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基于管理熵与RFID的九寨沟游客高峰期“时空分流”导航管理模式研究 被引量:25
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作者 冯刚 任佩瑜 +2 位作者 戈鹏 朱忠福 冉建华 《旅游科学》 CSSCI 2010年第2期7-17,共11页
九寨沟旅游高峰期游客时空分布不均,直接造成三个方面的负面影响。一是各界对九寨沟景区严格实行游客限量的诉求增强,二是景区生态环境保护压力加大,三是游客满意度降低。本文在管理熵理论的指导下,拟采用RFID、eB和3S等信息技术,在时... 九寨沟旅游高峰期游客时空分布不均,直接造成三个方面的负面影响。一是各界对九寨沟景区严格实行游客限量的诉求增强,二是景区生态环境保护压力加大,三是游客满意度降低。本文在管理熵理论的指导下,拟采用RFID、eB和3S等信息技术,在时间和空间两个维度上对景区游客进行科学分流设计,建立游客高峰期时空分流导航管理模型,以期降低景区景点瞬时负荷,均衡游客时空分布,同步实现景区游客容量增加、环境保护水平提升、游客满意度增大三个目的。 展开更多
关键词 管理熵 RFID(射频识别技术) 游客高峰期 时空分流 九寨沟
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基于复杂系统控制的景区游客时空分流导航管理研究 被引量:11
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作者 邱厌庆 戈鹏 +1 位作者 刘柱胜 任佩瑜 《软科学》 CSSCI 北大核心 2011年第9期54-57,共4页
分析了系统在稳态阶段的实时预测反馈调度分流过程,采用马尔可夫过程和系统动力学模型,对系统小时域内的景区客流状况进行预测,结合仿真调度引擎,以构建景区旅游管理耗散结构为目标,为景区旅游管理人员提供有效的实时分流方案,缓解有限... 分析了系统在稳态阶段的实时预测反馈调度分流过程,采用马尔可夫过程和系统动力学模型,对系统小时域内的景区客流状况进行预测,结合仿真调度引擎,以构建景区旅游管理耗散结构为目标,为景区旅游管理人员提供有效的实时分流方案,缓解有限的景区旅游环境承载力与日益增长的游客规模之间的矛盾。为解决景区旅游复杂系统动态性和预测性的现实问题奠定了理论基础。 展开更多
关键词 复杂系统控制 管理耗散结构 时空分流导航 景区旅游系统
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基于计算机推理技术的主题公园游客时空分流决策支持系统研究——设计、仿真与比较 被引量:10
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作者 郑天翔 吴蓉 《旅游科学》 CSSCI 北大核心 2016年第1期60-77,共18页
本文针对主题公园游客时空分流的决策支持系统问题进行了研究。首先分析了游客在景区中的一次完整游憩行为,归纳出涉及这一行为的若干要素和状态。其次,为模拟这些要素并实现状态切换,设计了一种基于现场环境的游憩方向决策算法,该算法... 本文针对主题公园游客时空分流的决策支持系统问题进行了研究。首先分析了游客在景区中的一次完整游憩行为,归纳出涉及这一行为的若干要素和状态。其次,为模拟这些要素并实现状态切换,设计了一种基于现场环境的游憩方向决策算法,该算法借助计算机推理技术并综合考虑游客自身的个性化需求、景点设施的运营情况和其他游客的排队位置等环境信息来确定下一个游憩方向。再者,为验证算法的有效性,基于离散事件建模开发了一个计算机仿真系统,并采用虚拟数据进行了实验模拟和比较分析。实验结果表明,与传统的基于最短距离的算法相比,本文算法在游客等待时间、游客游玩景点数量、景点容量利用率和景点平均等待时间4个评价指标上均有不错的表现,表明该决策支持系统具有时空一体化的特性。系统产生的推荐路线在理论上能让游客自动分流并导航到较少拥挤的景点上,既能均衡各景点的接待能力,同时降低游客的等待成本,有助于主题公园的客流时空分布调控。 展开更多
关键词 旅游流调控 时空分流导航 决策支持系统 计算机推理技术 时空一体化
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自然保护区旅游高峰期时空分流导航管理的模型构建与分析 被引量:6
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作者 姜向阳 任佩瑜 《旅游科学》 CSSCI 2012年第4期17-25,76,共10页
为了在一定程度上缓解生态旅游发展与保护生态环境的尖锐矛盾,必须而且可能实施旅游高峰期时空分流导航管理。本文讨论了最小Hamilton回路和最优旅行商问题的关系,分析如何将旅行商问题(TSP)转化为Hamilton回路问题,本文通过在TSP中引... 为了在一定程度上缓解生态旅游发展与保护生态环境的尖锐矛盾,必须而且可能实施旅游高峰期时空分流导航管理。本文讨论了最小Hamilton回路和最优旅行商问题的关系,分析如何将旅行商问题(TSP)转化为Hamilton回路问题,本文通过在TSP中引入虚拟点,使单旅行商问题转化为多旅行商问题(MTSP),从而更合乎实际情况,并给出了它们的一般数学模型和精确求解方法。在此基础上构建优化的游览导航路径管理,在信息综合集成技术支持下,实现时空分流导航管理,能达到消除安全隐患,扩大旅游规模,保护生态环境的目的。本文虽然主要讨论的是利用旅行商问题来解决景区旅游的时空分流的管理问题,但事实上我们可以借鉴这种方法和思路,去解决交通运输、物流配送、车辆调度等的路线优化问题。 展开更多
关键词 自然保护区 开发与保护 时空分流导航 多旅行商问题 HAMILTON回路
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基于智能手机平台的景区游客时空分流体系构建研究 被引量:4
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作者 潘航 明庆忠 《西华大学学报(哲学社会科学版)》 2014年第3期76-80,共5页
国内众多景区以其品牌的高知名度和独具特色的景观资源,吸引了众多的国内外游客前往参观,导致景区内旅游高峰期出现严重的客流拥堵现象,因此旅游旺季景区游客的控制和调节成为景区亟待解决的重大问题。文章从智慧景区视角,在分析国内景... 国内众多景区以其品牌的高知名度和独具特色的景观资源,吸引了众多的国内外游客前往参观,导致景区内旅游高峰期出现严重的客流拥堵现象,因此旅游旺季景区游客的控制和调节成为景区亟待解决的重大问题。文章从智慧景区视角,在分析国内景区游客分布总体特征的基础上,构建了基于智能手机平台的景区游客时空分流体系,并对该体系的分流理念、运行机制、分流功能的实现路径等进行了详细阐述,最后,文章指出了该体系对传统景区旅游服务系统的提升优化作用。 展开更多
关键词 智慧旅游 景区 客流拥堵 智能手机 时空分流
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基于动态实时调度的主题公园游客时空分流导航管理研究 被引量:9
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作者 郑天翔 《旅游科学》 CSSCI 2012年第4期8-16,共9页
本文针对主题公园游客时空分流导航问题进行了研究,提出了一种与现实情形极为吻合的最小代价实时策略,借此构建了面向景点负荷均衡的游客导航分流模型,并用实验模拟了整个动态调度过程。实验结果表明,该导航模型能有效地引导游客前往等... 本文针对主题公园游客时空分流导航问题进行了研究,提出了一种与现实情形极为吻合的最小代价实时策略,借此构建了面向景点负荷均衡的游客导航分流模型,并用实验模拟了整个动态调度过程。实验结果表明,该导航模型能有效地引导游客前往等候时间最短的景点,很好地解决在各景点上负载不均的问题。通过在时间和空间上的科学的分流设计,既能提高游客的满意度,又便于景区人员随时掌握景区内资源的使用情况,提高景区常态化管理的质量,从而加速旅游、经济和生态的可持续发展。 展开更多
关键词 时空分流导航 动态调度 主题公园 景点负荷
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景区地理尺度下游客时空分流研究进展与启示
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作者 郑天翔 吴蓉 +1 位作者 罗海媛 章牧 《旅游论坛》 2016年第2期64-71,共8页
景区地理尺度下游客时空分流是实现景区有序化管理的关键环节。通过对有关文献进行梳理,归纳出该领域的理论基础和关键技术,然后从5个研究内容介绍该领域的相关进展和影响,并对其特点、贡献和不足进行分析,发现现有研究中存在的主要问题... 景区地理尺度下游客时空分流是实现景区有序化管理的关键环节。通过对有关文献进行梳理,归纳出该领域的理论基础和关键技术,然后从5个研究内容介绍该领域的相关进展和影响,并对其特点、贡献和不足进行分析,发现现有研究中存在的主要问题:(1)缺乏景区内部空间分布的优化分析;(2)游客量提前预警机制的研究尚未广泛展开;(3)游客行为的智能化引导有待深入。基于此,探讨了该领域研究的前景,展望其未来可能的发展走向。 展开更多
关键词 时空分流 游客管理 旅游景区 游客行为 景区秩序
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九寨沟景区旅游高峰期时空分流导航优化初步研究
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作者 陈启胜 郑晓婕 《商情》 2010年第19期38-38,共1页
本文从九寨沟景区旅游高峰期的游客分布及景区管理面临的问题入手,得出目前景区在高峰期游客管理方面存在问题的根源是景区内游客在时空分布上不均,导致各个景点负荷失衡。以此为基点,提出了利用景区时空分流导航优化模型来解决高峰... 本文从九寨沟景区旅游高峰期的游客分布及景区管理面临的问题入手,得出目前景区在高峰期游客管理方面存在问题的根源是景区内游客在时空分布上不均,导致各个景点负荷失衡。以此为基点,提出了利用景区时空分流导航优化模型来解决高峰期游客分流的思路,并且从游客分流和系统影响等方面进行综合评价,以不断完善和改进景区的管理状况,提高游客满意度。 展开更多
关键词 九寨沟 旅游高峰期 时空分流导航优化
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国内景区旅游流调控研究综述 被引量:9
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作者 郑天翔 吴蓉 罗海媛 《地理与地理信息科学》 CSCD 北大核心 2015年第5期90-96,共7页
景区旅游流调控是消除安全隐患、提高游客满意度和扩大景区承载能力的一种方法,也是在很大程度上缓解旅游发展与保护生态环境的尖锐矛盾的重要手段。通过对国内景区旅游流调控的有关文献进行梳理,发现相关内容涉及理论研究和实证分析,... 景区旅游流调控是消除安全隐患、提高游客满意度和扩大景区承载能力的一种方法,也是在很大程度上缓解旅游发展与保护生态环境的尖锐矛盾的重要手段。通过对国内景区旅游流调控的有关文献进行梳理,发现相关内容涉及理论研究和实证分析,主要集中在客流特征分布与时空行为、模型构建与算法设计和系统实现与平台开发3个维度。作为实证分析中的基础研究,重点总结了景区旅游流调控模型构建与算法设计的假设约束、技术手段和分流效果。对国内该领域现有文献的研究局限作了详细分析,并展望其未来可能的发展走向,以期为国内微观尺度下旅游流调控研究提供理论、方法、操作上的参考与借鉴。 展开更多
关键词 旅游流调控 时空分流 游客管理 旅游景区
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北斗自助智慧导览在景区的示范应用
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作者 尹琪琪 《电子技术与软件工程》 2021年第16期201-202,共2页
本文主要通过建设北斗智慧导览监管服务系统,部署北斗自助智慧导览终端,一是有效的代替传统的景点导游、导览模式,避免聚集扎堆倾听现象;二是提升了景区等旅游机构的应急处置能力,以应对突发事件,保护游客生命安全;三是消除游客心理疑虑... 本文主要通过建设北斗智慧导览监管服务系统,部署北斗自助智慧导览终端,一是有效的代替传统的景点导游、导览模式,避免聚集扎堆倾听现象;二是提升了景区等旅游机构的应急处置能力,以应对突发事件,保护游客生命安全;三是消除游客心理疑虑,提振游客信心,促进旅游经济进一步复苏。 展开更多
关键词 北斗自助智慧导览终端 “GIS” 大数据 时空分流
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THERMAL EFFECTS OF BUILDING′S EXTERNAL SURFACES IN CITY——Characteristics of Heat Flux into and out of External Wall Surfaces 被引量:2
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作者 ZHANGYi-ping HEYun-ling +3 位作者 LIUYu-hong MAYou-xin LIYou-rong DOUJun-xia 《Chinese Geographical Science》 SCIE CSCD 2004年第4期343-349,共7页
This study examined the thermal effects of building′s external wall surfaces, using observational data of spatial-temporal distribution of surface temperature, air temperature, and heat flux into and out of external ... This study examined the thermal effects of building′s external wall surfaces, using observational data of spatial-temporal distribution of surface temperature, air temperature, and heat flux into and out of external surface. Results indicate that external wall surface temperature and nearby air temperature vary with the change of orientation, height and season. In general, the external wall surface temperature is lower near the ground, and is higher near the roof, than nearby air temperature. But north wall surface temperature is mostly lower than nearby air temperature at the same height; south wall surface temperature during the daytime in December, and west wall surface temperature all day in August, is respectively higher than nearby air temperature. The heat fluxes into and out of external wall surfaces show the differences that exist in the various orientations, heights and seasons. In December, south wall surface at the lower sites emits heat and north wall surface at the higher sites absorbs heat. In April, all external wall surfaces, emit heat near the ground and absorb heat near the roof. In August, west wall surface all day emits heat, and other wall surfaces just show the commensurate behavior with that in April. 展开更多
关键词 external wall surface thermal effect heat flux intensity spatial-temporal distribution
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Analysis of Turbulence Structure in the Stirred Tank with a Deep Hollow Blade Disc Turbine by Time-resolved PIV 被引量:6
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作者 刘心洪 包雨云 +1 位作者 李志鹏 高正明 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2010年第4期588-599,共12页
The turbulence structure in the stirred tank with a deep hollow blade(semi-ellispe) disc turbine(HEDT) was investigated by using time-resolved particle image velocimetry(TRPIV) and traditional PIV.In the stirred tank,... The turbulence structure in the stirred tank with a deep hollow blade(semi-ellispe) disc turbine(HEDT) was investigated by using time-resolved particle image velocimetry(TRPIV) and traditional PIV.In the stirred tank,the turbulence generated by blade passage includes the periodic components and the random turbulent ones.Traditional PIV with angle-resolved measurement and TRPIV with wavelet analysis were both used to obtain the random turbulent kinetic energy as a comparison.The wavelet analysis method was successfully used in this work to separate the random turbulent kinetic energy.The distributions of the periodic kinetic energy and the random turbulent kinetic energy were obtained.In the impeller region,the averaged random turbulent kinetic energy was about 2.6 times of the averaged periodic one.The kinetic energies at different wavelet scales from a6 to d1 were also calculated and compared.TRPIV was used to record the sequence of instantaneous velocity in the impeller stream.The evolution of the impeller stream was observed clearly and the sequence of the vorticity field was also obtained for the identification of vortices.The slope of the energy spectrum was approximately-5/3 in high frequency representing the existence of inertial subrange and some isotropic properties in stirred tank.From the power spectral density(PSD) ,one peak existed evidently,which was located at f0(blade passage frequency) generated by the blade passage. 展开更多
关键词 stirred tank time-resolved particle image velocimetry wavelet analysis energy spectrum power spectral density turbulent kinetic energy
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Spatial and Temporal Patterns of Soil Nitrogen Distribution under Different Land Uses in a Watershed in the Hilly Area of Purple Soil,China 被引量:10
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作者 YANG Xiao-lin ZHU Bo LI Yi-ling 《Journal of Mountain Science》 SCIE CSCD 2013年第3期410-417,共8页
Quantification of soil spatial and temporal variability at watershed scale is important in ecological modeling, precision agriculture, and natural resources management. The spatio-temporal variations of soil nitrogen ... Quantification of soil spatial and temporal variability at watershed scale is important in ecological modeling, precision agriculture, and natural resources management. The spatio-temporal variations of soil nitrogen under different land uses in a small watershed (12.10 km^2) in the hilly area of purple soil at the upper reaches of the Yangtze River in southwestern China were investigated by using conventional statistics, geostatistics, and a geographical information system in order to provide information for land management and control of environmental issues. A total of 552 soil samples (o to 15 cm) from 276 sites within the watershed were collected in April and August of 2o11, and analyzed for soil total nitrogen (STN) and nitrate nitrogen (NO3-N). We compared spatial variations of STN and NO3-N under different land uses as well as the temporal variations in April (dry season) and August (rainy season). Results showed that STN contents were deeply affected by land-use types; median STN values ranged from 0.94to 1.27g.kg-I, and STN contents decreased in the following order: paddy field 〉 foresfland 〉 sloping cropland. No significant difference was found for STN contents between April and August under the same land use. However, NO3- N contents were 23.26, 10.58, and 26.19 mg·kg^-1 in April, and 1.34, 8.51, and 3.00 mg·kg^-1 in August for the paddy field, sloping cropland and forestland, respectively. Nugget ratios for STN indicatedmoderate spatial dependence in the paddy field and sloping cropland, and a strong spatial dependence in forestland. The processes of nitrogen movement, transformation, absorption of plant were deeply influenced by land use types; as a result, great changes of soil nitrogen levels at spatial and temporal scales were demonstrated in the studied watershed. 展开更多
关键词 Land use Soil nitrogen Spatial variation Temporal variation Watershed scale
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Snowline and Snow Cover Monitoring at High Spatial Resolution in a Mountainous River Basin Based on a Timelapse Camera at a Daily Scale 被引量:1
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作者 LIU Jun-feng CHEN Ren-sheng WANG Gang 《Journal of Mountain Science》 SCIE CSCD 2015年第1期60-69,共10页
Snowline change and snow cover distribution patterns are still poorly understood in steep alpine basins of the Qilian Mountainous region because fast changes in snow cover cannot be observed by current sensing methods... Snowline change and snow cover distribution patterns are still poorly understood in steep alpine basins of the Qilian Mountainous region because fast changes in snow cover cannot be observed by current sensing methods due to their short time scale. To address this issue of daily snowline and snow cover observations, a ground- based EOS 7D camera and four infrared digital hunting video cameras (LTL5210A) were installed around the Hulugou river basin (HRB) in the Qilian Mountains along northeastern margin of the Tibetan Plateau (38°15′54″N, 99°52′53″E) in September 2011. Pictures taken with the EOS 7D camera were georeferenced and the data from four LIL521oA cameras and snow depth sensors were used to assist snow cover estimation. The results showed that the time-lapse photography can be very useful and precise for monitoring snowline and snow cover in mountainous regions. The snowline and snow cover evolution at this basin can be precisely captured at daily scale. In HRB snow cover is mainly established after October, and the maximum snow cover appeared during February and March. The consistent rise of the snowline and decrease in snow cover appeared after middle part of March. This melt process is strongly associated with air temperature increase. 展开更多
关键词 Time-lapse camera Snow cover SNOWLINE Hulugou river basin Qilian Mountain
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Spatio-temporal Distributions of Tropospheric NO_2 over Oases in Taklimakan Desert, China
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作者 QI Yue 《Chinese Geographical Science》 SCIE CSCD 2015年第5期561-568,共8页
Soil biogenic NO emission is one of the most important sources of atmospheric nitrogen oxides(NOx) worldwide. However, the estimation of soil source, especially in arid areas presents large uncertainties because of th... Soil biogenic NO emission is one of the most important sources of atmospheric nitrogen oxides(NOx) worldwide. However, the estimation of soil source, especially in arid areas presents large uncertainties because of the substantial lack of measurements. In this study, we selected the Ruoqiang oases on the southeastern edge of the Taklimakan Desert, China as the study area and applied Ozone Monitoring Instrument(OMI) NO2 retrievals(DOMINO v2.0, 2005–2011) to investigate the spatial distribution and seasonal variations in tropospheric NO2 vertical column density(VCD). High NO2 VCDs were observed over the oases(farmlands and natural vegetation), with the highest value obtained during summer, and lowest during winter. Pulses were observed during spring. We conducted in-situ measurements in June 2011 in Milan oasis and employed ground-based multi-axis differential optical absorption spectroscopy(MAX-DOAS) instruments to validate satellite NO2 retrievals. The findings are as follows: 1) in the study area soil biogenic NO emission is the dominant source of tropospheric NO2; 2) oases(farmlands) are hotspots of tropospheric NO2, and a higher increase in tropospheric NO2 is found in oases from winter to summer; and 3) enhancement of soil biogenic NO emission due to soil managements is predictable. Given the rapid agricultural development in the southern Uygur Autonomous Region of Xinjiang, researches on soil biogenic NO emission and increase in tropospheric NOx should be given more importance. 展开更多
关键词 NO2 vertical column density ozone monitoring instrument (OMI) soil biogenic NO emission arid area agricultural management
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Spatial and Temporal Variations of Daily Ranges of the Geomagnetic Vertical Component in the Chinese Mainland
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作者 Li Junhui Li Qi +3 位作者 Wang Xingzhou He Kang Tao Yuechao Chen Jun 《Earthquake Research in China》 2013年第1期91-100,共10页
In this paper, we use the daily ranges of the vertical magnetic intensity of approximately 76 geomagnetic stations from January 1, 2008 to December 31, 2010 to analyze the spatial and temporal characteristics of Z ran... In this paper, we use the daily ranges of the vertical magnetic intensity of approximately 76 geomagnetic stations from January 1, 2008 to December 31, 2010 to analyze the spatial and temporal characteristics of Z ranges. The results are summarized as follows: (1) Temporally, we use regressive analysis and FFT analysis to analyze the data. The results show that the Z component daily ranges of all stations have an obvious cyclical variation, the computed Fourier spectra of all data sets have clearly resolved the required periodicities in the data, in the form of distinct peaks at days 365, 183, 22, and 73, and the power spectra of day 365 is the highest in all periods. (2) In terms of spatial variation, the daily ranges show nonlinear variation with latitude in China. The results show the existence of a point of inflexion (maximal value point) nearby at about 25°N, the daily ranges of Z rise from 15°~25°N and have a good linear decrease variation along with 25°~50°N. (3) Compared with the spatial and temporal variations of Z daily ranges with the Sq current inversion, we found that the spatial and temporal characteristics of Z ranges are decided mainly by the spatio-temporal evolution of the Sq current system. (4) If the latitudes of the maximum amplitudes of variation of the vertical component in the geomagnetic quiet days are roughly taken as the latitudes corresponding to the foci of Sq overhead current system, we can see that these latitudes of foci become higher in summer, are lowest in winter and highest during Equinoxes, displaying conspicuous monthly and daily variations. For two successive geomagnetic quiet days, the latitudes of foci may vary ten degrees. 展开更多
关键词 Chinese mainland GEOMAGNETIC Daily ranges of Z component Spatial and temporal variations
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Spatial and Temporal Variability of Water Availability in the Yellow River Basin
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作者 LI Ming-Xing MA Zhu-Guo 《Atmospheric and Oceanic Science Letters》 CSCD 2013年第4期191-196,共6页
The changes in hydrological processes in the Yellow River basin were simulated by using the Community Land Model(CLM,version 3.5),driven by historical climate data observed from 1951 to 2008.A comparison of modeled so... The changes in hydrological processes in the Yellow River basin were simulated by using the Community Land Model(CLM,version 3.5),driven by historical climate data observed from 1951 to 2008.A comparison of modeled soil moisture and runoff with limited observations in the basin suggests a general drying trend in simulated soil moisture,runoff,and precipitation-evaporation balance(P-E) in most areas of the Yellow River basin during the observation period.Furthermore,annual soil moisture,runoff,and P-E averaged over the entire basin have declined by 3.3%,82.2%,and 32.1%,respectively.Significant drying trends in soil moisture appear in the upper and middle reaches of the basin,whereas a significant trend in declining surface runoff and P-E occurred in the middle reaches and the southeastern part of the upper reaches.The overall decreasing water availability is characterized by large spatial and temporal variability. 展开更多
关键词 water availability VARIABILITY the Yellow River basin
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The Spatio-temporal Evolution of Ecological Risk and Its Drivers in the Weihe River Basin Landscape from 1990 to 2020
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作者 SUN Linlin XU Delan +2 位作者 MU Zhiqiang ZHAO Xiaowen LIU Baoguo 《Journal of Resources and Ecology》 CSCD 2024年第4期1004-1014,共11页
The Weihe River Basin has a significant number of tributaries and a delicate ecological environment.Understanding the spatial and temporal evolution and determinants of landscape ecological risk in the Weihe River Bas... The Weihe River Basin has a significant number of tributaries and a delicate ecological environment.Understanding the spatial and temporal evolution and determinants of landscape ecological risk in the Weihe River Basin(WRB)can improve the scientific protection and development of its watershed ecosystems.This study is based on land use statistics from the WRB for a 30-year period represented by 1990,2000,2010,and 2020.An initial model for the assessment of landscaping ecological hazards was created using the software that was also used to generate the landscape ecological risk index,such as ArcGIS 10.4 and Fragstats 4.2-64.Next,the spatial and temporal evolution of landscape ecological risk in the vicinity of the study area was characterized by the trajectory of the center of gravity migration and the spatial autocorrelation of GeoDa.Finally,Geodetector was used to analyze ecological risk drivers in the landscapes.According to the findings,the high-risk and relatively high-risk regions are steadily expanding,while the low-risk and relatively low-risk areas dominate the ecological risk landscape in the WRB.Within the Weihe River Basin,Xianyang and Xi'an are the areas to which the high-risk centers of gravity are migrating.Positive spatial correlations were found between the landscape ecological hazards in the study area,most prominently in the form of high-high and low-low aggregations.The primary drivers are the interplay between the GDP component,temperature,and elevation as a single factor. 展开更多
关键词 land use landscape ecological risk GIS spatio-temporal analysis geodetector Weihe River Basin
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Temporal and Spatial Distribution Patterns of Grain Crops in the West Liaohe River Basin 被引量:3
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作者 封志明 杨玲 杨艳昭 《Journal of Resources and Ecology》 CSCD 2014年第3期244-252,共9页
Here,we quantitatively determine temporal and spatial distribution characteristics of main grain crops in the West Liaohe River basin,Inner Mongolia,China,from 2000 to 2010 based on MODIS remote sensing data and NDVI ... Here,we quantitatively determine temporal and spatial distribution characteristics of main grain crops in the West Liaohe River basin,Inner Mongolia,China,from 2000 to 2010 based on MODIS remote sensing data and NDVI time series information for the years 2000,2005 and 2010.Phenological calendars and a decisionmaking tree extraction model were also used to obtain spatial distribution information of spring maize,spring wheat and soybean.We found that in 2010,the sown area of the main grain crops in the West Liaohe River basin was 11 965.08km2,of which,the sown area for spring maize accounted for 92.28%and was concentrated in the lower reaches of the region.Spring wheat accounted for 3.14% and was mainly in the middle reaches.Soybean accounted for 4.58% and was predominantly in the upper reaches.From 2000 to 2005,the sown area of these grain crops in the West Liaohe River basin grew by 29.77%,mainly in the lower reaches: spring maize grew by 38.99%,spring wheat by 39.04% and soybean by 21.27%.From 2005 to 2010,growth in the sown area of these crops was slow(5.18% growth) and mainly in the lower reaches of the basin.The sown area of spring maize increased,but decreased for both spring wheat and soybean. 展开更多
关键词 MODIS grain crops temporal and spatial distribution pattern West Liaohe River basin MAIZE SOYBEAN wheat.
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Temporal Behaviour of a Corner Separation in a Radial Vaned Diffuser of a Centrifugal Compressor Operating near Surge 被引量:6
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作者 A.Marsan I.Trébinjac +1 位作者 S.Coste G.Leroy 《Journal of Thermal Science》 SCIE EI CAS CSCD 2013年第6期555-564,共10页
The temporal behaviour of a flow separation in the hub-suction side comer of a transonic diffuser is studied thanks to unsteady numerical simulations based on the phase-lagged approach. The validity of the numerical r... The temporal behaviour of a flow separation in the hub-suction side comer of a transonic diffuser is studied thanks to unsteady numerical simulations based on the phase-lagged approach. The validity of the numerical re- sults is confn'med by comparison with experimental unsteady pressure measurements. An analysis of the instan- taneous skin-friction pattern and particles trajectories is presented. It highlights the topology of the separation and its temporal behaviour. The major result is that, despite of a highly time-dependent core flow, the separation is found to be a "fixed unsteady separation" characterized by a fixed location of the main saddle of the separation but an extent of the stall region modulated by the pressure waves induced by the impeller-diffuser interaction. 展开更多
关键词 Corner Separation Radial Vaned Diffuser Centrifugal Compressor SURGE
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