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261.
传统水质监测方法耗时且费力,而基于高光谱的水质监测技术可实现对水质的快速、直观、原位监测。以扬州古运河三湾段为研究区域,基于无人机高光谱成像仪与水质走航监测船相配合,采用空地协同模式和偏最小二乘回归算法对总磷(TP)、总氮(TN)、氨氮(NH3-N)、高锰酸盐指数(IMn)4个水质参数进行定量反演研究。结果表明:该反演模型的决定系数(R2)为91%~97%;拟合效果依次为NH3-N>IMn>TN>TP;各指标反演误差绝对值为0.2%~4%。该方法具有较好的反演效果,可快速、准确地获取城市河道水质分布情况,适用于城市水环境监测。  相似文献   
262.
D. Fleury 《Safety Science》1998,29(3):217-228
Road planning is based on technical rules, know-how acquired from experience and professional expertise. A more ergonomics approach to road planning and safety analyses the psychological procedures used by the drivers. Every intervention on road network has an influence on safety. Increasing the coherency of all the interventions in the same area is the only possible way of producing areas with a better level of security. This paper deals with safety procedures, diagnostics and tools which can be used at different levels of intervention.  相似文献   
263.
Extensive green areas generate a recognizable green identity of Ljubljana. Due to the challenges of climate change and urbanization the city's spatial policy highlights revitalization of degraded urban areas, preserving the quality and scope of the existing green network and the protection of multifunctional natural areas surrounding the city. Article describes the project of Rakova Jelša Park as a good example of these policies. With an NGO initiative a former degraded area with illegal dumping and non-indigenous vegetation was transformed into recreational park with increased biocultural diversity. Important lesson of the project is that opening up space for public use not only prevents degradation, but also improves the quality of urban ecosystems. One of the challenges for the city's future sustainable ecosystem development will be a more active cooperation with its citizens in the green infrastructure policy and later also a partial transfer of responsibility for green areas to them.  相似文献   
264.
Currently, most tools, guidelines and benchmarks for urban adaptation raise awareness on climate change impacts, assess the city’s vulnerability and/or address the need for adaptation on a policy-level. However, tools that have the ability to implement adaptation solutions in the actual urban planning and design practice seem to be missing. We developed and tested the Adaptation Planning Support Toolbox (APST) to fill this gap. This toolbox supports local policymakers, planners, designers and practitioners in defining the program of demands, in setting adaptation targets, in selecting from more than 60 blue, green and grey adaptation measures and with informed co-creation of conceptual adaptation plans. The APST provides quantitative, evidence-based performance information on (cost)effectiveness of adaptation measures regarding climate resilience and co-benefits. The APST can be used design workshops, to feed dialogues among stakeholders on where and how which ecosystem-based adaptation measures can be applied. Applications of the AST in various settings and context in cities on different continents have illustrated the added value of the toolbox in bringing policy and practice together with help of science. With more and more cities worldwide that will make the step from policymaking to actual adaptation-inclusive urban (re)development practice we foresee a growing demand for such tools.  相似文献   
265.
The need for environmental and urban planning reached a critical point in the year 2007, when one-half of the world's population could be defined as living in cities. Urbanisation in India is also increasing at a fast rate. Urban chaos in India, emanating from the continuous ignorance of fragile ecosystems, calls for the reshaping of existing cities as ‘eco-cities’. The ‘eco-city’—a well-known concept in the western world—is new to the Indian context. While western connotations of eco-cities should not be discarded outright in the context of India, core concerns vary significantly for obvious reasons. Recognising two facts—firstly, eco-city development is altogether a fresh approach to human settlement development in India, and, secondly, the manifold increase in the vulnerability of cities—this paper discusses documented good practice, reinforcing evolution towards the eco-city vision. Lessons drawn from the examples cited are further deconstructed in the light of their contribution to urban risk reduction, which provides direction to appreciating the ‘disaster-resilient eco-community’ concept in Puri, a coastal city in India. Further, this paper attempts to unravel existing community-based practices in Puri, which are boon to the local environment and invariably reduce disaster risk. These seemingly modest neighbourhood initiatives symbolise immense societal wealth, which can be calibrated appropriately for reducing urban environmental risk as well. This paper also illustrates how a ‘disaster resilient eco-community’ approach is inevitable in the present and future contexts not only to preserve sustainable development gains but also to secure human well-being.  相似文献   
266.
ABSTRACT: The Applachicola River basin in northwest Florida covers an area of 3,100 square kilometers. Fifteen percent of the area is a dense bottomland hardwood forest which is periodically flooded. The annual leaf-litter fall from the flood-plain trees is a potential source of nutrients and detritus which eventually can flow into Apalachicola Bay. Transport of such material is dependent on the periodic inundation of the flood plain. The U.S. Geological Survey Apalachicola Rim Quality Assessment measured a total organic carbon flux of 2.1 × 105 metric tons during the one-year period from June 3, 1979, to June 2,1980. Fluxes of total nitrogen and phosphorus during the same year were 2.1 × lo4 and 1.7 × lo3 metric tons, respectively. Flood characteirstics, such as prior hydrologic conditions, extent, and timing, are important in determining the amount and forms of materials transported. The 1980 spring flood produced a fourfold discharge increase over the annual mean outflow of 800 cubic meters per second. Nutrient concentrations varied little with discharge, but the 86-day spring flood accounted for 53, 60, 48, and 56 percent of the annual flux of total organic carbon, particulate organic carbon, total nitrogen, and total phosphorus, respectively. In 1980, the flood peaks, rather than the rise or recession, accounted for maximum nutrient and detritus transport.  相似文献   
267.
城市地铁工程主要穿越城市商业区和居民聚居区 ,施工过程中的安全技术问题可能对地表环境产生严重影响 ,甚至诱发地面塌陷等灾害发生。笔者结合广州地铁二号线鹭江站的施工实践 ,研究了城市地铁工程的施工安全技术 ;探讨了地铁车站施工安全监测中的维护桩变形、土体变形、支撑结构的受力状况、地下水水位、地下管线沉降和位移监测的实施细则 ;突出了对折返线施工过程的监测 ;研究了施工安全保障技术方法体系 ;对施工现场安全技术、施工工艺安全技术进行了深入分析 ;明确了基坑开挖、洞室掘进、空中作业等不同类型的施工场地和人工挖孔、爆破、模筑混凝土、钢支撑安装、防水层施做等各种施工工艺的安全保障技术方法 ;建立了安全施工和安全管理措施方法体系。  相似文献   
268.
城市火灾扑救调度指挥过程的Petri网模型研究   总被引:3,自引:1,他引:2  
在经典Petri网理论的基础上,发展了一类有色非自主Petri网方法,用以建立城市火灾扑救调度指挥过程的仿真模型,并通过实例,对火警出动等级判断规则及按火警出动等级调派车辆规则进行了初步仿真研究。  相似文献   
269.
A review of the difficulties associated with the definition of coastal flood frequencies and magnitudes leads to a recognition that there is considerable doubt in many parts of the world as to the precise nature of this particular hazard. Similarly, a review of the sea-level measurements that have been used to indicate a response to global warming shows that there is uncertainty about the amount of other controlling influences. What is clear, however, are that past management decisions about human endeavours in the coastal zone (including flood defences, occupance of flood-prone lands, extraction of ground water and natural gas) have had an impact on relative land and sea levels and have done more to increase the risk of coastal flooding than can be assigned so far to global warming. In addition, these changes induced by human activity may render inappropriate calculations of coastal-flood frequencies based on historical records since the latter relate to a period of time when the controls on flooding may have been very different.  相似文献   
270.
张毅  沈荣芳 《灾害学》1997,12(4):24-28
对上海当前防灾救灾系统管理中存在的问题进行了分析,并且提出了相应的对策,对上海及其它城市的防灾救灾系统管理体系的改进与完善有一定的借鉴作用。  相似文献   
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