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1.
National flood discharge mapping in Austria   总被引:5,自引:0,他引:5  
This article presents the approach and the results of a study in which 30, 100 and 200 year return period flood discharges were estimated for 26,000 km of Austrian streams. Three guiding principles were adopted: combination of automatic methods and manual assessments by hydrologists to allow speedy processing and account for the local hydrological situation; combination of various sources of information including flood peak samples, rainfall data, runoff coefficients and historical flood data; and involvement of the Hydrographic Services to increase the accuracy and enhance the acceptance of results. The flood discharges for ungauged catchments were estimated by the Top-kriging approach with manual adjustment to the local flood characteristics. The adopted combination approach proved to be very efficient both in terms of the project time required and in terms of the accuracy and acceptability of the estimated flood discharges of given return periods.  相似文献   
2.
Tassilo Herrschel 《Geoforum》2007,38(3):469-484
This paper investigates the dual nature of regionalisation between imposed institutionalised territoriality and self-made ‘ad hoc’ collaborative regional arrangements between localities. This involves, as the paper sets out to show, different, but concurrent imagineerings of ‘regions’ to two audiences - within and without a defined region. They are applied to the same territory, albeit with different images and sets of actors for internal (local) and external (national/international) consumption. These developments are examined within the context of the ‘new regionalism’ debate, in particular the notion of a replacement of ‘old’ through ‘new’ regionalism as a sequence. This duality of region making challenges the frequently somewhat simplistic presumption of regions forming as one complete entity, ‘out there’ to compete on a global market. They also have to fight for their recognition internally, but with different arguments, rationales and policies. This means that the possibility of overlapping single purpose ad hoc formed regions, as postulated under the new regionalism, needs to take into account the likelihood of several meanings of one and the same territory. The examples demonstrate that the two possibilities overlap - multi-territoriality and multi-meanings of (new) regionalism. The paper uses the example of post-unification eastern Germany, where in 1990 a completely new set of traditional regions was established, implementing a 1960s-derived western German model. Since this common starting point, strong economic, cultural and geographic differences have emerged, leading not only to policy adjustments, but also changes to the understanding of regionalisation and regional policy, and the actors involved.  相似文献   
3.
The aim of this study was to evaluate four metrics to define the spatially variable (regionalised) hillslope sediment delivery ratio (HSDR). A catchment model that accounted for gully and streambank erosion and floodplain deposition was used to isolate the effects of hillslope gross erosion and hillslope delivery from other landscape processes. The analysis was carried out at the subcatchment (~ 40 km2) and the cell scale (400 m2) in the Avon-Richardson catchment (3300 km2), south-east Australia. The four landscape metrics selected for the study were based on sediment travel time, sediment transport capacity, flux connectivity, and residence time. Model configurations with spatially-constant or regionalised HSDR were calibrated against sediment yield measured at five gauging stations. The impact of using regionalised HSDR was evaluated in terms of improved model performance against measured sediment yields in a nested monitoring network, the complexity and data requirements of the metric, and the resulting spatial relationship between hillslope erosion and landscape factors in the catchment and along hillslope transects. The introduction of a regionalised HSDR generally improved model predictions of specific sediment yields at the subcatchment scale, increasing model efficiency from 0.48 to > 0.6 in the best cases. However, the introduction of regionalised HSDR metrics at the cell scale did not improve model performance. The flux connectivity was the most promising metric because it showed the largest improvement in predicting specific sediment yields, was easy to implement, was scale-independent and its formulation was consistent with sedimentological connectivity concepts. These properties make the flux connectivity metric preferable for applications to catchments where climatic conditions can be considered homogeneous, i.e. in small-medium sized basins (up to approximately 3000 km2 for Australian conditions, with the Avon-Richardson catchment being at the upper boundary). The residence time metric improved model assessment of sediment yields and enabled accounting for climatic variability on sediment delivery, but at the cost of greater complexity and data requirements; this metric might be more suitable for application in catchments with important climatic gradients, i.e. large basins and at the regional scale. The application of a regionalised HSDR metric did not increase data or computational requirements substantially, and is recommended to improve assessment of hillslope erosion in empirical, semi-lumped erosion modelling applications. However, more research is needed to assess the quality of spatial patterns of erosion depicted by the different landscape metrics.  相似文献   
4.
A peaks over threshold (POT) method of analysing daily rainfall values is developed using a Poisson process of occurrences and a generalised Pareto distribution (GPD) for the exceedances. The parameters of the GPD are estimated by the method of probability weighted moments (PWM) and a method of combining the individual estimates to define a regional curve is proposed.  相似文献   
5.
Temporal variability of precipitation over the Iberian Peninsula (IP) has high spatial gradients. Therefore, statistics of the temporal behaviour of precipitation and derived quantities over the IP must be estimated taking into account these spatial gradients. Some statistics can be displayed over a map. However there are statistics, such as Probability Density Functions at each location of the IP, that are impossible to display in a map. Because of this, it is mandatory to reduce the number of degrees of freedom which, in this case, consists of a reduction of the time series representative of the IP domain. In this work, we present a spatial partition of the IP region into areas of similar precipitation. For that, an observed dataset of daily-total precipitation for the years between 1951 and 2003 was used. The land-only high resolution data was obtained on a regular grid with 0.2° resolution in the IP domain. This data was subjected to a k-means Cluster Analysis in order to divide the IP into K regions. The clustering was performed using the squared Euclidean distance. Four clusters of IP grid points, defining 4 IP regions, were identified. The grid points in each region share the same time-varying behaviour which is different from region to region. The annual precipitation discriminates the following regions: (1) north Iberia, (2) a large region extending from the centre to the Mediterranean shores of the IP, (3) a large region ranging from the centre to the western and southwestern shores of the Iberia, and (4) northwest Iberia. The regions obtained for the four seasons of the year are similar. These results are consistent with the thermodynamic characteristics described in the available literature. These Iberian regions were used to assess climate change of seasonal precipitation from the multi-model ensemble of the fifteen simulations provided by the European project ENSEMBLES. Probability Density Functions of annual- and seasonal-total precipitation, consecutive dry days, and total precipitation above the 95th percentile, averaged in each region were estimated for a reference climate (1961–1960), a near-future climate (2021–2050), and a distant-future climate (2069–2098). Climate change projections are based on comparisons of these functions between each future climate and the reference climate.Finally, we emphasize that: (i) the methodology used here, based on Cluster Analysis, can be used to regionalise other areas of the world, and (ii) the identified regions of the IP can be used to represent the Iberian precipitation by four time series that can be subjected to further analysis, whose results can be presented in a concise manner.  相似文献   
6.
River catchments have been the dominant form of regionalisation for natural-resource management in many countries since the 1980s. Local governments play a considerable role in planning with ever-increasing responsibilities for sustainable environmental management, planning and development controls. There has also been an increasing emphasis on community participation in resource management, which emphasises the need to re-examine the requirements for spatial definition of resource governance regions. This paper proposes three principles. First, the nature and reach of environmental externalities of resource use should determine the size and nesting of resource management regions. Second, the boundaries of resource governance regions should enclose areas of greatest interest and importance to local residents. Third, the biophysical characteristics of a resource governance region should be as homogenous as possible, which provides resource planning and management efficiencies. The paper describes a range of concepts and empirical techniques used to apply these principles to the derivation of a resource governance regionalisation of the State of New South Wales, Australia.  相似文献   
7.
In response to the shortcomings of the EU's Common Fisheries Policy, the European Commission has suggested regionalising fisheries management. Examples already exist of the more decentralised management of certain fisheries. Since 2007, the Commission has requested national eel management plans (EMPs) from all EU eel-fishing nations, giving national management bodies considerable freedom to develop their own EMPs. To examine the prerequisites for decentralisation, the Swedish EMP was chosen as a case. The European eel is critically endangered due to overfishing and environmental degradation. Analysis of the Swedish EMP reveals serious flaws: the conflict between the objectives of species and fishery preservation has not been clarified nor is the prioritisation clear. The plan has not been critically reviewed and alternative options are not considered. Though the basic data are uncertain, this uncertainty is viewed as support for not adopting any safety margin. Management is therefore directed towards mitigating the negative effects of fishing and other human activities rather than realising the conservation objective. The efficiency of the various protection measures is also disputable; for example, translocation is problematic, as translocated (i.e., stocked) eels display impaired navigational abilities. Another problematic aspect of this conservation strategy is the slow implementation of the EMP. In conclusion, this study emphasises the necessity of legal and social science as well as natural science research to evaluate the efficiency and implementation of fishery management.  相似文献   
8.
This paper undertakes the largest ever quantitative analysis of the distribution of surnames in Great Britain, in order to identify ‘surname regions’. Our empirical analysis uses hierarchical clustering and multidimensional scaling in a computationally intensive analysis of a near complete individual population register of Great Britain. The outcome of this classification is an inductive partitioning of space which, we suggest, reveals a unique and authoritative regional geography that is of use in improving our understanding of population dynamics, as well as of historic and contemporary migration.  相似文献   
9.
Commonly, the Baltic Sea is pictured as a proactive region with a long-standing tradition for cooperation and surrounded by the “greenest” EU countries. In contrast, southern countries often suffer from the “Mediterranean Syndrome” in which the heterogenous socio political situation is given as the “proof” that cooperation would not work. The Marine Strategy Framework Directive adopted by European Union in 2008 is an important step towards ecosystem-based marine management and provides a legal document suggesting marine regions as a scale for cooperation. In this paper, we aim to explore stakeholders׳ perspectives on key factors for good governance at the regional sea level covering the Eastern Baltic States and the south of France. We targeted a broad panel of professionals from different sectors with a political, economic or societal importance in the respective seas. We suggest that Baltic and Mediterranean stakeholders are going through very different stages of governance adjustment fitting the purpose of ecosystem-based marine management. Baltic institutions are well established, which in some way prevents structural analysis of whether the current governance model is the most appropriate reaching GES. In the Mediterranean, the EU strategies faces institutional challenges, which is leading stakeholders to think “out of the box” about what is really needed for implementing ecosystem-based marine management for this sea. It is suggested that a golden opportunity exists at present in the Mediterranean to create a regional platform of cooperation, not only to fit the MSFD implementation, but also to improve governance of the Mediterranean Sea and its environmental status.  相似文献   
10.
The European fisheries policy has undergone a substantial reform. The reform process was initiated by a Green Paper published by the European Commission in 2009. It was recently finalised with an agreement on a new Basic Regulation between the European Commission, the Council and the Parliament in October 2013. The reform of the Common Fisheries Policy will be an important step towards a more sustainable fisheries policy in Europe. The most important reform steps are the introduction of maximum sustainable yield as the new management target, a landing obligation for bycatch and a governance shift towards regions. Although the mentioned reform elements are in generally very promising, their concrete design does not always meet existing expectations.  相似文献   
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