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排序方式: 共有339条查询结果,搜索用时 15 毫秒
231.
地质灾害问题的数据本构分析意义 总被引:2,自引:0,他引:2
本文结合上海市地面沉降和西安市地裂灾害问题,阐述了数据本构分析研究地质灾害问题的方法、步骤及意义。 相似文献
232.
背景噪声的测量和用于修正计算的问题分析及建议 总被引:3,自引:0,他引:3
在诸多有关噪声排放的标准中,背景噪声的定义在时间和空间位置方面的规定不够完备;相关的测量的规范方法也未对背景噪声的测量作了规定。实际操作上的“非同时性”给背景噪声的测量结果及用于修正均带来一些失准问题。文中分析了这些问题并提出了初步建议。 相似文献
233.
234.
水质污染总量的合理分配研究 总被引:1,自引:0,他引:1
水质污染总量削减分配的目的应该是实现各种资源的合理组合和高效利用.本文利用运筹学中的DEA方法,对企业的经济、管理及排污三个方面的素质进行了评价,进而形成企业素质综合指数.企业素质综合指数为我们确定总量控制对象和总量削减分配权重提供了必要的依据. 相似文献
235.
中国中东部地区的空气污染主要集中在京津冀、长三角、珠三角、东北地区及汾渭平原等区域,各区域的污染排放特征各异.本文应用基于CMAQ(The Community Multiscale Air Quality)模式的自适应"nudging"源反演方法,反演中国中东部地区2016年12月—2017年1月逐日NOx污染源,分析上述主要污染区的污染物排放强度空间分布特征,并与2016年MEIC(The Multi-resolution emission inventory for China)排放源进行比较,检验反演源的可靠性.结果表明,2016年冬季各个区域反演源NOx排放强度空间分布特征与2016年MEIC排放源基本一致.京津冀地区高强度排放区域形成沿山前区域东北-西南走向的NOx高强度排放带;长三角地区NOx高强度排放区域位于常州、苏州、上海和湖州等城市构成的城市群;珠三角地区NOx高强度排放区域位于以广州为中心的大范围城市群且排放强度呈现向四周逐渐降低的放射状分布;东北地区NOx高强度排放区域空间分布特征呈现以城市为中心且稀疏分布;汾渭平原排放区域呈现以城市为中心且向峡谷中间集中分布,排放区域轮廓与汾渭平原狭长的新月状相符. 相似文献
236.
在微机数据库管理系统中,运行一自编程序,进行试验数据的处理及试验报告的自动打印.使用该程序处理试验数据,不仅速度快,而且内容准确、规范,可大大地提高工作效率. 相似文献
237.
K. R. Reddy E. Flaig L. J. Scinto O. Diaz T. A. DeBusk 《Journal of the American Water Resources Association》1996,32(5):901-915
ABSTRACT: The ability to predict how streams and wetlands retain phosphorus (P) is critical to the management of watersheds that contribute nutrients to adjacent aquatic systems such as lakes. Field and laboratory experiments were conducted to determine the P assimilatory capacity of a stream (Otter Creek) in the Taylor Creek/Nubbin Slough Basin located north of Lake Okeechobee, Florida. Dominant soils in this basin are sandy Spodosols; landuse is primarily dairy farms and beef cattle pastures. Estimates of P assimilation show that sediments assimilate approximately 5 percent of the P load. Phosphorus assimilation rates in the stream were estimated using first-order relationships based on the total P concentration of the water column as a function of distance from the primary source. This method assumes minimal lateral inputs. Stream lengths required for one turnover in P assimilation were estimated to be in the range of 3–16 km. Laboratory studies using intact sediment cores indicated a P assimilation rate of 0.025 m day?1, and equilibrium P concentration of 0.16 ± 0.03 mg L?1 in the water column. Dissolved P concentration gradients in the sediments showed upward flux of P at water column P concentration of <0.16 mg L?1. Approximately 56–77 percent of the P assimilated in the above-ground vegetation during active growth was released or translocated within six months of senesence, suggesting short-term storage in above-ground vegetation. Bottom sediments and recalcitrant detrital plant tissue provide for long-term P assimilation in the creek. Although stream sediments have the potential to adsorb P, high flow rate and low contact period between water and sediment limits this process. 相似文献
238.
Johan G. Borchert 《Journal of Environmental Planning and Management》1983,26(2):68-74
This paper is based on a shopping study carried out by the Department of Geography, University of Utrecht, during 1983. It is concerned with retail planning research for larger regions and starts with a state of the art review of retail planning research in the Netherlands. The aim, in developing a new research strategy, was to reduce time and costs through using computer facilit es for both data handling and data collection. There is discussion of methodology and some outcomes to demonstrate the possibilities of the strategy. 相似文献
239.
Water quality monitoring conducted routinely over time at fixed sites has been a part of most water quality management efforts for many years. It has been assumed that such monitoring plays a major role in management. However, the lack of routine data analysis, and reporting of information derived from such analysis, points up the fact that the exact nature of the role of routine, fixed-station monitoring is poorly defined.There is a need to very clearly define this role in the design of such systems if routine monitoring is to efficiently and effectively meet the information expectations placed on it. Design of routine monitoring systems will therefore have to consider not only the where, what, and when of sampling, but also why. A framework for including the why of monitoring in the design process is proposed and experience with using the framework in New Zealand is discussed. 相似文献
240.
H. J. O’Neill R. A. Bingham Geoffrey D. Howell F. Colin Duerden Christopher Roberts 《Environmental management》1993,17(2):257-265
The ability to access information for use in decision making is a well-recognized need within the context of management sciences.
A similar need exists in order to make effective technical decisions pertaining to environmental resource management. Data
bases are the principle vehicle by which scientists, engineers, and resource managers store and access environmental information.
An integrated data-base mechanism is essential in order for federal agencies to manage programs such as enforcement of the
Canadian Environmental Protection Act (CEPA), state of the environment (SOE) reporting, and the environmental assessment and
review process (EARP). A data-base structure and data dissemination mechanism under current development within Environment
Canada, Conservation and Protection, Atlantic Region, is presented along with some of its operational benefits and constraints. 相似文献