A dynamic network model for two‐phase immiscible flow     

Helge K. Dahle  Michael A. Celia 《Computational Geosciences》1999,3(1):1-22

A dynamic pore‐scale network model is formulated for two‐phase immiscible flow. Interfaces are tracked through the pore throats using a modified Poiseuille equation, whereas special displacement rules are used at the pore bodies. The model allows interfaces to move over several pore‐lengths within a time step. Initial computational results are presented for a drainage experiment to demonstrate some of the features of the model. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Mapping runoff generating areas using AGNPS-VSA model     

Kishor Panjabi  Pradeep Goel  Prasad Daggupati  Narayan Kumar Shrestha  Rituraj Shukla 《水文科学杂志》2020,65(13):2224-2232

ABSTRACT

In humid regions, surface runoff is often generated by saturation-excess runoff mechanisms from relatively small variable source areas (VSAs). However, the majority of the current hydrologic models are based on infiltration-excess mechanisms. In this study, the AGricultural Non-Point Source Pollution (AGNPS) model was used to integrate the VSA concept using topographic wetness index (TWI). Both the original and AGNPS-VSA models were evaluated for a small agricultural field in Ontario, Canada. The results indicate that the AGNPS-VSA model performed better than original model. The AGNPS-VSA model predicted that only the saturated portion of the field with higher TWI values produced runoff, whereas the original AGNPS model showed uniform hydrologic response from the entire field. The results of this study are important for accurately mapping the locations of VSAs. This new model could be a powerful tool in identifying critical source areas for applying targeted best management practices to minimize pollutant loads to receiving waters.  相似文献   

利用核磁共振技术对丘陵油田低渗储层可动油的研究   总被引：1，自引：0，他引：1  

刘曰强  朱晴  梁文发  阳兴华 《新疆地质》2006,24(1):52-54

为了定量评价储层可动油饱和度及渗流能力,应用核磁共振技术对丘陵油田40块岩心的可动油饱和度进行了定量测试.研究表明,丘陵油田低渗透储层可动油饱和度值的分布范围是4.8%~56.7%,平均值为33.4%.可动油饱和度高低与岩心孔隙度、渗透率及驱油效率呈正相关关系.各类储层可动油饱和度差异较大,储层沉积微相及物性决定了可动油饱和度和渗流能力的大小.  相似文献   

天然气水合物资源量估算方法及应用   总被引：2，自引：0，他引：2  

梁金强吴能友  杨木壮王明君　沙志彬 《地质通报》2006,25(9):1205-1210

近年大量的勘探与研究成果表明,中国南海海域具有良好的水合物资源前景.根据所掌握的勘探资料,尝试利用"概率统计法"对南海海域水合物资源前景进行了初步预测,在50%概率的条件下,南海海域的水合物资源量约为649.68×1011m3,与众多学者对全球天然气水合物资源量的估算相似.由于目前勘探程度较低和很多评价参数不能准确给定,因此对南海海域天然气水合物资源量的估算是初步的.该项研究旨在探索天然气水合物资源量的评估方法,随着勘探、研究程度的深入和评价资料的增多,水合物资源量的评价精度将会得到进一步的提高.  相似文献   

天然气水合物资源量估算方法及应用     

梁金强  吴能友  杨木壮  王明君  沙志彬 《地质通报》2006,(Z2)

近年大量的勘探与研究成果表明,中国南海海域具有良好的水合物资源前景。根据所掌握的勘探资料,尝试利用“概率统计法”对南海海域水合物资源前景进行了初步预测,在50%概率的条件下,南海海域的水合物资源量约为649.68×1011m3,与众多学者对全球天然气水合物资源量的估算相似。由于目前勘探程度较低和很多评价参数不能准确给定,因此对南海海域天然气水合物资源量的估算是初步的。该项研究旨在探索天然气水合物资源量的评估方法,随着勘探、研究程度的深入和评价资料的增多,水合物资源量的评价精度将会得到进一步的提高。  相似文献   

数字航空影像辐射信息精处理问题的探讨   总被引：1，自引：0，他引：1  

胡珂  钟裕标  刘丽华 《测绘与空间地理信息》2007,30(3):162-164

在分析数字航空影像辐射信息的基础上,针对数字航空像片的特点,探讨对数字航空影像进行匀光和匀色处理的技术方法,以及实现批量化处理的方法研究。  相似文献   

泥沙颗粒形状对非均匀沙起动条件的影响   总被引：1，自引：3，他引：1       下载免费PDF全文

李文萍  曹叔尤  刘兴年 《水科学进展》2007,18(3):342-345

根据非均匀沙颗粒的不均匀性,引入颗粒形状系数,通过分析泥沙颗粒形状系数和相对暴露度的影响,建立了等效粒径表达式;并通过泥沙起动受力分析,推导得到泥沙起动临界条件表达式.实测资料验证表明,计算值与实测值符合较好.  相似文献   

非均匀饱和广义湿位涡在暴雨分析与预测中的应用   总被引：7，自引：0，他引：7       下载免费PDF全文

周玉淑曹洁  王东海 《应用气象学报》2007,18(6):754-759

考虑实际大气非均匀饱和特性, 通过引入广义位温及广义湿位涡方程, 对华北暴雨和江淮梅雨锋暴雨的发生及落区进行了广义湿位涡异常的诊断分析, 表明暴雨形成时大气低层有广义湿位涡的异常出现。对广义湿位涡倾向的计算表明:它对暴雨的发生有一定指示作用, 因而可利用广义湿位涡的异常来识别暴雨的出现。  相似文献   

九江台震级偏差讨论与校正     

李道叶 《地震地磁观测与研究》1998,19(1):51-57

通过选取大量震例,分析了九江台所产生的震级偏差的可能原因,并提出了校正意见。  相似文献   

Delineating runoff processes and critical runoff source areas in a pasture hillslope of the Ozark Highlands     

M. D. Leh  I. Chaubey  J. Murdoch  J. V. Brahana  B. E. Haggard 《水文研究》2008,22(21):4190-4204

The identification of runoff contributing areas would provide the ideal focal points for water quality monitoring and Best Management Practice (BMP) implementation. The objective of this study was to use a field‐scale approach to delineate critical runoff source areas and to determine the runoff mechanisms in a pasture hillslope of the Ozark Highlands in the USA. Three adjacent hillslope plots located at the Savoy Experimental Watershed, north‐west Arkansas, were bermed to isolate runoff. Each plot was equipped with paired subsurface saturation and surface runoff sensors, shallow groundwater wells, H‐flumes and rain gauges to quantify runoff mechanisms and rainfall characteristics at continuous 5‐minute intervals. The spatial extent of runoff source areas was determined by incorporating sensor data into a geographic information‐based system and performing geostatistical computations (inverse distance weighting method). Results indicate that both infiltration excess runoff and saturation excess runoff mechanisms occur to varying extents (0–58% for infiltration excess and 0–26% for saturation excess) across the plots. Rainfall events that occurred 1–5 January 2005 are used to illustrate the spatial and temporal dynamics of the critical runoff source areas. The methodology presented can serve as a framework upon which critical runoff source areas can be identified and managed for water quality protection in other watersheds. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献