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1.
Geomorphologic maps are one of the most fundamental materials of the natural environment. They have been widely used in scientific research, resource exploration and extraction, education and military affairs etc. An editorial committee was established in 2001 to collect materials for researching and compiling a set of new 1:1,000,000 geomorphologic atlas of China. A digital geomorphologic database was created with visual interpretation from Landsat TM/ETM imageries and SRTM-DEM etc. The atlas compiled from the database was finished. The main characteristics of the atlas are as follows: Firstly, Landsat TM/ETM imageries, published geomorphologic maps or sketches, geographical base maps, digital geological maps, and other thematic maps were collected, which were uniformly geometrically rectified, clipped into uniform sheets, and stored in the foundation database. Secondly, based on the legends of 15 sheets 1:1,000,000 maps published in the 1980s, a geomorphologic classification system was built by combining morphology and genesis types. The system comprised seven hierarchical layers: basic morphology, genesis, sub-genesis, morphology, micro-morphology, slope and aspect, material composition and lithology. These layers were stored in the database during visual image interpretation. About 2000 kinds of morpho- genesis and 300 kinds of morpho-structure were interpreted. Thirdly, the legend system was built, which included color, symbol bases and note bases etc., compilation standards and procedures were developed, 74 sheets of 1:1,000,000 covering all land and sea territories of China were compiled, the 1:1,000,000 geomorphologic atlas of the People’s Republic of China was finished and published. The atlas will fill the blanks in national basic scale thematic maps, and the geomorphologic database could be applied widely in many fields in the future.  相似文献   

2.
The publication of the European Landscape Convention (2000) had a stimulating effect on the development of both new systems of landscape classification and new methods of their evaluation and mapping. As an example, a new classification of physiognomic landscape types was developed in Poland in 2014. The objectives of the paper are to (1) popularize, on the international scale, the classification of physiognomic landscape types in a new, improved version, (2) present the original method of physiognomic landscape types mapping with the use of the system of basic landscape units, and (3) present the results of testing of the method in the area of the Kazimierz Landscape Park, Poland. In the area of the Kazimierz Landscape Park, 491 basic landscape units were delimited, within which, on the basis of the leading traits of land relief and cover forms, the physiognomic landscape types were identified. Maps of this type can be important tools in implementing the recommendations of the European Landscape Convention. The total number of physiognomic landscape types identified within a specific area can be one of the key indicators of landscape diversity.  相似文献   

3.
长江三角洲城市群发展展望   总被引:28,自引:1,他引:28  
长江三角洲城市群是中国最大的城市群,其发展和演变对中国城市发展、中国沿海经济乃至亚太地区的发展均具有举足轻重的地位和作用。改革开放以来,中国经济的迅速增长,经济全球化过程的加速,均为长江三角洲城市群的发展提供难得的机遇与挑战。重点论述长江三角洲城市群发展展望。  相似文献   

4.
合成了3种单核配合物,通过元素分析、摩尔电导和红外光谱进行了表征。在动态空气下,采用热重和差热技术研究了N,N′-双氨烷基草酰胺合铜(Ⅱ)配合物热分解动力学。用Achar法和Coats-Redfen法分析了非等温动力学数据,并对比动力学参数提出了最合适的热分解动力学模型。由热重曲线计算出了热分解反应的活化能、热焓和指前因子。对比配合物N,N′-双-2氨乙基草酰胺合铜(Ⅱ)、N,N′-双-2氨丙基草酰胺合铜(Ⅱ)和N,N′-双-3-氨丙基草酰胺合铜(Ⅱ)初始分解温度,配合物的热稳定性排序为:Cu(oxpn)>Cu(oxap)>Cu(oxen)  相似文献   

5.
采用 TG- DTG- DTA热分析技术研究了 N,N’-双 (3-氨丙基 )草酰胺合胴 ( )配合物在动态空气气氛中的热行为 ;用微分法 (Achar法 )和积分法 (Coats- Redfen法 )协同处理非等温 TG数据 ,通过对比热分解动力学参数 E和 ln A,提出了配合物第一阶段热分解动力学方程 :dα/ dt =Ae- E/ RT (1-α ) 2 及第二阶段热分解动力学方程 :dα/ dt=Ae- E/ RT(1-α) ;并由动力学补偿效应获得了 E和 ln A的数学表达式  相似文献   

6.
We present some improvements of a gravity inversion method to determine the geometry of the anomalous bodies for priori density contrasts. The 3-D method is based on an exploratory process applied, not for the global model, but for the steps of a growth approach. The (positive and/or negative) anomalous structure is described by successive aggregation of cells, while its corresponding gravity field remains nearly proportional to the observed one. Moreover, a simple (e.g. linear) regional trend can be simultaneously adjusted. The corresponding program is applied to new gravity data on the volcanic island of Faial (Azores archipelago). The inversion approach shows a subsurface anomalous structure for the island, the main feature being an elongated high-density body. The body is interpreted as a compact sheeted dyke swarm, emplaced along Faial-Pico Fracture Zone, a leaky transform structure that forms the current boundary between Eurasian and African plates in the Azores area. The new results in this paper are (1) a Bouguer gravity anomaly map, (2) several improvements in the inversion process (robust process, optimal balance fitness/model magnitude), (3) a new gravimetric method for estimating the mean terrain density, (4) a 3-D model for subsurface mass anomalies in Faial and (5) some interpretative conclusions about a main intrusive complex detected under the island as a wall-like structure extending from a depth of 0.5 to 6 km b.s.l., with a N100°E trend and corresponding to an early fissural volcanic episode controlled by the regional tectonics.  相似文献   

7.
戴光全  谭健萍 《地理学报》2012,67(8):1109-1124
从报纸媒体的角度研究广交会作为重大事件的综合影响力的时空分布特点.以中国知网()所属“中国重要报纸全文数据库”(CCND) 2000-05-05到2011-05-30时间段内“广交会”为主题的4333条新闻报道为研究文本,通过传播学中的内容分析法建构分析类目,统计类目包括新闻的时间、所属的届数与期数、报社所在城市、新闻版面、新闻字数等,共由3个编码员进行统计,并对类目编码进行信度检测.在对新闻内容进行计量统计的基础上,引进信息熵度量信息量,利用信息熵和报道篇数构建广交会综合影响力指标,进一步构建广交会空间综合影响力指数方程,分析广交会综合影响力在全国的分布情况,并检验综合影响力指标和经济指标的相关性.结果发现:①从时间分布来看,以新闻报道数量来衡量,在事件(广交会)进行时其综合影响力存在时间衰减现象,各展期综合影响力的年际变化则呈现为周期性的年度重复现象.②从空间分布来看,广交会综合影响力空间分布与城市参展商数量、经济情况和距离有着密切的联系:受影响大的城市主要集中在沿海经济发达的省份,受影响小的城市主要分布在西部和北部,整体上综合影响力大小和城市分布的密度由东到西递减;综合影响力总体上存在显著的空间距离衰减,但对于北京和上海这两个特殊城市而言,空间距离已经不是广交会综合影响力的主要因素,而在广交会举办地的“当地”(广东省内)较短的距离内,距离衰减并不显著,当空间距离超出一定范围,则存在明显的距离衰减现象.  相似文献   

8.
吉林省西部草业经济发展刍议--以羊草、紫花苜蓿为例   总被引:2,自引:0,他引:2  
基于实地调查资料的基础上,作者从吉林省西部草业经济发展的必要性入手,着重论述了吉林省西部草业经济发展障碍性因素及其运行机制,认为思想意识与启动资金障碍是关键环节,并针对发现的障碍因素,提出了一系列对策。  相似文献   

9.
The purpose of the present study is the analysis of landslide risk for roads and buildings in a small test site (20 km2) in the area north of Lisbon (Portugal). For this purpose, an evaluation is performed integrating into a GIS information obtained from multiple sources: (i) landslide hazard; (ii) elements at risk; and (iii) vulnerability. Landslide hazard is assessed on a probabilistic basis for three different types of slope movement (shallow translational slides, translational slides and rotational slides), based on some assumptions such as: (i) the likelihood of future landslide occurrence can be measured through statistical relationships between past landslide distribution and specified spatial data sets considered as landslide predisposing factors; and (ii) the rainfall combination (amount–duration) responsible for past slope instability within the test site will produce the same effects (i.e. same type of landslides and similar total affected area), each time they occur in the future. When the return period of rainfall triggering events is known, different scenarios can be modelled, each one ascribed to a specific return period. Therefore, landslide hazard is quantitatively assessed on a raster basis, and is expressed as the probability for each pixel (25 m2) to be affected by a future landslide, considering a rainfall triggering scenario with a specific return period. Elements at risk within the test site include 2561 buildings and roads amounting to 169 km. Values attributed to elements at risk were defined considering reconstruction costs, following the guidelines of the Portuguese Insurance Institute. Vulnerability is considered as the degree of loss to a given element resulting from the occurrence of a landslide of a given magnitude. Vulnerability depends not only on structural properties of exposed elements, but also on the type of process, and its magnitude; i.e., vulnerability cannot be defined in absolute terms, but only with respect to a specific process (e.g. vulnerability to shallow translational slides). Therefore, vulnerability was classified for the three landslide groups considered on hazard assessment, taking into account: (i) landslide magnitude (mean depth, volume, velocity); (ii) damage levels produced by past landslide events in the study area; and (iii) literature. Finally, a landslide risk analysis considering direct costs was made in an automatic way crossing the following three layers: (i) Probabilistic hazard map for a landslide type Z, considering a particular rainfall triggering scenario whose return period is known; (ii) Vulnerability map (values from 0 to 1) of the exposed elements to landslide type Z; and (iii) Value map of the exposed elements, considering reconstruction costs.  相似文献   

10.
This paper examines the soil-water behaviour of sandy soils representative of a broad area in the Duero river basin (Spain), with semi-arid bioclimatic characteristics. Soil-moisture measurements of the first 25 cm of soil profile were taken using time domain reflectometry (TDR) methodology. The infiltration process was studied by means of field experiments combining rainfall simulations and TDR techniques. Finally, a set of hydrodynamic variables was calculated in the laboratory (i.e. available soil-water content, soil-water-retention curves and hydraulic conductivity).The average available soil-water content is 0·07 cm3 cm−3, in accordance with the predominance of the sandy textural fraction (85%). The rainfall simulation experiments show that infiltration prevails over overland flow, with a steady-state infiltration rate higher than rainfall application (40mmh−1) in most cases; a low water-retention capacity was also observed. The evolution of soil-moisture over time indicates a close dependence on intra-annual rainfall variability due to the low water-retention capacity of sandy soils. With a maximum water-storage capacity of around 0·18 cm3 cm−3, the soils studied show high sensitivity to dry spells and may remain with <50% of the available soil-water content for several months during the year.  相似文献   

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