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Application of a Geomatics Approach for the Diachronic Study of the Meditterannean Coastline Case of Tangier Bay
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作者 Fatima Zahra Salim Mohammed Yassine El Habti +2 位作者 Lech-Hab Khadija Ben Hamman Ahmed Raissouni Abdelkrim El Arrim 《International Journal of Geosciences》 2018年第6期320-336,共17页
The coastline is one of the country’s most important environmental and economic resources. However, it is a delicate and highly coveted environ-ment on which many factors of evolution interact, both anthropogenic and... The coastline is one of the country’s most important environmental and economic resources. However, it is a delicate and highly coveted environ-ment on which many factors of evolution interact, both anthropogenic and natural. This work is concerned with the diachronic study of the coastline of the Mediterranean coast, particularly the coastal fringe at the level of Tangier Bay. In order to experimentally confirm the numerical models used and to take part in the development of an accurate, reliable and rapid decision support system for the assessment and remediation of the risks of accretion and coastal erosion, the methodology followed consists of the application of automatic analytical techniques, based on a geomatics approach, using a multi-temporal photo-interpretation, a Geographical Information System (GIS) and a computerized data analysis system (DSAS: Digital Shoreline Analysis System). The change rate will be calculated from the multi-date maps (1981-96 and 2017) using the End Point Rate (EPR). To achieve our objective, the study area was divided into three sectors from East to West: El Ghandouri Beach, Malabata Beach and the municipal square adjacent to the port. The GIS analysis of the data obtained shows that the coastline is present by location and for the three periods of comparison of the remarkable zones of erosion and sedimentation. 展开更多
关键词 Mediterranean COASTLINE (SIG) Geographic Information SYSTEM (dsas) Digital SHORELINE Analysis SYSTEM ACCRETION Erosion
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Drivers’ Reaction of Warning Messages in Work Zone Termination Areas with Left Turn
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作者 Boya You Fengxiang Qiao Lei Yu 《Journal of Transportation Technologies》 2016年第3期139-147,共9页
Work-zone crashes have always drawn public attention. A number of fatalities are recorded every year nationwide within work zone areas. Most existing countermeasures have been dedicated more to the advance warning are... Work-zone crashes have always drawn public attention. A number of fatalities are recorded every year nationwide within work zone areas. Most existing countermeasures have been dedicated more to the advance warning areas, transition areas, and activity areas of work zone, than the termination areas, where drivers might play less attention to safety threats. In this study, the vehicle-to-vehicle communication based left turn warning system was applied at a work zone termination area, which is immediately followed by a T-intersection. The work-zone is located on the minor road side, while left turn vehicles will be appearing from the major street through the said T-intersection. A smart phone application was designed using Android coding system to provide several types of warning messages to drivers. Corresponding scenarios were designed in a driving simulator, and 20 subjects were recruited to participate in the simulation test followed by a questionnaire survey. The subjects received a warning message when driving to the termination area of a work zone on the coming left turn vehicles. Twenty test drivers’ driving speed, acceleration rates, and break reaction distance to the warning messages were studied in four different scenarios. Results show that the smartphone application has a great impact on driving behaviors, especially the female voice and the beep tone warning, which are recommended for possible field tests. Besides, the developed smartphone applications can be further updated for practical applications of similar needs. 展开更多
关键词 Left-Turn Warning Message Drivers’ Smart Advisory System (dsas) Driving Simulator Test Smartphone Application Workzone Termination Area
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气候变化对北方农牧交错带界线变迁影响的定量探测方法研究 被引量:14
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作者 史文娇 刘奕婷 石晓丽 《地理学报》 EI CSSCI CSCD 北大核心 2017年第3期407-419,共13页
气候对北方农牧交错带界线变迁的定量影响是目前生态脆弱敏感区对气候变化响应领域的研究热点问题。前人已在气候变化对农牧交错带界线的定性影响方面有较为深刻的认识,但仍缺乏在时间和空间上对气候贡献率进行有针对性的定量辨识。本... 气候对北方农牧交错带界线变迁的定量影响是目前生态脆弱敏感区对气候变化响应领域的研究热点问题。前人已在气候变化对农牧交错带界线的定性影响方面有较为深刻的认识,但仍缺乏在时间和空间上对气候贡献率进行有针对性的定量辨识。本文利用1970年以来长时间序列的国家气象站点数据和土地利用遥感解译数据,分别提取了基于气候要素和土地利用的20世纪70年代、80年代、90年代和21世纪前10年4个时期的北方农牧交错带界线,通过垂直和水平方向变动探测方法(Fish Net)和界线变迁方向变动探测方法(DSAS)对气候界线与土地利用界线的时空变化进行探测,定量分析了不同时期气候对农牧交错带界线变迁影响的贡献率。结果表明,气候与土地利用界线空间分布格局及气候贡献率在不同时期、不同区域差异较大,在西北地区变幅最小,东北地区变幅最大。在大兴安岭东南缘农田控制水源涵养生态功能区西北段以及内蒙古高原东南缘农、林、牧业生态—生产功能区西北段,气候与土地利用界线空间耦合关系最为密切,在该地区基于Fish Net方法下水平方向上气候贡献率达10.7%~44.4%,垂直方向上达4.7%~55.9%;基于DSAS方法下气候贡献率为1.1%~16.8%。两种方法探测结果大部分趋于一致,但DSAS方法精度高,适用于小范围精确探测;Fish Net方法更简单,适用于精度要求不高、快速直观的统计分析。本研究可为北方农牧交错带内农牧业生产适应气候变化、合理开发土地生产潜力、保护农牧交错带区内生态环境提供科学依据和指导。 展开更多
关键词 北方农牧交错带 气候变化 土地利用 垂直和水平方向变动探测方法(FishNet方法) 界线变迁方向变动探测方法(dsas方法) 定量探测
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基于遥感影像提取山东半岛复杂海岸线及海岸线多年变迁研究 被引量:9
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作者 张翔 王霄鹏 +5 位作者 黄安齐 李咏沙 张莎 白雲 Malak Henchir 张佳华 《海洋湖沼通报》 CSCD 北大核心 2021年第2期171-181,共11页
海岸线变迁的研究有助于对海岸带保护和可持续发展提供科学依据。本文针对山东半岛复杂的海岸线类型,选取1984—2018年的6期Landsat系列遥感影像,采用改进的归一化差异水体指数(Modified NDWI)和边缘检测算法(Canny)对图像进行阈值分割... 海岸线变迁的研究有助于对海岸带保护和可持续发展提供科学依据。本文针对山东半岛复杂的海岸线类型,选取1984—2018年的6期Landsat系列遥感影像,采用改进的归一化差异水体指数(Modified NDWI)和边缘检测算法(Canny)对图像进行阈值分割实现海陆分离,使用面向对象法提取了山东半岛海岸线,并结合高分影像和实地勘测对提取结果进行对比验证,并分析了半岛海岸线时空变化规律,通过数字海岸线分析系统(DSAS,Digital Shoreline Analysis System)的末点变化速率(EPR,End Point Rate)和线性回归变化速率(LRR,Linear Regression Rate)分析半岛不同类型岸线长度变化情况,通过净海岸线运动(NSM,Net Shoreline Movement)计算并分析面积变化情况。研究结果表明:海岸线提取精度为94.43%,满足精度要求。山东半岛海岸整体呈逐年增长趋势,35 a来共增长335.81 km,约9.59 km/a。人工岸线共增长长度1728.5 km,自然岸线减少长度1392.69 km。岸线类型中砂质岸线和基石岸线变化分别减少了53.40%和51.80%;淤泥质岸线、码头岸线变化显著,其中淤泥质岸线减少了74.92%,码头增加了34.73%;半岛沿岸地区中的黄河三角洲、莱州湾,青岛港面积变化显著,面积变化率分别为65.94%,~10.19%,39.87%。 展开更多
关键词 海岸线 LANDSAT 数字海岸线分析系统(dsas) 长度变化 面积变化 山东半岛
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