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441.
Google Earth数据具备免费、直观、时效性强等特点,在道路工程设计中具有巨大的应用前景。本文以乌拉泊饮水源保护工程吐乌大高速公路段项目为例,提取项目区Google Earth最新卫星影像图和高程点数据,通过ArcGIS地统计学工具和Sufer克里金差值法进行项目区前期设计分析,获得最优路线和蓄水池的设置点,从而使前期项目设计节约劳动时间,降低劳动强度,提高工作效率。具有较强的实用性和可操作性。 相似文献
442.
Geomorphological features are essential parts of the environment and they represent an important conditioning factor for the
development and distribution of certain biological assemblages, as well as for a variety of human activities. However, environmental
geomorphology usually receives very limited or no attention at all in the process of environmental impact assessment (EIA).
Nevertheless, the site selection process for hazardous wastes in environmental impact studies for individual projects plays
an essential role. In order to determine the most suitable site in a region for municipal/hazardous wastes, several criteria
are used, including geology, groundwater condition, climate, and land use. The present work describes a methodology taking
advantage of environmental geomorphological features, and reducing these criteria in the site selection procedure in land
disposal of waste; in addition, a case study is presented to demonstrate the applicability of the proposed methodology. The
validity of the adopted site screening method is explained. This methodology comprises the use of a single geomorphological
map to locate suitable landfilling sites for hazardous waste, instead of using separate maps for geological features, climatic
features (temperature, precipitation, and speed and direction of the prevailing wind), slope and erosion. Furthermore, the
present study is compared with a previous study performed in the GAP region, where the use of land resources is crucial for
agricultural and water management purposes. The application of the described selection process and the verified method in
this region shows that the adopted method and detailed criteria are valid. 相似文献
443.
工程外包能很好地解决地方测绘部门人员少、基础测绘任务重的难题,本文从项目的招标、合同的签署、监理队伍的组建及全过程质量管理四方面对厦门市测绘工程外包的质量管理作了详细地阐述,并进行实例介绍,测绘工程实施过程监理的经验和做法对各地具有普遍的借鉴意义. 相似文献
444.
盾构法地铁隧道施工测量中,提高联系测量对隧道贯通起着决定的作用。本文对地铁施工测量贯通测量的误差来源进行了分配,对二井定向利用激光铅垂仪向上投点方案进行了精度分析,并和钢丝投点法的计算成果进行了比较,提出了激光铅垂仪向上投点法方案措施。 相似文献
445.
南水北调中线输水渠道中,针对同时操作闸门是否仍能维持闸前水位为常值,模拟计算了同时改变渠首流量、闸门开度和分水口流量时渠道中的非恒定过渡过程。结果显示,中线主干渠中所有闸门开度不论是同时增加还是减小,渠道中的水流均需要很长时间才能达到新的恒定状态,且闸门开度减小比闸门开度增大所需的过渡时间要长很多。非恒定过渡过程中,闸前水位的变化幅度都较大,各闸前水位最终都能回复到初始时刻的水位。由于非恒定过渡过程时间很长,实际运行条件下,要实现闸前常水位运行方式还需要对闸门的调度方式做更多的研究。 相似文献
446.
Stephen Bell 《Geographical review》2016,106(1):5-27
Beyond Germany, Leo Waibel (1888–1951) built a distinguished reputation for his work in Africa and the Americas. Today he is remembered especially in Brazil, where he boosted the development of geography as a research discipline in the years 1946–1950. During his tenure of the chair in geography at Bonn (1929–1937), Waibel's main research preoccupation became the role of the tropics in the world economy. In early 1937, he sought research leave to make an extended field trip to Brazil. Stripped on political grounds in the same year of his chair, Waibel came to the United States, where he became the only geographer to receive help from the Emergency Committee in Aid of Displaced Foreign Scholars. He would eventually serve as one of the very limited core staff on President Franklin Roosevelt's “M” Project on migration and settlement. This paper reconstructs the context of his work in the United States, clarifying especially the nature of his collaborations with Isaiah Bowman, widely regarded at the time as the leading geographer within the United States. Waibel's correspondence from the United States, and later from Brazil, reveals an international career marked by contradictions. 相似文献
447.
The South-to-North Water Diversion Project is a major national water conservancy project, but the effect of the water transfer depends on the utilization of water in the receiving areas. Water Diversion and Source Supplement Project is a specific utilization of the South-to-North Water Diversion Project in Zouping City. In order to analyze the effect of Water Diversion and Source Supplement Project on groundwater recharge in Daixi River Basin, the authors adopted the water balance method to calculate the groundwater recharge and total recharge of water diversion sources, based on the analysis of the groundwater recharge items in Daixi River Basin after carrying out this project. The total recharge is regarded as the amount of exploitable groundwater resources. The exploitable potential of groundwater resources in this area is evaluated by the comparison of the amount of exploitable groundwater resources and the actual amount of groundwater exploitation, and the effect of Water Diversion and Source Supplement Project on the over-exploitation of groundwater on the remission area was also demonstrated. Besides, the effective replenishment effect of this project on the groundwater in the study area was also revealed based on the annual groundwater and multi-year groundwater level dynamic monitoring data, which provides some reference for the rational development and utilization of groundwater resources in this region. 相似文献
448.
449.
北京市水资源与水量平衡研究 总被引:4,自引:1,他引:3
以降雨-径流-蒸散发平衡和水资源供需平衡模式为基础进行研究,得到以下结论:北京市2001~2009年系列的水资源量与多年平均系列相比,水资源产量减少了约40.1%,减少的原因既有气候因素,也有人类活动导致土地覆被变化的原因,其中气候因素占30.1%,下垫面变化导致产流减少的比重为69.9%;同时由于人口的增长,北京市人均水资源占有量从270 m3下降到114 m3.在北京市水平衡分析中,采用不同下垫面蒸散发模式,计算得到2001~2009年北京市蒸散发为494 mm,河川径流量为46 mm,入境水量为4.34 亿m3,出境水量为8.03 亿m3,超采地下水、水库净补给以及外流域引水量为6.19 亿m3.在不考虑河道内生态需水条件下,北京市的现状缺水量为4.73~5.86 亿m3.到2014年南水北调中线水到达北京以后,北京将可以在75%来水年份下保障10~15年的水资源的基本供需平衡。但是如果遭遇95%来水频率的特枯年份,北京仍然将会面临较为严重的水资源短缺问题。 相似文献
450.
STABILITY ANALYSIS OF COFFERDAM SLUMP AND ITS APPLICATION IN THE CLOSURE OPERATION OF THREE GORGES PROJECT 总被引:1,自引:0,他引:1
WANG Guangqian Professor Dept. of Hydraulic Engineering Tsinghua University Beijing China ZHOU Hougui Senior Engineer Gezhouba Group Corporation Yichang Hubei China LIU Lubo Master Student Dept. of Hydraulic Engineering Tsinghu 《国际泥沙研究》1997,(3)
I.INTRODUCTIONTheclosureoperationofThreeGorgesprojectisfamousintheworldforitslargedischarge,deepwater,lowvelocityinclosuregaps,largequantitiesandhighintensityforfillingmaterials.Thus,thedikeconstT'Uctionintheclosureoperationprocessisverydifficult.Sothedesign,researchandconstrUctiongroupshavepaidmuchenergyinthedesignprinciplesandoptimalitymeasuresofthegrandriverclosureoperation.FromtheexperimentsofhydraulicsanddikeslumpinthesecondperiodofclosureoperationattheResearchinstitUteofYangtZeR… 相似文献