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11.
Space shuttle launches produce localized hydrochloric acid deposition. The interaction of solid rocket motor exhaust and deluge
water released on the pad at the time of launch results in the formation of an exhaust cloud. The spatial pattern and extent
of deposition from the launch cloud are predicted by the rocket exhaust effluent diffusion (REED) model. The actual pattern
of deposition has been mapped by field surveys for each shuttle launch since 1981. In this paper we use a geographical information
system (GIS) to compare model predictions with ground patterns for 49 shuttle launches. We also compile cumulative maps of
deposition patterns needed to consider long-term impacts. The direction of launch cloud movement did not differ significantly
from model predictions. The REED model overpredicted both the area that received deposition and the maximum distance from
the launch pad that deposition occurred. Severe vegetation damage was restricted to near-field deposition areas within 1980
m north of each launch pad. Total area impacted from launches has been 87.0 ha around pad 39A and 52.9 ha around pad 39B.
Far-field deposition has caused leaf spotting from acid droplets or aluminum oxide over a wider and more variable area than
near-field. A total of 19,397 ha has received deposition, but 63.6% of this area has received deposition only one time and
92.2% not more than three times. GIS techniques provide means to test spatial models and compile information useful for assessing
cumulative impacts. 相似文献
12.
Jerome P. Harkins Ph.D. 《Environmental management》1977,1(1):9-13
The United States National Aeronautics and Space Administration is an important real and potential source of global environmental data. This paper describes some of its capabilities as they relate to the their R&D and their data centers. 相似文献
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15.
Peter D. Craig 《Ecological modelling》2010,221(20):2425-446
Both observational and modelling studies of the natural environment are characterised by their ‘grain’ and ‘extent’, the smallest and largest scales represented in time and space. These are imposed scales that should be chosen to ensure that the natural scales of the system are captured in the study. A simple cellular automata model of habitat represents only the presence or absence of vegetation, with global and local interactions described by four empirical parameters. Such a model can be formulated as a nonlinear Markov equation for the habitat probability. The equation produces inherent space and time scales that may be considered as transition scales or the scales for recovery from disturbance. However, if the resolution of the model is changed, the empirical parameters must be changed to preserve the properties of the system. Further, changes in the spatial resolution lead to different interpretations of the spatial structure. In particular, as the resolution is reduced, the apparent dominance of one habitat type over the other increases. The model provides an ability to compare both field and model investigations conducted at different resolutions in time and space. 相似文献
16.
利用温度反演和数值模拟的方法,对田湾核电站航天遥感测量和数值模拟结果作对比分析。结果显示:遥感监测和数值模拟结果在田湾核电站附近海域的海面温度场羽迹展布方向、不同季节大小潮型、潮态规律上都是相似的,只是在规模和数量上存在着一定差异,两者可以相互验证。 相似文献
17.
Here we synthesize key findings from a series of experiments to gain new insight on inter-plant competition between juvenile beech (Fagus sylvatica) and spruce (Picea abies) under the influence of increased O3 and CO2 concentrations. Competitiveness of plants was quantified and mechanistically interpreted as space-related resource investments and gains. Stable isotopes were addressed as temporal integrators of plant performance, such as photosynthesis and its relation to water use and nitrogen uptake. In the weaker competitor, beech, efficiency in space-related aboveground resource investment was decreased in competition with spruce and positively related to Δ13C, as well as stomatal conductance, but negatively related to δ18O. Likewise, our synthesis revealed that strong belowground competition for water in spruce was paralleled in this species by high N assimilation capacity. We suggest combining the time-integrative potential of stable isotopes with space-related investigations of competitiveness to accomplish mechanistic understanding of plant competition for resources. 相似文献
18.
陕西省近10年自然灾害的损失规律 总被引:1,自引:1,他引:0
本文主要根据自然灾害损失资料,对陕西近10a自然灾害损失时空规律、各灾种特点、损失结构进行了较详尽讨论,并进行了损失强度分区。 相似文献
19.
佛山市区酸雨时空分布特征及其成因分析 总被引:1,自引:0,他引:1
从致酸源、地理环境、工业状况、气候条件等因素分析了佛山市酸雨的成因,提出一些控制酸雨污染的建议。 相似文献
20.
沈阳市突发性环境污染事故应急地理信息系统 总被引:2,自引:0,他引:2
本文简要介绍了突发性环境污染事故地理信息系统的空间数据显示方法 ,并探讨了在 VB集成环境下 ,用Map Basic语言、SQL语言及 DAO来实现 Map Info电子地图上的空间数据处理技术。 相似文献