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While it is recognized that protected areas are important for biodiversity conservation and human wellbeing, governments struggle to establish and/or enlarge protected areas. Land acquisition and the challenges encountered by governing institutions in funding protected area systems expansion is discussed in this paper using the Capital Regional District (CRD) Land Acquisition Fund as a case study. We briefly discuss land acquisition in British Columbia and in the CRD, and offer an overview of the CRD Land Acquisition Fund and the public participation process that led to its establishment. We emphasize the importance of developing political and citizen support, and a shared vision about expanding protected areas systems - a key element for nearly doubling the parkland base of CRD Regional Parks in less than 20?years. We conclude by offering the lessons learned through the case study and provide guidance for policy and governance directions with regard to land acquisition. 相似文献
23.
The Tharsis region is an 8000-km-wide structural dome that incorporates a concentration of the main volcanic and tectonic activity on the Planet Mars. The area of structural doming is characterised by giant radial graben-dike systems. Nested on a set of these giant dikes to the northern side of Tharsis, is Alba Patera, one of the largest volcanoes in the planetary system. The regional dikes there are in arcuate arrangement and imply an E-W to NW-SE regional extension at Alba Patera. To assess the influence of regional and local tectonics, we studied the dike orientations on the volcano with Viking mosaic data and simulated plausible stress fields with finite element modelling. We found that the influence of a NW-SE regional extension was strong near the volcano centre but decreased rapidly in importance towards the northern pole, i.e., far from the Tharsis centre. By combining this regional stress with a broad uplift that is due to a buoyancy zone of about 1400 km in lateral extent and centred under Alba Patera, we reproduced the radial pattern of dike swarms that diverge from the Tharsis trend. Regional tectonics may have dominated the early stages of dike injection. During the evolution of Alba Patera, however, local updoming controlled the dike pattern, supporting the idea of a hotspot under Alba Patera. The well-expressed dike geometry and characteristics of Alba Patera provide an ideal example for comparative study with analogue hotspots on Earth where plate tectonics and active erosion may complicate the reconstruction of volcanic and tectonic history and the understanding of involved geodynamic processes. 相似文献
24.
Use of shallow groundwater temperature profiles to infer climate and land use change: interpretation and measurement challenges 下载免费PDF全文
Temperature is often used to infer the effect of land use and climate conditions on aquifers. Reliable data are needed to examine the temperature behaviour in the subsurface; thus, the use of robust acquisition techniques is unavoidable. Three temperature measurement techniques were applied to assess the sources of bias that could occur during temperature logging in a shallow Quaternary coastal aquifer in Ferrara (Northern Italy). Open borehole temperature logging, multilevel sampling straddle packers isolated temperature measurements within a flow cell above ground and multilevel sampling straddle packers isolated temperature measurements via an in‐well level logger (MLS‐IW) were compared for several coastal monitoring wells to gain insights on the limitations of each technique. Results show that the source of bias between the three applied techniques are different: (i) the open borehole temperature logging method tends to record heat convection through the open borehole and is not representative of the aquifer temperature distribution; (ii) the multilevel sampling straddle packers isolated temperature measurements within a flow cell above ground method is swayed by the air temperature and the heating of the submersible pump used to lift groundwater above ground; and (iii) the MLS‐IW provides the most reliable vertical thermal profiling both in summer and winter, because groundwater temperature is directly measured at the selected monitoring depth. The implementation of a 1D flow model demonstrates that if precise temperature profiles are needed to infer the influence that land use and climate changes have on groundwater, the MLS‐IW method is a reliable method that could be applied to existing monitoring wells. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
25.
Computational Geosciences - A numerical method using discontinuous polynomial approximations is formulated for solving a phase-field model of two immiscible fluids with a soluble surfactant. The... 相似文献
26.
Beatrice M. Tinsley 《Astrophysics and Space Science》1971,12(2):394-407
The colors of giant elliptical (gE) galaxies in clusters out to redshiftz=0.2, observed by Oke and Sandage (1968), are studied for systematic color-redshift effects. To reveal any intrinsic changes, theK term is subtracted from each color, after correction for galactic reddening and the resulting (B-V)
c
-K
B-V
versus z relation analysed. If the Oke and SandageK terms (relevant to nuclear colors) are used, the best fitting linear relation shows negligible change withz. But if the Whitford (1970)K terms (relevant to integrated colors) are used, there is a trend to bluer colors, by 0.07 mag.atz=0.2 if higher weight is given the better observed clusters. An upper limit, of ±0.08 mag. atz=0.2, is set to possible systematic aperture effects, by the total change between nuclear and integrated B-V and U-B of nearbygE galaxies.The color-redshift trends, interpreted as evolutionary changes, are related to evolution in the magnitude-redshift relation by means of models of stellar evolution in agE galaxy. If one uses the linear fit to the color-redshift relation obtained with WhitfordK terms and neglect of any aperture effects (which is the appropriate case if Oke and Sandage used large enough apertures), and if one adopts plausible limits to the ratio between color and magnitude evolution, the effect of evolution in the magnitude-redshift relation results in a negative value ofq
0. There are still substantial observational and theoretical uncertainties affecting this conclusion. 相似文献
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Abstract. The amphipod population of the Fusaro coastal lagoon (Tyrrhenian Sea, Italy) was studied on a spatial-temporal scale. During a one-year period, samples were collected on hard and soft bottoms along a transect from the inland to the seaward side of the lagoon. Thirteen species were identified. The dominant taxa included species typical of lagoon environments, such as Corophium insidiosum and Microdeutopus gryllotalpa , and species typical of marine environments yet also inhabiting sheltered or semi-closed areas, such as Corophium acutum, Ericthonius brasiliensis , and Elasmopus rapax.
An inner-outer gradient was not evident, while a seasonal pattern was recognizable. At the community level, clear differences between the two substrata were not evident because of high algal growth and organogenic detritus on the soft bottoms. The importance of hydrodynamic forces in a euhaline lagoon in selecting amphipod communities - characterized by a typical trophic behaviour and way of life – is discussed. Information on the ecology of the collected species and a list of Mediterranean lagoons where they are present are also provided. 相似文献
An inner-outer gradient was not evident, while a seasonal pattern was recognizable. At the community level, clear differences between the two substrata were not evident because of high algal growth and organogenic detritus on the soft bottoms. The importance of hydrodynamic forces in a euhaline lagoon in selecting amphipod communities - characterized by a typical trophic behaviour and way of life – is discussed. Information on the ecology of the collected species and a list of Mediterranean lagoons where they are present are also provided. 相似文献
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In the global positioning system (GPS), code division multiple access (CDMA) signals are used. Because of the known spectral
characteristics of the CDMA signal, continuous wave (CW) interference has a predictable effect on the different pseudo random
noise (PRN) spreading codes (unique to each satellite) depending on the Doppler frequency of the signal. The Doppler frequency
for each signal is also predictable once the receiver position is known. As different satellite signals have different Doppler
frequencies, the effect on the signal quality is also different. In this paper first the effect is studied analytically. The
concept of an “exclusion zone” is defined and analyzed for each satellite. This exclusion zone, where that satellite should
not be used due to interference degradation, is shown to be predictable for each satellite as a function of time. Using this
prediction, the CW interference effect on the positioning quality of the receiver can be mitigated by ignoring the affected
satellites within exclusion zones when performing position evaluation. The threshold beyond which a satellite should be excluded
is then derived by studying the mutual effects of the geometry and the signal quality of that satellite on the positioning
quality. Receiver autonomous integrity monitoring (RAIM) uses redundancy in measurements to perform an internal consistency
check to see if all of the measurements are satisfactory. In this paper this technique is also used to mitigate the effect
of CW interference on the positioning accuracy. Finally it is shown that the prediction of the exclusion zone for each satellite
outperforms the RAIM algorithm in mitigation the effect of the interference when 5 satellites are visible.
An erratum to this article can be found at 相似文献