Naturgeografin i högskolan och samhället i Sverige

Mattsson, Jan O.: Naturgeografin i högskolan och samhället i Sverige. Geografisk Tidsskrift 83: 4–6. Copenhagen, June 1, 1983.

Geography as a national science in Sweden: Research and University training as well as the aplication of geography in the community. 1982.     

Geografin vid universiteten och i samhället i Finland

Fogelberg, Paul: Geografin vid universiteten och i samhället i Finland. Geografisk Tidsskrift 83: 3–4. Copenhagen, June 1, 1983.

Geography as a science in Finland: Research and University training as well as the application of geography in the community. 1982.     

Use of subfossil <Emphasis Type="Italic">Chaoborus</Emphasis> mandibles in models for inferring past hypolimnetic oxygen

Assemblages of subfossil Chaoboridae mandibles from 80 thermally-stratified shield lakes in southern central Canada were examined to explore the influence of subfossil Chaoborus on subfossil Chironomidae-based paleolimnological inference models of deepwater oxygen, as volume-weighted hypolimnetic oxygen (VWHO). Inclusion of subfossil Chaoborus in subfossil Chironomidae-based VWHO models only improved model performance modestly, however it produced substantively better inferences of hypolimnetic oxygen in anoxic lakes, because Chaoborus had a much stronger positive relationship with low VWHO compared to chironomid taxa indicative of anoxic conditions, such as Chironomus. A Chaoborus mandible:Chironomidae head capsule ratio (chaob:chir) may be a useful index in paleolimnological studies, as chaob:chir in a surface sediment training set was significantly related to VWHO, and displayed little co-variation with other limnological variables such as trophic status (e.g. TP, TN) or lake depth (e.g. Z _max). Chaob:chir values in a stratigraphic analysis tracked chironomid-inferred VWHO, however the use of chaob:chir in regional ‘top–bottom’ paleolimnological studies must be used with caution.     

RØMØ: NATURVURDERING PÅ GEOGRAFISK-ØKOLOGISK BASIS

Presentation of 3 maps concerning the island of Rømø: Plate 1: The landscape elements (ecotypes). Plate 2: The man-made constructions as settlements, roads, dam, dikes and a harbour as well as plantations. Plate 3: A land use map supplemented by noise zoning of road traffic, an interference leaving a minor part of the area as being untouched nature.

Plate 1: 1) Tidal flats, low lying, 2) Creek, 3) Channel, 4) Tidal inlet, 5) Tidal flat, sandy, 6) High sand, 7) Sandy salt marsh, 8) beach ridge, 9) Break-through of the sea, 10) Deflation plain, 11) Dunes, minor forms, 12) Dunes, greater forms, 13) Salt marsh of the foreland, 14) Muddy tidal flats, 15) Phragmites salt marsh, 16) Agricultural area, 17) Polder area, 18) Marine foreland, dike burst.

Plate 2: 1) Macadam main road, 2) Macadam road, 3) Gravel road, 4) Earth road, 5) Sand road, 6) Dike, 7) Line of poles, 8) Settlements, 9) Recreational area, 10) Camping, 11) Plantations.

Plate 3: 12) Agricultural area, diked in, 13) Agricultural area, undiked.

Principles of nature conservancy as well as the future problems of agriculture on the island are discussed.     

Visualisation and evaluation of flood uncertainties based on ensemble modelling

This study evaluates how users incorporate visualisation of flood uncertainty information in decision-making. An experiment was conducted where participants were given the task to decide building locations, taking into account homeowners’ preferences as well as dilemmas imposed by flood risks at the site. Two general types of visualisations for presenting uncertainties from ensemble modelling were evaluated: (1) uncertainty maps, which used aggregated ensemble results; and (2) performance bars showing all individual simulation outputs from the ensemble. Both were supplemented with either two-dimensional (2D) or three-dimensional (3D) contextual information, to give an overview of the area.

The results showed that the type of uncertainty visualisation was highly influential on users’ decisions, whereas the representation of the contextual information (2D or 3D) was not. Visualisation with performance bars was more intuitive and effective for the task performed than the uncertainty map. It clearly affected users’ decisions in avoiding certain-to-be-flooded areas. Patterns to which the distances were decided from the homeowners’ preferred positions and the uncertainties were similar, when the 2D and 3D map models were used side by side with the uncertainty map. On the other hand, contextual information affected the time to solve the task. With the 3D map, it took the participants longer time to decide the locations, compared with the other combinations using the 2D model.

Designing the visualisation so as to provide more detailed information made respondents avoid dangerous decisions. This has also led to less variation in their overall responses.     

青藏高原及横断山区地质灾害易发区空间格局及驱动因子

青藏高原及横断山区位中国西南部,地貌类型复杂,地质灾害频发,严重威胁到西南地区人民生命财产安全,尤其影响进藏交通线的通达度。系统研究该区地质灾害易发区空间格局及驱动因子,可为青藏高原及横断山区地质灾害风险防范及地质灾害的防灾减灾救灾提供重要理论支撑。研究结果表明,基于随机森林构建的判识模型对于灾害点的判识精度均高于80%,甚至达到91%,可准确模拟与预测研究区各分区的地质灾害点。研究区地质灾害易发点主要分布在横断山区南部与东北部以及青藏高原中南部地区,且以小型及中型规模地质灾害为主（占比为87%）。综合分区Ⅰ~Ⅲ的地质灾害易发区面积分别为17.5万km²、17.4万km²与27.5万km²。各综合分区地质灾害驱动因子研究表明,横断山区南部区域（综合分区Ⅰ内）小型及中型地质灾害的主要驱动力为道路建设导致的沿途坡面稳定性变化（贡献率为20.2%）;横断山区东北部区域及青藏高原地区（综合分区Ⅱ~Ⅲ）小型及中型地质灾害的主要驱动力为植被覆盖状况的变化对于坡面稳定性的影响（贡献率分别为23.6%与27.3%）。此外,综合分区Ⅱ~Ⅲ内影响小型及中型地质灾害空间格局的第二个驱动因子为道路建设导致的沿途坡面稳定性的变化（贡献率为15.7%）与河流对于周边坡面的侵蚀作用（贡献率为17%）。     

Land Classification Maps of Areas Basic to Agricultural Production

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.     

Books in Brief

Abstract

R. H. Osborne. EAST-CENTRAL EUROPE: AN INTRODUCTORY GEOGRAPHY. New York: Frederick A. Praeger, 1967 (originally published as EAST-CENTRAL EUROPE: A GEOGRAPHICAL INTRODUCTION TO SEVEN SOCIALIST STATES. London: Chatto and Windus, 1966). 384 pages, maps and statistical tables in appendix. $7.50.

Herbert Riehl. INTRODUCTION TO THE ATMOSPHERE. New York: McGraw-Hill Book Company, 1965. 365 pages. $8.95.     

Surface-sediment and epilithic diatom pH calibration sets for remote European mountain lakes (AL:PE Project) and their comparison with the Surface Waters Acidification Programme (SWAP) calibration set

A modern diatom-pH calibration data-set consisting of surface-sediment diatom assemblages from 118 lakes and 530 taxa is presented. The AL:PE data-set is from high-altitude or high-latitude lakes in the Alps, Norway, Svalbard, Kola Peninsula, UK, Slovenia, Slovakia, Poland, Portugal, and Spain (pH range = 4.5-8.0; DOC range = 0.2-3.2 mg l^-1). In addition, 92 epilithon samples from 22 high-altitude or high-latitude lakes comprise an AL:PE epilithon diatom-pH data-set. Weighted averaging partial least squares regression is used to develop pH-inference models. The AL:PE data-set has a root-mean-square-error of prediction (RMSEP) of 0.33 and a maximum bias of 0.36 pH units and r² of 0.82, as assessed by leave-one-out cross-validation. The epilithon data-set has, after data-screening and the deletion of one very obvious outlier, a RMSEP of 0.23 and a maximum bias of 0.18 pH units and r² of 0.88. The 167 sample SWAP diatom-pH data-set from lowland or upland lakes in the UK, Norway, and Sweden has a RMSEP of 0.29 and a maximum bias of 0.23 pH units and r² of 0.86.The pH optima, as estimated by weighted averaging and Gaussian regression, are compared for the three data-sets (AL:PE, SWAP, AL:PE epilithon). There is a good correspondence between the AL:PE and the AL:PE epilithon optima, but a consistent bias between the AL:PE and SWAP optima, with the SWAP optima being lower than the AL:PE estimates.The predictive performances of the AL:PE and SWAP calibration data-sets are compared using independent test samples and six core sequences, all from high-altitude lakes, one in south-east Siberia and five in eastern Scotland. The results show the importance of using the AL:PE data-set for inferring lake-water pH from diatom assemblages in high-altitude or high latitude lakes with low DOC concentrations.     

兰州-西宁-银川城市带与西部开发

通过对有关城市、区域的统计分析,在评述兰州-西宁-银川城市带基本特征的基础上,重点讨论其在西部大开发中四个方面的地位作用：我国内陆腹地的战略要地和开发据点,沟通我国东西部间、我国与中亚、欧洲国家间的桥梁和纽带,保障国家资源安全的能源重化工基地和重要进口通道,保障国家生态安全的重点生态建设区。并针对其在内部结构、市场化、开放度方面的主要问题,指出其发展趋势和战略选择：加快城市带交通通道建设,将潜在资源优势转化为现实经济优势,创造局部优势投资环境和开放社会,重视教育、科技和生态建设。     

Beyond Postmetropolis

Three recent developments have created new challenges and opportunities for urban geography and geographers: the rediscovery of the generative power of cities, the cross-disciplinary diffusion of critical spatial perspectives, and rising interest in regions and regionalism. With these new developments as background, I reflect upon some of the ideas and themes introduced in Postmetropolis: Critical Studies of Cities and Regions, published in 2000. Like the book, this effort to move beyond Postmetropolis is divided into three parts: Remapping the Geohistory of Cityspace; Six Discourses on the Postmetropolis; and Lived Space: Remembering 1992 in Los Angeles. Some of the same themes are taken up, often with a different emphasis, in the accompanying essays by Robert Beauregard, Mona Domosh, and Deborah Martin.     

SPLITAREA: an algorithm for weighted splitting of faces in the context of a planar partition

Geographic data themes modelled as planar partitions are found in many GIS applications (e.g. topographic data, land cover, zoning plans, etc.). When generalizing this kind of 2D map, this specific nature has to be respected and generalization operations should be carefully designed. This paper presents a design and implementation of an algorithm to perform a split operation of faces (polygonal areas).

The result of the split operation has to fit in with the topological data structure supporting variable-scale data. The algorithm, termed SPLITAREA, obtains the skeleton of a face using a constrained Delaunay triangulation. The new split operator is especially relevant in urban areas with many infrastructural objects such as roads. The contribution of this work is twofold: (1) the quality of the split operation is formally assessed by comparing the results on actual test data sets with a goal/metric we defined beforehand for the ‘balanced’ split and (2) the algorithm allows a weighted split, where different neighbours have different weights due to different compatibility. With the weighted split, the special case of unmovable boundaries is also explicitly addressed.

The developed split algorithm can also be used outside the generalization context in other settings. For example, to make two cross-border data sets fit, the algorithm could be applied to allow splitting of slivers.     

SCARING CROWS*

A long‐form essay, arranged in a sequence of eight segments, in which I travel the countryside in search of a missing person: the scarecrow. Different aspects of the centuries‐old practice of scarecrow making and bird scaring are described. Traditionally constructed as a likeness of the human form and erected in newly sown fields as a visual method for warding off feeding birds, the existence of this striking farmland contraption is variously reported: as having all but vanished and yet of making unexpected reappearances; as materially functional and complexly meaningful; as a figure summoned up by cultural memory and personal recollection; and as a focus for mixed feelings of loss, nostalgia, estrangement, and community. A version of “geographical portraiture” accumulates, in which a single, scenic landmark stands as the essay's central fascination and simultaneously operates as a cipher for stories old and new, of agricultural society, country life, landscape politics, and rural values.     

流域地貌演化的不同阶段沟壑密度与切割深度关系研究

主要探讨了在流域地貌演化的不同阶段,沟壑密度与切割深度的复杂关系,建立了沟壑密度随切割深度变化的理论极值模型及相应阶段的函数,补充了各演化阶段地貌形态要素的定量、定性描述;反之,可用沟壑密度与切割深度的关系推断流域地貌的演化阶段。     

CYBERSPACE AND VIRTUAL PLACES

ABSTRACT. Computer networks are often described in terms that imply a virtual space or place: electronic frontier, cyberspace, and information superhighway have been used to indicate computer networks as a whole; cafés, dungeons, and virtual offices are some of the “places” people refer to as being in or on networks. The use of this language, which I collectively call “virtual-place metaphors,” indicates three broad metaphorical themes: virtual architecture, electronic frontier, and cyberspace. The metaphors encourage control, surveillance, and capitalist expansion through computer technologies—and also evasion and resistance through computer technologies.     

青海海北高寒草甸五种植被生物量及环境条件比较

分析了高寒草甸不同植被类型植物种类组成、生物量变化规律及其差异。研究表明不同植被类型的分布与土壤湿度和温度有很大的关系。藏篙草草甸、金露梅灌丛草甸、矮篙草草甸、正恢复的矮篙草草甸、小嵩草草甸这5种不同植被类型所对应的土壤湿度依次降低，而所对应的土壤温度依次升高；植物种类数量表现为矮嵩草草甸＞金露梅灌丛草甸＞小篙草草甸＞正恢复的矮篙草草甸＞藏篙草草甸。地上生物量高低依次为小嵩草革甸＞矮嵩草草甸＞金露梅灌丛草甸＞正恢复的矮篙草草甸＞藏篙草草甸；地下生物量则表现出金露梅灌丛革甸＞矮嵩草甸＞小篙草草甸＞正恢复的矮篙草草甸的特征，而其在年内的周转值表现出金露梅灌丛草甸＞正承复的矮嵩草草甸＞小篙草草甸＞矮篙草草甸;土壤有机质的季节变化表现为0—40cn整层土壤有机质含量小嵩草草甸＞金露梅灌丛草甸＞矮嵩草草甸＞正恢复的矮篙草草甸，0—10cm的表层土壤有机质金露梅灌丛草甸＞矮嵩草草甸＞小嵩草草甸＞正恢复的矮篙草草甸。     

Comparison of input data with different spatial resolution in landscape pattern analysis – A case study from northern Latvia

A suitable spatial scale needs to be selected in geographical and landscape ecological research, and this requires great consideration as different scales have profound effect on derived landscape spatial patterns. Numerous studies have investigated the effects of different scales on landscape metrics using simulated patterns, but few have been conducted to compare different data sources with variable scale for regional- and landscape-scale assessments. Possibly this has occurred because researchers have been prone to use the best available source, a well-known standard, and easiest to use. This study was conducted to assess the impact of input data resolution on values of landscape pattern metrics in four landscapes at scales 1:10 000, 1:50 000 and 1:100 000. The aim was to determine the applicability of three data sources for thematic models in landscape pattern analyses in the Eastern Baltic region. We found that the utility of CORINE Land Cover data for comprehensive structural assessment in mosaic-type landscapes was very limited, as the level of cartographic generalization excluded many small and linear landscape structure elements with potentially high importance for landscape functioning, such as habitat continuity. We also found that actual area harvested using clearcuts was considerably higher than shown in CORINE data, due to clearcuts size being much smaller than the minimum mapping unit. In the light of this, we suggest using data with spatial resolution corresponding to a cartographic scale of at least 1:50 000, in cases when spatial patches have size up to 25 ha.