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971.
汶川地震前后的气象异常 总被引:1,自引:0,他引:1
有研究认为局地气象异常与地震之间存在着一定的相关性,那么震惊中外的汶川大地震前后有没有气象异常呢?应用NCEP再分析资料,以1988~2007年20年间局地气象要素的平均值和标准偏差为基准,通过构建气象异常指数对2008年5月12日汶川发生的大地震前后的日平均气温、日最高气温、日最低气温、日平均降水强度和日平均气压等5项气象要素指标的异常状况进行了分析,结果表明在地震前2个月的时间内有异常状况出现,并且其变化幅度和持续时间都比较长,在地震过后这些异常并未立即消失;从5项气象要素异常空间分异来看,汶川是气象异常的中心地带,表征了汶川地震与局地气象之间存在着一定的相关性。尽管气象异常是否是地震发生的必然前兆尚待进一步考证,但出现在汶川特大地震前后的气象异常再次给我们一个提示,即气象异常与地震的关系值得深入研究。 相似文献
972.
A mean sea surface model is used as the frame of reference in processing altimeter data. This article focuses on ascertaining the extent to which results depend on the different mean sea surface models used. In particular, we have analyzed the results from the OSU95MSS and the CLS_SHOMv.98.2 models in an area in the North Atlantic Ocean comprising the Canary and Azores Islands. Special attention has been paid to data editing and several criteria were proposed. The amount of detected data is quite small because we used a well corrected data set. However, it was enough to show important relations between the applied criteria and the kind of area. Therefore we analyzed the best way to apply these criteria according to the areas where the points have been found. Singular areas related to several factors have been detected by all the suggested criteria. In particular, rough sea bottom features, dynamic circulation, and amphidromic points of the tidal waves, among others. As a result of this analysis, we have not considered it appropriate to remove all the detected points. Two time-averaged and corrected mean sea surfaces were determined in the test area. 相似文献
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975.
Babatunde Anifowose Damian M. Lawler Dan van der Horst Lee Chapman 《Applied geography (Sevenoaks, England)》2012,32(2):636-651
In countries with insufficient investments in infrastructure and weak environmental governance, oil leakage from pipelines often occurs as a result of poor management and maintenance. Nigeria has its share of such incidents, but also, it suffers a large number of deliberate attacks (‘interdictions’) on oil pipelines. Often these attacks are accompanied by oil theft, carried out by well-equipped professionals and/or at a smaller scale by opportunistic local residents. The causes of these attacks, and the extent of subsequent damage to local communities and the environment, are obscured by a complex web of stakeholders, claims and actions. Any efforts to mitigate the negative impacts of interdiction on the environment and people require a better understanding of its spatiotemporal pattern of occurrence. This article presents a first quantitative and regional exploration of the problem of oil pipeline interdiction in Nigeria. It illustrates geographic patterns through choroplethic and bivariate GIS (Geographical Information Systems) map overlays. We examine interdiction statistics, identify spatiotemporal patterns and discuss correlations with socioeconomic factors. Findings include: (a) strong negative correlation between pipeline interdiction and poverty; and (b) statistically and non-statistically significant mean differences in the pattern of interdiction occurrence amongst the five geographic regions. Finally, we highlight the need for much better data collection and reporting for the mitigation of the negative socio-environmental impacts of interdiction incidences. 相似文献
976.
Daniel F. Merriam 《Environmental Geology》2009,56(8):1697-1706
The State of Kansas, as an energy-producing and agriculture-based state, faces problems in production of natural resources
and potential pollution from their production. To coordinate information on the exploration, production, and use of coal,
nuclear, petroleum, natural gas, hydro, wind, geothermal, coalbed methane, biofuel, solar, and other energy resources, the
Kansas Energy Council and the University of Kansas Energy Research Center were created. Water, surface and subsurface, is
the other important and maybe the most important natural resource in the welfare of the state. To ease the problems of contamination,
situations are monitored by regulatory agencies: the Kansas Corporation Commission, Kansas Department of Health and Environment,
and Division of Water Resources of the Kansas Department of Agriculture. The Kansas Geological Survey (KGS) at the University
of Kansas serves as the archive for energy and natural resource data and conducts research pertinent to the exploration and
exploitation of mineral resources, including energy and water. The Kansas Energy Research Center coordinates and supports
energy activities. The Kansas Water Office and the staff for the Kansas Water Authority are charged with water planning and
preparing reports on water problems and possible solutions. The cost of preserving the environment in a relatively pristine
state really is of no concern considering the possible consequences; living conditions should be preserved to assure future
generations, a suitable, sustainable, stable environment. With all the dire predictions for the future and energy-producing
and pollution problems, Kansas is a model state in this modern industrial age for protecting the environment and is a leader
in conservation.
相似文献
Daniel F. MerriamEmail: |
977.
The homogenization of climate data is of major importance because non-climatic factors make data unrepresentative of the actual
climate variation, and thus the conclusions of climatic and hydrological studies are potentially biased. A great deal of effort
has been made in the last two decades to develop procedures to identify and remove non-climatic inhomogeneities. This paper
reviews the characteristics of several widely used procedures and discusses the potential advantages of geostatistical techniques.
In a case study, the geostatistical simulation approach is applied to precipitation data from 66 monitoring stations located
in the southern region of Portugal (1980–2001). The results from this procedure are then compared with those from three well
established statistical tests: the Standard normal homogeneity test (SNHT) for a single break, the Buishand range test, and
the Pettit test. Promising results from the case study open new research perspectives on the homogenization of climate time
series. 相似文献
978.
基于离散小波变换(DWT)方法,提出了一种可用于计算三维数值模拟样本面密度的平滑算法.为检验方法的有效性,利用该算法研究了两组不同质量解析度的引力透镜数值模拟样本,样本采用了暗物质晕的等温椭球模型,使用蒙特卡罗方法生成.计算结果表明此算法能够在很高的精度上构建引力透镜模拟样本的面密度分布轮廓,由面密度计算出来的透镜的临界曲线和焦散曲线也能较好地和理论曲线吻合,结果是令人满意的.同时比较了三组不同的小波基的计算结果,包括Daub4,Daub6和B-spline 3th,给出了最优的选择.在不损失平滑效果的同时,此算法具有非常高的速度,非常适合于处理以后更高精度的N体数值模拟. 相似文献
979.
We explore the capability of a method of mapping the depth distribution of a hydrogen-rich layer in the top meter of Mars from the neutron currents measured by the Mars Odyssey Neutron Spectrometer. Assuming the soil can be modeled by two layers of known composition having different hydrogen contents, simulations allow an inversion of the neutron data into knowledge of depth and hydrogen content of the lower layer. The determination of these variables is sensitive to the hypothesis of chemical composition of the soil. We quantify this contribution to the uncertainty in the method first in terms of individual chemical elements and then in terms of macroscopic absorption cross sections. To minimize this source of error, an average composition was inferred from Mars Exploration Rover data. Possible compositions having a wide range of macroscopic absorption cross sections were used to evaluate the uncertainty associated with our calculations. We finally compare our results to ice table depth estimates predicted by two published theoretical models at locations where the composition is relatively well known. The fit is excellent in the southern high latitudes but questionable in the northern high latitudes. Possible explanations of these differences include the high geographical variations of the neutron currents relative to the spatial width of the response function of the instrument and the overly simple model we, of necessity, used for surface layering. 相似文献
980.
地理编码原理及其本地化解决方案 总被引:6,自引:0,他引:6
地理编码技术具有广阔的发展前景,使用它可以利用记录的属性数据直接定位出其地理坐标。完整阐述了地理编码的技术核心及实现方式,并对实现其本地化的关键技术-数据标准化提出了解决方案。在文章的最后阐述了相关的结论。 相似文献