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1.
Concurrent water data were collected by the U.S. Geological Survey, the U.S. Corps of Army Engineers, and the Maryland Department of Health and Mental Hygiene at the same site in order to describe present conditions and predict future environmental change in the Georges Creek basin in western Maryland. Evaluation of the data sets reveals measurement errors and weaknesses in sample design so that published complications contain significant errors. Unless these errors can be identified, policy based on such information may have unfortunate results.  相似文献   

2.
菲尔德斯形变监测网质量分析   总被引:1,自引:0,他引:1       下载免费PDF全文
从数理统计角度出发,对西南极菲尔德斯形变监测网进行综合质量评估。文中主要讨论了形变监测网粗差检验,形变监测网的可靠性及可监测性。同时结合菲尔德斯形变监测网实测数据进行分析。本文认为该形变监测网有利于监测菲尔德斯海峡断层的剪切运动。  相似文献   

3.
为了研究南极现代地壳运动,中国在西南极菲尔德斯海峡地区布设了形变监测网,并用DI-20测距仪和GPS定位仪对该网进行了监测。同时,中国也参加了SCAR组织的全南极GPS联测。本文讨论了将形变参数纳入误差方程的水平形变数据处理方法,并对刚体平移、旋转、均匀应变几种典型形变模型在测边网平差中的运用进行了讨论。通过对经典自由网与秩亏自由网的基准分析,提出对形变参数以及其它附加参数和点位参数分别给定参考基准的方法。相应于上述方法,编制了一系列数据处理程序并将之应用于对西南极菲尔德斯海峡形变监测网的数据分析。本文还利用监测网应变分析原理,对GPS监测数据进行了讨论和分析,结果表明,菲尔德斯断裂地区存在微小的断裂剪切运动,但位移量不大。  相似文献   

4.
综述国内外数篇论文,从强对流天气监测、预报预警、模式同化3个方面总结分析了近年来地面稠密观测资料的应用与优劣之处。综述表明:地面加密自动站、风廓线雷达、地基GPS、雨滴谱仪等多种观测仪器组成的地面稠密观测网具有时间尺度密集、覆盖面积广泛、能捕捉较多细微变化的优势,通过该观测网所得数据总结出的一系列指示性指标在强对流监测预警中具有重要的指示意义。但因中国地形天气情况复杂多变、数据缺失、仪器造价昂贵等问题,导致该观测网所得指示性指标不能适用于中国全境,应根据该观测网数据分析总结适应本地的预报指标。  相似文献   

5.
Timber removal on publicand private land surrounding Redwood National Park exacerbates naturally high rates of erosion that are common to this region and alters hydrologic processes within the park boundaries. These alterations of the natural environment complicate the efforts of the National Park Service to preserve a remnant of the once extensive coastal redwood ecosystem in the park. A watershed model for Redwood Creek calibrated to pre-logging conditions is employed to define and quantify changes in the hydrologic response of the basin during the years when timber harvesting reduced significantly the acreage of redwoods. Analysis of modeled and observed runoff indicates that timber removal is related to increased runoff during wet months and wet years, but runoff is reduced during dry months and dry years. These alterations in the hydrologic system occur at the least beneficial time because they augment high flows, whereas low flows are depleted. Such changes in runoff contribute to magnified erosion and deposition problems and increased stress for the flora and fauna that reside in and along Redwood Creek. [Key words: Redwood National Park, hydrology, watershed model, timber harvesting.]  相似文献   

6.
采用美国Davis公司成熟电子自动气象站产品采集气象数据,通过移动无线GPRS方式,TC-PIP链接,进行数据传输,应用VB、VC和C语言混合编程,完成数据的收集、处理及管理,采用微软SQL数据库软件建立中心站数据库,实现数据的存储、查询、管理等功能,采用LED大屏幕显示系统实现气象要素、天气预报、气象预警等信息的接收、处理和显示。系统经过一年的实际应用,结果表明:系统运行稳定,各项技术指标基本符合设计要求,能够满足气象研究、气象服务工作需要。系统建设集数据采集、接收处理、信息发布、综合显示为一体,具有良好的推广应用前景。  相似文献   

7.
陈春明 《极地研究》1997,9(3):67-71
本文对西南极菲尔德斯形变网GPS监测数据的误差特性进行分析,利用数理统计原理检验了数据中的系统误差,提出了削弱这类系统误差的方法。该方法有3个特点:1.以监测网中两个稳定点为基准;2.对监测网数据进行尺度因子改正与坐标变换迭代计算;3.归算后监测网点位结构不变。经改化处理后的数据,基本上消除了系统误差的影响。  相似文献   

8.
本文报道了 1 990年初南极长城站生活污水处理前和处理后 ,污水排海管道口水样粪大肠菌群和余氯含量的测定结果。结果表明 :在污水处理前 ,粪大肠菌群的数量较高 ,达 2 4 0 0 0 /1 0 0 0 ml,经处理后 ,菌量急剧地降低 ,低于有关水质规定的标准 ;菌量的降低与污水处理的加氯量有关 ,加氯越多 ,菌量下降也越多。余氯浓度过高 ,可能对近海生态造成影响 ,因此在对污水进行有效处理时 ,要尽量注意控制加氯量  相似文献   

9.
泥石流监测预警站利用的是泥石流预警报系统,以便对泥石流进行监测后,作出泥石流预警报。泥石流预警报系统由三个子系统组成,这就是:1.暴雨类泥石流预报子系统;2.泥石流地声报警子系统;3.泥石流规模报警子系统。三个子系统分别用在泥石流监测预警站所属的雨量、地声、泥位三类泥石流监测点上。泥石流预警报系统由中国科学院东川泥石流观测研究站在蒋家沟研制而成,1985年底通过鉴定,获1986年度中国科学院科学技术进步三等奖。  相似文献   

10.
张帆  王利 《中国沙漠》1998,18(2):175-177
以河北省蔚县水土流失遥感动态监测为例,扼要介绍和探讨遥感信息解译及如何应用GIS空间地理数据管理和空间分析功能,完成水土流失因子的分析、计算、成果输出和治理成效的评价。  相似文献   

11.
ABSTRACT. The article identifies important themes and future research directions for analyzing water and conflict dynamics at the subnational scale in the Indus Basin. A historical overview of water development in the Indus Basin suggests that the water‐security nexus was always a salient theme in the minds of water developers, even in the nineteenth century. Conflicts over contemporary large‐scale water‐development projects in the Indian and Pakistani parts of the Indus Basin are reviewed. Engineers' single‐minded focus on megaprojects, to the neglect of the wider set of values that societies attach to water resources in the eastern and western Indus Basin are largely to blame for continuing low‐grade conflict in the basin. A review of local‐level conflicts over water supply and sanitation in Karachi and the distribution of irrigation water in Pakistani Punjab illustrates the critical role of governance and differential social power relations in accentuating conflict. The article argues against neo‐Malthusian assumptions about the inevitability of conflict over water because of its future absolute scarcity. Instead, the article seeks to demonstrate that, despite evidence suggesting that international armed conflict over water does not exist, the potential for political instability over domestic water distribution and development issues is real. The question of whether conflict at the subnational scale will culminate in violence will depend on how water‐resources institutions in the basin behave.  相似文献   

12.
13.
In 1977, I published a set of coarse-resolution dot maps that showed the general distributions of soil orders in the 48 states. Through a sequence of copies made by various people, one of those maps eventually appeared in a planning document as a shaded-area map with the title “Principal Peatlands of the United States.” Along the way a saline desert muck of conjectural extent and location was “transformed” into a documented energy resource for the nation. The history of this map offers a clear lesson for mapmakers: we have a three-fold duty, to the data, to the map reader, and to any third party who might be affected by a foreseeable misinterpretation of our maps.  相似文献   

14.
1998年 1 2月 1 1日至 1 999年 1月 1 3日在中山站近岸海域进行了一次较为全面的生态环境监测 ,监测内容包括∶ p H、T、盐度 (电导率 )、浊度、DO、COD、营养盐 (NO3 - N、NO2 - N、NH4 -N和 PO4 - P)和叶绿素 ,部分监测站位海水样品分层采集 ;其间还进行两次中山站区排污口生活污水连续 2 4小时监测。结果表明 ,冰缝间以及海冰底层下 1 m内的海水为各种环境理化因子的急剧变化层 ,大于冰底 1 m深的海水中的各要素变化梯度趋于平稳 ,营养盐垂直分布具有一定规律。p H和 DO为一类海水水质 ,无机氮属一、二类水质 ,无机磷属超三类水质 ,表层海水中叶绿素 a的平均值为 0 .6 71 mg/m3。中山站排放的生活污水中 COD、p H和悬浮物均符合我国的废污水排放标准 ,仅无机磷超一级排放标准。文中还探讨了在中山站近岸海域开展生态环境监测的监测方法  相似文献   

15.
山新疆为例论述了我国西北干旱区水土资源开发中所面临的环境及存在的突出问题,并在此基础上,提出了提高水土综合开发的基本途径和措施。  相似文献   

16.
Shuttle Imaging Radar-A data are employed to study the settlement, population and land use in the Baoding and Dezhou areas of the North China Plain. By applying nearest neighbor and quadrat analyses, the settlements are found to exhibit a mixed random-clustering pattern which defied the application of Christaller's central place theory. The distinctly visible boundaries from the images permitted accurate estimation of population in both areas. The linear land use forms, notably transportation lines, could also be accurately mapped; the Chinese practice of lake reclamation was also revealed. It is concluded that SIR-A data are useful for much human geography research.  相似文献   

17.
环境由自然环境和社会环境两个方面构成,自然环境是社会环境得以存在的基础和条件,社会环境是自然环境得以维系的机制和保证。反自然性、反人性是环境问题的实质,解决环境问题的目标是建设人与环境和谐的社会。将人类对自然资源的利用,限定在自然生态系统的承载力的范围内,同时使人类创造的文化有利于精神生活的丰富和提高,是建立人与环境和谐的社会的价值取向。以顺应自然规律的方式发展社会经济,创设实现人性需求的社会经济体制和社会运行机制,是建立人与环境和谐社会的途径。滇池流域地区存在的环境危机问题,应通过寻求建立人与环境和谐社会的途径得到解决。  相似文献   

18.
ComparativehydrologyisthesciencedealingwithdifferentiationofhydrologicalphenomenaandinherentlawsofhydrologicaltyPesonthebasisofgnograPhy.Tllecomparativestudiesonstrea1llrunoffofEuropeandCl1ina11avebeendoneinthispaPerinordertodeepentheunderstandingofregionaldifferentiationandthecauseofforll1ationofstrea111nlnoffinbothregio11s.ThecomparisonbetweenChineseandEuropeanstreamrunoffcanalsogiveafurtl1erknoWedgeonChinesestreamrtl1offcl1aracteristic5andtheirinfltlenceo11l1u111a11.I.ComparisonorNatura…  相似文献   

19.
ABSTRACT. After the Mexican Revolution of 1910 the Mexican federal government created a communal resource‐holding institution, the ejido, to redress long‐standing land‐tenure inequality. Between the 1930s and the late 1970s, the period of active redistribution of federalized and previously private resources, half of Mexico's entire area was transferred to the ejido sector. Local ejidos became the driving political and economic force at the municipio level for agrarian reform, redistributing local power and affirming the national stamp of the Partido Revolucionario Institucional, the dominant national party of the twentieth century. Although the 1992–1993 reforms to Article 27 of the Mexican Constitution prohibited any future expansion of communal lands and allowed privatization of communal resources, few widespread privatization schemes have taken hold in the vast majority of ejidos. In this article I provide examples of this new communal framework and its implications, with illustrations based on fieldwork in the states of Guanajuato and Sonora.  相似文献   

20.
This article examines the geography of pisco, a South American brandy claimed as the national drink of both Peru and Chile. The historic tension between these two nations—based notably on the nineteenth‐century War of the Pacific—is used as a backdrop to understanding the cultural and political contestation over the “ownership” of this beverage. Although both countries see exportation of pisco as a means of agricultural development, much of the animosity of this trade dispute is couched in cultural and historical terms. International trade policies, including the use of geographical indications (labels of geographical origin) for the purposes of trademarking, and the physical geography that makes pisco production possible are discussed.  相似文献   

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