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排序方式: 共有355条查询结果,搜索用时 15 毫秒
91.
网格(Grid)是新型高效的分布式计算和资源管理基础设施。分析了空间数据基础设施(Spatial Data In-frastructure,SDI)与网格技术的集成需求,扩展了传统SDI层次体系,提出一种新的SDI—基于网格虚拟组织的SDI(Virtual Organization SDI,VOSDI)。VOSDI突破原有SDI以明确的地区或地域分类分层组织的方式,通过VO对地理上分布的人员、资料及空间信息进行有效组织和整合,具有灵活高效的特性。对VOSDI的功能、特性进行探讨后,进一步提出VOSDI的概念模型,并指出VOSDI实施中可能存在的问题。  相似文献   
92.
国土空间规划:基础设施与公共服务设施单幅总图的研制   总被引:1,自引:1,他引:0  
王姣娥  陈卓  景悦  黄洁  金凤君 《地理研究》2019,38(10):2496-2505
基础设施的建设与布局是在遵循自然系统格局的基础上,由人类活动所引致的物质环境再建构和空间秩序再安排,是构建和引领区域空间结构的重要支撑体系,因此一直是区域发展类规划的重要组成部分。结合省级空间规划试点工作,提出符合空间规划目标的基础设施与公共服务设施编制方案与技术流程,强调专项规划与“三区三线”、空间布局总图的关系,并以福建省为例,设计了基础设施与公共服务设施单幅总图的编制技术流程,以期为其他地区空间规划的编制提供借鉴意义。  相似文献   
93.
Land cover changes associated with urbanization have negative effects on downstream ecosystems. Contemporary urban development attempts to mitigate these effects by designing stormwater infrastructure to mimic predevelopment hydrology, but their performance is highly variable. This study used in situ monitoring of recently built neighbourhoods to evaluate the catchment‐scale effectiveness of landscape decentralized stormwater control measures (SCMs) in the form of street connected vegetated swales for reducing runoff volumes and flow rates relative to curb‐and‐gutter infrastructure. Effectiveness of the SCMs was quantified by monitoring runoff for 8 months at the outlets of 4 suburban catchments (0.76–5.25 ha) in Maryland, USA. Three “grey” catchments installed curb‐and‐gutter stormwater conveyances, whereas the fourth “green” catchment built parcel‐level vegetated swales. The catchment with decentralized SCMs reduced runoff, runoff ratio, and peak runoff compared with the grey infrastructure catchments. In addition, the green catchment delayed runoff, resulting in longer precipitation–runoff lag times. Runoff ratios across the monitoring period were 0.13 at the green catchment and 0.37, 0.35, and 0.18 at the 3 grey catchments. Runoff only commenced after 6 mm of precipitation at the decentralized SCM catchment, whereas runoff occurred even during the smallest events at the grey catchments. However, as precipitation magnitudes reached 20 mm, the green catchment runoff characteristics were similar to those at the grey catchments, which made up 37% of the total precipitation in only 10 of 72 events. Therefore, volume‐based reduction goals for stormwater using decentralized SCMs such as vegetated swales require additional redundant SCMs in a treatment train as source control and/or end‐of‐pipe detention to capture a larger fraction of runoff and more effectively mimic predevelopment hydrology for the relatively rare but larger precipitation events.  相似文献   
94.
交通系统是生命线工程重要的组成部分,交通系统的破坏对震后的抗震救灾以及社会功能的恢复影响重大。伽师M S6.4地震造成交通系统中桥梁构件破坏、路面开裂及路基受损等多种形式的震害,影响正常使用,造成了比较严重的经济损失。文中通过现场调查及资料收集,总结了伽师M S6.4地震中交通系统的震害现象,简要分析了交通系统的震害特点及原因,为今后交通系统抗震设防、减轻地震灾害以及抗震救灾工作提供依据。  相似文献   
95.
GeoStar is the registered trademark of GIS software made by WTUSM in China.By means of the GeoStar,multi-scale images,DEMs,graphics and attributes integrated in very large seamless databases can be created,and the multi-dimensional dynamic visualization and information extraction are also available.This paper describes the fundamental characteristics of such huge integrated databases,for instance,the data models,database structures and the spatial index strategies.At last,the typical applications of GeoStar for a few pilot projects like the Shanghai CyberCity and the Guangdong provincial spatial data infrastructure (SDI) are illustrated and several concluding remarks are stressed.  相似文献   
96.
Doris Schmied 《GeoJournal》2000,50(2-3):91-96
After the fall of the Berlin Wall in November 1989, East Germany experienced a demographic shock as the ensuing insecurity and disorientation of the population was mirrored in their demographic behaviour. The situation is examined with respect to marriage, fertility and mortality. There are now signs of recovery but most people in the New Länder are still traumatised by events: nuptiality and fertility are still extremely low, while mortality is rapidly moving towards West German levels. Future demographic development will very much depend on socio-economic development and the provision of both hard and soft infrastructure conducive to stable partnerships and families since the current 'framework' has proved to be particularly unfriendly to women and children.  相似文献   
97.
Using water budget data from published literature, we demonstrate how hydrologic processes govern the function of various stormwater infrastructure technologies. Hydrologic observations are displayed on a Water Budget Triangle, a ternary plot tool developed to visualize simplified water budgets, enabling side‐by‐side comparison of green and grey approaches to stormwater management. The tool indicates ranges of hydrologic function for green roofs, constructed wetlands, cisterns, bioretention, and other stormwater control management structures. Water budgets are plotted for several example systems to provide insight on structural and environmental design factors, and seasonal variation in hydrologic processes of stormwater management systems. Previously published water budgets and models are used to suggest appropriate operational standards for several green and grey stormwater control structures and compare between conventional and low‐impact development approaches. We compare models, characterize and quantify water budgets and expected ranges for green and grey infrastructure systems, and demonstrate how the Water Budget Triangle tool may help users to develop a data‐driven approach for understanding design and retrofit of green stormwater infrastructure.  相似文献   
98.
Municipalities and agencies use green infrastructure to combat pollution and hydrological impacts (e.g., flooding) related to excess stormwater. Bioretention cells are one type of infiltration green infrastructure intervention that infiltrate and redistribute otherwise uncontrolled stormwater volume. However, the effects of these installations on the rest of the local water cycle is understudied; in particular, impacts on stormwater return flows and groundwater levels are not fully understood. In this study, full water cycle monitoring data were used to construct and calibrate a two‐dimensional Richards equation model (HYDRUS‐2D/3D) detailing hydrological implications of an unlined bioretention cell (Cleveland, Ohio) that accepts direct runoff from surrounding impervious surfaces. Using both preinstallation and postinstallation data, the model was used to (a) establish a mass balance to determine reduction in stormwater return flow, (b) evaluate green infrastructure effects on subsurface water dynamics, and (c) determine model sensitivity to measured soil properties. Comparisons of modelled versus observed data indicated that the model captured many hydrological aspects of the bioretention cell, including subsurface storage and transient groundwater mounding. Model outputs suggested that the bioretention cell reduced stormwater return flows into the local sewer collection system, though the extent of this benefit was attenuated during high inflow events that may have exhausted detention capacity. The model also demonstrated how, prior to bioretention cell installation, surface and subsurface hydrology were largely decoupled, whereas after installation, exfiltration from the bioretention cell activated a new groundwater dynamic. Still, the extent of groundwater mounding from the cell was limited in spatial extent and did not threaten other subsurface infrastructure. Finally, the sensitivity analysis demonstrated that the overall hydrological response was regulated by the hydraulics of the bioretention cell fill material, which controlled water entry into the system, and by the water retention parameters of the native soil, which controlled connectivity between the surface and groundwater.  相似文献   
99.
Green roofs are a form of green infrastructure aimed at retaining or slowing the movement of precipitation as stormwater runoff to sewer systems. To determine total runoff versus retention from green roofs, researchers and practitioners alike employ hydrologic models that are calibrated to one or more observed events. However, questions still remain regarding how event size may impact parameter sensitivity, how best to constrain initial soil moisture (ISM), and whether limited observations (i.e., a single event) can be used within a calibration-validation framework. We explored these questions by applying the storm water management model to simulate a large green roof located in Syracuse, NY. We found that model performance was very high (e.g., Nash Sutcliffe efficiency index > 0.8 and Kling-Gupta efficiency index > 0.8) for many events. We initially compared model performance across two parameterizations of ISM. For some events, we found similar performance when ISM was varied versus set to zero; for others, varying ISM yielded higher performance as well as greater water balance closure. Within a calibration-validation framework, we found that calibrating to larger events tended to produce moderate to high performance for other non-calibration events. However, very small storms were notoriously difficult to simulate, regardless of calibration event size, as these events are likely fully retained on the roof. Using regional sensitivity analysis, we confirmed that only a subset of model parameters was sensitive across 16 events. Interestingly, many parameters were sensitive regardless of event size, though some parameters were more sensitive when simulating smaller events. This emphasizes that storm size likely influences parameter sensitivity. Overall, we show that while calibrating to a single event can achieve high performance, exploring simulations across multiple events can yield important insight regarding the hydrologic performance of green roofs that can be used to guide the gathering of in situ properties and observations for refining model frameworks.  相似文献   
100.
近几十年来,高强度人类活动导致海湾生态环境恶化、生态系统失衡,已严重威胁到海岸带地区经济和社会的可持续发展。营养物质输入是人类活动影响海湾生态环境的关键因素。海湾营养物质来源多样,形态转化多变,生态过程及其效应复杂,营养物质在海湾的迁移转化规律及其对海湾生态环境的影响过程与机理,是国际海洋生态环境研究的前沿。目前,国际海湾生态环境研究主要呈现出如下发展趋势:1从环境质量、生物群落结构等现象研究转向环境变化机理、生态系统结构与功能的响应机制研究;2从对海湾生态环境某个环节的研究转向对海湾生态系统的全过程、系统性研究;3从单纯研究海湾水体转向陆海相互作用的完整性研究,并从管理上提出海陆统筹的要求;4从对海湾生态环境某个时段变化的研究转向生态系统长期连续变化规律的研究。未来应重点开展的研究包括:营养物质在半封闭性海湾长期滞留聚集条件下的迁移转化规律;营养物质变化对海湾生态系统结构与功能的影响过程与机制;基于生态系统水平的海湾综合管理理论体系。  相似文献   
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