不透水地表盖度视角下中美城市群空间结构对比——以“京津冀”与“波士华”为例   总被引：3，自引：0，他引：3  

曹诗颂  胡德勇  赵文吉  陈姗姗  程庆文 《地理学报》2017,72(6):1017-1031

将城市不透水地表盖度产品应用于城市群空间结构研究具有重要价值。本文基于多源遥感数据提取了“京津冀”与“波士华”城市群近40年（1972-2011年）亚像元级不透水地表专题信息,构建了城市群空间结构对比分析数据集;并引入引力模型和景观格局理论,利用引力指数、景观格局指数以及空间结构参数等,采用地理信息系统空间分析方法,从城市群与城市两个尺度对城市群空间结构进行了对比研究。结果表明：① “京津冀”城市群不透水地表快速增长,而“波士华”城市群较为稳定;② “京津冀”城市群空间结构经历了城市孤立发展阶段、双核心城市群阶段、城市群组阶段以及城市群网络化阶段,“波士华”城市群空间结构较为稳定,空间结构呈现出“点—轴”带状分布;③ 中国城市不透水地表盖度“高—高”聚集区呈现出典型团块状“摊大饼”形态,而美国城市呈现出一种“多中心集聚、分散成组”的态势;④ “京津冀”城市群生态、生产与生活用地不透水地表面积占比均高于“波士华”城市群。最后,基于两国城市群空间结构的对比结果,从空间布局优化角度对“京津冀”城市群的发展提出了初步建议。  相似文献   

北京市不同功能区不透水地表时空变化差异   总被引：4，自引：1，他引：3  

乔琨  朱文泉  胡德勇  郝明  陈姗姗  曹诗颂 《地理学报》2017,72(11):2018-2031

目前有关北京市不透水地表的相关研究多数是从整体层面开展,忽略了其内部功能区的作用及差异。运用分类回归树（CART）及系列变化检测模型得到北京市1991年、2001年、2011年和2015年四期不透水地表分布,并运用标准差椭圆、洛伦兹曲线、贡献指数及景观格局理论对各功能区不透水地表的时空变化进行分析。结果显示：1991-2015年北京市不透水地表的总面积增加了约144.18%,分布的主导方向由早期的东北—西南趋向于当前的正北—正南。各功能区间不透水地表的空间分布异质性逐渐减弱,但贡献指数值存在很大差异：功能拓展区的贡献指数最高,其四年中的最低值（1.79）高于其他功能区四年最高值,是北京市不透水地表增长最主要的贡献区;功能核心区的蔓延度指数值最高,约为其他功能区的2倍,为不透水地表的优势聚集区;发展新区的贡献值由负值变为正值并成倍增长,成为北京市不透水地表增长的主要源区;生态涵养发展区的贡献指数始终为负,并逐年减小。不同类型不透水地表的景观指数和质心偏移均存在差异,高盖度不透水地表的形状指数和斑块密度值最小,分布最为集中,对生态环境影响较大,北京市在未来发展过程中应合理规划控制其空间格局及增长模式,尽量减缓其增长速度及团聚程度。  相似文献   

地下水封石油洞库水幕系统水力试验及水幕钻孔施工          下载免费PDF全文

胡谋鹏  陈雪见  杨征  梁久正  詹胜文 《探矿工程》2016,43(1):81-84

水幕系统是地下水封储油库最为关键的部分,主要由水幕巷道、水幕孔、附加水幕孔、监测井和仪表井组成。水力试验成果是水幕系统评价的依据,而水幕孔的施工质量又是水力试验顺利和试验效果的保证。结合辽宁某地下水封洞库工程,阐明了水幕系统在施工期间的水文试验方法,分析了施工期间各水文试验的作用及其相关性;介绍了水幕钻孔施工技术。  相似文献   

Mapping urban growth of the capital city of Honduras from Landsat data using the impervious surface fraction algorithm     

Nguyen-Thanh Son  Chi-Farn Chen  Cheng-Ru Chen  Shou-Hao Chiang 《国际地球制图》2016,31(3):328-341

This study developed an impervious surface fraction algorithm (ISFA) for automatic mapping of urban areas from Landsat data. We processed the data for 2001 and 2014 to trace the urbanization of Tegucigalpa, the capital city of Honduras, using a four-step procedure: (1) data pre-processing to perform image reflectance normalization, (2) quantification of impervious surface area (ISA) using ISFA, (3) accuracy assessment of mapping results and (4) change analysis of urban growth. The mapping results compared with the ground reference data confirmed the validity of ISFA for automatic delineation of ISA in the study region. The overall accuracy and Kappa coefficient achieved for 2001 were 92.8% and 0.86, while the values for 2014 were 91.8% and 0.84, respectively. The results of change detection between the classification maps indicated that ISA increased approximately 1956.7 ha from 2001 to 2014, mainly attributing to the increase of the city’s population.  相似文献   

Spatiotemporal changes of urban impervious surface area and land surface temperature in Beijing from 1990 to 2014   总被引：1，自引：0，他引：1  

Pengyu Hao  Zheng Niu  Yunchao Wu  Li Wang  Yonghong Liu 《地理信息系统科学与遥感》2016,53(1):63-84

This study examined changes in urban expansion and land surface temperature in Beijing between 1990 and 2014 using multitemporal TM, ETM+, and OLI images, and evaluated the relationship between percent impervious surface area (%ISA) and relative mean annual surface temperature (RMAST). From 1990 to 2001, both internal land transformation and outward expansion were observed. In the central urban area, the high-density urban areas decreased by almost 7 km², while the moderate- and high-density urban land areas increased by 250 and 90 km², respectively, outside of the third ring road. From 2001 to 2014, high-density urban areas between the fifth and sixth ring roads experienced the greatest increase by more than 210 km², and RMAST generally increased with %ISA. During 1990–2001 and 2001–2014, RMAST increased by more than 1.5 K between the south third and fifth ring roads, and %ISA increased by more than 50% outside of the fifth ring road. These trends in urban expansion and RMAST over the last two decades in Beijing can provide useful information for urban planning decisions.  相似文献   

哈尔滨市城乡结合部不透水面时空变化及驱动力分析   总被引：4，自引：1，他引：3  

李苗  臧淑英  吴长山  田旸 《地理学报》2017,72(1):105-115

本文选取哈尔滨市城乡结合部为研究区,以1984年、1993年、2002年和2010年的TM影像数据为数据源,利用混合像元分解方法提取了哈尔滨市城乡结合部的不透水面信息。分析了不透水面的时空变化特征。选取坡度、坡向、DEM、距河流距离、距高速公路距离、距铁路距离、距主要路距离和距1984年城区距离8个因子,利用增强回归树法进一步分析了1984-2010年哈尔滨市城乡结合部不透水面扩张的主要影响因素。结果表明：1984年哈尔滨市城乡结合部不透水面所占比例为3.9%、1993年为6.6%、2002年为9.0%、2010年为16.52%。高速公路、铁路、主要路等交通要素带动周边地区的发展,从而导致道路沿线城市扩张速度较快。  相似文献   

A Study on Impervious and Heat-Insulating Performance of Geomembrane Composites Within Breakwater     

Tao Tongkang  Yu Long  Yan Jun Dong Zhiyong Prof.  Senior Engineer  Hydraulic Engineering Department  Nanjing Hydraulic Research Institute  Nanjing Graduate Student  Hydraulic Engineering Department  Nanjing Hydraulic Research Institute  Nanjing Engineer  Hydraulic Engineering Department  Nanjing Hydraulic Research Institute  Nanjing Associate Professor  Hydraulic Engineering Department  Nanjing Hydraulic Research Institute  Nanjing 《中国海洋工程》1997,(2)

This paper investigates the performance of geomembrane composites used as impervious andheat-insulating lining within a breakwater for a power station.The seepage field,distribution ofstress-strain contour and seepage discharge of hot water which has been treated as the inner thermalsource in the calculation of heat-insulation,have been given by three-dimensional calculation method coup-ling seepage with stress.The results indicate that the impervious and heat-insulation effect ofgeomembrane composites is significant.  相似文献   

Hydrologic metrics for status‐and‐trends monitoring in urban and urbanizing watersheds          下载免费PDF全文

Derek B. Booth  Christopher P. Konrad 《水文研究》2017,31(25):4507-4519

Local governmental agencies are increasingly undertaking potentially costly “status‐and‐trends” monitoring to evaluate the effectiveness of stormwater control measures and land‐use planning strategies or to satisfy regulatory requirements. Little guidance is presently available for such efforts, and so we have explored the application, interpretation, and temporal limitations of well‐established hydrologic metrics of runoff changes from urbanization, making use of an unusually long‐duration, high‐quality data set from the Pacific Northwest (USA) with direct applicability to urban and urbanizing watersheds. Three metrics previously identified for their utility in identifying hydrologic conditions with biological importance that respond to watershed urbanization—T_Qmean (the fraction of time that flows exceed the mean annual discharge), the Richards‐Baker Index (characterizing flashiness relative to the mean discharge), and the annual tally of wet‐season day‐to‐day flow reversals (the total number of days that reverse the prior days' increasing or decreasing trend)—are all successful in stratifying watersheds across a range of urbanization, as measured by total contributing area of urban development. All metrics respond with statistical significance to multidecadal trends in urbanization, but none detect trends in watershed‐scale urbanization over the course of a single decade. This suggests a minimum period over which dependable trends in hydrologic alteration (or improvement) can be detected with confidence. The metrics also prove less well suited to urbanizing watersheds in a semi‐arid climate, with only flow reversals showing a response consistent with prior findings from more humid regions. We also explore the use of stage as a surrogate for discharge in calculating these metrics, recognizing potentially significant agency cost savings in data collection with minimal loss of information. This approach is feasible but cannot be implemented under current data‐reporting practices, requiring measurement of water‐depth values and preservation of the full precision of the original recorded data. With these caveats, however, hydrologic metrics based on stage should prove as or more useful, at least in the context of status‐and‐trends monitoring, as those based on subsequent calculations of discharge.  相似文献   

A solution to estimate the total and effective stresses in backfilled stopes with an impervious base during the filling operation of cohesionless backfill     

Jian Zheng  Li Li  Yu-Chao Li 《国际地质力学数值与分析法杂志》2020,44(11):1570-1586

Mining backfill is commonly used in underground mines. A critical concern of this practice is to evaluate the pressures and total stresses in backfilled stopes to ensure a safe and economic design of barricades, constructed to retain the backfill. When a slurried backfill is placed in a mine stope, excess pore water pressure (PWP) can instantaneously generate and progressively dissipate. The dissipation of the excess PWP and consolidation lead to the development of effective stresses, which in turn lead to an arching effect in the backfilled stope. Until now, arching effect has been largely considered for stress estimation in dry or submerged backfill. The former corresponds to the final state at the end process of the drainage and consolidation of the backfill with a pervious while the latter with an impervious barricade. However, previous studies have shown that the most critical moment for the stability of barricades is during the stope filling. Therefore, the design of barricades requires a proper estimation of the pressure and total stresses during the filling operation. This in turn needs joint consideration of the arching effect and consolidation of the backfill. In this paper, a new solution is developed to evaluate the pressures and stresses in backfilled stopes during the filling operation of cohesionless backfill by considering the self-weight consolidation and arching effect. The proposed solution is validated by numerical modeling with Plaxis2D. It can thus be used to evaluate the pressures and stresses in backfilled stopes during the stope filling with an impervious barricade.  相似文献   

融合多源时序遥感数据大尺度不透水面覆盖率估算   总被引：1，自引：0，他引：1  

李方刚  李二珠  阿里木·赛买提  张连蓬  刘伟  胡晋山 《遥感学报》2020,24(10):1243-1254

不透水面信息是监测城市扩张及区域生态环境变化研究的重要指标，基于遥感技术对地表不透水面信息进行快速提取具有重要意义。传统大范围不透水面覆盖率估算模型主要基于单一遥感信息与不透水面比例之间的相关性，通过单因子回归模型实现不透水面覆盖率的估算。受限于单一遥感信息的信息量及普适性等影响，这类方法在大尺度不透水面提取中具有较大局限性，估算结果的区域适应性存在较大差异。针对该问题，本文提出基于多特征遥感信息进行不透水面估算的方法，以弥补单一特征在大范围不透水面提取中的不确定性。该方法首先以多时相MOD13Q1、MOD09A1产品、夜间灯光数据（NPP-VIIRS）和Landsat 8 OLI为遥感数据源，从不同角度构建突出不透水面信息的多个指数特征；在此基础上利用多元回归模型建立多因子不透水面覆盖率估算模型，进而实现大尺度不透水面覆盖率的遥感估算。本研究选择分布于全国范围内13个典型城市作为主要研究区对提出的模型进行了验证，结果表明：该方法能够适应不同区域不透水面覆盖率的估算，在复杂城市区域表现出较传统方法更好的效果，明显改善了城市内部不透水面覆盖率的估算精度。  相似文献