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青藏高原植被垂直带与气候因子的空间关系 总被引：7，自引：1，他引：6
集成了青藏高原气候区149个山地植被垂直带数据,利用国家基本气象台站自建站以来到2001年的地面观测日气象数据,计算了地面的温暖(WI)、寒冷(CI)、湿润(MI)、吉良龙夫(Kira)干湿指数、干燥度(Idm)等水热指数,运用GIS的空间分析模块,模拟了青藏高原水热条件的空间分布形势,探讨山地植被垂直带谱分布规律与制约因子的定量指标.结果表明:在高原的东北部、西北边缘,以荒漠、荒漠草原、山地森林、山地草原、灌丛、草甸为组合的半干旱、干旱结构向高原腹地以高寒草原、高山草甸、荒漠带组合的高寒干旱带谱结构的变化;东南、南部边缘,以温暖湿润为特征的以森林带为优势带谱组合结构逐渐向寒冷的高原中心变化;高原的地势效应,致使的水热形势旱现从中央向边缘变化的趋势是致使青藏高原植被垂直带谱分布的重要原因. 相似文献
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区域生态安全研究的科学基础与初步框架 总被引：23，自引：3，他引：20
生态安全研究涉及多种尺度（种群、生态系统、流域、区域、国家）,其中区域生态安全是区域和国家可持续发展的基础,是建立和谐社会及环境友好型社会的必要条件,是人类生态安全的核心,应该处于中心的地位。但目前为止进行的区域生态安全研究多集中在综合指标评价、生物安全及土地利用变化效应的分析,比较缺乏严格的判定区域生态安全的科学基础。本文认为,地理地带性应是区域生态安全研究的基本准则;景观（土地类型）的原生态值可以作为区域生态安全的客观标准;景观退化程度是区域生态安全的重要指标;三者共同构成区域生态安全研究的科学基础。本文提出了区域生态安全研究的地理学方法,其框架体系应包括：（1）地理地带性分析及景观原生态定值;（2）景观退化程度的确定;（3）区域退化景观格局分析;（4）周围区域的生态影响分析;（5）区域生态安全水平的判别模式;（6）区域生态安全的指标体系。 相似文献
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山体效应及其对林线分布的影响(英文) 总被引：7，自引：2，他引：5
The concept of mass elevation effect(massenerhebungseffect,MEE) was intro-duced by A.de Quervain about 100 years ago to account for the observed tendency for temperature-related parameters such as tree line and snowline to occur at higher elevations in the central Alps than on their outer margins.It also has been widely observed in other ar-eas of the world,but there have not been significant,let alone quantitative,researches on this phenomenon.Especially,it has been usually completely neglected in developing fitting mod-els of timberline elevation,with only longitude or latitude considered as impacting factors.This paper tries to quantify the contribution of MEE to timberline elevation.Considering that the more extensive the land mass and especially the higher the mountain base in the interior of land mass,the greater the mass elevation effect,this paper takes mountain base elevation(MBE) as the magnitude of MEE.We collect 157 data points of timberline elevation,and use their latitude,longitude and MBE as independent variables to build a multiple linear regres-sion equation for timberline elevation in the southeastern Eurasian continent.The results turn out that the contribution of latitude,longitude and MBE to timberline altitude reach 25.11%,29.43%,and 45.46%,respectively.North of northern latitude 32°,the three factors’ contribu-tion amount to 48.50%,24.04%,and 27.46%,respectively;to the south,their contribution is 13.01%,48.33%,and 38.66%,respectively.This means that MBE,serving as a proxy indi-cator of MEE,is a significant factor determining the elevation of alpine timberline.Compared with other factors,it is more stable and independent in affecting timberline elevation.Of course,the magnitude of the actual MEE is certainly determined by other factors,including mountain area and height,the distance to the edge of a land mass,the structures of the mountains nearby.These factors need to be included in the study of MEE quantification in the future.This paper could help build up a high-accuracy and multi-scale elevation model for alpine timberline and even other altitudinal belts. 相似文献
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山地垂直带谱的数字识别方法探讨 总被引：4，自引：0，他引：4
在地学信息图谱思想和数字带谱体系的基础上,阐明了垂直带谱数字识别的概念和方法.通过AML语言组合ArcGIS功能模块,实现了昆仑山北侧垂直带谱的数字识别,通过评价认为其成果能够适用于山系尺度的带谱研究;探讨了Matlab软件编程实现山体360°带谱数字识别的算法;进一步分析了垂直带研究中带谱界限自动识别的前景和挑战.在对两种程序设计方法进行对比和分析的基础上,确立了山体单侧、山体360°两种垂直带谱模式的构建技术.研究表明,带谱数字识别技术能够为山地垂直带谱的构建提供可行的支持,促进地学信息图谱的进一步发展. 相似文献
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阿尔金山-祁连山山地植被垂直带谱分布及地学分析 总被引：6，自引：2，他引：6
本文揭示阿尔金-祁连山区垂直带谱空间分布模式并进行地学解释。研究表明:北坡荒漠草原带的上限具有随经度变化的二次曲线分布模式,草原带的上限分布为线性模式,亚冰雪带的分布与7月份气温的零度层分布模式基本相同;北坡镜铁山以西的带谱中没有森林带,以东含有森林带,分布在25003300米的高度范围内。利用气象台站的地面及高空数据,计算了湿度———生长季平均温度露点差随海拔变化的梯度、多年平均温度、1月多年均温、多年平均降水指标以解释带谱分布,结果表明:由东向西,湿度梯度增大,以酒泉为界,西侧的露点温度差梯度大于0.12℃/100米,东部小于0.09℃/100米,与北坡山地森林带分布基本吻合。 相似文献
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近600年来北极与中国气候变化的对比 总被引：2，自引：2，他引：0
许娟 《地理学报(英文版)》2004,14(3):289-295
A compilation of paleoclimate records from lake sediments, trees, ice cores, and historical documents provide a view of China and Arctic environmental changes in the last 600 years. Many of these changes have also been identified in sedimentary and geochemical signatures in deep-sea sediment cores from the North Atlantic Ocean, Arctic and Greenland and ice cores from the Qinghai-Tibet Plateau, confirming the linkage of environmental changes of different time scales between the Arctic and China. It is shown that the changes of precipitation, temperature and sea ice cover in Arctic were correlated with climate changes in China. This paper also developed a comparative research on the climate changes between Arctic and China both during the Little Ice Age (LIA) and the instrumental observation period. Cycles and trend of temperature variations during LIA and temperature and precipitation during the instrumental observation period are performed. We found some similarities and differences of environmental changes between Arctic and China. 相似文献
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山地植被带的提取及分析是地学和生态学研究的基础问题之一.利用野外点/线调查和历史文献资料,可以对局域尺度山体的植被带进行归纳和描绘,而在区域乃至全球尺度上更多依赖于学者的经验和知识.利用内蒙古大青山地区1∶100万植被图、1∶10万土地利用图、1∶25万DEM等,设计逻辑判别规则,提取典型的山地植被带斑块;然后基于贝叶斯识别算法,利用地形、水热和太阳辐射等因子对区域尺度山地植被带进行空间分布模拟,最终提取的植被带具有较高的精度,总体精度为74.53％,Kappa系数为0.69.研究表明,利用多源数据可以提取和模拟区域尺度山地植被带连续分布格局,中小比例尺空间数据的集成应用使得该方法的推广具有较大的可行性,为进一步获取大陆及全球尺度的山地植被带数据奠定了基础. 相似文献
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Based on temperature reconstruction and proxy data from 14 sites in the Northern Hemisphere, this paper focused on comparing the cycles of temperature variations between the Arctic and other areas, including Atlantic, Europe, China, Asia, Pacific, Indian Ocean, and America during the transition from the last Interstade to the Last Glacial Maximum, from the Last Glacial Maximum to megathermal period in Holocene and the transition of the Little Ice Age （LIA） by the methods of Singular Spectrum Analysis （SSA） and Maximum Entropy Spectrum （MES）. The results showed that environmental changes in the Arctic are most similar to that in the North American and better similar to Asia, Atlantic and Pacific, the least similar to Indian Ocean and Europe. The 1500-year oscillation of temperature existed both in Arctic and Europe. 相似文献
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以成都市为研究区,定量分析了各地表特征参数与地表温度之间的线性关系。通过对地表温度与归一化植被指数(NDVI)、归一化建筑指数(NDBI)、归一化水汽指数(NDMI)进行局部区域逐像元分析和总体区域统计分析,结果表明NDVI,NDMI,NDBI与地表温度间都存在明显的线性关系,可用于说明地表温度的动态变化,在3月份,NDMI与地温的相关性更优于NDVI。对传统城市热现象研究中,NDMI与NDBI能够用来以NDVI作为分析地表温度随季节而变化的互补的度量标准。 相似文献