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1.
Cities and city regions are on the global agenda as key sites for contemporary societal development, in terms of agglomeration of economic activity, places of everyday life and dense networks. The majority of economic, political and social activities is today formed by urbanisation, and an increasing number of people are living and working in city regions. At the same time, many cities and peripheral regions are struggling with job losses, industrial restructuring and depopulation, and thus, many countries face new forms of spatially economic and social inequalities. This special issue is about the contemporary urbanisation processes and the transformation of cities and urban systems in the European context using Denmark as a particular case. Denmark provides a present-day example of urban transformation, and its urban system resembles that of many other European countries – Denmark having one large urban centre and a long tail of smaller cities and towns. Thus, the papers in this issue provide insights into contemporary urban changes.  相似文献   

2.
I argue that the tension between cities and nation states go through the countryside, or rural areas, at least in the U.S. Further, cities are decidedly constrained in their abilities to effectuate many of the changes associated with them: addressing climate change, economic inequality and more. What is missing is the way in which rural alienation from economic prosperity plays out politically.  相似文献   

3.
A deglaciation chronology of the last ice sheet in Lofoten - Vesterålen - Ofoten based on regional shore displacement is presented. An isobase system and a shore zone diagram have been constructed. The heights of raised shore features refer to present mean tide level, and have been adjusted according to the variation in height of recent forms. Owing to this variation in particular, and deformation of features due to shore displacement, a shore zone diagram has been substituted for the traditional shore line diagram. Seven stages in the ice recession have been traced. The outermost probably occurred at a time close to the maximum of the last ice sheet. During its retreat, the ice became increasingly directed by topography. The situation of deposits in the landscape was determined by this. The regional shore displacement seems to indicate that the highest mountains in the area were nunataks during the last glacial maximum.  相似文献   

4.
In this paper we aimed to explain differences in agricultural labour productivity at microregional level. We tested the effects of three major independent variables – farmland fragmentation, urbanization economies and farm size structure with particular emphasis on the relationship between land-use fragmentation and microregional differences in agricultural labour productivity. Our principal question therefore was if higher agricultural labour productivity at microregional level is associated with internal scale economies resulting from large average farm size (in terms of employment), proximity to large cities as a proxy for urbanization economies and lower levels of land-use fragmentation. We also asked if productivity gains from large average size of plots is higher than potential losses resulting from land tenure (tenants are generally less productive than farmland owners). Drawing on a case study of Czechia – a country with extremely fragmented farmland ownership, but the largest average size of plots in the EU and a strong role of farmland rental market – we confirmed our initial expectation that land-use fragmentation affects negatively microregional agricultural labour productivity. Larger average size of plots is positively related to microregional agricultural labour productivity despite potentially negative effects of land tenure. At the same time, no significant effects of urbanization economies and farm size structure were documented.  相似文献   

5.
Environmental (geomorphological, hydrological and ecological) processes are controlled by rainfall, particularly in the Mediterranean, semi-arid and arid regions. Rainfall was analyzed using the concept of rain-spells, i.e., a period of successive rain days preceded and followed by at least one day without rainfall. Daily data from 13 stations along a climatic transect extending from the Judean Mountains with a Mediterranean climate to the Dead Sea arid region in Israel were studied. Rain-spell characteristics (number, yield and duration), based on these data, are presented for different rainfall thresholds, which might be used for different environmental processes such as rock weathering, soil organic matter dynamics, landslides, overland flow and floods and soil erosion. Three estimation models have been developed in order to predict the mean annual Number of Rain-Spells (NRS), mean Rain-Spell Yield (RSY), and mean Rain-Spell Duration (RSD) for the mean annual rainfall and for any given rainfall threshold. These models can be used for current climatic conditions and for scenarios in which the rainfall total changes.  相似文献   

6.
Current knowledge of caves and karst regions of Ecuador is scarce and broadly limited to discrete areas such as that of the Galápagos volcanokarst. In continental Ecuador, carbonate karst mostly outcrops in the Amazonian basin and accounts for 5–10% of the surface of the country. However, owing to the difficulties of access within the Amazonian rainforest, most surface and subterranean karst is yet to be revealed. In this review, we present an updated map of the solutional karst of Ecuador based on the most recent geological surveys and our own research. We describe the principal karst regions of Ecuador from the Amazonian basin (Napo and Santiago) as well as the Galápagos pseudokarst. We show that Ecuador karst research may be of considerable importance for both basic and applied research owing to its geographical position and intrinsic vulnerabilities. We discuss the main challenges of karst-related research in Ecuador, such as paleoclimatic studies, subterranean biodiversity, and archeology. We discuss the main vulnerabilities and hazards related to karst uses in Ecuador, considering the paramount importance of tourism for the country.  相似文献   

7.
8.
Stokkan, J. The potential model – an analysis of some methodological problems. Norsk geogr. Tidsskr. 29, 111–132.

The article is concerned with operational problems of the potential model. In connection with a general discussion of operational problems, a base model is constructed. This model is applied to a study area in order to determine the model's sensitivity to the area of the analytical unit, the distance exponent, and distances within the unit. The analysis shows that the potential is to a large degree dependent upon the definition of these three factors.  相似文献   

9.
It is widely accepted that environmental change can influence human migration. In particular, the environment plays a role in migration processes in drylands, in which environmental change—including increasing variability of rainfall, increasing frequency of droughts, chronic water shortage, and land degradation—can heavily influence migration. However, systematic large-scale studies of the relationship between environmental factors and human migration are rare, and a global, consistent picture of environmental drivers of migration is lacking. In this study, we sought to fill this gap by analysing spatial patterns of environmental drivers of migration in drylands by performing a cluster analysis on spatially explicit global data. In this analysis, we focused explicitly on precipitation, aridity, drought, land degradation, soil constraints, and availability of cropland and pastures as potential environmental drivers of migration in drylands. In addition, we linked the identified clusters to two observed hotspots of out-migration—Burkina Faso and Northeast Brazil—to gauge the cluster results. Our results show that environmental drivers can be grouped into eight distinct clusters, and we identified the most severe environmental constraints for each cluster. These results suggest that out-migration—both in absolute and relative terms—occurs most frequently in a cluster that is constrained primarily by land degradation rather than water availability.  相似文献   

10.
In this paper, we report efforts to develop a parallel implementation of the p-compact regionalization problem suitable for multi-core desktop and high-performance computing environments. Regionalization for data aggregation is a key component of many spatial analytical workflows that are known to be NP-Hard. We utilize a low communication cost parallel implementation technique that provides a benchmark for more complex implementations of this algorithm. Both the initialization phase, utilizing a Memory-based Randomized Greedy and Edge Reassignment (MERGE) algorithm, and the local search phase, utilizing Simulated Annealing, are distributed over available compute cores. Our results suggest that the proposed parallelization strategy is capable of solving the compactness-driven regionalization problem both efficiently and effectively. We expect this work to advance CyberGIS research by extending its application areas into the regionalization world and to make a contribution to the spatial analysis community by proposing this parallelization strategy to solve large regionalization problems efficiently.  相似文献   

11.
The aim of the Norwegian Nature Index (NI) is to provide an overview of the state of biodiversity within and across major ecosystems. The index is composed of a series of indicators, each representing individual species or diversity measures. The indicators are standardized and scaled in relation to a reference state, and combined for ecosystems or geographical regions, to give a number between 1 (reference state) and 0 (seriously degraded biodiversity). In 2010, the state of biodiversity was highest in mountains, ocean, coastal waters, and freshwater (NI=0.69–0.80), intermediate for mires and wetlands (NI=0.55), and lowest for open lowlands and forests (NI=0.43–0.44). The NI increased 8–10% in freshwater and the ocean (bottom and pelagic) from 1990–2010, but decreased by>10% in open lowlands during the same period. Since its launch in September 2010, the Nature Index has been approved by the Ministry of Finance as an indicator for biodiversity in the set of sustainable development indicators and approved by the Ministry of Environment as an indicator of the state of major ecosystems.  相似文献   

12.
Successful implementation of a forest based climate change mitigation mechanism such as REDD + depends on robust and available methods for measurement and estimation of forest degradation. Currently available methods are for application in single-hit degradation incidents in high density humid forests. However, it has been suggested that gradual degradation, especially in dry forests, is more widespread and that methods are needed for measuring and estimating associated emissions. We assess the applicability of an indirect remote sensing approach for monitoring forest degradation: infrastructure and other indicators of human activities are mapped and used for spatial prediction of degradation activities. For proxy variables we tested distance to forest edge, distance to roads, and population pressure calculated as the sum of inhabitants per pixel in the Landscan 2010 population raster dataset multiplied by an inverse power distance decay function. Wood extraction incidents were counted in 160 plots in two dry forests in Tanzania with infrastructural entry from one side only. We analyzed the spatial pattern of forest degradation as a function of the chosen proxy variables using zero inflated count models which allows for an excess of zero counts. A jack-knife bootstrap using 10,000 runs was applied to optimize the population distance decay function. We found that the impact of forest degradation is highest near high population concentration, above 1000 individuals. Furthermore, distance to nearest forest edge or road was a significant proxy for estimation of the number of wood extraction incidents (p < 0.001), where degradation incidents decreased with increasing distance to forest edge or road. At 3000 m from the forest edge towards the forest core the probability of wood extraction is 20% and dropping. The population distance decay function was found to have a steep decline indicating a relative small impact on forest degradation. Further, and perhaps larger, studies are needed to be able to recommend a distance decay function for general application in Tanzania. However, the results are useful for understanding spatial patterns of wood harvesting as a function of distance to nearest forest edge or road in dry Miombo woodland areas with average population pressure at 1685 ± 101 persons within a radius of 4000 m from the wood extraction sites.  相似文献   

13.
In this article, we investigate drivers behind land use changes in a peri-urban landscape. The research focuses on the motives and factors behind landowners’ decision-making in relation to land use changes, with the objective of improving our knowledge of the dynamics of land use change processes on farmland. An actor-centred conceptual framework is developed on the basis of the concept of lenses of decision-making. Data on farm and farmer characteristics were collected through a survey conducted in Roskilde Municipality, Denmark, a peri-urban landscape with a high level of landscape dynamics. A logistic regression analysis was used to analyse the relationship between nine purposively selected farm and farmer characteristics and the landscape activities of 93 landowners in the municipality. The results indicate that small farms, farms without livestock and landowners with a basic level of education are less likely to engage in landscape activities. A cluster analysis was used to analyse patterns of motives associated with land use changes. The results correspond with the intrinsic interests and family considerations suggested in the lenses of the decision-making framework, and in addition shows that the desire to improve the qualities of the property was the dominant motive.  相似文献   

14.
ABSTRACT

To answer the question “what has changed the surface temperatures of water bodies around Iran under climate change conditions,” Moderate Resolution Imaging Spectroradiometer (MODIS) sea surface temperature (SST) data with 9.2-km spatial resolution and monthly time step were evaluated. A significant increasing trend was obtained using Pearson’s correlation coefficient and Mann-Kendall trend test on data from the Caspian Sea (June) and the Southern Gulfs (September). High correlations of 0.69 and 0.97 between remotely sensed data and ERA-Interim reanalysis data were also obtained for June and September, respectively. To assess the impact of some climatic parameters on SST variability in those two months, zonal and meridional wind at 10 m, wind speed at 10 m, air temperature at 2 m, and mean sea level pressure were evaluated. High correlations between meridional wind and the Southern Gulf SST, and meridional wind and Caspian SST were ?0.86 and 0.75, respectively. Moreover, the results showed an important role of air temperature (0.96) and sea level pressure (?0.77) in the rising temperature trends of the Southern Gulfs. Wind speed was also detected in both regions as a booster of the trend.  相似文献   

15.
Multi-proxy data, both lithostratigraphic and biostratigraphic, are presented from Efstadalsvatn, a lake in NW Iceland. The sequence covers the period 10,000 to 3500 14C yr B.P. The biostratgraphic data include the first Icelandic chironomid-based reconstruction of Holocene mean July air temperatures, using a Norwegian training set in the absence of modern Icelandic data. The results show that deglaciation and ecosystem development probably began before 10,000 14C yr B.P. and that July temperatures were around 4°C at ca. 9500 14C yr B.P. Temperatures then rose to ca. 8°C at the time of the deposition of the Saksunarvatn tephra (9100 14C yr B.P.), reaching ca. 10°C by 8500 14C yr B.P., high enough for the growth of tree birch, although successful birch colonisation did not take place until 6750 14C yr B.P. There is some evidence for cooling immediately preceding 9100 14C yr B.P. There is little firm biostratigraphic evidence for the 8200 cal. B.P. event, although this may be due to a relatively low resolution pollen sampling interval, but there are changes at this time in the total carbon (TC) and mass susceptibility (MS) data. Optimal temperatures and relative vegetation stability may have occurred between 8000–6100 14C yr B.P. but the chironomid assemblages indicate higher temperatures after 5000 14C yr B.P. This latter interpretation may, however, reflect delayed colonisation of thermophilous taxa and requires further investigation. There is evidence in the lithostratigraphy for greater local terrestrial instability after 6100 14C yr B.P. but it seems unlikely that this led to the redevelopment of ice in the catchment. The biostratigraphic records appear to show a degree of resistence to climate forcing throughout the early and middle Holocene. The new chironomid-based temperature reconstruction needs to be refined by further studies in Iceland, particularly the development of an Icelandic training set, but has already demonstrated the problems of paleoclimatic interpretations based on pollen and/or macrofossil evidence alone.  相似文献   

16.
ABSTRACT

The aim of the article is to determine what a local Digital Agenda (DA) implies for ICT development at the local level and how such a policy can be realised in practice. The topic is discussed in relation to the EU and Swedish Digital Agendas, which have motivated the definition of a local DA for the examined Swedish municipality of Linköping. An analytical model is used both to examine the balance of supply-side and demand-side policies of the local DA, and in an attempt to determine what a local DA implies for local ICT development. The empirical material shows that local policy focused on supply-side strategies towards households and businesses, while demand-side policy was present to a greater extent in the management of the municipality’s own operations. The local authority has provided a major expansion in broadband infrastructure to rural areas of the municipality. This complies with mandates from local authorities to manage local infrastructure development and services to the local population. The authors conclude that the policy implications of the results suggest that although operations through the local DA are substantial, complementary measures to support increasing demands across households and businesses are important when dealing with challenges of uneven access and underutilisation of the large investments for ICT infrastructure.  相似文献   

17.
The article examines the role of ‘local paths’ and ‘substrates’ (networks, stakeholders, and human and economic capital) in the revitalization strategies of shrinking cities. Relationships between local stakeholders as well as their initiatives to revitalize declining cities determine not only future decision-making but also the demographic, economic, environmental, and social evolution of those cities. The article analyses two medium-sized declining cities in the old industrial region of Asturias, Spain. After a presentation of the processes that led to the studied cities' rise and decline, their revitalization strategies are analysed and interpreted on the basis of the local stakeholders' role. In these cities, the impact of local factors may largely explain the uneven evolutionary path in each city following crisis in their respective leading industries.  相似文献   

18.
Innovation systems and clusters are perhaps the most widely used concepts found in recent economic geography literature focusing on innovative industrial production and locational agglomeration. Both concepts have been universally embraced since the early 1990s onwards. However, recent literature has expressed criticism of their use as tools for policymaking. The authors studied innovation and cluster rhetoric in a geographical context by using empirical evidence obtained from the policy documents of the Finnish regional councils. They used a theoretical conception of spatial scaling as a geographical framework. Spatial scales proved to be a black box for regional strategies in Finland. Regional strategic programmes use a similar language that ignores the spatial variations of their locations. Clusters and regional innovation systems should be considered as parts of vertical and horizontal interlinkages within the economy and not as individual islands of organizational proximities in isolated contexts. The authors argued that an imprecise understanding of the innovation systems and cluster approaches, both conceptually and practically, has led to some ambiguity, resulting in the use of the terms clusters and innovation systems as buzzwords. This misuse hampers the ability of administrations to execute regional development in their respective areas.  相似文献   

19.
There is a major trend in forest management that local managers are being replaced by entrepreneurs, who are often less place-dependent. Entrepreneurs are also more updated when it comes to scientific knowledge and national and international trends in forest values and functions, as well as knowledge about general planning and management concepts that have high value for tourism and recreation. Parallel with the observed changing management culture, there also seems to be an increased abstraction of forest values and functions in forest certification programmes. The article briefly presents some key aspects of Aldo Leopold's thinking that are of relevance for forest stewardship, and discusses these in relation to main forest stewardship trends in a Nordic forestry context. In a Nordic tradition, forest management and planning are deeply rooted in local management practice carried out by official local supervisors in cooperation with forest owners and other stakeholders. Local traditions and accumulated local knowledge over time were, in addition to updated scientific knowledge, important skills for local managers. Today's post-modern forestry includes complex multi-valued forest situations on different scales, which are even more complex and challenging to manage than the more utilitarian historical forest was.  相似文献   

20.
The abandoned Roman/Early Islamic city of Resafa in the Syrian desert steppe was supplied with drinking water by an elaborate floodwater harvesting system. This paper investigates its construction, reliability and chronology. Previous excavations showed that the system consisted of a dam that blocked a wadi adjoining the enclosed city and channeled retained floodwater to large subsurface cisterns. Aerial photos from the early 20th century suggest that additionally embankments were part of the system. Physical evidence of such constructions is largely lacking nowadays.The reliability analysis of the floodwater system is conducted by applying a curve-number-based rainfall-runoff model driven by current satellite rainfall estimates. Flow pattern analysis is used to assess the probable effects of the assumed embankments on flood behavior by applying the hydraulic module of the Caesar-Lisflood model.We show that the system would be reliable under present conditions and probably also functioned when the system was in operation. Furthermore, it is shown that the floodwater harvesting system most likely consisted of a several hundred meter long embankment system.  相似文献   

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