1961—2013年威海市气温变化特征及突变分析     

郝玲玲  ;苏春生 《内蒙古气象》2014,(6):16-18

文章采用1961—2013年威海市所辖4个气象站地面观测气温资料,统计分析了威海市近53a气温变化特征,并利用Mann-Kendall法对年平均气温突变特征进行了分析。结果表明:威海市年平均气温明显呈增暖趋势,气候变化趋势倾向率为0.3°C/10a,年平均最高、最低气温气候变化趋势倾向率分别为0.2°C/10a、0.3°C/10a;近53a威海市年平均气温在1987年发生了由冷转暖的突变,增暖趋势自1992年开始趋于显著。  相似文献   

Carbon cycle and sea-water palaeotemperature evolution at the Middle–Late Jurassic transition,eastern Paris Basin (France)     

《Marine and Petroleum Geology》2014

A very high-resolution carbon and oxygen stable isotope analysis (bulk-carbonate) of a biostratigraphically well-constrained Callovian–Oxfordian series is provided here for the first time. The homogeneity of the clayey series and the weak diagenetic alteration allow the isotopic signal variations to be considered as primary in origin. A prominent and brief negative excursion in the δ¹³C curve (−2‰), occurring at the start of the Middle Callovian (Jason Zone – Obductum Subzone) and correlated regionally, suggests a possible methane release. The increasing δ¹³C values thereafter up to the Early Oxfordian, concomitant with a warming episode, highlight the burial of carbon in organic-rich layers which, in return, may have triggered a decrease in atmospheric pCO₂. At higher frequencies, observed fluctuations of the δ¹³C and δ¹⁸O values are orbitally driven (405-kyr and 100-kyr eccentricity cycles) and may correspond to the salinity and temperature variability recorded in sea water. The δ¹⁸O isotopic measurements from well-preserved diagenetically screened belemnites and bivalves along the series, compared to available data from Tethyan domains, agree with the scenario of a global cooling at the Middle-Late Jurassic transition. The well-dated δ¹⁸O isotopic curve suggests that the onset of this cooling event occurred at the end of the Coronatum Zone (Middle Callovian).  相似文献   

渤海莱州湾地区晚更新世以来有孔虫特征反映的古环境变化     

姚菁  于洪军  徐兴永  易亮  陈广泉  苏乔 《海洋学报(英文版)》2014,33(10):10-18

Controlled by climate changes, there were three large-scale transgressions and regressions around the Bohai Sea during the late Quaternary, which were accepted by most geologists. However, a big controversy still exists about the time when the transgressions occurred separately. In order to find out the process of the paleoenvironmental changes around the Bohai Sea in the late Quaternary, the foraminifera assemblages from a new borehole Lz908 in the southern coast of the Laizhou Bay were studied, and then the transgressive strata were indentified. Combined with accelerator mass spectrometry radiocarbon 14C（AMS14C） and optically stimulated luminescence（OSL） ages, the occurrence time of these transgressions were re-determined. The result showed that three major large-scale transgressions occurred separately at the beginning of marine isotopic stage 7（MIS7）, the last interglacial period（MIS5） and the Holocene. In addition, a small-scale transgression occurred in the mid-MIS6, and the corresponding transgressive stratum was deposited. The transgressive deposition of MIS3 was also discovered in this study. However, the characteristics of the foraminifera indicated the environment during this period was colder than that in the MIS5. By comparison with the global sea-level changes, the paleoenvironmental changes around the Bohai Sea in the late Quaternary can be consistent with the global climate changes.  相似文献   

近40年来海州湾海岸线时空变化分析   总被引：1，自引：0，他引：1       下载免费PDF全文

陈晓英  张杰  马毅 《海洋科学进展》2014,32(3)

以Landsat MSS、TM、ETM+影像和HJ-1A CCD1影像为数据源,对海州湾大陆海岸线1973-2013年的变迁进行了连续监测,定量获取了海岸线信息,解译了岸线摆动区内土地利用类型,对近40 a来海州湾大陆海岸线时空变化和海岸开发方式进行了系统分析.结果表明:海州湾岸线长度及类型动态变化显著,岸线长度整体增加,海湾面积不断减少,岸线类型以人工岸线为主;岸线整体向海推进导致陆域面积净增65.54 km2,变迁速率时空分布不均,变迁主要发生在岚山港、绣针河口至柘汪河口、兴庄河口至西墅、连云港港岸段,城镇扩张导致20t0-2013年变迁最为剧烈,速率达122.9m/a;海岸人为开发是海州湾岸线变化的主导因素,且开发方式时间异质性显著,早期以盐业、养殖业为主,20世纪80年代开始港口码头建设比例显著增加,进入新世纪以来,用于城镇建设的围填海规模大幅增长,尤其是2010年之后已成为海州湾地区海岸开发的首要方式.  相似文献   

Sediment records of environmental changes in the south end of the Zhejiang-Fujian coastal mud area during the past 100 years     

王琳淼  李广雪  高飞  刘玲  刘勇 《中国海洋湖沼学报》2014,32(4):899-908

Previous studies carried out in the East China Sea （ECS） mud area focused on long-term environmental changes in sedimentary records during the Holoeene, especially during the mid-Holocene high-stand water levels period. These results indicate that sensitive grain size groups can be used as a sedimentary proxy to reconstruct the evolution of the East Asian Winter Monsoon （EAWM）. The studies have been carried out mainly in the northern and middle portions of the Zhejiang-Fujian coastal mud, however, similar research in the southern portion and the comparison between sedimentary proxy and modern measured data of EAWM are lacking. In this paper, we focused on a sedimentary record of the past 100 years with an enhanced resolution of 1.8 years. Investigations of the southern end of the Zhejiang-Fujian coastal mud area were conducted on the basis of 21~Pb chronology, grain-size analysis and chemical element analysis. The correspondence between the mean grain size （Mz） of sediment sensitive grain size and the measured EAWM was confirmed for the first time. We found that during the recent 100 years, the variation of the mean grain size of the sensitive population in the southern portion of the Zhejiang-Fujian mud was mainly controlled by the EAWM intensity changes; and not directly related to changes in the sediment discharge from Datong station of the Changjiang River （DTSD）. Finally, recent changes in the content of heavy metals in study area reflect the impact of human activities on the environment.  相似文献   

近70a泾河流域径流变化及其驱动因素研究     

刘宇  管子隆  田济扬  刘荣华  关荣浩 《干旱区地理》2022,45(1):17-26

定量评价流域径流变化特征并开展其归因识别研究是应对气候变化实现水资源合理开发利用的基础.本研究以泾河流域为研究区,采用M-K检验、滑动t检验、小波分析等方法分析流域近70 a的水文气象要素变化特征,并基于Budyko假设评价气候变化和人类活动对径流变化的贡献率.结果表明:(1)泾河流域年径流深以0.41 mm·a-1的...  相似文献   

Seagull Lake,Western Eyre Peninsula,South Australia:A Saline Lake to Benefit from Climate Change? Ⅱ. Hydrology and Plants     

Peri COLEMAN 《《地质学报》英文版》2014,(Z1)

正Seagull Lake is an unusual saline lake,having a marine spring connected to a large continental ecosystem.With climate change the balance between marine,meteoric and groundwater inputs to,and evaporitic and groundwater  相似文献   

Long-term Changes in the Saline Lake Qarun(Egypt)     

Gamal EL-SHABRAWY  Mohamed GOHAR  Mousa GERMOUSH  Elena ANUFRIIEVA  Nickolai SHADRIN 《《地质学报》英文版》2014,88(Z1):180-182

正1 Introduction There is now ample evidence of the impacts of the recent climate change and anthropogenic activities on different saline lake ecosystems.All over the world salt lakes are threatened by climate change,water diversions upstream for agricultural purposes,watershed changes,introduction of aliens,etc.that result in catastrophic  相似文献   

渤海西岸全新世气候演化与海陆变迁     

李凤林  阎玉忠  商志文 《江苏地质》2014,38(2):173-186

应用第四纪地质学和海相生物等化石数量统计,以天津马棚口海岸带BQ1孔化石鉴定与统计结果,对古气候、古事件进行对比研究。通过岩芯编录,在岩性层中划分出4个海相层、5个过渡层、9个海面波动。结合研究区广泛分布的贝壳堤和牡蛎礁,利用其大量的测年资料,重现了6道海岸线;根据海相化石个体统计数,画出全新世气候演化曲线,与孢粉和物候所画的古气候演化曲线大体一致。研究历代海陆变迁,必然涉及到历史上长期争论不休的西汉大海侵等问题,谭其骧（1965）圈定的大海侵范围、海岸线分布以及考古结果几乎都能联系在一起,因此,大海侵之谜终于尘埃落定。考古界对河北平原自东汉—金的空白也有了初步答案,同时,发现中国朝代兴衰与气候冷暖有明显的对应,从而建立了气候分期。  相似文献   

韩国济州岛柑橘园景观与空间分布演变（1526—2019年）     

黄普基  吴俊范 《热带地理》2022,42(5):834-842

韩国济州岛的柑橘园景观具有重要的文化遗产价值,是当地人利用济州岛特殊的气候、水文、植被环境所塑造的独特农业景观。16世纪朝鲜王朝建立柑橘进贡制度,济州官府设置柑橘园,此后至今,济州岛柑橘园区域分布与地理景观都呈现较大变迁。文章结合气候、水资源等自然因素与韩国柑橘产业政策、市场、社会变化与技术进步等人文因素,分析16世纪以来济州岛柑橘园景观与空间分布变化,探讨济州岛柑橘生产空间变迁原因与驱动力。结果显示：16世纪至2019年,济州岛柑橘生产经历了发展、没落、强力复兴的大起大落发展历史,呈现从北到南的生产空间大迁移,柑橘生产空间逐渐扩大。济州岛的柑橘园生产经历从朝鲜时期的官府果园到现代观光体验农场的转变。柑橘生产空间变迁与地理景观变化的原因与驱动力较复杂,水资源是影响朝鲜时期柑橘园分布的主要自然因素。社会制度、交通与市场是16世纪以来影响柑橘园生产空间扩展的主要人文因素,在近500年的柑橘生产空间发展变迁的过程中,人文因素不断加强,影响柑橘空间与地理景观的优化调整。20世纪70年代以来,水资源开发技术的进步改变了现代柑橘园生产空间分布格局。对济州岛柑橘园长时段的生产空间与地理景观变化及其作用机制的研究,可以为中国传统柑橘栽培地区打造具有地方特色柑橘园文化景观与民俗、文化产品,以及中国柑橘产业的升级发展提供参考。  相似文献