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1.
《The Journal of geography》2012,111(7):429-435
Abstract

This paper is a response to the two-fold thesis of Bartz; namely, that (1) maps are not really important in our society today, and (2) educators say that they value maps and mapping, but the evidence of children's performance in using maps is contradictory. In exploring problems related to Bartz's contention, the author arrives at four tentative conclusions :

  1. A child can and does learn many but not all of the map concepts and skills at an earlier age when taught them developmentally, systematically, functionally, and effectively.

  2. Mere manipulation of materials does not constitute a concrete experience for a child.

  3. Map-related concepts must be taught prior to, and continued concurrently with, map skills.

  4. The commercially prepared map tends to appear near the highest level of abstract mapping and is therefore not necessarily the most effective means of map instruction for the elementary teacher.

A most significant implication from the conclusions is the need to re-examine the preparation of the elementary teacher. If the focus of the education of a teacher moves in the direction outlined in this paper, Bartz's premise could be reversed.  相似文献   

2.
This article reviews the theoretical foundations for the concept of peak minerals; drawing on similarities and differences with peak oil as modelled using Hubbert style curves. Whilst several studies have applied peak modelling to selected minerals, discussion of the appropriateness of using Hubbert style curves in the minerals context remains largely unexplored. Our discussion focuses on a comparison between oil and minerals, on the key variables: rates of discovery, estimates of ultimately recoverable resources and demand and production trends. With respect to minerals, there are several obstacles which complicate the application of Hubbert style curves to the prediction of future mineral production, including the lack of accurate discovery data, the effect of uncertain reserve estimates, and varying ore quality and quantity. Another notable difference is that while oil is often combusted during use, minerals are used to make metals which are inherently recyclable. Notwithstanding, by using a range of estimates of resources and/or reserves, a period of time can be identified which indicates when a peak in minerals production may occur. This information may then be used to plan for a transition from using a potentially constrained resource, to using substitutes if available, or to reducing demand for that mineral in society.  相似文献   

3.
The preproposal stage of the rulemaking process is notoriously understudied, but enormously important in determining regulatory outputs. Recently, Rinfret (2011c Rinfret , S. R. 2011c . Frames of influence: U.S. environmental rulemaking case studies . Rev. Policy Res. 28 ( 3 ): 231245 .[Crossref], [Web of Science ®] [Google Scholar]) analyzed the U.S. Fish and Wildlife Service (USFWS) rulemaking process and developed a frame analysis model to interpret stakeholder influence during the preproposal stage. Rinfret argues that stakeholders use three frames to influence agency rulemaking, including an expertise, a fiscal feasibility, and an information frame. This article tests this model to determine whether it is applicable to other federal agencies such as the National Park Service (NPS). Through an analysis of stakeholder framing within the 2012 NPS Yellowstone Winter Use Rule, this research confirms that Rinfret's model is indeed applicable to the NPS process. Therefore, this research suggests that this theoretical model examining stakeholder influence is applicable to other public land agencies, and arguably can be applied across the bureaucracy.  相似文献   

4.
Presented is a detailed characterization of the present state and pollution of soil cover in the influence area of the Dzhidinskii tungsten-molybdenum plant which takes into consideration the spatial geological inhomogeneity and the functional purpose of urban territories. As part of the investigation, we determined the content levels of heavy metals and metalloids in background soils, and the elements which are the main pollutants of urban soils in the zones of different functional purposes, ascertained the degree of technogenic geochemical transformation of soil cover in the city of Zakamensk, and identified the leading soiland landscape-geochemical factors for accumulation of heavy metals and metalloids in the urban topsoil (0?10 cm) horizons. An assessment was also made of the ecological hazard of soil pollution by a set of heavy metals and metalloids in the main functional zones of the city. A soil-geochemical survey was carried out, and the ICP-MS method was used to determine the total content levels of 14 heavy metals and metalloids of hazard classes I?III as well as Be, Sn, Cs and Bi. The elements were determined, which are the main pollutants of the soils in Zakamensk: W, Bi, Cd, Pb and Mo. The study revealed a need to take into account the metallogenic specific character and geological inhomogeneity of the area by using the local coefficients of concentration (EF l ) and dispersal (DF l ) which must be calculated not with respect to the average regional background but from the individual (for each parent material) background value in order to more accurately determine the degree of technogenic geochemical transformation of soils, and the ecological hazard of pollution. It is suggested that the ecological hazard should be assessed on the basis of the Integrated Pollution Index (IPI) which is calculated with respect to the world’s average concentrations of heavy metals and metalloids in soils and takes into account hazard classes of elements.  相似文献   

5.
6.
This paper uses annual data on world oil price and consumption from 1965 to 2006 to calibrate a Hotelling model of optimal nonrenewable resource extraction. Numerical solutions are generated for various specifications of the elasticity of demand for both isoelastic demand and linear demand under each of two possible market structures: perfect competition and monopoly. Prior to the 1973 oil crisis, the model that best fits actual data is one of perfect competition with linear demand and a demand elasticity of −0.4. For the periods 1973–1981 and 1981–1990, the model that best fits actual data is one of monopoly with linear demand and demand elasticities of −0.8 and −0.7, respectively, suggesting that the market was strongly influenced by OPEC during this time. Under the model that best fits the most recent period (perfect competition with linear demand and demand elasticity −0.5), the real oil price (in 1982–1984 U.S.$) should fall in the range $60.87–$66.31/barrel over the years 2010–2030.
C.-Y. Cynthia LinEmail:
  相似文献   

7.
Supplying worldwide demand of metallic raw materials throughout the rest of this century may require 5–10 times the amount of metals contained in known ore deposits. This demand can be met only if mineral deposits containing the required masses of metals, in excess of present day ore reserves, exist in the Earth’s crust. It is, by definition, not known whether or not such mineral deposits exist. On the basis of the statistical distribution of metal tonnages contained in known ore deposits, however, it is possible to place constraints on the size distribution of the deposits that must be discovered in order to meet the expected demand. A nondimensional analysis of the distribution of metal tonnages in deposits of 20 metals shows that most of them follow distributions that, although not strictly lognormal, share important characteristics with a lognormal distribution. Chief among these is the observation that frequency falls off symmetrically and geometrically with deposit size, relative to a median deposit size that is approximately equal to the geometric mean deposit size. An immediate consequence of this behavior is that most of the metal endowment is concentrated in deposits that are several orders of magnitude larger than the median deposit size, and that are much rarer than the most common deposits that cluster around the median deposit size. The analysis reveals remarkable similarities among the statistical distributions of most of the metals included in this study, in particular, the fact that distribution of most metals can be fully described with essentially the same value (about 2–3) of the scale parameter, σ, which is the only parameter needed to describe the behavior of a normalized lognormal variable. This observation makes it possible to derive the following general conclusions, which are applicable to most metals—both scarce and abundant. First, it is unlikely that undiscovered mineral deposits of sizes comparable to those that contain most of the known metal endowment exist in sufficient quantities to supply the expected worldwide demand throughout the rest of this century. Second, if the expected demand is to be met, one must hope that very large deposits, perhaps up to one order of magnitude larger than the largest known deposits, exist in accessible portions of the Earth’s crust, and that these deposits are discovered.  相似文献   

8.
Over the past three decades, feminist historiography of geography has begun to situate women's contribution to the production of geographical knowledge within the histories of geography, at times against the conviction of skeptical colleagues. In this Focus Section introduction, we renew Domosh's (1991a Domosh, M. 1991a. Beyond the frontiers of geographical knowledge. Transactions of the Institute of British Geographers 16 (4): 48890.[Crossref], [Web of Science ®] [Google Scholar], 1991b ———. 1991b. Toward a feminist historiography of geography. Transactions of the Institute of British Geographers 16 (1): 95104.[Crossref], [Web of Science ®] [Google Scholar]) call for creating more inclusive feminist histories of geography by situating the three focus section articles on the careers and contributions of women in twentieth-century geographical practice and knowledge production in the United Kingdom and the United States within wider debates about diverse, unfamiliar, and previously hidden aspects of geographical knowledge production. We argue that feminist historiography of geography and feminist historical geography could benefit from continuously diversifying inclusive and comparative research perspectives, and from unlocking diverse archives, to enhance understanding of why and how some male and some female gatekeepers have been more supportive of women than others.  相似文献   

9.
10.
ABSTRACT

In this article, I scrutinize three art, design, and architecture projects engaging with “cultured,” or “in vitro,” meat (primarily muscle cells cultured outside of bodies) to illuminate the entanglements of academic and extra-academic environments that have characterized cultured meat’s history to date, and the conversations that this technology has spurred. In envisioning new ways of eating, and living, these projects (a book of hypothetical recipes, The In Vitro Meat Cookbook, Catts and Zurr’s bioartistic engagements with tissue engineering, and Terreform1’s tissue-house prototype “The In Vitro Meat Habitat”) illustrate cultural practices thought to be enabled by cell culturing’s new applications. Emphasizing such visions and conversations allows me to highlight an inattention to discursive dynamics within research on natures subsumed to industrial production processes (Boyd, Prudham, and Schurman 2001 Boyd, W., W. S. Prudham, and R. A. Schurman. 2001. Industrial dynamics and the problem of nature. Society and Natural Resources 14 (7):55570. doi:10.1080/089419201750341862[Taylor & Francis Online], [Web of Science ®] [Google Scholar]). But engaging with the “subsumption of nature” framework simultaneously allows me to problematize artistic visions presenting nature as fully malleable.  相似文献   

11.
The objective of this study is the production and visualization of an emotional map to reveal the unique emotions inherent to the areas surrounding the Yeongsan River, which is often referred to as ‘the cradle of civilization’ in Korea. The sites selected for this study are the 11 cities and districts (5667.6 km2) that cut across the vast granary in the southeastern region of Korea, near the Yeongsan River. The emotional map was produced by extracting features of historical and cultural heritage distributed throughout this region and by using a geographic information systems program and its functions for spatial analysis. A database was constructed through interviews with locals and Global Positioning System to index 4318 pieces of cultural heritage to achieve the visualization of emotions. Among the 558 historical relics considered for representing the regional culture, 100 with the largest emotional impact were selected. It was determined that loyalty (), justice (), courtesy (), resentment (), and anger () should be the major emotional elements. Methodologically, a set of regional, periodic, historical, and emotional classification codes were first systematized. After subjecting this data to inverse distance weight interpolation and vertical exaggeration coefficients, the three-dimensional emotional map could be visualized.  相似文献   

12.
To evaluate the comparability of neo- and paleo-limnology, we made year-to-year as well as seasonal comparisons of contemporary zooplankton data and cladoceran remains in thick (9–42 mm) annual laminations in sediment of Lake Vesijärvi, southern Finland. We calculated the expected annual exuviae production of nine planktonic taxa in the water column using contemporary zooplankton records, and compared the value to the observed net accumulation of their remains in deep sediment for 7 years. Although all of the species studied occur commonly in the lake pelagic zone, deposition of remains differed significantly among taxa. The observed accumulation of three Bosmina species and Chydorus sphaericus was similar to or exceeded expected values, suggesting good preservation of their remains as well as focusing of sediment into the deepest part of the lake. The accumulation of Limnosida and Leptodora remains exceeded expected values several fold, suggesting under-representation of these species in pelagic plankton samples, as well as efficient transportation and spatial averaging of their remains in the sediment. Daphnia, Diaphanosoma, and Ceriodaphnia were clearly under-represented in the sediment due to poor preservation of their remains and use of a 50-μm sieve in sediment processing. Thus, sieving should be taken into account as a possible source of bias. Correlation between relative abundances of all species in the sediment and in the plankton was weak (r s = 0.54, P < 0.001), but for well-preserved species, the correlation was strong (r s = 0.91, P < 0.001). Inter-annual variation in the deposition of remains suggested that resuspension and sediment focusing may vary between years, thus making it difficult to interpret absolute abundances, even though the deepest part of the basin shows clear varve formation and seasonality is well recorded. Detailed study of the uppermost lamination showed the seasonal succession of a cladoceran community within an annual varve as well as differences in the seasonality and intensity of ephippia production among the species. We recommend that results of cladoceran analyses be expressed in several ways (relative abundances, per unit dry weight, per unit organic matter, and as net accumulation values) before drawing final conclusions, as each approach may reveal a different aspect of the deposition process. In addition, sedimentation differences between epilimnetic and hypolimnetic species should be considered in stratified lakes.  相似文献   

13.
Rainfall erosivity is an important climatic factor for predicting soil loss. Through the application of high-resolution pluviograph data at 5 stations in Huangshan City, Anhui Province, China, we analyzed the performance of a modified Richardson model that incorporated the seasonal variations in parameters α and β. The results showed that (1) moderate to high seasonality was presented in the distribution of erosive rainfall, and the seasonality of rainfall erosivity was even stronger; (2) seasonal variations were demonstrated in both parameters α and β of the Richardson model; and (3) incorporating and coordinating the seasonality of parameters α and β greatly improved the predictions at the monthly scale. This newly modified model is therefore highly recommended when monthly rainfall erosivity is required, such as, in planning soil and water conservation practices and calculating the cover-management factor in the Universal Soil Loss Equation (USLE) and Revised Universal Soil Loss Equation (RUSLE).  相似文献   

14.
Preventing biodiversity loss is a key aim of modern conservation, and paleolimnology can inform conservation strategies for target species and habitats where other data are unavailable. Care must be taken to fully understand the possibilities and limits of such techniques, particularly where they concern single species. This study uses plant and seed distribution data to inform macrofossil reconstructions of the rare macrophyte Najas flexilis (Slender Naiad) in Scotland, UK. It answers three questions: (a) How does the location of N. flexilis seeds in the surface sediments relate to the distribution of N. flexilis plants? (b) How do the numbers of seeds in surface sediments correlate with % cover of N. flexilis plants across lakes with differing N. flexilis abundances? (c) What are the implications of these findings for paleolimnology? Percentage N. flexilis cover and number of N. flexilis seeds in surface sediments were recorded at ~100 sample points at each of three sites; one where the species was abundant, one where it was occasional and one where it was extinct. At all sites, N. flexilis seeds were present in surface sediments across the entire lake. No correlation between % cover N. flexilis and the number of seeds in surface sediments was found within individual sites. The distribution of seeds in these lakes appeared to be related to multiple environmental and ecological variables including latitude and longitude (proxies for water currents). This is attributed to the ability of seed-bearing N. flexilis plants to fragment and float large distances on water. Between sites, there was a significant difference in the mean seed counts, with higher mean seed counts corresponding to higher abundances of N. flexilis plants. It is concluded that N. flexilis is likely to be well represented in sediment cores taken from any location within a basin, but that care should be taken when inferring changes in N. flexilis abundance from changes in the numbers of seeds in sediment samples. This work demonstrates that the reproductive ecology (number of seeds produced and dispersal mechanisms) is an important factor to consider when attempting reconstructions of single aquatic plant populations from macrofossil records.  相似文献   

15.
Higher-order active contours or snakes show much promise for the extraction of complex objects from noisy imagery. These models provide an elegant mathematical framework for specifying the desired properties of target objects through energy functionals that can be minimized with standard optimization techniques. However, techniques to allow quadratic snakes to change topology during segmentation have not been fully exploited. Additionally, external forces for improving convergence of quadratic snakes have similarly yet to be explored. In this article, we propose a model that allows multiple quadratic snakes to split, merge, and disappear. Although the separate components of our approach have been introduced elsewhere by Cohen (1991 Cohen, L.D. 1991. On active contour models and balloons. CVGIP: Image Understanding, 53(2): 211218.  [Google Scholar]), Xu and Prince (1997 Xu, C. and Prince, J.L. Gradient vector flow: a new external force for snakes. IEEE Conference on Computer Vision and Pattern Recognition (CVPR). June, San Juan. pp.6671.  [Google Scholar]), and Rochery et al. (2006 Rochery, M., Jermyn, I.H. and Zerubia, J. 2006. Higher order active contours. International Journal of Computer Vision, 69(1): 2742.  [Google Scholar]), this article is the first comprehensive empirical study of their performance on real-world complex network extraction tasks. We analyze the applicability of the model to road extraction from satellite images that vary in complexity from simple networks to large networks with multiple loops. We also analyze the effects of external forces enhanced by oriented filtering, gradient vector flow fields, and Canny edge detection. In a series of experiments, we found that the multiple cooperating quadratic snake model performs well on complex, noisy images. Our experiments also establish a performance improvement when the proposed quadratic model is coupled with the Canny-based gradient vector flow technique.  相似文献   

16.
This paper examines how legal structures interact with land‐use decisions in the coastal zone. The emphasis is on NSW where there has been a steady evolution of legislative and other measures to regulate how the coast is to be planned and managed. These measures arise from a long history of individual, corporate, local government and State agency actions directed more at private benefit than at protecting and conserving environmental values for the public good. Alienation of foreshores, restrictions on access, buildings located in hazardous areas, canals exposing soils rich in acids, and pollution of waterways are examples of degradation on this coast. Yet much remains to be protected. Expansion of coastal national parks over the past decade has helped. But new planning controls have been introduced to support the NSW Coastal Policy (1997 NSW Coastal Policy (1997) A sustainable future for the New South Wales coast NSW Government, Sydney  [Google Scholar]). In essence, there is evidence that the State government seeks to implement environmentally sustainable development principles to ensure that as the population continues to grow, decisions on future land uses will reflect the functioning of ecosystems and the dynamics of coastal and catchment geomorphology and hydrology. Pressures from individuals and corporations exercising traditional property rights need to be managed within a statutory framework that facilitates sustainability of coastal environmental values cherished by so many.  相似文献   

17.
Fuzzy Geographical Entities (FGEs) refer in this paper to geographical entities with fuzzy spatial extent. The use of FGEs in geographical information systems requires the existence of operators capable of processing them. In this paper, our contribution to that field focuses on the computation of areas. Two methods are considered, one crisp due to Rosenfeld (1984 Rosenfeld, A. 1984. The diameter of a fuzzy set. Fuzzy Sets and Systems, 13: 241246. [Crossref], [Web of Science ®] [Google Scholar]), which has limited applicability, and the other fuzzy, which is a new approach. The new fuzzy area operator gives more information about the possible values of the area and enables the fuzziness in the spatial extent of the entity to be propagated to the area. Crisp and fuzzy areas have different meanings, and the use of one or the other depends not only on the purpose of the computation but also on the semantics of the membership functions. When the FGEs are represented by normal fuzzy sets, the fuzzy area operator generates fuzzy numbers, and therefore arithmetic operations can be performed with them using fuzzy arithmetic. However, we show that care must be taken with the use of the fuzzy arithmetic operators because, in some situations, the usual operators should not be applied. Properties of the Rosenfeld and fuzzy area operators are analysed, establishing a parallel with properties of the areas of crisp sets.  相似文献   

18.
The notion of ‘eco‐civic regionalisation’ has been applied recently to New South Wales by Brunckhorst, Coop and Reeve (2004 Brunckhorst D Coop P Reeve I 2004 An eco‐civic regionalisation for rural New South Wales: final report to the NSW government Institute for Rural Futures and Centre for Bioregional Resource Management, University of New England, Armidale  [Google Scholar]) in order to identify the appropriate administrative boundaries for ‘socio‐civic’ regions and ‘biophysical’ regions. On the basis of this analysis, they recommended inter alia that 49 future non‐metropolitan ‘local government areas’ be established. This proposal was adopted with alacrity by advocates of the NSW government's program of compulsory council amalgamation, including official ‘Facilitators’ appointed by the State government to draft formal consolidation proposals. This paper disputes the applicability of ‘eco‐civic regionalisation’ as the foundation for local government boundaries in Australia.  相似文献   

19.
Desertification in the Arab Region: analysis of current status and trends   总被引:2,自引:0,他引:2  
The total area of the Arab Region is about 14·2 million km2, 90% of it lies within arid, semi-arid and dry sub-humid areas. The area is characterized by harsh environment, fragile ecosystems and limited water resources and arable lands. Throughout its long history these lands were the main source of grain and animal production.By the end of this century and in spite of the national, regional and international efforts to combat desertification and mitigate the effect of drought and desiccation, desertification is still one of the major environmental problems in the Arab Region. The rapid increase in population by some 3% annually, considered among the highest worldwide, along with the changing of consumption patterns and life styles, resulting in increasing food demand, have hastened land degradation in this arid environment.Land degradation in the Arab Region due to misuse is widespread and is proceeding at accelerating rates. Failures of resource management policies are aggravated by overgrazing, overexploitation of water and land resources, overcultivation of marginal lands, deforestation, and the use of inappropriate technologies.This paper attempts to provide:
• A synthesis and analysis of the status of desertification in the Arab Region.
• Identification of the major causes and trends of land degradation.
• Highlighting the limitations and constraints on combating desertification in the Arab Region.
Keywords: desertification; matrix of desertification; population growth and urbanization; water demand; cost; future outlook  相似文献   

20.
This study represents a step towards developing seasonal climate inferences by using high-resolution modern data sets. The importance of seasonal climate changes is highlighted by the instrumental record of a meteorological station close to our study site (lac du Sommet in the Laurentian Mountains, Québec, Canada): Between 1966 and 2001, May temperatures increased significantly by 3.1°C (r = 0.41, n = 35, p < 0.01) but annual mean temperatures only by 0.6°C (r = 0.21, n = 35, p > 0.05). Comparison of this instrumental record with fossil diatom assemblages in a sediment core from lac du Sommet showed that axis one of a principal component analysis (PCA) of the fossil diatoms was best correlated with wind velocity in June (r = 0.62, n = 19, p < 0.005) and that past diatom production was significantly enhanced in periods with colder July temperatures (r =  ?0.77, n = 19, p < 0.0005) and higher wind velocity in June (r = 77, n = 19, p < 0.0005). The strong impact of the spring and summer conditions on overall diatom composition and productivity suggests that seasonal lake responses to climate are more important than annual mean temperatures. However, the seasonal dynamics of diatom communities are not well understood, and seasonality is rarely inferred effectively from lake sediment studies. Our research presents a pilot study to answer a twofold question: Is it possible to identify diatom communities which are typical for warmer or colder seasonal climate using sediment traps, and if it is, can this knowledge be used to infer seasonal climate conditions from fossil diatom assemblages? To address these questions, the seasonal dynamics of diatom communities and water chemistry were studied using sediment traps and water samples at biweekly intervals in four lakes distributed along an altitudinal gradient in the Laurentian Mountains from May through October 2002. Date of ice break-up was significantly related to the diatom assemblages taken in spring and uncorrelated to other significant environmental variables. Summer water temperature, circulation of the water column and pH explained a significant part of the biological variance in summer, and total nitrogen (TN) explained most of the biological variance in autumn. To infer these variables, weighted averaging partial least squares models were applied to the seasonal data sets. Inferred ice break-up dates were significantly correlated with number of days below 0°C in April (r = 0.52, n = 19, p < 0.025), inferred circulation of the water column was significantly related to measured wind velocity in June (r = 0.64, n = 19, p < 0.005), inferred summer water temperature and inferred pH was significantly related to measured July air temperature (r = 0.50, r =  ?53, n = 19, p < 0.025) and inferred TN autumn concentrations had an inverse relationship to August temperatures (r =  ?0.53, n = 19, p < 0.01). This comparison of the historical record with diatom-inferred seasonal climate signals, based on the comparison of fossil diatom assemblages with modern sediment trap data of high temporal resolution, provides a promising new approach for the reconstruction of seasonal climate aspects in paleolimnological studies.  相似文献   

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