高速铁路对城市空间影响的研究框架及实证

高速铁路的发展对区域、城市及站点周边地区的空间发展产生不同影响.本文总结评析在区域、城市和站点周边地区三个空间层面上交通设施与城市的影响研究,提出高速铁路发展对城市空间影响的分析框架,并以京沪高速铁路为案例进行初步实证分析.京沪高速铁路沿线站点地区与主城区间的联系主要表现为站点与城市中心的距离、站点是否在建成区范围内、...     

极端降水时空分布特征研究——以江苏省为例

文章基于江苏省1981—2014年逐日降水资料,根据极端降水的时间趋势、空间分布特征,从年际变化和季节变化两个尺度研究极端降水特征。结果表明:(1)时间趋势上,在研究的近30年(1981—2014年)里,极端降水频率呈下降趋势,而极端降水量明显增多。(2)时间突变上,1991年为一个时间突变点。(3)空间分布上,苏南地区受极端降水影响的程度比苏北地区大。(4)四季变化上,夏季是受极端降水影响最大的季节,春季和冬季极端降水较有规律。     

重庆市中心型轨道站点地区紧凑度研究

当前我国正值轨道交通快速发展 的关键时期,城市轨道站点地区是影响城市 空间结构、提高城市土地空间利用效率、提 升城市环境品质的重要地区,因此对轨道站 点的周边地区规划研究显得尤为紧迫。本文 选取了重庆轨道交通的六个中心型站点作为 研究对象,使用GIS对站点周围800 m范围进 行矢量化绘制,获取基础的量化数据。分别 针对站点地区的空间效率以及空间质量的建 立客体紧凑度和主体紧凑度评价指标,对每 个站点的指标结果进行统计分析。然后,进 一步从宏观层面研究不同指标结果的影响 机制,发现地理环境、区位因素、功能定位 和发展模式是站点地区空间形态的主要影响 因素。最后提出轨道站点地区空间的优化策 略,为轨道站点地区的规划设计提供参考。     

日本山阳新干线站点片区空间发展特征分析

该研究以日本山阳新干线沿线19个站点周边地区作为实证研究对象,探讨站区开发的空间特征。首先分析站点对城市整体空间发展的影响规律,再具体分析站点周边用地规模与空间形态的基本特征,所研究的站区基本超过40年的发展,站区形态趋于稳定,但发现各站点周边地区空间形态差异较大,部分站点周边开发强度较大且功能较为集约。但仍有少部分站点地区在平面与竖向空间布局呈现不利的形态。最后把空间形态要素分为路网与平面布局两个维度进一步分析山阳新干线的空间特征,并分析影响其形态的部分因素。     

轨道交通站点与城市中心节点耦合规划设计研究

轨道交通有助于快速拓展城市空间、优化和完善城市空间结构、加强城市时空的整体性。在实际操作中,可达性的改善能够引起轨道交通站点周边地区土地价格的上抬、土地使用功能的变迁、开发强度的提升及周边空间环境的改善等,因此轨道交通对于城市空间的直接影响作用主要集中在站点周边地区。研究从轨道交通站点与中心节点空间耦合的内涵入手,分别从经济、社会和生态的角度分析二者空间耦合的影响因子,探讨二者空间耦合的作用机制,构建实现二者空间耦合的目标引导体系,并分别从微观和宏观两个层面阐述了实现二者空间耦合的路径和方法。     

中心型地铁站点周边地区街道可步行性研究——以成都地铁1号线天府三街站点周边地区为例

为评价中心型地铁站点地区步行空间品质及特征对其可步行性的影响,促进构建地铁周边地区宜人的步行空间。该研究以邻里环境可步行量表模型（NEWS,Neighborhood Environment Walkability Scale）为基础构建中心型地铁站点地区街道步行空间评分表,运用空间语义差异问卷调查法（n=180）及空间环境注记法,以成都地铁1号线天府三街站点地区为对象进行研究。研究发现,在所有的指标中天府三街功能性指标评价最高,其次是安全性和舒适性,评价较高的因子主要有步行目的地距离、步行换乘公共交通便利性、指向和标识系统、街道视觉景观等。总体而言,评分表说明评价指标体系在科学化、精准化定量评价街道空间现状,以及探索已建成街道步行空间突出特点上具有可行性,可为政策制定者、城市规划者和研究学者提供参考。     

1961—2010年云南省气候变化特征分析

为了研究云南气候变化特点,利用1961—2010年云南25个站点的平均气温、最低气温和最高气温、降水量资料,分析研究云南近50年来的气候变化。结果表明:(1)云南升温趋势明显,升温率达0.24℃/10 a;(2)一年四季中,冬季升温的趋势最明显,春季、夏季和秋季的升温幅度大致相等;(3)年降水量呈略减少趋势,长期变化趋势不显著。年降水量呈周期性的波动变化,且年际变化较大;(4)年平均降水日数变化总体呈下降趋势,其中下降最显著的是小雨日数,中雨日数略为下降,而大雨和暴雨日数却略为增加;(5)年降水强度总体呈上升趋势。     

西部城市新型聚合空间规划研究

正城市新型聚合空间将对城市发展产生重要的乃至结构性的影响,这里特别关注两大类型的聚合空间:一是高铁站点及周边地区;二是现代服务业集聚区。由于我国西部地区城市有其发展阶段的不同特点,及时对上述两大类型聚合空间进行相关研究,总结经验并发现问题,对指导相关规划建设有特殊意义。(1)高铁站点及周边地区。随着我国高铁线网及站场建设逐步由东部向西部地区推进,围绕高铁站点     

高铁站点周边地区空间演化及驱动因素研究 ——基于京沪高铁的实证分析

空间演化规律是探究高铁站周边地区发展的重要途径。以京沪高铁线24个站区为例,以2008年~2018年期间站区范围内的土地开发量、开发功能和设站城市相关数据为研究依据,探究其半径3km圈层范围内的土地开发特征和驱动因素。研究发现,部分城市建成区扩张较快,站点选址对站点周边发展仍然起着至关重要的作用。大部分站点周边开发的空间演变特征可分为由内向外、由外向内和内外均衡三类,城市能级和站点区位越好,则核心圈层的商业、商务功能越优先开发,逐渐带动外圈层发展。驱动因素受到站点区位和资源禀赋的影响,可分为大型公共设施带动型、房地产带动型和产业带动型三类。最后,提出了站点选址、功能分布、开发时序和驱动方式等方面的相关对策。     

犀浦站区域的城市问题浅析

随着我国主要城市轨道交通快速建设和城市空间结构的持续优化,轨道交通节点在城市的地位和作用越发重要,它拥有巨大的承载能力与疏散能力,但同时给城市整体空间结构造成了很大影响。文章通过相关理论研究,结合现状对站点地区人群需求及分布特征等进行剖析,以提高站点周边地区空间绩效和合理的规划模式为目标,对站点地区空间结构及形态、功能布局、交通系统、设施支撑、建筑景观等方面提出优化方式和设计对策,通过本文的研究希望能对未来城市轨道交通节点的设计提供一些思路。     

Monitoring climate at Jungfraujoch in the high Swiss Alpine region

A homogenized temperature record measured at Jungfraujoch, the highest permanently manned meteorological station in Europe at 3580 m asl, is presented based on almost 70 years of record (1937-2005). The observed decadal variability as well as the overall trend (1.8 degrees C/69 years) in the homogenized data is comparable to other homogenized Swiss time series at other altitudes. A detailed analysis of seasonal mean temperature trends revealed no significant height dependence for the period 1961-2005. The dominant trend features are the weaker trends in autumn, significant only at low altitudes. Temperature indices such as thawing days, derived from newly homogenized minimum temperature series, exhibit strong vertical and seasonal trend dependence. Strongest relative trends occur in winter at an altitude around 1000 and 1600 m asl. For the summer season relative trends in thawing days are strongest at the highest stations, as expected. At Jungfraujoch an increase of about 50% is observed for the period 1961-2005 even when the extraordinary warm summer of 2003 is excluded.     

长江流域降水的季节变化对流域水资源的影响研究

通过分析1961—2005年长江流域降水的季节变化与旱涝分布,发现45年来长江流域春季、秋季降水下降,而夏季、冬季降水增加,其中上游秋季和中下游夏季、冬季降水变化都通过了95%显著性检验.近年来,长江流域降水的季节分配不均,长江流域洪涝较多的时期,夏季降水一般显著增加;而干旱发生时,秋季降水一般下降显著.20世纪80年代中期以来,长江上游干旱化趋势加重,而中下游洪涝增多,这种旱涝并存的格局加剧了长江流域的旱涝灾害.     

基于河南百泉泉域降水量的小波分析

文章利用1951—2016年百泉泉域降水量进行小波分析,揭示了百泉泉域不同时间尺度的降水特征,对百泉泉水流量的动态分析和百泉泉域裂隙岩溶地下水资源评价具有重要意义,也可为类似地区降水分析和资源评价提供参考。小波分析结果显示:(1)百泉泉域年降水量Z值为-2.49,总体呈下降的趋势,且趋势显著。春季降水量Z值为-0.01,降水量几乎无明显变化;夏季降水量Z值为-2.67,降水量明显减少,且趋势显著;秋、冬两季降水量Z值分别为-0.98和-0.95,降水量呈减少趋势,下降不显著。(2)年降水量和四季降水量存在多个主要周期变换。在大时间尺度内,年降水量和四季降水量震荡较强;而在小时间尺度内,秋、冬两季降水量震荡较强,突变点增多。(3)2016年百泉泉域为丰水期,但未来将步入枯水期。     

Evaluation of phosphorus concentrations in relation to annual and seasonal physico-chemical water quality parameters in a UK chalk stream

The aim of this paper was to examine historical physico-chemical water quality parameters (1990-1997) in the River Frome, East Stoke (NGR SY867868), in order to show both annual and seasonal (monthly) trends. EpCO2 (defined as the partial pressure of CO2 in natural water divided by the equilibrium partial pressure of CO2) levels ranged from mean values of 6.32+/-0.41 in spring/summer to 7.86+/-1.17 in autumn/winter. A decreasing trend in mean annual EpCO2 was also observed, with a high of 9.61 in 1990 and a low of 5.22 in 1996. The variations were attributed to changes in pH, which showed an inverse relationship with river discharge (r2=0.47). Both pH and EpCO2 levels were strongly linked to biological activity with increases caused by primary productivity. Filterable reactive phosphorus (FRP) and total phosphorus (TP) concentrations correlated with river discharge. The results showed that the majority of the phosphorus load was transported during storm events, which agrees with results from an export coefficient model predicting phosphorus loading in the Frome catchment. Recent River Frome monitoring campaigns using an in situ flow-injection (FI)-based monitor were in agreement with phosphorus concentration and related physico-chemical trends observed during historical sampling and laboratory analysis.     

Air pollution and meteorological processes in the growing dryland city of Urumqi (Xinjiang, China)

Seven years (2000-2006) of monthly PM₁₀ (particulate matter, d ≤ 10 μm), SO₂, and NO₂ concentrations are reported for Urumqi, the capital of Xinjiang in NW China. Considerably high mean annual concentrations have been observed, which ranged between 150 and 240 μg m^− 3 (PM₁₀), 31 and 50 μg m^− 3 (NO₂), and 49 and 160 μg m^− 3 (SO₂). The shapes of seasonal variation of all pollutants were remarkably similar; however, winter/summer ratios of concentrations were quite different for PM₁₀ (2-3) and NO₂ (≈ 4) compared to SO₂ (up to 30). Very high consumption rates of fossil fuels for energy generation and domestic heating are mainly responsible for high annual pollution levels, as well as the (very) high winter/summer ratios. Detailed analysis of the 2000-2006 records of Urumqi's meteorological data resulted in inter-annual and seasonal frequency distributions of (a) (surface) inversion events, (b) heights of surface inversions, (c) stability classes of Urumqi's boundary layer, and (d) the “Air Stagnation Index (ASI)”. Urumqi's boundary layer is shown to be characterized by high mean annual and seasonal frequencies of (surface) inversions and by the dominance of stable dispersion classes. A further outcome of the meteorological analysis is the proof of Urumqi's strong diurnal wind system, which might have particularly contributed to the stabilization of the nocturnal boundary layer. Annual and seasonal variations of pollutant's concentrations are discussed in the context of occurrences of inversions, boundary layer, stability classes, and ASI. The trend of Urumqi's air pollution indicates a strong increase of mean annual concentrations 2000-2003, followed by a slight increase during 2003-2006. These are in strong contrast to (a) the growth of Urumqi's fleet of motor vehicles and (b) to the growing number of stable regimes of Urumqi's boundary layer climate during same period. It is concluded that the (regional and) local administrative technical countermeasures have efficiently lowered Urumqi's air pollution levels.     

PM_(10)浓度及微观特征季节分布分析——以乌鲁木齐天山区2004年为例

利用2004年乌鲁木齐城区(以天山区为例)PM10日平均浓度和气象要素观测资料,对不同季节PM10浓度变化特征、不同级别污染日数进行统计分析．同时,结合环境扫描电镜／X射线能谱(ESEM-EDX)对不同季节的颗粒物的形貌及来源进行了初步探讨。结果表明2004年PM10浓度变化为:冬季>秋季>春季>夏季;冬季出现4级以上污染日数最多,占39．5％;夏季最为洁净,好于2级的日数占到76．1％．PM10和气象因子的相关分析表明浓度与风速成正比,与降水成反比,与温度,相对湿度和逆温层厚度相关比较复杂,有时成正相关,有时呈负相关。颗粒物的形貌在不同季节特征明显,冬季颗粒物多呈圆球形,春季形貌不规则,夏季既有圆球形又有不规则形貌的颗粒,而秋季颗粒物多呈链状．     

再生水中氨氮和总氮的相关性分析研究

通过检测某再生水厂生活出水中的氨氮和总氮含量,分析了氨氮和总氮含量之间的相关性.结果表明,再生水中氨氮和总氮两个监测因子之间的相关关系为：秋季最好,R为0.992 5;冬季其次,R为0.934 6;最后是春季和夏季,R分别为0.777 0和0.725 7.氨氮和总氮含量之间的比例系数为0.010～0.310,波动较大,根据各不同季节氨氮和总氮的比例系数K季均值,可以得到氨氮和总氮含量的比例系数K年均值为0.078.     

Annual cycle of nitrogen removal by a pilot-scale subsurface horizontal flow in a constructed wetland under moderate climate

The annual course of nitrogen removal in a stable operating subsurface horizontal flow constructed wetland (SSF) in a moderate climate was evaluated using a large pool of data from 4 years of operation. In spring and autumn removal efficiencies were found to depend on the nitrogen load in a linear mode. The efficiencies in winter and summer differed extremely (mean removal rates of 0.15/0.7 g m(-2) d(-1) (11%/53%) in January/August) and were independent of the nitrogen load (0.7-1.7 g m(-2) d(-1)) in principle. Oscillations of the removal rates in spring, forming several maxima, suggest seasonal specific effects caused by the dynamics of the plant-physiology finally determining the nitrification efficiency, i.e. via O(2)-supply. Nitrification is limited by temperature during all seasons and surprisingly in midsummer additionally restricted by other seasonal aspects forming a clear-cut relative nitrification minimum (mean rate of 0.43 g m(-2) d(-1) (32%)) in July. The importance and the effect of the plants' gas exchange and oxygen input into the rhizosphere are discussed. Denitrification was nearly complete in midsummer and was clearly restricted at seasonal temperatures below 15 degrees C.     

Behavior of trihalomethanes and haloacetic acids in a drinking water distribution system

This investigation focused on the seasonal variation and spatial fate of chlorination disinfection by-products (CDBPs) in a drinking water distribution system located in a region where very significant seasonal variations in water temperature and surface water quality occur. The analysis of a large number of collected samples showed that the seasonal and geographical variations of both groups of CDBPs under study—trihalomethanes (THMs) and haloacetic acids (HAAs)—were particularly important in this region. THM levels in summer and fall were, on average, about five times higher than in winter, whereas average HAAs in spring were about four times higher than in winter. THMs increased and stabilized in the extremities of the distribution system, whereas HAAs begin to increase, and then decrease (mainly due to a reduction of dichloroacetic acid). This decrease was significantly higher in warm waters than in cold waters, which led to the hypothesis of microbial degradation of HAAs as water approaches the system extremities. In fact, regression models for the occurrence of both CDBPs showed that the residence time of water was one important parameter in explaining the fate of both CDBPs. The spatio-temporal portrait of both groups of CDBPs that was generated demonstrates that, due to their high intra-seasonal changes, the calculation of average annual levels of these substances for compliance with regulations can vary widely. The results used in the portrait of CDBP behavior are also relevant in terms of exposure assessment for future epidemiological studies on human reproductive outcomes in the region.     

Living with uncertainty: climate change,river flows and water resource management in Scotland

The recent increased variability of Scotland's hydroclimate poses major problems for water resource managers charged with making informed investment decisions given the likely impact of future climate change. Two strategies are developed in this paper to assist managers faced with this environmental uncertainty. The first involves trend analysis of precipitation and runoff since the 1960s and 1970s viewed against longer-term variability reported from instrumental records. The second strategy is based upon current climate change scenarios coupled with GCMs, and downscaling of precipitation and temperature to provide inputs to rainfall-runoff models. The long-term records of precipitation (back to the 1860s) and runoff (back to the 1930s) reveal the late 1980s and early 1990s as the wettest period on record for the west but not for the east. Over the period 1961-1996 the precipitation gradient has intensified across Scotland: wetter west; relatively dry east. Changes in runoff over the period 1970-1996 are also reported with increases in annual flows at 33 out of 38 stations (significantly at 12 stations) and decreases in low flows at 21 out of 38 stations (significantly at one station). The bulk of these flow increases occurred in the south and west especially in the autumn and spring. In terms of high flows over the period 1970-1996, four out of 44 stations reported a change in magnitude and 15 reported an increase in the frequency of POT events. In terms of future climate change, Hulme and Jenkins (1998) predict annual precipitation increases of 6-16% (Scotland) and 6-14% (Scottish Borders) from the 2020s to the 2080s based on the Hadley Centre model (HadCM2) medium-high scenario. Seasonal changes are concentrated in the autumn (SON) and winter (DJF) with increases as high as 24 and 29% for the autumn by the 2080s. (Arnell NW, et al. Institute of Hydrology Report No. 107, Wallingford, 1996), using an earlier transient Hadley experiment (IS92a), predict a 5-15% increase in annual runoff across Scotland by the 2050s, locally rising to 25%. Simulation flow duration curves for the 2050s generate Q95 values up by 5% or less (Rivers Don, Almond and Nith) and Q5 up by 10-24% (Rivers Don, Almond, Nith and Lyne Water). In terms of water resource planning, these predicted changes should be regarded as first order approximations, as they take no account of natural climatic variability, and could generate different absolute values if other scenarios were used. The predictions are, however, broadly consistent with trends in precipitation and runoff for Scotland since the 1970s. Major issues of concern to water resource managers are identified and commented upon in the light of these predictions.