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1.
There is a growing demand for reliable information about land cover and land resources. The Norwegian area frame survey of land cover and outfield land resources (AR18X18) is a response to this demand. AR18X18 provides unbiased land cover and land resource statistics and constitutes a baseline for studying changes in outfield land resources in Norway and a framework for a national land resource accounting system for the outfields. The area frame survey uses a systematic sampling technique with 0.9 km2 sample plots at 18 km intervals. A complete wall-to-wall land cover map of an entire plot surveyed is obtained in situ by a team of fieldworkers equipped with aerial photographs. The use of sample plots with extended coverage (0.9 km2) ensures that the survey also deals with local variation, thus strengthening the estimates well beyond simple point sampling. The article documents the methodology used in the survey, followed by a discussion of issues raised by the choice of methodology. These issues include the problem of calculating uncertainty and a confidence interval for the estimates, the focus on common rather than rare land cover categories, and the prospect of downscaling the results in order to obtain statistics for subnational regions.  相似文献   

2.
The vast accumulation of environmental data and the rapid development of geospatial visualization and analytical techniques make it possible for scientists to solicit information from local citizens to map spatial variation of geographic phenomena. However, data provided by citizens (referred to as citizen data in this article) suffer two limitations for mapping: bias in spatial coverage and imprecision in spatial location. This article presents an approach to minimizing the impacts of these two limitations of citizen data using geospatial analysis techniques. The approach reduces location imprecision by adopting a frequency-sampling strategy to identify representative presence locations from areas over which citizens observed the geographic phenomenon. The approach compensates for the spatial bias by weighting presence locations with cumulative visibility (the frequency at which a given location can be seen by local citizens). As a case study to demonstrate the principle, this approach was applied to map the habitat suitability of the black-and-white snub-nosed monkey (Rhinopithecus bieti) in Yunnan, China. Sightings of R. bieti were elicited from local citizens using a geovisualization platform and then processed with the proposed approach to predict a habitat suitability map. Presence locations of R. bieti recorded by biologists through intensive field tracking were used to validate the predicted habitat suitability map. Validation showed that the continuous Boyce index (Bcont(0.1)) calculated on the suitability map was 0.873 (95% CI: [0.810, 0.917]), indicating that the map was highly consistent with the field-observed distribution of R. bieti. Bcont(0.1) was much lower (0.173) for the suitability map predicted based on citizen data when location imprecision was not reduced and even lower (?0.048) when there was no compensation for spatial bias. This indicates that the proposed approach effectively minimized the impacts of location imprecision and spatial bias in citizen data and therefore effectively improved the quality of mapped spatial variation using citizen data. It further implies that, with the application of geospatial analysis techniques to properly account for limitations in citizen data, valuable information embedded in such data can be extracted and used for scientific mapping.  相似文献   

3.
深圳市地形对土地利用动态的影响   总被引:5,自引:0,他引:5  
基于RS和GIS的技术支持,以深圳市为案例,利用多时段土地利用数据和地形数据,分析土地利用变化的时空分异,研究城市地域地形对土地利用动态的影响。分析表明,土地利用在空间上的变化引起其垂直重心的变化,耕地重心降低,林地和建设用地重心上升。深圳市地形对土地利用动态有明显的制约作用,主要表现为:随着高程和坡度的升高,土地利用动态度大致呈降低趋势。随着城市化的加深,同一高程带和坡度带上土地利用动态度呈加大趋势。土地利用动态度的情景分析指出,在自然景观时期、农业景观成熟期和后城市化时期,土地利用在高程带和坡度带上都比较稳定,动态度低;在这三个时期之间是农业化时期和快速城市化时期,土地利用动态度高。  相似文献   

4.
Abstract

Einevoll, O. 1968. Land Classification Maps of Areas Basic to Agricultural Production. Norsk geogr. Tidsskr. 22, 264–270.

In Norway, a detailed land survey, based on photogrammetry, is now proceeding for land classification maps of the scale 1:5,000 (for certain minor areas 1:10,000) covering agricultural areas and including forest land. The areas to be mapped are classified according to land capability and general conditions of management. Containing a great deal of additional information as well, these maps will serve as a valuable aid in land use planning. The survey is designed to be completed in 12–15 year's time.

More roughly designed maps for the entire country on the scale 1:100,000 and 1:250,000, printed in colour, will be produced within two years' time. Intermediate maps of 1:20,000, containing an extended number of land types, will be undertaken gradually, after the appearance of the large scale map series. Property boundaries recorded in connexion with the surveying for the large scale maps will serve as the basis for a complete land register containing exact information about size and land properties of individual holdings.  相似文献   

5.

Maps are an important source of data for planning and land use analysis of flood-prone areas. Map users with inadequate training are not aware that map errors can lead to ineffective decisions. Although inherent errors introduced by transformation, map construction, and symbolization are never identified on maps, they limit the effectiveness of maps as sources of data. Additional vertical and horizontal errors can be introduced during map use. Knowledge of the sources and amounts of such errors should result in more effective decisions regarding flood hazards.  相似文献   

6.
Abstract

Crucial aspects of the referent phenomena which provide the subject matter for cartographic symbolism are often overlooked by map interpreters in their haste to “read maps at a glance.” The blame rests largely on those practitioners of the environmental sciences who stress the simple, intuitive nature of maps, while effectively ignoring the true complexity of the cartographic communication process. Those persons who are responsible for traditional map interpretation training programs are also at fault for implying, through long emphasis, that symbol identification, position location, and navigation constitute the essence of map analysis. The intuitive acceptability of map symbols in spite of their abstract character is also a deceptive factor. The fact that there is far “more than meets the eye” to map interpretation is easily demonstrated by looking closely at several basic cartographic symbols. In order to become an effective map user the environmental scientist apparently must go well beyond the mastery of conventional map reading principles and learn to deal with diverse informational dimensions in the context of the map use purpose and the physical/cultural make-up of the geographical region under study.  相似文献   

7.
Multifactorial correlation analysis is a new method used to predict the land subsidence caused by groundwater exploitation. This article introduces and applies the method to establish the function of t...  相似文献   

8.
In the field of phylogenetic analyses, the rbcL gene encoded large subunit Ribulose-1,5-biphosphate carboxylase/oxygenase (Rubisco, EC4.1.1.39), which plays a crucial role in the process of photosynthesis for most terrestrial plants, has been considered to be conserved; however, recent controversy regarding rbcL conservation has appeared since it was proposed to be under natural selection within all principal lineages of land plants. In this study, by examining the variation of DNA and protein sequences among 17 species in the family Tamaricaceae, three nonsynonymous mutations were identified to be under positive selection. The favored sites were located in the alph-helix domains of Rubisco, with decreased hydrophobicity and increased entropy, which could facilitate CO2 penetration into the active site of Rubisco. We also found that the expression level of rbcL in different genotypes of Reaumuria soongarica shifted in response to various stresses such as drought, temperature, salt, and light. This study not only sheds light on the functional/structural features of Rubisco in the evolution scenarios from C3-like into C4 in Tamaricaceae but also provides useful information on directing genetic performance to enhance photosynthesis efficiency of desert plants for sustaining fragile desert ecosystems; furthermore, it promotes the ability to cope with desert aridification and global warming.  相似文献   

9.
This study demonstrates use of compound-specific radiocarbon analysis (CSRA) for dating Holocene lacustrine sediments from carbonate-hosted Ordy Pond, O‘ahu, Hawai‘i. Long-chain odd-numbered normal alkanes (n-alkanes), biomarkers characteristic of terrestrial higher plants, were ubiquitous in Ordy Pond sediments. The δ13C of individual n-alkanes ranged from −29.9 to −25.5‰, within the expected range for n-alkanes synthesized by land plants using the C3 or C4 carbon fixation pathway. The 14C ages of n-alkanes determined by CSRA showed remarkably good agreement with 14C dates of rare plant macrofossils obtained from nearby sedimentary horizons. In general, CSRA of n-alkanes successfully refined the age-control of the sediments. The sum of n-alkanes in each sample produced 70–170 μg of carbon (C), however, greater age errors were confirmed for samples containing less than 80 μg of C. The 14C age of n-alkanes from one particular sedimentary horizon was 4,155 years older than the value expected from the refined age-control, resulting in an apparent and arguable age discrepancy. Several lines of evidence suggest that this particular sample was contaminated by introduction of 14C-free C during preparative capillary gas chromatography. This study simultaneously highlighted the promising potential of CSRA for paleo-applications and the risks of contamination associated with micro-scale 14C measurement of individual organic compounds.  相似文献   

10.
Nilsen, R. 2014. Rural modernisation as national development: The Norwegian case 1900–1950. Norsk Geografisk TidsskriftNorwegian Journal of Geography Vol. 68, 50–58. ISSN 0029-1951.

The aim of the article is to explain the maintenance of a pattern of scattered rural settlement in Norway during industrialisation and modernisation. The ‘master narrative’ of Norwegian transformation, based on the development of waterpower and the metallurgical and fertiliser industries, is only one of three narratives that can be told about the national transformation in the 20th century. A second narrative concerns the modernisation along the coast, and a third concerns the development of a varied, mostly rural, manufacturing and import-substituting industry. It is suggested that this attempt at rewriting the history of Norwegian modernisation can do what the master narrative does not do, namely explain the transformation from a poor to a rich society while more than half of the national population continued to live in rural areas.  相似文献   

11.
Soil erosion is a complex process determined by mutual interaction of numerous factors. The aim of erosion research at regional scales is a general evaluation of the landscape susceptibility to soil erosion by water, taking into account the main factors influencing this process. One of the key factors influencing the susceptibility of a region to soil erosion is land cover. Natural as well as human-induced changes of landscape may result in both the diminishment and acceleration of soil erosion. Recent studies of land-cover changes indicate that during the last decade more than 4.11% of Slovak territory has changed. The objective of this study is to assess the influence of land-cover and crop rotation changes over the 1990–2000 period on the intensity and spatial pattern of soil erosion in Slovakia. The assessment is based on principles defined in the Universal Soil Loss Equation (USLE) modified for application at regional scale and the use of the CORINE land cover (CLC) databases for 1990 and 2000. The C factor for arable land has been refined using statistical data on the mean crop rotation and the acreage of particular agricultural crops in the districts of Slovakia. The L factor has been calculated using sample areas with parcels identified by LANDSAT TM data. The results indicate that the land-cover and crop rotation changes had a significant influence on soil erosion pattern predominately in the hilly and mountainous parts of Slovakia. The pattern of soil erosion changes exhibits high spatial variation with overall slightly decreased soil erosion risks. These changes are associated with ongoing land ownership changes, changing structure of crops, deforestation and afforestation.  相似文献   

12.
During the last two decades, a variety of models have been applied to understand and predict changes in land use. These models assign a single-attribute label to each spatial unit at any particular time of the simulation. This is not realistic because mixed use of land is quite common. A more detailed classification allowing the modelling of mixed land use would be desirable for better understanding and interpreting the evolution of the use of land. A possible solution is the multi-label (ML) concept where each spatial unit can belong to multiple classes simultaneously. For example, a cluster of summer houses at a lake in a forested area should be classified as water, forest and residential (built-up). The ML concept was introduced recently, and it belongs to the machine learning field. In this article, the ML concept is introduced and applied in land-use modelling. As a novelty, we present a land-use change model that allows ML class assignment using the k nearest neighbour (kNN) method that derives a functional relationship between land use and a set of explanatory variables. A case study with a rich data-set from Luxembourg using biophysical data from aerial photography is described. The model achieves promising results based on the well-known ML evaluation criteria. The application described in this article highlights the value of the multi-label k nearest neighbour method (MLkNN) for land-use modelling.  相似文献   

13.
Underthun, A., Kasa, S. & Reitan, M. 2011. Scalar politics and strategic consolidation: The Norwegian Gas Forum's quest for embedding Norwegian gas resources in domestic space. Norsk Geografisk Tidsskrift–Norwegian Journal of Geography Vol. 65, 226–237. ISSN 0029-1951.

The article discusses political initiatives and networks that aim to enhance the use of Norwegian natural gas resources in domestic space. Through perspectives on state rescaling and scalar politics, the authors explore the strategies of the Norwegian Gas Forum (NGF). This political network serves as an umbrella organization for regional political initiatives for local distribution and exploitation of natural gas along the Norwegian coast. It is argued that the initiatives demonstrate a scalar politics that counter tendencies of state rescaling in the realm of petroleum politics, where the state is less willing to invest and intervene in domestic natural gas utilization. The article examines the NGF's policy work, organizational composition, and ‘networks of association’ with other organizations. This is framed in the analysis as ‘scalar politics’ aiming to secure the member regions’ current and future dependence on domestic gas supplies. The important networks of association in relation to the Norwegian Confederation of Trade Unions (LO) and the Confederation of Norwegian Enterprise (NHO) implied compromise and consolidation among the regional members of NGF, but also empowered NGF on important policy issues.  相似文献   

14.
A generic problem associated with different land cover maps that cover the same geographical area is the use of different legend categories. There may be disagreement in many areas when comparing different land cover products even though the legend shows the same or very similar land cover class. To capture the uncertainty associated with both differences in the legend and the difficulty in classification when comparing two land cover maps, expert knowledge and a fuzzy logic framework are used to map the fuzzy agreement. The methodology is illustrated by comparing the Global Land Cover 2000 data set and the MODIS global land cover product. Overall accuracy measures are calculated, and the spatial fuzzy agreement between the two land cover products is provided. This approach can be used to improve the overall confidence in a land cover product, since areas of severe disagreement can be highlighted, and areas can be identified that require further attention and possible re-mapping.  相似文献   

15.
根据1995年和2000年土地利用数据,运用ARC/INFO软件和景观生态学方法,研究了青藏公路沿线格尔木、曲麻莱、治多3个县(市)的土地利用变化和景观格局变化,修订了单一土地利用类型动态度计算公式,重点分析了公路缓冲带的土地利用变化、景观格局变化和建设用地缓冲带的土地利用变化。主要结论如下:①研究区建设用地增加迅速,林地、水域、未利用土地增加,耕地大量减少,草地退化严重,其中曲麻菜县草地减少22.8%,未利用土地增加 43.96%;②景观破碎化程度加剧,分维数、多样性指数和景观破碎度均增加;③与其它交通干线对沿线的 “轴向”影响不同,该段青藏公路以“点”型的辐射效应为标志,且仅仅影响建设用地周围的区域,格尔木市的影响范围是3 km,五道梁的影响范围是1km; ④K=(Ua+Ub-2Uc)Ua-1T-1×100%,可准确地反映单一土地利用类型变化特点。  相似文献   

16.
《Urban geography》2013,34(2):263-300
Negative spatial autocorrelation (NSA), the tendency for dissimilar neighboring values to cluster on a map, may go undetected in statistical analyses of immature Anopheles gambiae s.l., a leading malaria mosquito vector in Sub-Saharan Africa. Unquantified NSA generated from an inverse variance-covariance matrix may generate misspecifications in an An. gambiae s.l. habitat model. In this research, we used an eigenfunction decomposition algorithm based on a modified geographic connectivity matrix to compute the Moran's I statistic, to uncover hidden NSA in a dataset of georeferenced An. gambiae s.l. habitat explanatory predictor variables spatiotemporally sampled in Malindi and Kisumu, Kenya. The Moran's I statistic was decomposed into orthogonal synthetic map patterns. Global tests revealed that |zMC|s generated were less than 1.11 for the presence of latent autocorrelation. The algorithm captured NSA in the An. gambiae s.l. habitat data by quantifying all non-normal random variables, space-time heterogeneity, and distributional properties of the spatial filters.  相似文献   

17.
This study compares two types of intermediate soft-classified maps. The first type uses land use/cover suitability maps based on a multi-criteria evaluation (MCE). The second type focuses on the transition potential between land use/cover categories based on a multi-layer perceptron (MLP). The concepts and methodological approaches are illustrated in a comparable manner using a Corine data set from the Murcia region (2300 km2, Spain) in combination with maps of drivers that were created with two stochastic, discretely operating, commonly used tools (MCE in CA_MARKOV and MLP in Land Change Modeler). The importance of the different approaches and techniques for the obtained results is illustrated by comparing the specific characteristics of both approaches by validating the suitability versus transition potential maps to each other using a Spearman correlation matrix and, between the Corine maps, using classical ROC (receiver operating characteristic) statistics. Then, we propose a new use of ROC statistics to compare these intermediate soft-classified maps with their respective hard-classified maps of the models for each category. The validation of these results can be beneficial in choosing a suitable model and provide a better understanding of the implications of the different modeling steps and the advantages and limitations of the modeling tools.  相似文献   

18.
天山北坡城镇化进程中的水土资源效益及其时空分异   总被引:3,自引:1,他引:3  
杨宇  刘毅  金凤君  董雯  李莉 《地理研究》2012,31(7):1185-1198
通过空间分析的Global Moran''s I指数和Getis-Ord Gi*指数以及协调发展度函数选取1995年、2000年、2005年和2008年4个年份数据对天山北坡城镇化进程中的土地资源效益、水资源效益的集聚扩散状态及其冷热点空间格局演化与空间联动发展效应进行分析,研究发现:(1)天山北坡在绿洲自然地理格局下发育起来的城镇,受自然地理条件和水土资源分布特点及城镇发展水平不一、城镇性质各异而对水土资源利用程度不一等因素影响,其城镇化水平和水土资源效益的空间格局表现出不同的发展状态。(2)土地资源效益相似的县市具有明显的空间差异,呈现出分散的格局并保持相对稳定的态势。(3)水资源效益的空间集聚和扩散状态不稳定,变化显著。(4)水土资源效益在城镇化进程中各自的空间演化格局与路径迥异,区域联动效应差异显著。绿洲城镇发展的实际决定了水土资源效益的冷热点区域演化相比自身发展水平更具敏感性。  相似文献   

19.
陕西大理河流域土地利用/覆被变化的水文效应   总被引:5,自引:3,他引:2  
近年来,土地利用/覆被变化的水文效应研究已成为国际的前沿和重点。在大理河流域,LUCC(包括水土保持措施)对水循环和水量平衡产生了深远影响,该流域LUCC水文效应的研究势在必行。根据研究区1990年代三期土地利用数据分析了LUCC的时空变化特征,采用特征变量时间序列法及降水-径流模型对LUCC水文效应进行了研究。结果表明:流域土地利用类型以耕地和草地为主,近10年来,耕地和草地面积有所减少,而林地和建设用地面积持续增加;流域年径流和月径流演化过程均表现出明显的下降趋势;LUCC及水土保持具有减少流域年径流、汛期流量以及增加枯季流量的作用,相对于降水因素,人类活动对流域水文的作用占主导地位;在1990~2000年期间,主要由LUCC引起的年均径流减少量达2616.6×104 m3,占该期间实测减水总量的62.19%。  相似文献   

20.
This study aims to understand GIS based ecotourism potential of Munessa Shashemene Concession Forest and its surrounding area in Ethiopia. Landsat images from 2009/2010 and 2013 were used to drive baseline data including land cover, land use, stream and road. Elevation based agro-ecology and slope map were derived from SRTM DEM. Rapid wild animals survey, identifying the location of known historical, cultural and unique features were carried out in the filed with the help of key-informants. A suitability model was designed in GIS environment to assess the suitability of an area for tourism considering suitability factors such as land cover types, wild animal zone, unique features, topography and distance to a road. The result showed areas which are highly suitable, moderately suitable, marginally suitable, or unsuitable for tourism. The old giant, Podocarpus (Podocarpus falcatus) trees that serve as habitat of the endangered and endemic mountain nyala (Tragelaphus buxtoni), were identified as very high suitable areas for tourists. The highly suitable areas include forest area along the lake which is seasonally visited by mountain nyala and areas of plantation forest that are found adjacent to natural forest. These areas follow remnants of the natural forest and found along boundary between the mid-highland and the highland agro-ecologies. The agricultural land use types consisting of maize/haricot-bean and wheat/barley were evaluated as marginally suitable, nevertheless these could be considered as potential for agri-tourism. The study revealed that the concession area is found to be a suitable area with its huge potential for ecotourism development.  相似文献   

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