A Comparison between WCS and OPeNDAP for Making Model Results and Data Products Available through the Internet     

Fedor Baart  Gerben de Boer  Wim de Haas  Gennadii Donchyts  Marc Philippart  Mark van Koningsveld  Maarten Plieger 《Transactions in GIS》2012,16(2):249-265

Numerical models produce output with a large number of variables, grid cells and time steps. The same applies to algorithms that produce gridded datasets from sparse or abundant raw data. Further use of the resulting data products has been challenging, especially for dissemination outside the institute of origin. Due to the gradually increasing size of data products, simply downloading copies of them is becoming impossible. A gradual transition from traditional download methods to web services is therefore observed. Web services allow for on‐the‐fly access to subsets of data that were hitherto considered as indivisible granules. Here we compare the most mature candidates to serve gridded data through the web: the Open‐source Project for a Network Data Access Protocol (OPeNDAP) and Web Coverage Service (WCS) protocols. In the framework of the new Dutch National Model and Data Centre (NMDC.eu) a distributed data storage has been created by coupling OPeNDAP servers. A WCS service layer is provided for the same data. This allows us to compare OPeNDAP and WCS. Using several use cases, we compare the usability, performance and features of the two protocols.  相似文献   

Partnering between a geography department and a community initiative to provide a wind resource assessment for the Blueskin Bay region,Otago, New Zealand     

Nicolas Cullen  Alice Bowden  Rachel Spronken‐Smith 《New Zealand geographer》2012,68(1):49-61

This paper explores the partnership between a community group and a geography department to assess the wind energy potential of the Blueskin Bay region in southern New Zealand. The partnership has provided opportunities for research and is of strategic importance. Year‐long wind observations and numerical modelling have revealed that the hills surrounding Blueskin Bay show potential for wind energy generation. Despite challenges for both parties, the university–community partnership has allowed a successful research platform to be established.  相似文献   

Freshwater geographies: Experimenting with knowing and doing geography differently   总被引：1，自引：0，他引：1  

Brendon Blue  Claire Gregory  Kiely McFarlane  Marc Tadaki  Petra van Limburg‐Meijer  Nick Lewis 《New Zealand geographer》2012,68(1):62-66

The fair and effective governance of freshwater is an increasingly prominent issue in New Zealand. Emerging from a complex of cultural, economic and biophysical narratives, freshwater geographies are multiple, varied and increasingly acknowledged as worthy of interdisciplinary scrutiny. In this commentary, we reflect on a series of generative spaces that we – as group of postgraduate geographers (plus supporting staff) – created to engage with the multiplicity of freshwater meanings both within and beyond the academy. Through this evolving epistemic‐political project, we significantly reframed our own understandings about what freshwater ‘is’ and how it ought to be governed. By pursuing a deeper understanding of how the world gets made, we expand our ability to know and make it differently.  相似文献   

Agricultural land use dynamics in the Brazilian Amazon based on remote sensing and census data     

Giovana M. de Espindola  Ana Paula D. de AguiarEdzer Pebesma  Gilberto CâmaraLeila Fonseca 《Applied geography (Sevenoaks, England)》2012,32(2):240-252

The potential impact of deforestation in the Brazilian Amazon on greenhouse gas emissions to the atmosphere calls for policies that take account of changes in forest cover. Although much research has focused on the location and effects of deforestation, little is known about the distribution and reasons for the agricultural uses that replace forest cover. We used Landsat TM-based deforestation and agricultural census data to generate maps of the distribution and proportion of four major agricultural land uses throughout the Brazilian Amazon in 1997 and 2007. We built linear and spatial regression models to assess the determinant factors of deforestation and those major agricultural land uses - pasture, temporary agriculture and permanent agriculture - for the states of Pará, Rondônia, and Mato Grosso. The data include 30 determinant factors that were grouped into two years (1996 and 2006) and in four categories: accessibility to markets, public policies, agrarian structure, and environment. We found an overall expansion of the total agricultural area between 1997 and 2007, and notable differences between the states of Pará, Rondônia, and Mato Grosso in land use changes during this period. Regression models for deforestation and pasture indicated that determinant factors such as distance to roads were more influential in 1997 than in 2007. The number of settled families played an important role in the deforestation and pasture, the effect was stronger in 2007 than 1997. Indigenous lands were significant in preventing deforestation in high-pressure areas in 2007. For temporary and permanent agricultures, our results show that in 1997 the effect of small farms was stronger than in 2007. The mapped land use time series and the models explain empirically the effects of land use changes across the region over one decade.  相似文献   

Topodata: Brazilian full coverage refinement of SRTM data   总被引：2，自引：0，他引：2  

Márcio de Morisson Valeriano  Dilce de Fátima Rossetti 《Applied geography (Sevenoaks, England)》2012,32(2):300-309

This work presents the selection of a set of geostatistical coefficients suitable for a unified SRTM data refinement from 3″ to 1″ through kriging over the entire Brazilian territory. This selection aimed at data potential for geomorphometric derivations, given by the preservation of detailed geometric characteristics of the resulting digital elevation models (DEM), which are sensitive to refining procedures. The development contained a long-term experimentation stage, when data refinement through kriging was locally developed to support distinct regional projects, followed by a unified selection stage, where the acquired experience was applied to select a single and unified interpolation scheme. In this stage, the selected geostatistical models with promising performances were tested for unified refinement on 40 Brazilian areas with distinct geological settings. Tested areas encompass reliefs varying from mountainous to plain. The effects of data preparation were observed on the perception of patterns (texture and roughness), as well as of singularities (edges, peaks, thalwegs etc.). Results were evaluated mainly through the examination of shaded reliefs, transects and perspectives observed in different scales. Terrains with low slopes and small amplitudes had their DEM promptly affected by the refining methods, as opposed to mountainous terrains. The evaluation, unambiguously confirmed by all consulted interpreters, converged into a refining model with outstanding performance in all tested conditions.  相似文献   

Analysis of the Devonian (Frasnian) platform from Belgium: a multi‐faceted approach for basin evolution reconstruction     

Anne‐Christine Da Silva  Frédéric Boulvain 《Basin Research》2012,24(3):338-356

This study undertakes a multi‐disciplinary approach (sedimentology, carbon isotopes, magnetic susceptibility and thickness distribution) to improve understanding of a major Palaeozoic carbonate platform, the Frasnian platform of Belgium. These combined techniques are used to reconstruct the platform history, which evolved in two main steps. During the first phase, the basin was strongly influenced by faulting, producing notable thickness and facies variations, with open ocean conditions, with good water circulation and no/or limited barrier reef. The second phase of platform development was less influenced by differential subsidence, as indicated by homogeneous facies distribution. However, this platform developed under restricted waters, with low circulation which is likely related to the development of a barrier reef.  相似文献   

Costing the impact of climate change on tourism in Europe: results of the PESETA project     

Bas Amelung  Alvaro Moreno 《Climatic change》2012,112(1):83-100

Climate change might lead to large shifts in tourist flows, with large economic implications. This article simulates the effect of future climate change by the 2080s on outdoor international tourism expenditure within Europe. The assessment is based on the statistical relationship between bed nights and a climate-related index of human comfort, after accounting for other determinants of bed nights such as income and prices. It is concluded that climate change could have significant impacts on the regional distribution of the physical resources supporting tourism in Europe. For example, in summer, Southern Europe could experience climate conditions that are less favourable to tourism than the current climate, while countries in the North could enjoy better conditions. The economic effects of these changes are likely to be sizeable, albeit difficult to assess. Crucially, they are shown to depend on tourists’ temporal flexibility with respect to holiday planning. The greater the prominence of institutional rigidities such as school holidays, the larger the differences between winning and losing regions in terms of economic impact.  相似文献   

Nitrous oxide emissions from gasohol, ethanol and CNG light duty vehicles     

Vanderlei Borsari  Jo?o Vicente de Assun??o 《Climatic change》2012,111(3-4):519-531

A sample of 21 light duty vehicles powered by Otto cycle engines were tested on a chassis dynamometer to measure the exhaust emissions of nitrous oxide (N₂O). The tests were performed at the Vehicle Emission Laboratory of CETESB (Environmental Company of the State of Sao Paulo) using the US-FTP-75 (Federal Test Procedure) driving cycle. The sample tested included passenger cars running on three types of fuels used in Brazil: gasohol, ethanol and CNG. The measurement of N₂O was made using two methods: Non Dispersive InfraRed (NDIR) analyzer and Fourier Transform InfraRed spectroscopy (FTIR). Measurements of regulated pollutants were also made in order to establish correlations between N₂O and NO_x. The average N₂O emission factors obtained by the NDIR method was 78?±?41?mg.km^?1 for vehicles running with gasohol, 73?±?45?mg.km^?1 for ethanol vehicles and 171?±?69?mg.km^?1 for CNG vehicles. Seventeen results using the FTIR method were also obtained. For gasohol vehicles the results showed a good agreement between the two methods, with an average emission factor of 68?±?41?mg.km^?1. The FTIR measurement results of N₂O for ethanol and CNG vehicles were much lower than those obtained by the NDIR method. The emission factors were 17?±?10?mg.km^?1 and 33?±?17?mg.km^?1, respectively, possibly because of the interference of water vapor (present at a higher concentration in the exhaust gases of these vehicles) on measurements by the NDIR method.  相似文献   

Detection and quantification of local anthropogenic and regional climatic transient signals in temperature logs from Czechia and Slovenia     

Petr Děde?ek  Jan ?afanda  Du?an Rajver 《Climatic change》2012,113(3-4):787-801

The paper reports on detection and quantification of the impact of local anthropogenic structures and regional climatic changes on subsurface temperature field. The analyzed temperature records were obtained by temperature monitoring in a borehole in Prague-Spo?ilov (Czechia) and by repeated logging of a borehole in ?empeter (Slovenia). The observed data were compared with temperatures yielded by mathematical 3D time-variable geothermal models of the boreholes’ sites with the aim to decompose the observed transient component of the subsurface temperature into the part affected by construction of new buildings and other anthropogenic structures in surroundings of the boreholes and into the part affected by the ground surface temperature warming due to the surface air temperature rise. A direct human impact on the subsurface temperature warming was proved and contributions of individual anthropogenic structures to this change were evaluated. In the case of Spo?ilov, where the mean annual warming rate reached 0.034°C per year at the depth of 38.3?m during the period 1993–2008, it turned out that about half of the observed warming can be attributed to the air (ground) surface temperature change and half to the human activity on the surface in the immediate vicinity of the borehole. The situation is similar in ?empeter, where the effect of the recently built surface anthropogenic structures is detectable down to the depth of 80?m and the share of the anthropogenic signal on the non-stationary component of the observed subsurface temperature amounts to 30% at the depth of 50?m.  相似文献   

Numerical simulation of the diurnal cycle of rainfall in SW Amazon basin during the 1999 rainy season: the role of convective trigger function     

Cláudio Moisés Santos e Silva  Saulo Ribeiro de Freitas  Ralf Gielow 《Theoretical and Applied Climatology》2012,109(3-4):473-483

In continental areas, the maximum rainfall simulated with the Brazilian developments on the Regional Atmospheric Modeling System (BRAMS) occurs around 4?h earlier than the one observed with rain gauges. This work presents the successful implementation of a new convective trigger function (CTF) in the convective parameterization scheme used in BRAMS that corrects this misfit between model and observations. The importance of the CTF formulation on the diurnal cycle of rainfall over the Amazon Basin is reflected by the following numbers: Over Rondonia (SW Amazonia), the original version of BRAMS simulates the maximum rainfall at 1400 UTC (1000 LST), with the new CTF maximum shifting to 1800?UTC (1400?LST), while the S-band radar rainfall maximum is at 1900?UTC (1500?LST). This is attributed to two factors: (1) the new CTF is now coupled to the sensible and latent heat fluxes at surface; (2) during the early morning, the convective available potential energy is reduced.  相似文献