北京地区的闪电时空分布特征及不同强度雷暴的贡献

利用北京闪电定位网(BLNET,Beijing Lightning Network)和SAFIR3000(Surveillance et Alerte Foudre par Interometrie Radioelectrique)定位网7年共423次雷暴的闪电资料,并按照雷暴产生闪电多少,同时参考雷达回波和雷暴持续时间,将雷暴划分为弱雷暴(≤1000次)、强雷暴(>1000次且≤10000次)和超强雷暴(>10000次),分析了北京地区的闪电时空分布特征及不同强度等级雷暴对闪电分布的贡献。北京总闪电密度最大值约为15.4 flashes km-2a(^-1),平均值约为1.9 flashes km^-2a(^-1),大于8 flashes km^-2a(^-1)的闪电密度高值区基本分布在海拔高度200 m等高线以下的平原地带。不同强度雷暴对总雷暴闪电总量贡献不同,弱雷暴(超强雷暴)次数多(少),产生的闪电少(多),超强雷暴和强雷暴产生的闪电分别占总雷暴闪电的37%和56%。不同强度雷暴对总雷暴的闪电密度高值中心分布和闪电日变化特征影响显著,昌平区东部、顺义区中东部和北京主城区是总雷暴闪电密度大于12 flashes km-2a(-1)的三个主要高值区中心,前两个高值中心受强雷暴影响大,而主城区高值中心主要受超强雷暴影响。总雷暴晚上频繁的闪电活动主要受超强雷暴和强雷暴影响,这两类雷暴晚上闪电活动活跃,分别占各自总闪电的69%和65%,而弱雷暴闪电活动白天陡增很快,对总雷暴午后的闪电活动影响大。另外,不同下垫面条件闪电日变化差异大,山区最强的闪电活动出现在白天,午后闪电活动增强很快,主峰值出现在北京时间18:00,而平原最强的闪电活动发生在晚上,平原(山麓)的主峰值比山区推迟了约1.5小时(1小时)。     

大同市矿山地质环境风险评价

文章从矿业开发影响和地质环境脆弱性相互作用的角度出发,提出了矿山地质环境风险评价的定义及方法。将大同市作为评价对象,建立了矿业开发影响力和地质环境脆弱性评价指标体系,利用层次分析法进行指标权重分析,进而通过模糊综合评判数学模型进行计算和对比;最终将大同市划分为矿山地质环境高风险区、中风险区和低风险区。并根据评价分区结果,提出了风险防控建议。     

Fine description of structure and sedimentary microfacies of Li32 block of Lijin oilfield,Dongying depression,China

Considering that available data in Li32 block is limited, log phase method and core analysis were used to divide sedimentary facies and sequence, the former is principal, and two short-term cycles, five middle term cycles, and fifteen short-term cycles were divided. Combined seismic interpretation with fault point and fault rod, the instantaneous phase profile explained small fault more clearly and accurately. The sever faults were analyzed, and integrated structure was constructed. Lithofacies in cored wells were observed; the grain-size probability curves mainly are suspension and jumping transport; grain size is mainly for the siltstone and fine sandstone; the color of mud in the second segment of Shahejie formation (ES2) is mainly gray–green, gray to dark gray, these reflect that sediment environment is delta front, which included underwater distributary channel, mouth bar, distal bar, and so on. Well data and structural maps were integrated to build 3D structure model and sedimentary microfacies model of Li32 reservoirs using stochastic simulations with geometry data. The integrated 3D geological model is a valuable tool of reflecting geologic body with great reality and can accurately represent and describe the complex reservoir heterogeneity.     

PS剂驱油矿场先导性试验研究

PS碱木素磺酸盐 (简称 PS剂 )是由造纸废液经浓缩加入酚、醛和硫酸等在高温下复配或反应后提炼出的 1种新型表面活性剂。由于其具有降低原油粘度和油水界面张力的特性[1 -2 ] ,因而可作为提高原油采收率的驱替剂应用到油田开采中。本文通过室内实验和 W31断块的现场驱替试验 ,进一步探讨了 PS剂的驱替机理和驱油效果、探索了注 PS剂驱油的现场经验。     

Late Pleistocene glaciation of the Hulifang Massif of Gongwang mountains in Yunnan Province

Late Pleistocene glaciation was restricted to only a few high mountains in eastern China. The Gongwang mountains constitute one of the typical places once glaciated. Geomorphic mapping of the area and the TL dating provides evidence for at least four distinct glaciations. YJT-I glacial advance occurred about 100 ka BP and two TL absolute ages (101,100 ±7780 a BP; 104,000±8300 a BP) indicate this advance happened during the Penultimale Glaciation. The early stage glacial advance (YJT-II advance) during the last glaciation occurred about 40,920±3400 a BP. The last glacial maximum advance (YJT-III advance) about 18-25 ka BP, which sustained by two TL ages (18,230 ±1420 a BP; 25,420 ±2110 a BP). The Penultimale and the early stage glaciations were more extensive and the last glacial maximum (LGM) and the late-glacial period (YJT-IV advance, 10 ka BP) were progressively less extensive. Correlated with the other mountains in eastern China, these glacial advances in the Gongwang mountains just like the advances in the western part such as Diancang mountains, Yulong mountains of Yunnan Province and the glacier series are more complete than the adjacent mid-latitude regions such as Taibai mountain and Taiwan mountains and are roughly representative of climate changes during the last glacial cycle in Yunnan Province.     

林地景观点格局的样带梯度分布与空间聚集特征——以重庆三峡库区生态屏障区为例

从点格局角度研究林地及其不同类型景观格局的空间分布特征,以探求空间异质性在林地景观中的连续变化和分布趋势.选取点格局密度和RipleyK函数,建立重庆库区生态屏障区不同样带和1997-2005年间林地景观的点格局数据库,以此分析林地及其3种不同类型景观的样带梯度分布和空间聚集特征变化.结果表明:①研究区林地景观点格局的样带梯度分布在整体上表现出空间极不均衡特征,中心点上游林地景观点格局密度呈“双峰”梯度空间分布特征,下游呈“阶梯”梯度空间分布特征;②在各级空间尺度和时间变化上,屏障区林地景观格局都表现出局部空间聚集分布,与1997年相比,2005年林地分布范围在扩张,且空间分布均匀程度在提高,而空间聚集分布的特征在减弱;③有林地景观空间聚集特征与整体林地景观接近一致,有林地的基质优势在减弱.灌木林地分布在空间上比有林地更为集聚,在时间上聚集程度也在加强.疏林地由于在空间上扩张速度快致使其空间聚集发生减弱,空间分散性更大.     

Diagenesis of Clastic Reservoirs: Advances and Prospects

Along with the widely used experimental testing technology within 40 years,a number of significant knowledge and results have been achieved in diagenesis of clastic reservoirs an important branch of sedimentology and basin research,which has promoted the exploration and development of hydrocarbon bearing basins. This article encompasses the knowledge system to start an overview of the concept and research history of diagenesis, and to collate some representative classification viewpoints of clastic diagenetic stage. Several advances in recent theoretical and applied aspects of diagenesis, which have enriched the systems and technology series, have been introduced and summarized, including: ① improvement of alkaline diagenesis theory; ② increasingly widespread application in numerical simulation of clastic diagenesis; ③ rapid development of diagenesis within the framework of sequence stratigraphy or depositional facies; ④ preliminary investigation of structural diagenesis; ⑤ in-depth quantitative evaluation of diagenetic facies. Additionally, the research trends of the discipline system of diagenesis should be closely combined and discussed with diagenesis of tight sandstone reservoirs, diagenesis and its temporal properties of hierarchical systems, quantitative research of diagenesis, and integration of diagenesis and other fields. Frontier research and development directions have been prospected in order to bring forward further development of diagenesis, which is benefit for the forecasting and evaluation of the spatial and temporal distribution of hydrocarbon bearing clastic reservoirs.     

山东平邑县德埠庄石膏矿区北矿段水文地质特征分析

德埠庄石膏矿区北矿段位于平邑凹陷的西部,通过研究区内地质孔简易水文地质编录、水文地质孔分层抽水试验,查明了矿床水文地质条件及石膏矿带含水特征,确定水文地质单元边界条件模型,采用“水文地质比拟法”预测矿床正常涌水量和最大涌水量,在此基础上划定矿床水文地质条件属于中等型。     

全新世中期相对稳定的长江水位造成约3000年的湖泊沉积缺失

长江中下游地区浅水湖泊密布,全新世该区湖泊沉积的模式还不清晰。本研究在长江中下游的南漪湖、升金湖和菜子湖这3个湖泊开展了多钻孔AMS^14C测年工作,测年结果显示这些湖泊沉积地层中广泛出现长时间尺度的沉积物缺失。南漪湖湖泊钻孔的沉积物14C年龄介于5668~7828cal.aB.P.,菜子湖湖泊钻孔的沉积物^14C年龄介于6221~7929cal.aB.P.,升金湖围垦区钻孔14C年龄介于6302~7049cal.aB.P.。结合该地区以往湖泊钻孔研究资料,发现全新世长江中下游两岸洼地湖泊存在较广泛的6~3ka的沉积间断。结合长江水位重建资料,笔者提出关于全新世湖泊沉积存有长期间断的新认识:即6~3ka,长江水位相对平稳,湖泊沉积物虽有堆积,但易于被侵蚀搬运造成沉积间断;与此对应的是,在约8~7ka,海面上升造成长江水位较快上升,由于顶托作用,湖泊沉积物持续堆积;在约3ka以来,由于人类活动的影响,以及长江水位的进一步上升,湖泊沉积物也易于堆积,但在一些湖区沉积物也会被侵蚀。在6~3ka之间湖泊沉积物易于被侵蚀的一个可能原因是该时段长江上游来沙来水减少,自然堤易被破坏,对两岸湖泊洼地的封堵作用减少,使得湖泊泥沙易被侵蚀入江。     

Sensitivity Evaluation of Snow Simulation to Multi-parameterization Schemes in the Noah-MP Model

On account of the latest community Noah land surface model with multi-parameterization (Noah-MP) schemes and its uncertainty breadth in simulation results being difficult to be determined, this study assessed the sensitivity of snow to physics options using meteorological data from the Altay Station in northern Xinjiang. The Noah-MP physics ensemble simulation with the total number of 13 824 was designed without the consideration of the uncertainties of forcing data and parameters. The natural selection approach was used to analyze the sensitivity of physical processes. Based on the results of sensitivity analysis, the uncertainty of ensemble simulation results was further discussed. The results showed that snow was sensitive to the physical processes of surface-layer exchange coefficient, partitioning precipitation into rainfall and snowfall, lower boundary condition of soil temperature, and first-layer snow or soil temperature time scheme; Uncertainties in multi-parameterization ensemble simulation experiments were mainly from sensitive physical processes under the condition of disregarding uncertainties of forcing data and parameters. After removing the parameterization schemes that notably reduced simulation performance in sensitive physical processes, the uncertainty breadth in ensemble simulations decreased significantly. Finally, an optimal combination group of parameterization schemes for this station was configured.