基于GIS和AIS的渤海海上船舶活动时空特征分析     

陈仁丽  王宜强  刘柏静  宫萌  吴晓青 《地理科学进展》2020,39(7):1172-1181

基于2018年海上船舶自动识别系统(Automatic Identification System, AIS)数据,借助GIS空间分析方法,对渤海海上船舶位置及密度、船舶速度等空间分布特征以及船舶流量日、月和季节变化的时间特征进行分析,得到以下结论：① 渔业船舶多活动于近岸海域,呈团聚状分布;商业船舶多聚集在公共航道区,整体呈带状分布;货船数量占商业船舶总量的78.58%,主要为中型货船,客船与油轮以中小型船舶所占比重相对较大。② 渤海船舶速度以中低速为主,尤其是渔业船舶;较高速度的船舶主要是大中型货船和客船。③ 渔业船舶活动时间和季节变化特征显著,秋季休渔期结束后以及白天工作时间段渔船活动较频繁;与渔业船舶相比,渤海商业船舶活动受季节变化和昼夜交替影响较小。分析发现,渤海交通流密度高,船舶会遇频繁,发生船舶碰撞以及重大污染事故的风险较大;东西向和南北向的海上交通与渔业捕捞作业船舶之间存在较大的海域空间利用冲突,需要引起足够的重视。自然环境与资源条件、沿岸社会经济发展与港口建设、海域管制等因素影响海上船舶时空分布。  相似文献   

Relative effects of human activities and climate change on the river runoff in an arid basin in northwest China          下载免费PDF全文

Wen Dong  Baoshan Cui  Zhihui Liu  Kejiang Zhang 《水文研究》2014,28(18):4854-4864

Understanding the mechanisms of river runoff variation is important for the effective management of water resources in arid and semi‐arid regions. This study uses long‐term observational data as a basis for examining the effects of human activities and climate change on the runoff variation of Jinghe River Basin, a typical arid inland basin in northwest China. A distributed hydrological model called the Soil and Water Assessment Tool, combined with a sequential cluster method and a separation approach, was used to quantify and distinguish the effects of human activities and climate change on runoff. The hydrological sequence before 1981 can be considered natural. However, human activities have significantly affected runoff since 1981. The runoff reduction caused by human activities between 1981 and 2008 accounted for 85.7% of the total reduction in the downstream of Jinghe River, whereas that caused by climatic variation was only 14.3%. This observation suggests that human activities are the major driver of runoff variation in the basin. Although the role of climate change in driving runoff variation has been identified to be prevalent and dominant in arid regions, this study highlights the importance of human activities. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

近30年来东海长江口泥质区浮游植物生产力与群落结构变化的生物标志物记录     

郭新宇  张海龙  李莉  毕蓉 《中国海洋大学学报(自然科学版)》2020,(2):85-94

随着人类活动的增加和全球气候变化的加剧,东海生态环境受到了人类活动和自然环境变化的双重影响。本文选择位于东海长江口泥质区的柱状样DH3-1进行生物标志物分析,利用多种生物标志物含量及相对比例重建了东海近30年(1983-2010年)浮游植物生产力、群落结构和陆源输入相对贡献的变化,并探究人类活动与自然因素产生的综合影响。结果表明:近30年来,浮游植物生产力呈现上升趋势;约1992-2001年,硅藻比例下降、甲藻比例上升,约2001年后硅藻比例上升、甲藻比例下降。陆源有机质含量在约1992-2004年呈现增加趋势,约2004年后相对降低;海源有机质含量则呈现持续增加趋势。东海近30年来浮游植物生产力的升高主要是因为人类活动剧增与上升流引发东海营养盐输入量增加。群落结构与陆源有机质含量交替变化可能是由不同年份人类活动与自然因素的作用强度不同导致的。  相似文献   

Land use change and anthropogenic driving forces: A case study in Yanhe River Basin   总被引：4，自引：0，他引：4  

Halina LAMPARSKI 《中国地理科学(英文版)》2011,21(5):587-599

Human activities alter land use patterns and affect landscape sustainability. It is therefore very important to investigate the relationship between land use change and human activities. This study focuses on the detection of changing land use patterns in the Yanhe River Basin in northern Loess Plateau of China between 1995 and 2008. Landscape metrics were used to analyze the changing land use patterns and to explore the related anthropogenic driving forces. Results show that:1) Totally, 186 590 ha of cropl...  相似文献   

北京城市办公活动空间满意度分析   总被引：2，自引：2，他引：0  

张景秋  郭捷 《地理科学进展》2011,30(10):1225-1232

以北京城市办公集聚区为调查范围,选取公司周边绿化、交通、商业配套设施状况以及公司所在地整体环境感受4项主观评价指标,采取问卷调查方式,对北京城市以写字楼为载体的工作场所满意度进行调查和分析。研究认为,北京城区办公活动空间满意度综合评价良好,其中对商业配套设施最为满意,对绿化状况最为不满。从被调查的6个行政区看,位于前3名的分别是朝阳区、丰台区和东城区,海淀区因交通、商业配套不满意导致其综合评价为合格;从满意度的空间分布来看,北高南低,并向北和东北方向延展,形成岛状和片状高值区,与北京办公集聚区空间分布特点一致。城市工作者需要更加舒适的工作环境,对于北京城市工作场所的满意度研究,将有助于对城市从人的满意度和幸福感出发进行规划和建设。北京城市今后应注重对办公空间的整体规划,并依据功能定位和作用进行重点建设,从地方文化入手建设有中国特色和北京特点的办公空间,以办公空间优化引导北京南北城区之间均衡发展。  相似文献   

长江上游社会经济因子对侵蚀产沙的影响   总被引：1，自引：0，他引：1  

杜俊  师长兴  范小黎  周园园 《地理学报(英文版)》2011,21(2):359-371

In recent years,the role of human activities in changing sediment yield has become more apparent for the construction of hydraulic engineering and water conservation projec-tions in the Upper Yangtze River,but it has not been evaluated at the macro scale.Taking Sichuan Province and Chongqing City as an example,this paper studies the relationship between socio-economic factors and sediment yield in the Upper Yangtze River based on section data in 1989 and 2007.The results show that sediment yield is significantly correlated with population density and cultivated area,in which the former appears to be more closely related to sediment yield.Moreover,in the relation of sediment yield vs.population density,a critical value of population density exists,below which the sediment yield increases with the increase of population density and over which the sediment yield increases with the decrease of population density.The phenomenon essentially reflects the influence of natural factors,such as topography,precipitation and soil property,and some human activities on sediment yield.The region with a higher population density than critical value is located in the east of the study area and is characterized by plains,hills and low mountains,whereas the opposite is located in the west and characterized by middle and high mountains.In the eastern region,more people live on the lands with a low slope where regional soil erosion is slight;therefore,sediment yield is negatively related with population density.In contrast,in the western region,the population tends to aggregate in the areas with abundant soil and water resources which usually lead to a higher intensity of natural erosion,and in turn,high-intensity agricultural practices in these areas may further strengthen local soil erosion.It is also found that popu-lation tends to move from the areas with bad environment and high sediment yield to the areas with more comfortable environment and less sediment yield.The natural factors have greater influence on sediment yield of western region than that of eastern region.Generally,the natural factors play a dominant role on sediment yield in the Upper Yangtze River.  相似文献   

波兰湖泊面积变化因素     

AdamCHOI 《资源与生态学报(英文版)》2011,2(2):175-180

摘波兰北部有众多斯堪的纳维亚冰盖冰期形成的湖泊。通过湖泊区的研究,发现湖泊面积在逐渐减少,甚至导致消失．本文对变化的程度进行了观测,指出影响波兰湖泊面积变化的主要自然与人为因素,包括气候变化、湖盆深度、生物量增长、森林砍伐、水利工程建修、农药利用和排污等。  相似文献   

THE IMPACTS OF MADDEN-JULIAN OSCILLATION ON SPRING RAINFALL IN EAST CHINA   总被引：3，自引：1，他引：2  

白旭旭  李崇银  谭言科  关志佳 《热带气象学报(英文版)》2013,19(3):214-222

Phase composite analyses are conducted to investigate the possible effect of the Madden–Julian oscillation(MJO)on the spring rainfall anomalies in East China by using the Real-time Multivariate MJO(RMM)index from Australian Meteorological Bureau.The results show that the rainfall anomalies over the mid-and lower-valley of Yangtze River are positive when the MJO shifts eastward to the mid-and eastern-Indian Ocean,and anomalous precipitation over South China are positive when the MJO moves further eastward to the maritime continent,whereas spring rainfall anomalies over East China are negative in the other MJO episodes.The MJO impacts on the precipitation over East China result from the changes in large-scale atmospheric circulation as well as vorticity and water vapor transportation in the mid-and lower-troposphere.  相似文献   

智能网格预报在重大活动气象服务保障中的应用——以环广西公路自行车世界巡回赛为例     

史彩霞  郑凤琴  曾鹏  王振国  李红花 《气象研究与应用》2020,(1):61-64

在智能网格气象预报产品的基础上,采用B/S+C/S混合架构,建立了"环广西"赛道气象服务产品共享平台。通过共享平台,快速完成精细化气象服务产品的制作和发布,为做好重大活动气象服务保障提供借鉴和参考。  相似文献   

基于CMIP6强迫模拟分析人为气溶胶的气候效应(二)——诊断方法在分类评估中的重要性          下载免费PDF全文

史湘军  刘娇娇  朱寿鹏  吉璐莹  张海鹏  沈沛洁  陈伯民  李震坤 《大气科学学报》2020,43(4):630-639

对气溶胶气候效应开展分类评估并探讨诊断方法的合理性。人为气溶胶辐射效应对计算云辐射强迫的影响为0.38 W·m~(-2)。诊断评估气溶胶对云辐射强迫的影响需要排除这个偏差。两种基于不同试验设计诊断得出的半直接效应分别为0.21和0.09 W·m~(-2),存在显著差异。主要原因可能是人为气溶胶影响云辐射强迫的不同机制之间在模式模拟过程中不断地相互交织,不是简单的线性叠加关系。模式诊断得出的Twomey效应不仅包括Twomey效应本身,还包括Twomey效应引起的部分快速调整。总之,利用模式评估分析人为气溶胶气候效应需要注意审查试验设计和诊断方法的合理性。  相似文献