大型人工湖气候效应观测研究——以密云水库为例   总被引：2，自引：1，他引：1  

郑祚芳  任国玉  王耀庭  窦军霞 《地理科学》2017,37(12):1933-1941

应用近5 a自动气象站观测资料,分析了华北地区最大人工湖——密云水库的局地气候效应。结果表明：① 密云水库库区相比于附近平原地带具有气温偏低、湿度偏高、风速偏弱、降水量偏大等特点。水库对区域气候的影响范围约在10 km内,离水库越近的地方,受影响越大。② 密云水库的气候效应主要体现在夏半年,尤以气温和降水最为明显。③ 水库南、北两侧受到的局地环流的影响具有明显的差异,库区东西方向的年平均局地风速约为0.14 m/s,南北方向约为 0.10 m/s。下垫面属性的热力差异及特殊地形条件使得密云水库附近同时存在山谷风和湖陆风现象,其叠加效应是导致区域内不同位置间气象要素出现季节性及日变化差异的主要原因。  相似文献   

Microseismic Precursory Characteristics of Rock Burst Hazard in Mining Areas Near a Large Residual Coal Pillar: A Case Study from Xuzhuang Coal Mine,Xuzhou, China     

An-ye Cao  Lin-ming Dou  Chang-bin Wang  Xiao-xiao Yao  Jing-yuan Dong  Yu Gu 《Rock Mechanics and Rock Engineering》2016,49(11):4407-4422

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Assessment of vertical TEC mapping functions for space-based GNSS observations   总被引：1，自引：1，他引：0  

Jiahao Zhong  Jiuhou Lei  Xiankang Dou  Xinan Yue 《GPS Solutions》2016,20(3):353-362

The mapping function is commonly used to convert slant to vertical total electron content (TEC) based on the assumption that the ionospheric electrons concentrate in a layer. The height of the layer is called ionospheric effective height (IEH) or shell height. The mapping function and IEH are generally well understood for ground-based global navigation satellite system (GNSS) observations, but they are rarely studied for the low earth orbit (LEO) satellite-based TEC conversion. This study is to examine the applicability of three mapping functions for LEO-based GNSS observations. Two IEH calculating methods, namely the centroid method based on the definition of the centroid and the integral method based on one half of the total integral, are discussed. It is found that the IEHs increase linearly with the orbit altitudes ranging from 400 to 1400 km. Model simulations are used to compare the vertical TEC converted by these mapping functions and the vertical TEC directly calculated by the model. Our results illustrate that the F&K (Foelsche and Kirchengast) geometric mapping function together with the IEH from the centroid method is more suitable for the LEO-based TEC conversion, though the thin layer model along with the IEH of the integral method is more appropriate for the ground-based vertical TEC retrieval.  相似文献   

Parallel viewshed analysis on a PC cluster system using triple-based irregular partition scheme     

Xiao-Dong?Song  Guo-An?TangEmail author  Xue-Jun?Liu  Wan-Feng?Dou  Fa-Yuan?Li 《Earth Science Informatics》2016,9(4):511-523

Using digital elevation models (DEMs), viewshed analysis algorithms determine the visibility of each point on the terrain at a given location in space. As a data-parallel algorithm, real-time viewshed analysis from grid DEM poses a practical challenge to personal computer (PC) users, particularly when dealing with higher resolution and accuracy of large terrain data. Therefore, this paper presents a universal domain decomposition algorithm based on an equal-area strategy for the parallel viewshed analysis on a PC cluster system. The approach uses a scan-line filling method for data partitioning of the irregular bounding polygon of the terrain. The terrain data are divided into sectors of the same area that are connected by the viewpoint and the region vertices, ignoring the null value (or NODATA) points. Furthermore, each sector is assigned to one processor and is organized in the form of triples composed of location and elevation at one point. An index of triples is built to store all of the locations of terminal vertices row-by-row and thus the random access of any point is achieved by using the offsets in each row. Two commonly applied viewshed algorithms, namely, “reference plane” and “Xdraw” algorithms are employed to verify the performance. In addition, two experiments focus on evaluating the efficiency performance and comparing traditional implementation, respectively. Experimental results demonstrate a significant performance improvement compared with the sequential computing method. The memory usage gradually decreases as the number of processors increases. Based on the equal-area decomposition, partitions in terms of sectors can guarantee a suitable load balance. Additional benefits of the proposed solution also include high storage efficiency and program portability.  相似文献   

A web-based land surface remote sensing products validation system (LAPVAS): application to albedo product     

Xingwen Lin  Yong Tang  Mingguo Ma  Dongqin You  Baocheng Dou 《International Journal of Digital Earth》2018,11(3):308-328

Quantitative remote sensing product (QRSP) validation is a complex process to assess the accuracy and uncertainty independently using reference data with multiple land cover types and long-time series. A web-based system named as LAnd surface remote sensing Product VAlidation system (LAPVAS) is described in this paper, which is used to implement the QRSPs validation process automatically. The LAPAVS has two subsystems, the Validation Databases Subsystem and the Accuracy Evaluation Subsystem. Three functions have been implemented by the two subsystems for a comprehensive QRSP validation: (1) a standardized processing of reference data and storage of these data in validation databases; (2) a consistent and comprehensive validation procedure to assess the QRSPs’ accuracy and uncertainty; and (3) a visual process customization tool with which the users can register new validation data, host new reference data, and readjust the validation workflows for the QRSP accuracy assessment. In LAPVAS, more than 100 GB of reference data warehoused in validation databases for 13 types of QRSPs’ validation. One of the key QRSPs, land surface albedo, is selected as an example to illustrate the application of LAPVAS. It is demonstrated that the LAPVAS has a good performance in the land surface remote sensing product validation.  相似文献   

陆相页岩层系石油富集区带优选、甜点区段评价与关键技术应用     

杨智  唐振兴  李国会  贾希玉  吴颜雄  陈旋  黄东  江涛  方向  王岚  吴因业  吴松涛  付蕾  李嘉蕊  李奇艳  赵家宏  王天煦 《地质学报》2021,95(8):2257-2272

陆相页岩层系石油包括致密油和页岩油,是国内陆上"进(近)源找油"的主要对象,目前已进入战略突破期.以"十三五"国家油气重大专项课题联合攻关研究成果为基础,本文系统阐述了近5年我国陆相页岩层系石油聚集条件、富集区带、甜点区段、关键技术等方面的研究进展:①陆相湖盆主要发育陆源、内碎屑和混积岩-沉凝灰岩3种类型富液态烃页岩层系,提出有利储集相带、近源或源内、构造背景3个共性富集要素,评选出页岩层系石油富集区带33个,资源规模约110×108 t;②储层甜点评价是页岩层系石油甜点区段评价的核心内容,发现砂岩、混积岩-沉凝灰岩集中发育段是主要有利储层甜点段,形成以储层甜点为核心的测井甜点段评价、地震甜点区预测方法,预测优选出55个甜点区,资源规模约32×108 t;③以"甜点+水平井+密切割"为核心,集成配套地质评价、甜点预测、优快钻井、复杂缝网、效益开发等关键技术系列,支撑了 5个亿吨级页岩层系油区快速发展.页岩层系石油预计待识别甜点区面积约17000 km2,待探明资源约130×108 t,有望成为"十四五"乃至今后一个时期中国石油工业增储上产的重要现实领域.  相似文献   

Geothermal energy exploitation from depleted high-temperature gas reservoirs by recycling CO2:The superiority and existing problems     

Guodong Cui  Shaoran Ren  Bin Dou  Fulong Ning 《地学前缘(英文版)》2021,12(6):428-443

CO2 can be used as an alternative injectant to exploit geothermal energy from depleted high-temperature gas res-ervoirs due to its high mobility and unique thermal properties.However,there has been a lack of systematic anal-ysis on the heat mining mechanism and performance of CO2,as well as the problems that may occur during geothermal energy exploitation at specific gas reservoir conditions.In this paper,a base numerical simulation model of a typical depleted high-temperature gas reservoir was established to simulate the geothermal energy exploitation processes via recycling CO2 and water,with a view to investigate whether and/or at which condi-tions CO2 is more suitable than water for geothermal energy exploitation.The problems that may occur during the CO2-based geothermal energy exploitation were also analyzed along with proposed feasible solutions.The re-sults indicate that,for a depleted low-permeability gas reservoir with dimensions of 1000 m × 500 m × 50 m and temperature of 150℃using a single injection-production well group for 40 years of operation,the heat mining rate of C02 can be up to 3.8 MW at a circulation flow rate of 18 kg s-1 due to its high mobility along with the flow path in the gas reservoir,while the heat mining rate of water is only about 2 MW due to limitations on the injectivity and mobility.The reservoir physical property and injection-production scheme have some effects on the heat mining rate,but CO2 always has better performance than water at most reservoir and operation condi-tions,even under a high water saturation.The main problems for CO2 circulation are wellbore corrosion and salt precipitation that can occur when the reservoir has high water saturation and high salinity,in which serious salt precipitation can reduce formation permeability and result in a decline of CO2 heat mining rate(e.g.up to 24％reduction).It is proposed to apply a low-salinity water slug before CO2 injection to reduce the damage caused by salt precipitation.For high-permeability gas reservoirs with high water saturation and high salinity,the supe-riority of CO2 as a heat transmission fluid becomes obscure and water injection is recommended.  相似文献   

Catastrophic debris flows triggered by the 20 August 2019 rainfall,a decade since the Wenchuan earthquake,China     

Yang  Fan  Fan  Xuanmei  Siva Subramanian  Srikrishnan  Dou  Xiangyang  Xiong  Junlin  Xia  Bing  Yu  Zongyang  Xu  Qiang 《Landslides》2021,18(9):3197-3212

Landslides - Enhanced debris flow activity observed after the 2008 Wenchuan earthquake, Sichuan Province, SW China, is still intense more than a decade since the earthquake. A heavy rainstorm on 20...  相似文献   

闪电定位数据快速传输的通信应用     

窦以文  屈玉贵  宛霞  史君卿  燕东渭 《气象科技》2007,35(4):293-596

北京市气象局是国内首次使用SAFIR3000闪电定位系统的用户。闪电定位系统对数据的传输实时要求很高,而国内通信线路和国外通信线路有些差别,选择合理有效的传输方式对提高闪电定位系统的应用非常重要。闪电定位系统实时数据的传输方法有很多种。目前主要有专线接入传输方式、Internet和无线通信相结合的VPN接入传输方式、Internet转发传输方式,这些通信方法是实时采集气象数据非常有效的手段。北京市气象局的闪电定位系统采用的是Internet转发传输方式。  相似文献   

应用高分辨率质谱分析苏丹高酸值原油成因   总被引：3，自引：1，他引：2  

程顶胜  窦立荣  万仑坤  史权 《岩石学报》2010,26(4):1303-1312

苏丹Muglad和Melut盆地是苏丹乃至整个中、西非剪切带最富含油气的盆地,所发现的原油主要为中质油(重度为20°～34°API),其次为重质油(重度小于20°API),普遍高含沥青质、高含蜡、高酸值、低含硫。为了探讨高酸值原油的成因,选择了苏丹地区18个不同酸值的原油样品,尝试高分辨率质谱分析上述原油有机酸的组成。结果表明,高酸值原油的有机酸主要由环烷酸组成;环烷酸的平均相对分子质量随降解作用程度增加而增大,分子碳原子数分布范围变宽;环烷酸以一环、二环、三环环烷酸为主。生物降解作用是形成高酸值原油的主要原因。  相似文献