海域使用活动对海湾生态环境的压力评估——以莱州湾为例          下载免费PDF全文

刘柏静  吴晓青  杜培培  高猛  都晓岩 《海洋学研究》2018,36(3):76-83

以莱州湾为例,基于GIS和地理空间模拟框架,结合海洋生态红线区分布,建立了海域使用活动对海洋生态环境的潜在压力评估模型,空间量化评估多种海域使用活动对海洋生态环境的潜在影响。结果显示,多种海域使用活动的潜在压力总体呈近岸高于远岸、湾顶>东部>西部的分布特征;压力高值区集中于距岸10 km以内海域和5 m水深以内海域;海洋特别保护区、海洋自然保护区及重要河口生态系统等类型的海洋生态红线区受到开放式养殖、围海养殖、盐业用海活动的压力较大,需要对其进行重点监控。研究揭示了莱州湾海域使用活动对海洋生态环境潜在压力的空间分布格局,为海洋生态红线落地实施和海域使用管理提供决策依据。  相似文献   

砒砂岩的微结构定量化特征研究   总被引：11，自引：0，他引：11  

吴利杰  李新勇  石建省  叶浩  郭娇  程彦培  王强恒 《地球学报》2007,28(6):597-602

应用光学显微照相和图像分析处理技术,对8份砒砂岩样进行了微结构定量化特征分析;运用多元线性回归对砒砂岩物理力学性质与其各微结构定量化参数进行了关联分析.研究表明,砒砂岩的抗压和抗拉强度与其颗粒的大小、形态、分布及排列及孔隙分布密切相关.一般而言,颗粒的粒径、平面分布分维和定向分维越小,砒砂岩的物理力学强度就越高,抗压和抗拉强度就越好.  相似文献   

Revisiting the palaeoenvironmental and climatic history of the Cherangani Hills using fungal spores     

Vicky Chelangat Cheruiyot  Daniel Gebregiorgis  Benjamin Opiyo  Lawrence Morara Kiage 《第四纪科学杂志》2020,35(6):737-742

Fungi are highly sensitive to environmental and climatic changes. Palaeoecological reconstructions utilising tropical African fungal spores, however, are rare and patchy. Here, we show that fossil fungal spores preserved in core KAP-01 from the Cherangani Hills in Kenya tracks critical environmental changes in the African tropics since the Last Glacial Maximum (LGM), largely synchronous with observations in the pollen record from the same site. Consistent with the pollen record, the presence of fungal taxa in the record, albeit meagre, during the LGM point to an intermittent wetter Cherangani that allowed for the presence of the observed taxa and the prevalence of cool, dry conditions during the last deglaciation. The elevated fungal spore activity during the Late Holocene is evidence for warm, moist environmental conditions and broadly consistent with the pollen record. These different fungal spore taxa, which can be employed to track distinct environmental conditions and processes, provide a dimension that can be overlooked if the reconstruction of the palaeoenvironment were to rely solely on pollen. Thus the fungal spore record enables us to affirm the interpretation of the prevalence of warm, moist conditions evident from such as the Holocene pollen record.  相似文献   

Lateglacial/early Holocene palaeoenvironments in the southern North Sea Basin: new data from the Dudgeon offshore wind farm          下载免费PDF全文

Alex Brown  John Russell  Rob Scaife  Louise Tizzard  John Whittaker  Sarah F. Wyles 《第四纪科学杂志》2018,33(6):597-610

  相似文献   

地震相技术在煤层气勘探中的应用     

祁雪梅  董守华 《物探与化探》2012,(2):170-173,179

在分析了采用地震相技术预测煤层气含量可行性的基础上,首先利用无监督向量量化网络对研究区地震资料进行了地震波形划分,然后在钻孔实测煤层气含量值的指导下,依赖地震波形特征反演与煤层气含量有关综合特征,完成了使用地震相分布图对勘探区煤层气含量的预测。预测结果与实测值相符,具有较高的预测分辨率,从而证明了该方法的有效性和实用性。  相似文献   

Quantitative assessment of vegetation cover and soil degradation factors within terrain units for planning,monitoring and assessment of renaturation along oil and gas pipelines     

Emil Bayramov  Manfred Buchroithner  Eileen McGurty 《国际地球制图》2013,28(7):535-555

This paper evaluates the renaturation activities applying the quantification of vegetation cover (VC), the site suitability analysis (SSA) based on the predefined criteria (slope steepness category (SSC), soil erodibility factor (K) and VC) and soil erosion model (SEM) results within the terrain units (TUs) along pipeline rights-of-way (RoW). Quantification of VC percentage is performed to assess the overall restored VC from 2005 to 2007. The results of the quantitative analysis in 2007 show that the total area of restored VC is 10.7 km², and 8.9 km² still needs to be restored to comply with the environmental acceptance criteria. As a result of SSA, TUs were prioritized by erosion vulnerability and this allowed to better understand the landscape behaviour in regards to erosion processes. SEM provided more detailed predictions of erosion classes falling into TUs. SEM identified 40% of erosion sites occurred from 2005 to 2010.  相似文献   

Digital Terrain Modeling and Industrial Surface Metrology: Converging Realms   总被引：1，自引：0，他引：1  

Richard J. Pike 《The Professional geographer》2013,65(2):263-274

Digital terrain modeling has a micro- and nanoscale counterpart in surface metrology, the numerical characterization of industrial surfaces. Instrumentation in semiconductor manufacturing and other high-technology fields can now contour surface irregularities down to the atomic scale. Surface metrology has been revolutionized by its ability to manipulate square-grid height matrices that are analogous to the digital elevation models (DEMs) used in physical geography. Because the shaping of industrial surfaces is a spatial process, the same concepts of analytical cartography that represent ground-surface form in geography evolved independently in metrology. The surface topography of manufactured components, exemplified here by automobile-engine cylinders, is routinely modeled by variogram analysis, relief shading, and most other techniques of parameterization and visualization familiar to geography. This article introduces industrial surface-metrology, examines the field in the context of terrain modeling and geomorphology and notes their similarities and differences, and raises theoretical issues to be addressed in progressing toward a unified practice of surface morphometry.  相似文献   

武汉城镇化与热岛效应的定量研究   总被引：1，自引：0，他引：1  

谢启姣  陈昆仑  金贵 《测绘科学》2017,42(9)

针对目前城市化进程加快对城市增温和城市热岛效应的促进作用尚不十分明确的问题,提出基于遥感技术的城镇化与热岛效应数量关系的构建。结果表明,1987-2013年间,武汉市中城镇化水平(50%~80%ISA)面积增加了14.5倍,高城镇化水平(80%~100%ISA)面积增加了2.8倍,城镇化范围沿着武汉市主城区和主要干道不断扩张;不透水面值与地表温度表现出明显正相关,不透水面值平均增加1%,可使地表温度增温0.06℃~0.19℃,城镇化水平对武汉城市热岛效应作用明显。研究结果为探讨城市热岛效应的缓解对策提供了基础,对合理规划和管理城市化意义重大。  相似文献   

A unified assessment of marine Mediterranean assemblages: a lesson from benthic hydroids          下载免费PDF全文

Manuel M. González‐Duarte  Cesar Megina  Doris De Vito  Cristina Goia Di Camillo  Stefania Puce  Stefano Piraino 《Marine Ecology》2016,37(1):155-163

Hydroids are important components of the communities of rocky bottom shallow coastal areas. The hydrozoan fauna of the Mediterranean Sea is probably one of most investigated in the world, with lots of faunistic and biogeographical studies. However, quantitative studies using the same sampling methodology and controlled sampling effort have been restricted to areas in the Western and Central Mediterranean. We compared hydroid assemblages in four areas of the Mediterranean Sea, from the Gulf of Cádiz to the South Adriatic Sea, following the same sampling and quantification methodology. Our analysis showed the dominant Atlantic character of the assemblages of the Gulf of Cádiz and the South Alboran Sea because of the influence of the inflowing Atlantic waters. Conversely, the hydroid assemblages of the North Alboran Sea were more similar to the assemblages in the Ligurian and in the South Adriatic, and with a number of species ranking between the observed in these two Mediterranean zones. Fourteen species were identified as making the most significant contributions to characterizing the Mediterranean hydroid species pool from a quantitative point of view. These taxa include species previously named as typical components of the Mediterranean hydroid fauna as well as those only recently recorded in the region (Eudendrium moulouyensis) and invaders such as Clytia hummelincki.  相似文献   

Palaeoenvironmental and diagenetic reconstruction of a closed‐lacustrine carbonate system – the challenging marginal setting of the Miocene Ries Crater Lake (Germany)     

《Sedimentology》2018,65(1):235-262

Chemostratigraphic studies on lacustrine sedimentary sequences provide essential insights on past cyclic climatic events, on their repetition and prediction through time. Diagenetic overprint of primary features often hinders the use of such studies for palaeoenvironmental reconstruction. Here the potential of integrated geochemical and petrographic methods is evaluated to record freshwater to saline oscillations within the ancient marginal lacustrine carbonates of the Miocene Ries Crater Lake (Germany). This area is critical because it represents the transition from shoreline to proximal domains of a hydrologically closed system, affected by recurrent emergent events, representing the boundaries of successive sedimentary cycles. Chemostratigraphy targets shifts related to subaerial exposure and/or climatic fluctuations. Methods combine facies changes with δ ¹³C–δ ¹⁸O chemostratigraphy from matrix carbonates across five closely spaced, temporally equivalent stratigraphic sections. Isotope composition of ostracod shells, gastropods and cements is provided for comparison. Cathodoluminescence and back‐scatter electron microscopy were performed to discriminate primary (syn‐)depositional, from secondary diagenetic features. Meteoric diagenesis is expressed by substantial early dissolution and dark blue luminescent sparry cements carrying negative δ ¹³C and δ ¹⁸O. Sedimentary cycles are not correlated by isotope chemostratigraphy. Both matrix δ ¹³C and δ ¹⁸O range from ca −7·5 to +4·0‰ and show clear positive covariance (R  = 0·97) whose nature differs from that of previous basin‐oriented studies on the lake: negative values are here unconnected to original freshwater lacustrine conditions but reflect extensive meteoric diagenesis, while positive values probably represent primary saline lake water chemistry. Noisy geochemical curves relate to heterogeneities in (primary) porosity, resulting in selective carbonate diagenesis. This study exemplifies that ancient lacustrine carbonates, despite extensive meteoric weathering, are able to retain key information for both palaeoenvironmental reconstruction and the understanding of diagenetic processes in relation to those primary conditions. Also, it emphasizes the limitation of chemostratigraphy in fossil carbonates, and specifically in settings that are sensitive for the preservation of primary environmental signals, such as lake margins prone to meteoric diagenesis.  相似文献