly through lower B horizons. Consequently, riparian soils were less important and hillslopes contributed more than 50% of the stream DOC export in subcatchments without wetlands during storms. Wetlands and adjacent soils contributed significantly to DOC export in Harp 3A; 8% of the total catchment area exported 32 to 46% of the storm runoff DOC. DOC export dynamics in wetlands and riparian soils were distinctly different. In wetlands, transport was affected by leaching and flushing of DOC at the wetland surface leading to lower DOC concentrations with successive storms. In riparian soils, groundwater flowpaths were more important and stronger positive relationships between discharge and DOC concentration were observed. Precipitation, throughfall and stemflow were minor sources of stream DOC during storms and contributed less than 20% of the total export.  相似文献   
49.
在大鼠动情前期促黄体生成激素峰形成前后测定了血清雌、孕激素水平变化、下丘脑正中隆起促黄体生成激素释放激素含量及弓状核区雌、孕激素受体密度改变和弓状核前阿黑皮素mRNA水平变化。结果表明:动情前期14小时时血清雌激素水平开始升高(P<005),于16小时时达高峰。此时弓状核雌激素受体密度降低(P<005),孕激素受体密度增加(P<005),前阿黑皮素mRNA水平减少(P<005)。前阿黑皮素mRNA水平与血清雌激素及正中隆起的促性腺激素释放激素水平呈负相关(P值分别小于001及005),与弓状核雌激素受体密度变化呈正相关(P<001)。提示弓状核的前阿黑皮素mRNA水平在此过程中可能受雌激素及其受体调控,下丘脑β内啡肽合成减少可能参与了排卵前促性腺激素释放激素/促黄体生成激素峰的形成。  相似文献   
50.
笋秀夜蛾的求偶及交配行为   总被引:1,自引:0,他引:1  
笋秀夜蛾(Apamea apameoides)是我国南方地区最为重要的笋期害虫,了解其求偶和交配行为是性信息素分离鉴定和应用的关键之一。在室内条件下,对笋秀夜蛾的性比、寿命和求偶、交配行为进行了研究。结果表明:笋秀夜蛾雌雄性比为1∶0.76;雌蛾和雄蛾的平均寿命因交配缩短;笋秀夜蛾的求偶和交配行为仅发生在暗期,日龄对其求偶和交配行为影响显著。雌蛾羽化当天便可求偶,第2日雌蛾求偶率达最高,求偶的起始时间随着日龄的增加逐渐提前。成虫羽化当日便可交配,第3日达到交配高峰;随日龄的增加,开始交配的时间逐渐提前,日龄对成虫交配高峰出现的时间影响不显著。  相似文献   
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