广州市南沙区万顷沙网河区排涝调蓄演算研究     

刘树锋  刘一休  杨晨  陈记臣  谭丹  沈学明 《亚热带资源与环境学报》2021,16(1):1-8

快速城市化进程改变了城市地区原有下垫面,不透水层面积增加,暴雨期间汇流时间缩短,洪峰流量加大,进而导致城市内涝加剧,严重影响城市的防洪安全.本研究以广州市南沙区万顷沙网河区为研究对象,基于水量平衡的调蓄演算方法,对研究区域蓄排设施的规模进行分析;构建MIKE11一维网河模型,对涝区水情进行模拟,校核排涝工程规模,并对工...  相似文献   

Human occupation of the northern Arabian interior during early Marine Isotope Stage 3          下载免费PDF全文

Richard P. Jennings  Ash Parton  Laine Clark‐Balzan  Tom S. White  Huw S. Groucutt  Paul S. Breeze  Adrian G. Parker  Nick A. Drake  Michael D. Petraglia 《第四纪科学杂志》2016,31(8):953-966

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High-resolution climate variability of southwest China during 57-70 ka reflected in a stalagmite δ18O record from Xinya Cave   总被引：1，自引：0，他引：1  

Li TingYong  Yuan DaoXian  Li HongChun  Yang Yan  Wang JianLi  Wang XinYa  Li JunYun  Qin JiaMing  Zhang MeiLiang  Lin YuShi 《中国科学D辑(英文版)》2007,50(8):1202-1208

A 26-cm-long stalagmite (XY2) from Xinya Cave in northeastern Chongqing of China has been ICP-MS ²³⁰Th/U dated, showing a depositional hiatus at 2.3 cm depth from the top. The growth of the 2.3–26 cm interval determined by four dates was between 57 ka and 70 ka, with a linear growth rate of 0.023 mm/a. We have analyzed 190 samples for δ ¹⁸O and δ ¹³C, mostly in the 2.3–26 cm part. The δ ¹⁸O and δ ¹³C values between 57 ka and 70 ka reveal decadal-to-centennial climatic variability during the glacial interval of Marine Isotope Stage 4 (MIS4), exhibiting much higher resolution than that of the published Hulu and Dongge records during this interval. Speleothem δ ¹⁸O in eastern China, including our study area can be used as a proxy of summer monsoon strength, with lighter values pointing to stronger summer monsoon and higher precipitation, and vice versa. Two decreases in the δ ¹⁸O signature of XY2 record around 59.5 and 64.5 Ka are argued to correspond to the Dansgaard-Oeschger (D-O) events 17 and 18 respectively. The Heinrich event 6 (H6) can be identified in the record as a heavy δ ¹⁸O peak around 60 ka, indicating significant weakening of the monsoon in Chongqing during the cold period. The XY2 δ ¹⁸O record shows very rapid change toward to the interstadial condition of the D-O event, but more gradual change toward to the cold stadial condition. This phenomenon found in the Greenland ice core records is rarely observed so clearly in previously published speleothem records. According to SPECMAP δ ¹⁸O record, the glacial maximum of MIS 4 was around 64.5 ka with the boundary of MIS 3/4 around 60 ka. Unlike the marine record, the speleothem record of XY2, China, exhibits much high frequency variations without an apparent glacial maximum during MIS 4. However, the timing of MIS 3/4 boundary seems to be around 60 ka when the H6 terminated, in agreement with the marine chronology. The growth period of sample XY2 during glacial times probably reflects a local karstic routing of water, rather than having climatic significance. Supported by the National Natural Science Foundation of China (Grant Nos. 40672165, 90511004, 40672202) and the Academician Special Project of Chongqing Science Committee (Grant No. 2003-7835)  相似文献   

An abrupt cooling event early in the last interglacial in the northern South China Sea     

TU Xia  ZHENG Fan  Wang Jiliang  CAI Huimei  WANG Pinxian  C.Bühring  M.Sarnthein 《中国科学D辑(英文版)》2001,44(10):865-870

The high-resolution quantitative analysis of the planktonic foraminifera and the δ¹⁸O records of the section between 96.49– 137.6 mcd at ODP Site 1144 on the continental slope of northern South China Sea reveals an abrupt cooling event of sea surface temperature (SST) during the last interglacial (MIS 5.5, i.e. 5e). The dropping range of the winter SST may come to 7.5°C corresponding to 1.2‰ of the δ¹⁸O value of sea surface water. This event is comparable with those discovered in the west Europe and the northern Atlantic Ocean, but expressed in a more intensive way. It is inferred that this event may have been induced by middle- to low-latitude processes rather than by polar ice sheet change. Since the Kuroshio-index speciesPulleniatina obliquiloculata displayed the most distinct change at the event, it may also be related to the paleoceanographic change of the low-latitude area in the western Pacific Ocean. This event can be considered as one of “Younger Dryas-style coolings” and is indicative of climate variability of the last interglacial stage.  相似文献   

矿产资源管理信息系统设计与开发   总被引：1，自引：0，他引：1  

沈泉飞  顾和和  张海荣  曹敏  钟立喜  房友东 《国土资源信息化》2006,(5):19-22

基于GIS的矿产资源管理信息系统采用地理信息系统(GIS)技术、SQL Server数据库技术以及网络技术,实现了矿产资源信息图形数据与属性数据统一管理,为矿产资源管理工作提供了现代化的科学管理手段和决策支持。本文介绍了系统的设计与实现、系统包含的工作模块、各个模块的功能结构以及采用的技术特点。  相似文献   

基于GIS的图文一体化关键技术探讨     

范玉茹  赵夫来  王战举  刘成江 《测绘学院学报》2006,(3)

随着计算机技术的发展,地理信息系统所包含的概念、引用的技术手段已逐渐渗透到管理领域的各个方面。以地图数据为基础结合其他管理数据构建图文一体化系统已成现代管理的新技术。GIS技术与多媒体技术、以及MIS技术的集成是基于GIS构建图文一体化系统的核心内容。文中针对基于GIS的图文一体化的特点,对GIS支持下的图文一体化系统的开发模式、图文数据管理、功能集成等关键技术进行了探讨。  相似文献   

三甲胺[N(CH_3)_3]MIS传感器的研制     

吴英才 《广东海洋大学学报》1998,(3)

研制探测鱼鲜度的传感元件。用含铟（In）杂质的TiO2材料作溅射靶,采用氩离子束镀膜机在硅片上镀膜,用常规蒸铝技术和光刻技术制成MIS结构。结果表明：在1MHz的测试频率下,当三甲胺浓度从0变化到0．1％时电容发生了250％的变化。在3V的偏压下,电流改变了450％。直接用鲜鱼测试时,在25h内该结构的电容和电流的响应很敏感,且接近线性关系。  相似文献   

Y11B航空物探(电/磁)综合站西北找水初步成果   总被引：1，自引：1，他引：0  

孟庆敏 《物探与化探》1998,22(4):241-246

1997年9月23日～10月8日,在甘肃省安西—敦煌地区用Y11B航空物探(电/磁)综合站和GPS导航定位进行了地下水勘查试生产工作。用均匀大地模型,结合已知的水文地质资料,初步圈定了淡水区、过渡类型水区、咸水区和苦水区及泉水湖。所推断的水质和土壤含盐量与大的水文地质单元和1:20万水文地质普查报告都吻合得很好,且细节更为清楚。对差异较大的地方做了分析和解释。  相似文献   

A new chronological framework for Middle and Upper Pleistocene landscape evolution in the Sussex/Hampshire Coastal Corridor, UK     

Martin R. Bates  Rebecca M. Briant  Jean-Luc Schwenninger 《Proceedings of the Geologists' Association. Geologists' Association》2010,121(4):369-392

The unique Middle and Late Pleistocene sedimentary record preserved along the Sussex/Hampshire Coastal Corridor between Romsey and Brighton contains a wealth of deposits including highstand marine sediments associated with a variety of different aged beaches, fluvial sediments associated with rivers crossing the coastal plain and cold stage deposits accumulating above the marine and fluvial sediments. Although quarrying activity has been extensive across much of the area it has been undertaken in flooded workings due to the high level of the watertable. Consequently little is known in detail about the sequences except where they outcrop on the foreshore around the coast. This paper examines recent work from the lower coastal plain using a multi-disciplinary approach these deposits to elucidate the age of the sequences and their associated environments of deposition.OSL dates from two of the beaches, the Aldingbourne and Brighton/Norton Beaches, place both within MIS 7. Although these OSL dates cannot differentiate between sub-stages within MIS 7, coupling these results with inferences from local geography, lithology and contained microfossils it is clear that the beaches belong to two different phases within MIS 7. These two beaches are clearly divided by a major phase of erosion and downcutting associated with a fall in sea-level. Fluvial sediments from Solent Terrace 2 and Arun Terrace 4 also date within MIS 7 and are tentatively ascribed to the downcutting event between the beaches. Together this information allows us to propose, for the first time, a robust independently dated framework for the lower parts of the coastal plain integrating for the first time the marine and terrestrial record.  相似文献   

Evidence from the Trent terrace archive, Lincolnshire, UK, for lowland glaciation of Britain during the Middle and Late Pleistocene   总被引：1，自引：1，他引：0  

Tom S. White  Andy J. Howard 《Proceedings of the Geologists' Association. Geologists' Association》2010,121(2):141-153

The late Middle Pleistocene fluvial terrace sequence of the lower Trent system, Lincolnshire (eastern England), provides an excellent record of environmental change, including evidence for the last two interglacial episodes. It also provides important stratigraphical evidence for the timing and extent of three separate glaciations. Two of these, the Anglian and Devensian, are well-established correlatives of Marine Isotope Stages (MIS) 12 and 2 respectively; the third is a hitherto un-named post-Anglian-pre-Devensian glaciation in eastern England that has been the subject of much previous speculation, but can now be attributed with some confidence to MIS 8. Crucially, the recognition of MIS 7 interglacial deposits within the Balderton-Southrey terrace of the proto-Trent indicates that the underlying Wragby Till, which is ascribed to this additional glaciation, was emplaced no later than MIS 8. The oldest terrace preserved within the lower Trent staircase, the Eagle Moor-Martin Terrace, is considered to be a complex glacial outwash terrace related to the Wragby Till glaciation. It is suggested that deposits representing MIS 11-9, which are conspicuously absent throughout the Trent system, were removed by this glaciation. This is a departure from previous interpretations, which have suggested MIS 10 or MIS 6 as the most likely stages in which an extensive post-Anglian-pre-Devensian lowland glaciation might have occurred in Britain. However, the widespread preservation of undisrupted post-MIS 8 fluvial sequences throughout the Trent valley and in neighbouring systems, within which MIS 7 interglacial deposits have now been recognized at a number of localities, indicates that ice sheets are unlikely to have advanced further into this catchment during MIS 6 than during the Devensian (MIS 2). Recognition of a British glaciation during MIS 8 corresponds with widespread evidence in Europe, which suggests that glacial deposits classified as ‘Saalian’ represent both MIS 8 and MIS 6; in many areas, distinguishing these remains controversial, as confident correlation with either stage is often only possible where glacial sediments interdigitate with well-constrained fluvial records.  相似文献