“21·7”河南特大暴雨降水特征及极端性分析     

杨浩  周文  汪小康  李山山  王婧羽  王晓芳  胡泊 《气象》2022,48(5):571-579

利用国家气象信息中心提供的2 373个国家气象观测站（以下简称国家站）和区域气象观测站（以下简称区域站）小时降水量资料,从累计降水量、降水强度和时间演变等角度,分析了“21·7”（2021年7月17—22日）河南特大暴雨的极端性特征。结果表明:此次暴雨过程具有持续时间长、累计降水量大、突发性强、暴雨落区集中等特点。6天累计降水量平均达到219.05 mm·站^-1,有155个站超过600 mm。全省5.43万km²累计过程降水量大于250 mm,超过“75·8”过程（1975年8月）的3.45万km²。强降水主要出现在3个时段（18日15时至19日04时、19日09时至21日08时、21日09时至22日14时）,最大降水时段发生在19—21日,落区集中在太行山东南侧、伏牛山东北侧的豫中北地区。有1514个站出现至少1个时次的短时强降水(≥20 mm·h^-1),大值中心分别位于郑州、新乡和鹤壁等地,部分区域短时强降水贡献率超过70%。强降水中心在20日中午至21日夜间由河南中部向河南北部移动,强度由强变...  相似文献   

Automating adjoint wave-equation travel-time tomography using scientific workflow     

Xiaofeng Zhang  Po Chen  Satish Pullammanappallil 《地震科学（英文版）》2013,26(5):331-339

Recent advances in commodity high-performance computing technology have dramatically reduced the computational cost for solving the seismic wave equation in complex earth structure models. As a consequence, wave-equation-based seismic tomography techniques are being actively developed and gradually adopted in routine subsurface seismic imaging practices. Wave-equation travel-time tomography is a seismic tomography technique that inverts cross-correlation travel-time misfits using full-wave Fréchet kernels computed by solving the wave equation. This technique can be implemented very efficiently using the adjoint method, in which the misfits are back-propagated from the receivers (i.e., seismometers) to produce the adjoint wave-field and the interaction between the adjoint wave-field and the forward wave-field from the seismic source gives the gradient of the objective function. Once the gradient is available, a gradient-based optimization algorithm can then be adopted to produce an optimal earth structure model that minimizes the objective function. This methodology is conceptually straightforward, but its implementation in practical situations is highly complex, error-prone and computationally demanding. In this study, we demonstrate the feasibility of automating wave-equation travel-time tomography based on the adjoint method using Kepler, an open-source software package for designing, managing and executing scientific workflows. The workflow technology allows us to abstract away much of the complexity involved in the implementation in a manner that is both robust and scalable. Our automated adjoint wave-equation travel-time tomography package has been successfully applied on a real active-source seismic dataset.  相似文献   

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陈坡  孙付平  景晓鹏  周本才 《大地测量与地球动力学》2013,33(2):101-104

??????GNSS??????????????????????????α??????INS????GNSS??????????????????????????????????α??????????????????????????INS?????α??α????????????GNSS?????????????????????й?????????????????????????????????????GNSS??????????????????????????????????????????α?????????????????????  相似文献   

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陈华  袁鹏  龙洋洲  桂坡 《大地测量与地球动力学》2013,33(5):97-100

??????е????????????????????????￡????????????????????????????????????????GDAL??????????shp?????tif???????????????????????????????shp??tif??????????????????????????????????????????????????????÷??????????????á?  相似文献   

基于GIS的贵州省县域经济发展环境约束研究     

吴克华  车家骧  苏维词  李坡  廖凤林 《地理与地理信息科学》2008,24(2):57-60

借助反距离权重(IDW)空间插值及空间相关分析方法,对贵州省县域经济发展的空间分异特征及自然环境因素与县域经济发展的相关程度及限制作用进行分析。结果表明,贵州省县域经济发展水平在空间上存在较大差异,经济发展水平较高区域主要分布于贵阳、遵义、凯里、铜仁、都匀、兴义等政府所在地,其他县(市)人均GDP水平相对较低;经济发展水平与环境限制因子相关程度各异,其中六盘水、安顺及贵阳地区经济发展水平与环境限制因子关系密切,其他地区相关程度不明显。  相似文献   

地浸采铀矿山失效钻孔修复技术初探   总被引：1，自引：0，他引：1  

梁其深  秦昊  胡柏石  常京涛  杨立志  李坡 《铀矿地质》2017,(1):55-58

经过多年运行,地浸采铀矿山存在大量的失效钻孔,严重影响矿山产能。因过滤器堵塞而造成的失效钻孔占总报废钻孔的80%以上,为此采用切割原有过滤器,下入内置过滤器的方式进行修复,使失效钻孔恢复正常的抽、注液能力。修复结果表明,钻孔抽水量恢复到成孔时初始洗孔水量的95%以上。钻孔修复技术对降低地浸矿山的运营成本,提高矿山服务年限有积极的作用。  相似文献   

Characteristics of nonlinear internal waves observed in the northern South China Sea     

司广成  侯一筠  齐鹏  胡珀 《中国海洋湖沼学报》2010,28(5):1068-1072

The South China Sea (SCS) is one of the most active areas of internal waves. We undertook a program of physical oceanography in the northern South China Sea from June to July of 2009, and conducted a 1-day observation from 15:40 of June 24 to 16:40 of June 25 using a chain of instruments, including temperature sensors, pressure sensors and temperature-pressure meters at a site (117.5°E, 21°N) northeast of the Dongsha Islands. We measured fluctuating tidal and subtidal properties with the thermistor-chain and a ship-mounted Acoustic Doppler Current Profiler, and observed a large-amplitude nonlinear internal wave passing the site followed by a number of small ones. To further investigate this phenomenon, we collected the tidal constituents from the TPXO7.1 dataset to evaluate the tidal characteristics at and around the recording site, from which we knew that the amplitude of the nonlinear internal wave was about 120 m and the period about 20 min. The horizontal and vertical velocities induced by the soliton were approximately 2 m/s and 0.5 m/s, respectively. This soliton occurred 2–3 days after a spring tide.  相似文献   

Path transition of the western boundary current with a gap due to mesoscale eddies: a 1.5-layer, wind-driven experiment     

胡珀  侯一筠 《中国海洋湖沼学报》2010,28(2):364-370

Using a 1.5 layer nonlinear shallow-water reduced-gravity model, we executed numerical simulations to investigate the possibility of a western boundary current (WBC) path transition due to mesoscale eddies based on the background of the Kuroshio intrusion into the South China Sea (SCS) from the Luzon Strait. Because the WBC existed different current states with respect to different wind stress control parameters, we chose three steady WBC states (loop current, eddy shedding and leaping) as the background flow field and simulated the path transition of the WBC due to mesoscale eddies. Our simulations indicated that either an anticyclonic or cyclonic eddy can lead to path transition of the WBC with different modes. The simulation results also show that the mesoscale eddies can lead to path transition of the WBC from loop and eddy shedding state to leaping state because of the hysteresis effect. The leaping state is relatively stable compared with the mesoscale eddies. Moreover, an anticyclonic eddy is more effective in producing the WBC path transition for the path transition than a cyclonic eddy. Our results may help to explain some phenomena observed regarding the path transition of the Kuroshio due to the mesoscale eddies at the Luzon Strait.  相似文献   

水足迹与主成分分析法耦合的新疆水资源承载能力评价   总被引：2，自引：0，他引：2  

于钋  尚熳廷  姚梅  刘佩贵 《水文》2021,41(1):49-54,34

通过耦合水足迹理论与主成分分析方法,构建基于水足迹的新疆地区水资源承载力评价指标体系,分析研究区2010～2015年间水资源承载能力变化情况.结果表明:2010～2015年间新疆地区的水资源承载力呈先增大后减小的现象,2014年水资源承载力最差,供水压力最大.其中,研究区的承载力主要受水资源和社会因素以及进出口贸易中虚...  相似文献   

CALINE4模型扩散参数的城市建筑影响     

王莹  李成名  赵占杰  刘振东  王飞  刘坡 《测绘科学》2019,44(8):142-148

机动车尾气排放已经成为城市空气污染的主要原因之一,为了更好地了解机动车尾气扩散,在GIS领域为机动车尾气的治理提供帮助,该文基于CALINE4模型对城市道路中机动车尾气的扩散特性进行研究。通过ENVI-met软件模拟验证了建筑物对污染气体扩散的显著影响,在CALINE4模型的基础上综合考虑了道路两侧建筑物对机动车尾气的反射作用和阻塞作用,结合道路的街谷高宽比和阻塞比的概念,提出了一种在建筑物影响下CALINE4模型中扩散参数的修正方案,并定性分析了建筑物对模型中扩散参数的影响以及对机动车尾气扩散过程的影响。分析结果表明,建筑物对机动车尾气的扩散有明显的反射与阻塞作用,尤其在建筑密集的区域会产生二者的叠加,使该区域污染物浓度分析更加复杂。  相似文献