聚驱后二元复合泡沫驱不同气液比实验研究     

王海峰  李金珠  苏伟明  栗钢  吕正 《海洋地质译丛》2011,(3):64-67

通过对比聚驱后聚表二元复合泡沫驱四种不同气液比（1：2、1：1、2：1、3：1）的实验结果,优选出最优的气液比,并对泡沫驱油机理进行进一步的阐述,为现场矿场试验提供理论依据和参考。实验结果表明,在水驱和聚驱效果相似的条件下,聚驱后二元复合泡沫驱四种不同气液比方案采出程度的大小关系是3：1〈1：2〈2：1〈1：1,最优气液比为1：1。  相似文献   

Zooplankton dynamics from inundation to drying in a complex ephemeral floodplain-wetland     

Cassandra S. James  Martin C. Thoms  Gerry P. Quinn 《Aquatic Sciences - Research Across Boundaries》2008,70(3):259-271

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文13西块油藏岩石形变对采收率影响研究   总被引：1，自引：0，他引：1  

王锐  岳湘安  张风义  李丰辉  庞宏伟 《岩土力学》2008,29(6):1634-1638

低渗透、异常高压油藏弹性能量充足,储层欠压实,岩石易发生弹塑性变形。根据这些油藏特性,从达西定律的角度推导出了室内一维岩芯中最终采出程度与岩石物性变化的近似关系式,并引入渗透率变化因子分析采收率的影响因素,进而以文13西块油藏岩石为例,通过不同流体介质的渗透率压敏性试验,以及不同加压方式下渗透率变化试验,结合降压弹性开采试验和水驱物理模拟试验,以渗透率变化因子为基础,分析并讨论该类油藏的开采方法。结果表明：该类油藏在保持较慢降压速度、较高孔隙压力水平时,能够获得较高的油藏采收率。  相似文献   

江苏里下河地区洪涝灾害演变趋势与成灾机理分析   总被引：4，自引：0，他引：4  

叶正伟  许有鹏  徐金涛 《地理科学》2009,29(6):880-885

江苏里下河地区是相对封闭的水网地区,洪涝频繁。研究该地区洪涝演变趋势和成灾机理对区域防洪减灾具有重要意义。里下河地区洪涝演变趋势表现在洪涝类型的多样性,高水位日益频繁、高水位发生机率加大,致灾暴雨频率增大等方面。在自然成因方面,流域暴雨是成灾的主要原因,锅底洼的形态是洪涝发生的地貌大背景,水系的复杂格局也加剧了洪涝的程度和频度。在人类活动方面,不合理的圩垸垦殖导致湖荡萎缩,减弱了水体调蓄能力;闸坝建设引起河道淤积、排涝能力降低致使洪水位趋高;城镇化改变下垫面性质的水文效应也是洪涝频繁的主要因素。  相似文献   

1998长江大水期间对流云团活动特征研究   总被引：17，自引：0，他引：17  

师春香  江吉喜  方宗义 《气候与环境研究》2000,5(3):279-286

运用1998年6～8月逐日逐时GMS辐射亮度温度TBB资料,统计和分析了长江流域4个大暴雨时段中各自中尺度对流云团活动的一些主要特征,指出长江流域的这场罕见大水是在特定的环流形势下,由315个β中尺度和α中尺度对流云团直接造成的.与此同时,对7月21～22日发生在武汉及其以东黄冈地区的特大暴雨作了较详细的分析,发现它是由4次强对流云团形成发展及向西传播造成的,并指出低空强西南风急流与切变线及特定的地形条件是对流云团形成和发展的根本原因.  相似文献   

陆相盆地层序地层学研究中几个问题的探讨   总被引：17，自引：5，他引：12  

蔡希源  张明学 《现代地质》1999,13(3):287-290

将层序地层学理论应用于陆相盆地研究仍处于探索阶段。陆相盆地的层序界面、最大洪泛面和首次洪泛面的识别标志都有别于海相地层。依据层序地层学理论和对松辽盆地的探索性研究, 对陆相盆地提出了层序界面、最大洪泛面和首次洪泛面的识别标志。  相似文献   

Hillslopes in humid-tropical climates aren't always wet: Implications for hydrologic response and landslide initiation in Puerto Rico     

Matthew A. Thomas  Benjamin B. Mirus  Joel B. Smith 《水文研究》2020,34(22):4307-4318

The devastating impacts of the widespread flooding and landsliding in Puerto Rico following the September 2017 landfall of Hurricane Maria highlight the increasingly extreme atmospheric disturbances and enhanced hazard potential in mountainous humid-tropical climate zones. Long-standing conceptual models for hydrologically driven hazards in Puerto Rico posit that hillslope soils remain wet throughout the year, and therefore, that antecedent soil wetness imposes a negligible effect on hazard potential. Our post-Maria in situ hillslope hydrologic observations, however, indicate that while some slopes remain wet throughout the year, others exhibit appreciable seasonal and intra-storm subsurface drainage. Therefore, we evaluated the performance of hydro-meteorological (soil wetness and rainfall) versus intensity-duration (rainfall only) hillslope hydrologic response thresholds that identify the onset of positive pore-water pressure, a predisposing factor for widespread slope instability in this region. Our analyses also consider the role of soil-water storage and infiltration rates on runoff generation, which are relevant factors for flooding hazards. We found that the hydro-meteorological thresholds outperformed intensity-duration thresholds for a seasonally wet, coarse-grained soil, although they did not outperform intensity-duration thresholds for a perennially wet, fine-grained soil. These end-member soils types may also produce radically different stormflow responses, with subsurface flow being more common for the coarse-grained soils underlain by intrusive rocks versus infiltration excess and/or saturation excess for the fine-grained soils underlain by volcaniclastic rocks. We conclude that variability in soil-hydraulic properties, as opposed to climate zone, is the dominant factor that controls runoff generation mechanisms and modulates the relative importance of antecedent soil wetness for our hillslope hydrologic response thresholds.  相似文献   

Investigating potential future changes in surface water flooding hazard and impact     

Alison C. Rudd  Alison L. Kay  Steven C. Wells  Timothy Aldridge  Steven J. Cole  Elizabeth J. Kendon  Elizabeth J. Stewart 《水文研究》2020,34(1):139-149

Surface water flooding (SWF) is a recurrent hazard that affects lives and livelihoods. Climate change is projected to change the frequency of extreme rainfall events that can lead to SWF. Increasingly, data from Regional Climate Models (RCMs) are being used to investigate the potential water-related impacts of climate change; such assessments often focus on broad-scale fluvial flooding and the use of coarse resolution (>12 km) RCMs. However, high-resolution (<4 km) convection-permitting RCMs are now becoming available that allow impact assessments of more localised SWF to be made. At the same time, there has been an increasing demand for more robust and timely real-time forecast and alert information on SWF. In the UK, a real-time SWF Hazard Impact Model framework has been developed. The system uses 1-km gridded surface runoff estimates from a hydrological model to simulate the SWF hazard. These are linked to detailed inundation model outputs through an Impact Library to assess impacts on property, people, transport, and infrastructure for four severity levels. Here, a set of high-resolution (1.5 km and 12 km) RCM data has been used as input to a grid-based hydrological model over southern Britain to simulate Current (1996–2009) and Future (~2100s; RCP8.5) surface runoff. Counts of threshold-exceedance for surface runoff and precipitation (at 1-, 3- and 6-hr durations) are analysed. Results show that the percentage increases in surface runoff extremes, are less than those of precipitation extremes. The higher-resolution RCM simulates the largest percentage increases, which occur in winter, and the winter exceedance counts are greater than summer exceedance counts. For property impacts, the largest percentage increases are also in winter; however, it is the 12-km RCM output that leads to the largest percentage increase in impacts. The added-value of high-resolution climate model data for hydrological modelling is from capturing the more intense convective storms in surface runoff estimates.  相似文献   

淮河流域洪水极值非平稳性特征   总被引：1，自引：1，他引：0  

孙鹏  孙玉燕  张强  姚蕊  温庆志  王友贞  蒋尚明 《湖泊科学》2018,30(4):1123-1137

基于淮河流域9个水文站的月径流量数据,采用Pettitt非参数检验法、GAMLSS模型与洪水频率分析模型等方法,揭示了淮河中上游洪水频率的演变规律,分析基于平稳性和非平稳性条件下的洪水发生强度及洪涝灾害所带来的影响.研究发现:潢川、横排头和蚌埠站点未发生明显变异,其余6个站点发生均值或方差变异,变异时间主要集中在2000年左右.淮河流域的最优拟合分布函数是Weibull;班台、蒋家集和横排头站适宜于非平稳性模型,其余站点选择平稳性模型.各站点非平稳性条件下10年和20年一遇设计流量值与平稳性条件下皮尔逊Ⅲ型分布设计流量值相差不大,但30年一遇、50年一遇和100年一遇的设计流量相差逐渐变大.横排头站和蚌埠站洪水放大因子随着时间增加呈上升趋势且大于1,百年一遇重现期不足80年.各站点年最大洪峰流量与淮河流域、安徽省水灾面积通过了95%或99%的显著性检验.  相似文献   

Improving sustainability of urban drainage systems for climate change adaptation using best management practices: a case study of Tehran,Iran     

Negin Binesh  Amin Sarang  Wolfgang Rauch 《水文科学杂志》2019,64(4):381-404

Although the effectiveness of best management practices (BMPs) in reducing urban flooding is widely recognized, the improved sustainability achieved by implementing BMPs in upstream suburban areas, reducing downstream urban floods, is still debated. This study introduces a new definition of urban drainage system (UDS) sustainability, focusing on BMP usage to enhance system performance after adaptation to climate change. Three types of hydraulic reliability index (HRI) plus robustness and improvability indices were used to quantify the potential enhanced sustainability of the system in a changing climate, together with a climate change adaptability index (CCAI). The sustainability of UDS for the safe conveyance of storm-water runoff was investigated under different land-use scenarios: No BMP, BMP in urban areas, and BMP inside and upstream of urban areas, considering climate change impacts. Rainfall–runoff simulation alongside drainage network modelling was conducted using a storm-water management model (US EPA SWMM) to determine the inundation areas for both base-line and future climatic conditions. A new method for disaggregating daily rainfall to hourly, proposed to provide a finer resolution of input rainfall to SWMM, was applied to a semi-urbanized catchment whose upstream runoff from mountainous areas may contribute to the storm-water runoff in downstream urban parts. Our findings confirm an increase in the number of inundation points and reduction in sustainability indices of UDS due to climate change. The results present an increase in UDS reliability from 4% to 16% and improvements in other sustainability indicators using BMPs in upstream suburban areas compared to implementing them in urban areas.  相似文献