基于GIS的盐城国家级自然保护区生态安全评价（英文）     

李海萍  高戈  李菁 《资源与生态学报(英文版)》2020,11(1):38-49

本研究利用遥感和GIS技术,分析盐城自然保护区1983–2018年的景观格局变化,建立了基于区域自然-社会-经济复合生态系统安全格局的评价指标体系,分析了生态安全变化的空间特征和成因。结果表明,1983–2018年由于人类活动加剧,研究区内景观格局变化强烈,从以自然景观为主发展到自然景观与人工景观并存。在整体生态安全方面,目前保护区的生态安全状况不容乐观,从保护区丹顶鹤的生存状态看,保护区总体上还是适宜丹顶鹤栖息的,但由于人类活动的增加以及政策的调整,丹顶鹤的栖息地呈现破碎化并向核心区和缓冲区等局部区域聚集。我们应从管理、政策制定以及当地居民的环境保护意识上增加宣传和投入,并相应减少保护区内人类活动的强度。  相似文献   

花岗岩残积土动态冲击性能的SHPB试验研究     

刘新宇  张先伟  岳好真  孔令伟  徐超 《岩土力学》2020,41(6):2001-2008

为研究花岗岩残积土的动态冲击性能，开展了高速冲击下的分离式霍普金森压杆（SHPB）试验，与常规应变率下的试验结果比较，分析了高应变率对花岗岩残积土的应力?应变特性和强度的影响。结果表明：低、高应变率下的花岗岩残积土的?-?a（轴向应力?轴向应变）曲线均呈现出软化型。随着应变率 增加，?-?a曲线向?a增大的方向移动，破坏应变?af增加。但高应变率下?af增加的程度更加明显。花岗岩残积土的峰值强度普遍具有应变率依赖性，二者可用直线关系拟合，但低、高应变率下的拟合关系并不一致。提出了率敏性因子m定量评价依赖性强弱。研究发现，随着应变率的提高，强度的应变率依赖性减弱，低应变率下的m为26.694，而高应变率下仅为0.013。相关试验结果指出，高速冲击荷载对土体总体有害。工程中应该采取合理措施控制冲击荷载的危害。该研究有助于深化花岗岩残积土动态冲击性能的理解，为相关工程的施工与设计提供技术参考。  相似文献   

Spatial and Temporal Distribution of Dust‐Bound Trace Metal Elements around Kuhdasht Watershed Area in Iran     

Hamid Alipour  Ahmad Jalalian  Naser Honarjoo  Norair Tommanian  Fereidoon Sarmadian 《洁净——土壤、空气、水》2019,47(10)

Dust, as a source of trace metal elements, affects the health of society. The spatial and temporal concentrations of dust‐bound trace metals (Cd, Pb, Ni, Zn, Cu, and Mn) in Kuhdasht watershed (456 km²), Lorestan Province, Iran, is investigated. Dust is collected using glass traps placed in ten research stations in the region. The spatial and temporal distribution of dust trace metals are plotted using ARC‐GIS. The highest and the lowest concentrations of Zn (9751150 mg kg^?1), Pb (46.352.9 mg kg^?1), and Cd (2.443.30 mg kg^?1) are obtained in winter, of Ni (98110 mg kg^?1) and Cu in autumn (16.053.5 mg kg^?1), and of Mn in summer (385505 mg kg^?1). The spatial concentrations of dust‐bound trace metals indicate all, except Cu, show a decreasing trend from the mountains toward the plains, similar to that of soil and of dust, except for Zn, which shows higher concentrations in dust than in soil. The potential sources of dust‐bound trace metals and their rate of contamination are also investigated using the enrichment and contamination factors. The major sources of Cd and Zn in the dust of watershed are due to anthropogenic activities or from activities outside the borders.  相似文献   

全球主要河流流域碳酸盐岩风化碳汇评估   总被引：7，自引：0，他引：7  

李朝君  王世杰  白晓永  谭秋  李汇文  李琴  邓元红  杨钰杰  田诗琪  胡泽银 《地理学报》2019,74(7):1319-1332

碳酸盐岩风化吸收的大气CO₂主要以HCO₃ ^-形式连续地经由河流从大陆输送到海洋,成为陆地生态系统的重要碳汇。目前主要河流流域的碳酸盐岩风化碳汇估算存在不确定性,分布格局尚不清晰。基于GEMS-GLORI全球河流数据库提供的全球10万km ²以上主要河流流域多年平均监测数据,利用水化学径流法估算出全球主要河流流域碳酸盐岩对CO₂的吸收速率为0.43±0.15 Pg CO₂ yr ^-1,平均CO₂吸收通量为7.93±2.8 t km ^-2 yr ^-1。CO₂吸收通量在不同气候带下差异显著,热带和暖温带CO₂年吸收速率占全球主要河流流域年吸收速率的62.95%。冷温带CO₂年吸收速率占全球主要河流流域的33.05%,仅次于热带地区。本文划分出全球CO₂吸收通量的9个关键带,关键带的交汇处CO₂吸收通量较高。喀斯特出露流域碳酸盐岩对CO₂吸收通量的均值为8.50 t km ^-2 yr ^-1,约为非喀斯特流域的3倍。全球喀斯特出露流域碳酸盐岩风化碳汇在全球碳循环、水循环及碳收支平衡估算研究方面占据重要地位。  相似文献   

Volatile element chemistry during accretion of the earth     

《Chemie der Erde / Geochemistry》2020,80(1):125594

We review some issues relevant to volatile element chemistry during accretion of the Earth with an emphasis on historical development of ideas during the past century and on issues we think are important. These ideas and issues include the following: (1) whether or not the Earth accreted hot and the geochemical evidence for high temperatures during its formation, (2) some chemical consequences of the Earth’s formation before dissipation of solar nebular gas, (3) the building blocks of the Earth, (4) the composition of the Earth and its lithophile volatility trend, (5) chemistry of silicate vapor and steam atmospheres during Earth’s formation, (6) vapor - melt partitioning and possible loss of volatile elements, (7) insights from hot rocky extrasolar planets. We include tabulated chemical kinetic data for high-temperature elementary reactions in silicate vapor and steam atmospheres. We finish with a summary of the known and unknown issues along with suggestions for future work.  相似文献   

基于WebGIS的地震应急快速反应系统设计与实现     

余其鹏  汪波 《地震地磁观测与研究》2020,41(4):239-250

根据镇江地震地质情况及防震减灾工作实际，通过需求分析及系统整体设计，建立基于WebGIS的地震信息数据库管理系统。系统采用Oracle数据库、JavaScript语言、Tomcat网站服务器，开发了具有地方特色的地震应急处置快速反应系统，系统可实现震后快速评估、辅助决策、震后趋势分析、震后应急资料产出等功能。实际应用表明，该系统达到了低成本、高效率的预期目标。  相似文献   

Long‐term temporal and spatial patterns in bioeroding sponge distribution at the Abrolhos Bank,Brazil, Southwestern Atlantic     

Fernando Coreixas de Moraes  Fernanda Cervi  Cludia S. Karez  Leonardo T. Salgado  Rodrigo L. Moura  Gabriella A. Leal  Alex C. Bastos  Gilberto M. Amado‐Filho 《Marine Ecology》2019,40(3)

Bioeroding sponges belong to the most dominant bioeroders, significantly contributing to the erosion of coral reefs. Some species are tolerant or even benefit from environmental conditions such as ocean warming, acidification, and eutrophication. In consequence, increases in sponge bioerosion have been observed on some coral reefs over the last decades. The Abrolhos Bank is the largest coral reef system in the South Atlantic. It has been affected by sedimentation, eutrophication, overfishing, and climate change, mainly affecting coastal reefs, and at lesser intensity outer ones as well. This study aimed to describe spatial and temporal patterns in bioeroding sponge distribution in carbonate substrates in the Abrolhos Bank. Photo‐quadrats were used to compare bioeroding sponge abundance between two shallow reefs: a coastal, Pedra de Leste (PL), and an outer reef, Parcel dos Abrolhos (PAB). Each individual was delimitated over the substrate by determining the sponge surface through a line connecting the outermost papillae. The study was conducted over 6 years in 2008–2009 and 2013–2016. Four species of bioeroding sponges were identified: Cliona carteri Ridley, 1881, C. delitrix Pang, 1973, C. cf. schmidtii Ridley, 1881, and Siphonodictyon coralliphagum Rützler, 1971. The distribution and abundance of species varied between the inner and outer reefs and across the years, and displayed certain selectivity for the calcareous substrates recorded. Crustose coralline algae (CCA) were the main substrate excavated by the most abundant bioeroding species, C. carteri, and represented 70% of the substrate types occupied by this sponge (CCA, coral overgrown by CCA and plain coral). The highest abundance of bioeroding sponges observed in photo‐quadrats was 21.3 individuals/m² at the outer reefs (PAB) in 2014. The abundances or areal extents of bioeroding sponges were up to 10 times greater on the outer reefs than on the coastal ones, where sedimentation is higher and more strongly influenced by siliciclastic material. Moreover, a higher herbivorous fish biomass has been reported on outer reefs which could also influence the higher abundance of bioeroding sponges in outer reefs. During the study period of 6 years, an increase in bioeroding sponge abundance was observed at the outer reefs (PAB), with the sea surface temperature increase. As CCA have an important role in reefal cementation and carbonate production in the Abrolhos reefs, a bioerosion impact might be expected, in particular, on the outer reefs.  相似文献   

The spatial local accuracy of land cover datasets over the Qiangtang Plateau,High Asia     

Liu  Qionghuan  Zhang  Yili  Liu  Linshan  Li  Lanhui  Qi  Wei 《地理学报(英文版)》2019,29(11):1841-1858

We analyzed the spatial local accuracy of land cover (LC) datasets for the Qiangtang Plateau, High Asia, incorporating 923 field sampling points and seven LC compilations including the International Geosphere Biosphere Programme Data and Information System (IGBPDIS), Global Land cover mapping at 30 m resolution (GlobeLand30), MODIS Land Cover Type product (MCD12Q1), Climate Change Initiative Land Cover (CCI-LC), Global Land Cover 2000 (GLC2000), University of Maryland (UMD), and GlobCover 2009 (Glob-Cover). We initially compared resultant similarities and differences in both area and spatial patterns and analyzed inherent relationships with data sources. We then applied a geographically weighted regression (GWR) approach to predict local accuracy variation. The results of this study reveal that distinct differences, even inverse time series trends, in LC data between CCI-LC and MCD12Q1 were present between 2001 and 2015, with the exception of category areal discordance between the seven datasets. We also show a series of evident discrepancies amongst the LC datasets sampled here in terms of spatial patterns, that is, high spatial congruence is mainly seen in the homogeneous southeastern region of the study area while a low degree of spatial congruence is widely distributed across heterogeneous northwestern and northeastern regions. The overall combined spatial accuracy of the seven LC datasets considered here is less than 70%, and the GlobeLand30 and CCI-LC datasets exhibit higher local accuracy than their counterparts, yielding maximum overall accuracy (OA) values of 77.39% and 61.43%, respectively. Finally, 5.63% of this area is characterized by both high assessment and accuracy (HH) values, mainly located in central and eastern regions of the Qiangtang Plateau, while most low accuracy regions are found in northern, northeastern, and western regions.

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不同空间尺度的山洪灾害风险评价模型对比研究          下载免费PDF全文

田丰  张军  冉有华  刘金鹏  周翼 《干旱区地理》2019,42(3):559-569

以山洪灾害风险评价的多准则决策模型、最大熵模型、信息量模型三种常见模型为研究对象，选取河西走廊和张掖市为地理区划（大中）、市域（小）空间尺度研究区，构建山洪灾害风险评价指标体系，分别完成基于三种模型的两种空间尺度的山洪灾害风险评价制图，基于甘肃省地质灾害调查与区划报告数据从模型验证、空间自相关、精度对比和尺度效应等角度对比分析三个模型应用于不同空间尺度的适应性，并给出优选模型。结果表明：最大熵模型是河西走廊（地理区划）空间尺度上山洪灾害风险评价的优选模型；多准则决策模型不适用于张掖市（市域）空间尺度评价，且三个模型运行结果均没有河西走廊（地理区划）空间尺度上表现良好；三个模型的尺度效应明显，在地理区划空间尺度上应用较良好，缩小至市域空间尺度上模拟结果误差增大；不同空间尺度上，最大熵模型均优于多准则决策模型和信息量模型，适用于地理区划（大中）、市域（小）空间尺度的山洪灾害风险评价。  相似文献   

新疆和田地区耕地面源污染生态风险评价          下载免费PDF全文

田丰收  刘新平  原伟鹏 《干旱区地理》2019,42(2):295-304

随着化肥、农膜等在农业生产中的过量投入，耕地面源污染的程度随之加重。文章选取塔里木河流域上游和田地区为研究区域，依据P-S-R框架理论，构建和田地区耕地面源污染生态风险评价指标体系，加入土壤理化数据，使用生态风险评价模型对和田地区1980 年及2016 年耕地面源污染状况进行生态风险评价，运用耕地生态风险模型、生态风险转移矩阵、Arcgis分析和田地区耕地面源污染时空分异状况。研究结论如下：和田地区1980 年耕地生态风险等级均为II级或III级，呈“中间高，两侧低”分布；2016 年耕地生态风险等级上升至IV级或V级，呈“倒W型”分布，各县耕地面源污染程度较1980 年均有较大幅度的上升，其中墨玉县和于田县在2016 年耕地生态风险等级达到最高的V级，而民丰县因自身生态环境的强脆弱性，同样需要提高关注。根据面源污染“从源头治理”的原则，应切实推进和田地区耕地生态环境保护与治理，提高政府重视程度，增强技术指导，开展试点工作，改善和田地区耕地面源污染现状。  相似文献