New multifunctional hunting landscapes in Denmark     

Andreas Aagaard Christensen  Stig Roar Svenningsen  Maria Sofie Lommer  Jesper Brandt 《Geografisk tidskrift / udgivet af Bestyrelsen for Det Kongelige danske geografiske selskab》2014,114(1):25-40

Between 1992 and 2008 subsidization of mandatory set aside land under the EU Common Agricultural Policy (CAP) gave rise to the establishment of a characteristic type of multifunctional hunting landscapes in Denmark, primarily located on fallow land in tilled valley bottoms. A national survey of these landscapes in 2006 has been carried out and 1061 hunting areas have been identified nationwide. Subsidies relating to set aside land acted as a supplementary type of income, which supported the development of multifunctional land use on marginal soils where the income from hunting and subsidies in combination was a viable alternative to monofunctional rotational agriculture. Hunting landscapes developed as the consequence of landscape management strategies designed to comply with the requirements of the CAP while improving habitat conditions for wildlife and increasing income from hunting rental activities. Forty-seven percent of the hunting landscapes in 2006 were in rotational production in 2010 while 19% were used for other agricultural purposes and 34% were taken out of the subsidy regime and removed from the general agricultural register. In 2012, a total of 431 such areas ? 41% of the areas identified in 2006 ? were still used for hunting. The number and geographical distribution of the hunting landscapes seems closely related to the potential average hunting rent, the level of urbanisation and the occurrence of manorial estates with traditions for multifunctional land use as part of their economic strategy. Implications for the ongoing discussion on land use policy concerning land sharing vs. land sparing is discussed.  相似文献   

Explaining NDVI trends in northern Burkina Faso     

Kjeld Rasmussen  Rasmus Fensholt  Bjarne Fog  Laura Vang Rasmussen  Isidore Yanogo 《Geografisk tidskrift / udgivet af Bestyrelsen for Det Kongelige danske geografiske selskab》2014,114(1):17-24

Many studies have shown a ‘greening of the Sahel’ on the basis of analysis of time series of satellite images and this has shown to be, at least partly, explained by changes in rainfall. In northern Burkina Faso, an area stands out as anomalous in such analysis, since it is characterized by a distinct spatial pattern and strongly dominated by negative trends in Normalized Difference Vegetation Index (NDVI). The aim of the paper is to explain this distinct pattern. When studied over the period 2000–2012, using NDVI data from the MODIS sensor the spatial pattern of NDVI trends indicates that non-climatic factors are involved. By relating NDVI trends to landscape elements and land use change we demonstrate that NDVI trends in the north-western parts of the study area are mostly related to landscape elements, while this is not the case in the south-eastern parts, where rapidly changing land use, including. expansion of irrigation, plays a major role. It is inferred that a process of increased redistribution of fine soil material, water and vegetation from plateaus and slopes to valleys, possibly related to higher grazing pressure, may provide an explanation of the observed pattern of NDVI trends. Further work will focus on testing this hypothesis.  相似文献   

Special issue dedicated to Professor Anette Reenberg     

Kjeld Rasmussen 《Geografisk tidskrift / udgivet af Bestyrelsen for Det Kongelige danske geografiske selskab》2014,114(1):1-2

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Kinematics and Dynamics of the Galactic Stellar Halo     

Jesper Sommer-Larsen 《Astrophysics and Space Science》1999,265(1-4):123-131

The structure, kinematics and dynamics of the Galactic stellar halo are reviewed including evidence of substructure in the spatial distribution and kinematics of halo stars. Implications for galaxy formation theory are subsequently discussed; in particular it is argued that the observed kinematics of stars in the outer Galactic halo can be used as an important constraint on viable galaxy formation scenarios. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Automated rainfall simulator for variable rainfall on urban green areas   总被引：1，自引：0，他引：1  

Kristoffer T. Nielsen  Per Moldrup  Sren Thorndahl  Jesper E. Nielsen  Lene B. Duus  Sren H. Rasmussen  Mads Uggerby  Michael R. Rasmussen 《水文研究》2019,33(26):3364-3377

Rainfall simulators can enhance our understanding of the hydrologic processes affecting the total runoff to urban drainage systems. This knowledge can be used to improve urban drainage designs. In this study, a rainfall simulator is developed to simulate rainfall on urban green surfaces. The rainfall simulator is controlled by a microcomputer programmed to replicate the temporal variations in rainfall intensity of both historical and synthetic rainfall events with constant rainfall intensity on an area of 1 m². The performance of the rainfall simulator is tested under laboratory conditions with regard to spatial uniformity of the rainfall, the kinetic energy of the raindrops, and the ability to replicate historical and synthetic rainfall events with temporally varying intensity. The rainfall simulator is applied in the field to evaluate its functionality under field conditions and the influence of wind on simulated rainfall. Finally, a field study is carried out on the relationship between runoff, soil volumetric water content, and surface slope. Performance and field tests show that the simulated rainfall has a uniform spatial distribution, whereas the kinetic energy of the raindrops is slightly higher than that of other comparable rainfall simulators. The rainfall simulator performs best in low wind speed conditions. The simulator performs well in replicating historical and synthetic rainfall events by matching both intensity variations and accumulated rainfall depth. The field study shows good correlation between rainfall, runoff, infiltration, soil water content, and surface slope.  相似文献   

The Continuum Voronoi Block Model for simulation of fracture process in hard rocks     

Erick Rgenes  Mrcio Muniz de Farias  Leandro Lima Rasmussen 《国际地质力学数值与分析法杂志》2022,46(1):89-112

In this paper, a numerical model is presented to represent the fracture process in hard rocks based on a pseudo-discontinuum method called the Continuum Voronoi Block Model (CVBM). To validate this tool, numerical models for one Brazilian test, one unconfined compression test, and multiple triaxial compression tests with different confining stress were calibrated to match laboratory test results for Creighton granite. The model proved robust and matched the following macro-properties: crack initiation (CI) stress, (CD) stress, peak strength, tensile strength, Young's Modulus, and Poisson's ratio. The calibrated model served as a basis for a sensitivity study to analyze how micro-properties influence the rock's macroscopic responses. From the sensitivity study, a calibration methodology was proposed, which shall facilitate the use of the CVBM in future works.  相似文献