中国亚热带地区柑桔气候风险评估   总被引：3，自引：0，他引：3  

段海来  千怀遂  杜尧东 《地理学报》2010,65(3)

综合考虑柑桔气候适宜性水平及其变率变化,构建柑桔的风险度模型,运用滑动建模技术对中国亚热带地区柑桔的气候风险性进行动态分析与评估。根据风险分布强度将中国亚热带地区柑桔温度、降水、日照和气候风险大致分为三类型:低风险型、中风险型和高风险型。温度风险度大致呈纬度地带性分布,除西部高山区外,由低纬向高纬风险度依次增高;降水风险度呈现亚热带中部低,北部和西部高;与降水风险度相反,日照风险度在亚热带中部高,北部和西部低;气候风险度受温度变化的主导,也大致呈现纬度地带性,呈现高纬和西部高海拔区高,低纬和东部沿海区低。柑桔气候风险在时间和空间变化上都存在着差异,近46年来,中国亚热带地区柑桔气候风险度有逐渐增加的趋势,尤其以20世纪80年代初以来增加的最快;由于全球气候变暖的影响,亚热带东部和南部风险较低的区域分布有逐渐减少的趋势,而北部和西部风险高的区域分布有进一步增大并向东部和南部扩展的可能。从中国亚热带地区柑桔减产率大于10%、20%、30%的气候风险度分布区域变动过程来看,柑桔各减产率的气候风险度分布具有很明显的区域性和连续性,大体上由东南向西北呈增高趋势。  相似文献   

基于家庭的购物行为时、空间 决策模型及其应用   总被引：6，自引：1，他引：5  

张文佳  柴彦威 《地理研究》2010,29(2):338-350

基于家庭的购物行为决策的概念模型,利用2007年北京市活动日志调查的第一手数据,建立购物出发时间决策和购物目的地决策的条件Logit模型,并探讨其在相关政策评估和预测上的应用。结果发现:家庭内部相互作用和决策层面要素对购物时、空间决策的影响比较显著;早晚高峰出行的人群具有不同的社会经济属性和购物行为属性;居民休息日的购物活动集中在离家6km以内或者高密度的商业中心;影响购物目的地选择的因素更多是购物地距离,而非商业密度。通过模拟发现,土地混合利用的政策可能会增加高峰期的交通拥挤程度,而商业设施分散布局可能更有利于城市交通状况的改善和居民日常生活质量的提升。  相似文献   

中国北方山区的土地压力及其缓解途径:21个小流域的经验分析(英文)     

朱会义  何书金 《地理学报(英文版)》2010,20(6):913-922

Land pressure and adaptation are the main factors determining environmental degradation in most of China’s mountainous regions. Little attention so far has been paid to the adaptation strategies based on evaluation of land pressure in these regions. We evaluated the grain production pressure and economic development pressure for 21 small watersheds undergoing soil conservation measures in the northern mountainous region of China, compared the evaluation results with actual production for each of the watersheds, and analyzed the adaptation strategies. The results imply that land pressure was spatially heterogeneous among the sample watersheds, but there was a balancing trend between land pressure and productive capacity for each watershed. Under rising pressure, these watersheds developed a variety of adaptation strategies such as labor migration, increasing fruit and nut production, and expanding rural tourism if possible. These strategies result from evolution of the market economy in China, and persistent development of the national economy determines the variation of environment in these mountainous regions.  相似文献   

五大危机事件对美国出入境旅游的影响——基于本底线模型的高分辨率分析   总被引：1，自引：0，他引：1  

孙根年  舒镜镜  马丽君  王洁洁 《地理科学进展》2010,29(8)

在重新阐述旅游本底趋势线理论及危机评估方法的基础上,依据1996年1月-2009年11月客流量统计值,采用月指数分解模型与本底线距平方法,分析了五大危机事件对美国出入境旅游的影响.结果显示:①1998年亚洲金融危机,使来自日韩及港台的入境游客显著减少,对美国入境旅游影响期16个月,累计损失游客221.7万人次,旅游收入累计损失76.45亿美元;②2001年9.11恐怖袭击事件对美国入境旅游影响持续26个月,累计损失游客1178.2万人次,出境旅游影响持续15个月,累计损失游客526.8万人次:旅游收入和旅游花费累计损失218.41亿美元和134.20亿美元;③2003年SARS危机与9.11事件相连,对入境旅游影响期12个月,损失游客773.6万人次,出境旅游影响期10个月,损失游客214.8万人次;旅游收入和旅游花费累计减少146.34亿美元和80.31亿美元;④2004-2006年间受到6次飓风灾害的影响,每次飓风对入境旅游影响期2～3个月,累计损失游客234万人次;出境旅游影响期2～3个月,累计损失游客106.8万人次.⑤2008年金融海啸对出境旅游的影响大于入境旅游,截至2009年11月,累计损失入境游客721.6万人次,出境游客463.9万人次;旅游收入损失168.66亿美元,旅游花费减少165.47亿美元.最后,本文还从事件性质、发生源地、影响机制和波形特征等方面,对五大危机事件的影响进行了横向比较,为清晰认识旅游危机提供了科学依据.  相似文献   

The comprehensive evaluation of China＇s urbanization and effects on resources and environment   总被引：11，自引：3，他引：8  

Mingxing Chen  Dadao Lu  Liangsong Zha 《地理学报(英文版)》2010,20(1):17-30

This paper constructs a comprehensive evaluation index system for the urbanization level in China in terms of four aspects of urbanization connotation: population, economy, society, and land. A comprehensive measurement is carried out for the Chinese urbanization between 1981 and 2006 based on the Entropy method. The results show that the comprehensive level of urbanization in China has a continuous increase with the major features of economic growth and a rapid evolution of the geographical landscape, followed by population urbanization and then social urbanization of health care standard; the distinguished evolutional characteristics can also be found in each of the subsystems. The integrated evolution of urbanization has a profound effect on the resources, energy and the environment, making the land resources and energy security situation under severe pressure. The environment pressure is also increased further.  相似文献   

地动噪声功率谱及动态范围的一致性分析   总被引：1，自引：1，他引：0  

段天山  袁顺 《地震地磁观测与研究》2010,31(5):122-126

在和田地震台阵中心子台安放9台CMG-40T型短周期地震计,采用EDAS-24IP数据采集器进行数据采集。对同一时段观测数据的地动噪声功率谱、动态范围等参数进行测定,并对测定结果进行对比,在使用者的角度分析该类型地震计的一致性。  相似文献   

地震震害微观与宏观方法快速盲估综述   总被引：2，自引：0，他引：2  

李智  王晓青 《地震》2010,30(2):134-142

本文以分类清单法和利用GDP进行震害评估法为例, 回顾地震损失微观、 宏观两类快速评估方法的原理、 流程及应用。 总结两种方法的特点, 并做简单对比。 结果表明, 根据要求的不同和掌握资料丰富程度的差异, 选择适当的方法进行震后快速盲估, 其结果对政府决策和抢险救灾具有重要意义。  相似文献   

Characteristics of horizontal ground motion measures along principal directions   总被引：1，自引：0，他引：1  

H. P. Hong  K. Goda 《地震工程与工程振动(英文版)》2010,9(1):9-22

<正>Ground motion records are often used to develop ground motion prediction equations(GMPEs) for a randomly oriented horizontal component,and to assess the principal directions of ground motions based on the Arias intensity tensor or the orientation of the major response axis.The former is needed for seismic hazard assessment,whereas the latter can be important for assessing structural responses under multi-directional excitations.However,a comprehensive investigation of the pseudo-spectral acceleration(PSA) and of GMPEs conditioned on different axes is currently lacking.This study investigates the principal directions of strong ground motions and their relation to the orientation of the major response axis, statistics of the PSA along the principal directions on the horizontal plane,and correlation of the PSA along the principal directions on the horizontal plane.For these,three sets of strong ground motion records,including intraplate California earthquakes,inslab Mexican earthquakes,and interface Mexican earthquakes,are used.The results indicate that one of the principal directions could be considered as quasi-vertical.By focusing on seismic excitations on the horizontal plane,the statistics of the angles between the major response axis and the major principal axis are obtained;GMPEs along the principal axes are provided and compared with those obtained for a randomly oriented horizontal component;and statistical analysis of residuals associated with GMPEs along the principal directions is carried out.  相似文献   

Remote sensing of ecosystem services: An opportunity for spatially explicit assessment   总被引：6，自引：5，他引：1  

FENG Xiaoming  FU Bojie  YANG Xiaojun  Lü Yihe 《中国地理科学(英文版)》2010,20(6):522-535

Ecosystem service is an emerging concept that grows to be a hot research area in ecology. Spatially explicit ecosystem service values are important for ecosystem service management. However, it is difficult to quantify ecosystem services. Remote sensing provides images covering Earth surface, which by nature are spatially explicit. Thus, remote sensing can be useful for quantitative assessment of ecosystem services. This paper reviews spatially explicit ecosystem service studies conducted in ecology and remote sensing in order to find out how remote sensing can be used for ecosystem service assessment. Several important areas considered include land cover, biodiversity, and carbon, water and soil related ecosystem services. We found that remote sensing can be used for ecosystem service assessment in three different ways: direct monitoring, indirect monitoring, and combined use with ecosystem models. Some plant and water related ecosystem services can be directly monitored by remote sensing. Most commonly, remote sensing can provide surrogate information on plant and soil characteristics in an ecosystem. For ecosystem process related ecosystem services, remote sensing can help measure spatially explicit parameters. We conclude that acquiring good in-situ measurements and selecting appropriate remote sensor data in terms of resolution are critical for accurate assessment of ecosystem services.  相似文献   

基于面向对象的高分辨率遥感建筑物震害信息提取与评估   总被引：3，自引：3，他引：0       下载免费PDF全文

赵妍  张景发  姚磊华 《地震学报》2016,38(6):942-951

为了快速地确定地震等自然灾害引起的受灾区域范围,并对其受灾程度进行及时评估,本文采用面向对象的建筑物检测方法,基于高分辨率遥感影像所包含的地物几何结构和纹理特征信息,提出了一种建筑物震害信息提取与评估的方法和技术流程.在此基础上,以2010年玉树M_S7.1地震部分地区地震前后的QuickBird影像为例,对受灾区域震前、震后建筑物的形状、面积等信息进行提取,提取精度分别为88.53%和90.21%,对该区域建筑物变化信息进行提取所获取的建筑物变化信息精度为79.68%,统计变化区域像素个数,确定变化面积为15 923.52 m2,占研究区域总面积的68.16%,因此评估其为中重度受灾区域.本文结果与实地考察结果一致,证实了这种快速的震害信息提取与评估流程切实有效,能够快速评估受灾区,为灾后第一时间抢险及救援提供重要参考.   相似文献