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We consider the use of two approaches in assessing landscape diversity of a territory: qualitative and quantitative analyses of the landscape structure on the basis of landscape maps, and a space imagery-based calculation of landscape diversity. This study revealed that the two approaches under consideration reflect different properties of landscape. It is established that the various indicators used in analyzing landscape maps unveil the aspects of a complicated and multifaceted notion of “landscape diversity”. A number of indicators overlap to a significant extent. Landscape diversity has a high degree of dependence on an island’s area.  相似文献   

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The spatial structure of the landscapes on the Southern and Middle Kuril Islands is considered. The main regularities of their landscape structure are described. The study revealed a landscape asymmetry that has a different genesis as well as the character of influence of the landscape-forming factors for the Southern and Middle Kurils, with the volcanic factor holds a special position.  相似文献   

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We characterize the main forms of manifestation of channel processes on first-order streams that have not been studied previously from this standpoint. The main morphological features of small streams are described, a typization of channel processes is provided, and differences from processes and forms of their manifestation in channels of larger rivers are identified.  相似文献   

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A rationale is given to the current importance of studying the consequences of the longterm pollutants transfer from industrial centers of East Kazakhstan. Available data on the pollution of the environmental components by elements of polymetallic ores are presented. An additional study was made of the characteristics of the distribution of 50 chemical elements in the snow cover and in the leaves of black poplar on the territory of Altai neighboring the East Kazakhstan region. A weak acid character of atmospheric precipitation, caused by increased sulfur content, is revealed. Annual flows of sulfur and nitrogen are estimated for the territory of the region. Distribution trends for chemical composition parameters of snowmelt and dust on the territory of Altai are determined. Two main groups of chemical elements in the natural environments studied are identified, namely the rock group represented by rock-forming elements, and the ore group dominated by polymetallic ores. It is found that the territory of the region polluted by these elements looks like a tongue-shaped halo with the area of 30 thou km2 extended along the northeastern direction over more than 400 km, with an average width of 100–120 km. Within the halo there is an increase in content of all the elements under study when approaching the territory of the East Kazakhstan region. It was also found that the chemical composition of snow dust on the territory of Altai is similar to the composition in the emissions from Kazzinc Metallurgical Complex in Ust’-Kamenogorsk which is supposedly one of the main sources of pollutants transferred to Altai.  相似文献   

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采用1959―2014年中国西沙站和涠洲岛站及其临近陆地台站的基本气象观测资料,分析了2个海岛的气候变化特征及其与近岸陆地的差异。结果表明:1)近56年西沙和涠洲岛及近岸陆地气温变化均呈上升趋势,西沙增暖速率(0.19℃/10 a)大于涠洲岛(0.104℃/10 a)。显著的差异出现在近10年,西沙持续增暖(0.38℃/10 a),而涠洲岛气温却呈下降趋势(-0.48℃/10 a)。从季节变化上,2个海岛都有春季越来越暖、冬季越来越冷的趋势。与周围陆地的气温相比,2个海岛的气温均高于近海陆地,但增温速率却小于近岸陆地。2)分析近56年降水量的变化,发现海岛降水量、降水强度和降水天数均小于陆地。受冬、夏季风转换的控制,海岛及近岸陆地有旱季、雨季的划分,且近半个世纪以来降水量波动大、变化趋势不显著,但伴随降水天数的减少,降水强度呈显著增长趋势。对比2个海岛近10年的降水变化特征,发现西沙站的旱季有越来越旱的趋势,涠洲岛及近岸陆地无论旱季、雨季降水量都有增加的趋势,表现为湿润化的趋势。  相似文献   

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福建省908专项海岛土地利用调查对全省l321个面积在500m。以上海岛的土地利用类型与分布进行了调查统计,将土地资源划分为12个一级类,采取多源信息相互印证及3s结合的工作方法,基本查明了海岛土地分布范围、面积和开发利用现状.经调查与测算,福建省海岛土地总面积为1628389432m^2。(包含海岛岸线外侧沿海滩涂面积474076929m^2),即海岛陆域土地总面积为1154312503m^2,其中有居民海岛陆域土地面积1106414004m^2,无居民海岛陆域土地面积47898499m^2.与1988年福建省海岛调查的14个海岛的土地利用调查结果进行对比并分析变化的原因.  相似文献   

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This study explores the spatial effects of two- and three-dimensional (2-D, 3-D) urban features in the formation of daytime and nighttime surface urban heat islands (SUHIs) with the help of satellite imagery and LiDAR. Spatially rectified statistical models are used to estimate parameters and understand the spatial spillover effects of urban drivers of SUHIs. In addition, nonlinear relationships among surface temperatures and urban features were included to improve the model fit. The empirical evidence from this study of Atlanta, Georgia, suggests that urban drivers of SUHIs exhibit different and contrasting effects depending on the time of day and their 3-D geometries. The study informs SUHI mitigation efforts by demonstrating that land use policies need to consider the differential effects of land use drivers over the diurnal cycle.  相似文献   

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利用常规气象观测资料、ECMWF ERA-Interim逐6h的0.75°×0.75°再分析资料,对河西走廊3次不同强度区域性典型冷锋型沙尘暴的大气环流形势和高低层水平螺旋度、uv分量场和垂直速度进行对比分析.结果 表明:(1)影响沙尘暴强度和范围的主要因素有高空冷空气强度、高低空风速、地面热低压中心、冷锋前后变压梯度...  相似文献   

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全球气候变暖对西沙、南沙海域珊瑚生长的潜在威胁   总被引:3,自引:0,他引:3  
利用近50年来西沙、南沙海域SST及全球温度资料,分析西沙、南沙海域SST的长期变化趋势及其与全球温度变化的关系,结果得出,西沙、南沙海域年均SST的增温率分别为(0.02±0.004)℃/a(1961-2007年)和(0.016±0.002)℃/a(1950-2007年),均高于全球温度的增温率[(0.012±0.001)℃/a,1950-2007年];西沙最热月6月份SST增温率高达(0.026±0.004)℃/a(1961-2007年),南沙最热月5月份SST增温率也达(0.011±0.003)℃/a(1950-2007年);并且西沙、南沙海域SST与全球温度存在显著的正相关性,意味着它们之间复杂的关系.预计到2030年西沙6月份SST将达30.6~1.3℃,南沙5月份SST将达30.3~30.8℃;到2050年西沙6月份SST将达31.0~32.3℃,南沙5月份SST将达30.6~31.4℃.依据珊瑚白化的温度上限(31℃),推测2030后,西沙、南沙海域将很有可能频繁地发生珊瑚白化现象,这对珊瑚生长极为不利.虽然珊瑚可能会调整自身以适应全球变暖,但采取一定的人为干预措施加以保护更为重要.  相似文献   

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唐盟 《热带地理》2015,35(5):739-744
以南海海域200 m等深线水深图和南沙群岛海域11幅1﹕250 000海图以及1﹕800 000海图为基础数据,使用ArcGIS 10.1,采用墨卡托投影,CGCS 2000坐标系对海图进行配准并进行矢量化处理,提取图中水深点、岛礁位置信息、礁坪、礁体位置信息。通过对被越南侵占的南沙群岛29座岛礁的空间分析,认为被占岛礁在空间上存在“一纵一横”的空间分布特征,南沙群岛被占岛礁南子岛、景宏岛、南威岛、六门礁从N至W构成了4个核心和广雅滩1个次核心的岛礁空间分布战略格局。通过对被占岛礁面积、礁坪面积及礁体面积进行插值处理,叠加分析,按重分类方法将插值结果按数值大小划分为5类,予以揭示被占岛礁的重要程度及未来开发潜力。通过分析越南侵占岛礁的岛屿面积与礁体面积比值,指出鸿庥岛、景宏岛、西礁、中礁、毕生礁、六门礁、柏礁有较大填海造陆潜力的岛礁。  相似文献   

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This article assesses the vulnerability to climatic and socioeconomic stresses in the Reef Islands, Solomon Islands, an atoll island group in the Southwest Pacific. Climate change and the associated sea-level rise are often seen as the most pressing challenges to atoll communities, yet this study aims at critically re-assessing this view by placing climate in the context of a range of other internal and external stressors affecting local livelihoods, including population growth, inadequate land use practices, and lack of economic potential, as well as external factors such as poorly developed infrastructure, economic marginalization and weak governance of Solomon Islands. Findings suggest that some of these non-climatic stresses are currently – and in the short term – more important determinants of local vulnerability than climate change and sea-level rise. Certainly, these stresses are likely to be exacerbated by different elements of climate change in the short, medium and long term, but generally speaking climate change does not appear to be a major driver of the current changes in the islands. On the basis of these observations, the possible adaptation options, relevant to different time scales, are discussed.  相似文献   

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