Reviews on books, internet and scientific media     

Anne Marie de Grosbois 《Environmental Earth Sciences》2012,66(2):693-694

  相似文献   

Uncertainties of geochemical modeling during CO<Subscript>2</Subscript> sequestration applying batch equilibrium calculations     

Frank?DethlefsenEmail author  Christoph?Haase  Markus?Ebert  Andreas?Dahmke 《Environmental Earth Sciences》2012,65(4):1105-1117

One of the uncertainties in the field of carbon dioxide capture and storage (CCS) is caused by the parameterization of geochemical models. The application of geochemical models contributes significantly to calculate the fate of the CO₂ after its injection. The choice of the thermodynamic database used, the selection of the secondary mineral assemblage as well as the option to calculate pressure dependent equilibrium constants influence the CO₂ trapping potential and trapping mechanism. Scenario analyses were conducted applying a geochemical batch equilibrium model for a virtual CO₂ injection into a saline Keuper aquifer. The amount of CO₂ which could be trapped in the formation water and in the form of carbonates was calculated using the model code PHREEQC. Thereby, four thermodynamic datasets were used to calculate the thermodynamic equilibria. Furthermore, the equilibrium constants were re-calculated with the code SUPCRT92, which also applied a pressure correction to the equilibrium constants. Varying the thermodynamic database caused a range of 61% in the amount of trapped CO₂ calculated. Simultaneously, the assemblage of secondary minerals was varied, and the potential secondary minerals dawsonite and K-mica were included in several scenarios. The selection of the secondary mineral assemblage caused a range of 74% in the calculated amount of trapped CO₂. Correcting the equilibrium constants with respect to a pressure of 125 bars had an influence of 11% on the amount of trapped CO₂. This illustrates the need for incorporating sensitivity analyses into reaction pathway modeling.  相似文献   

Engineering geological data in support of municipal land use planning—a case study in Analandia, southeast Brazil     

Ana Elisa S. de Abreu  Oswaldo Augusto Filho 《Environmental Earth Sciences》2012,65(1):277-289

This paper presents a method for transforming the information of an engineering geological map into useful information for non-specialists involved in land-use planning. The method consists of classifying the engineering geological units in terms of land use capability and identifying the legal and the geologic restrictions that apply in the study area. Both informations are then superimposed over the land use and a conflict areas map is created. The analysis of these data leads to the identification of existing and forthcoming land use conflicts and enables the proposal of planning measures on a regional and local scale. The map for the regional planning was compiled at a 1:50,000 scale and encompasses the whole municipal land area where uses are mainly rural. The map for the local planning was compiled at a 1:10,000 scale and encompasses the urban area. Most of the classification and operations on maps used spatial analyst tools available in the Geographical Information System. The regional studies showed that the greater part of Analandia’s territory presents appropriate land uses. The local-scale studies indicate that the majority of the densely occupied urban areas are in suitable land. Although the situation is in general positive, municipal policies should address the identified and expected land use conflicts, so that it can be further improved.  相似文献   

Morphosedimentary analysis of the Limoeiro Stream (center-northern Minas Gerais State,Brazil): clues to the eastward tilting of southern Espinhaco range sites     

Claudio E. Lana  Paulo de Tarso A. Castro 《Environmental Earth Sciences》2012,65(3):639-647

The morphosedimentary evolution of a sector of the southern Espinhaco range (northern Minas Gerais State, Brazil) and its regional neotectonic setting are presented herein. The studied site is a stream at base level flowing along the western border of the range. Its identification was accomplished by using remote sensing techniques including the analysis of 3D slope models generated with shuttle radar topography mission images. The main geomorphological features of the identified site were surveyed in a 1:500 scale. In addition, seven stratigraphic logs are described. A regional geologic compilation and facies diagrams were used as a basis for the integration of the geomorphological and stratigraphic data, which produced some conclusions about the recent tectonic reactivations at the eastern border of Sao Francisco Craton. The results point to a local eastward tilting of the Espinhaco range. This fact is in accordance with previous findings in neighboring areas and results in the asymmetric evolution of the fluvial valley, as well as the regional relief.  相似文献   

A Truncated Pareto Model to Estimate the Under Recovery of Large Diamonds     

Andréhette Verster  Daan de Waal  Robert Schall  Chris Prins 《Mathematical Geosciences》2012,44(1):91-100

The metallurgical recovery processes in diamond mining may, under certain circumstances, cause an under-recovery of large diamonds. In order to predict high quantiles or tail probabilities we use a Bayesian approach to fit a truncated Generalized Pareto Type distribution to the tail of the data consisting of the weights of individual diamonds. Based on the estimated tail probability, the expected number of diamonds larger than a specified weight can be estimated. The difference between the expected and observed frequencies of diamond weights above an upper threshold provides an estimate of the number of diamonds lost during the recovery process.  相似文献   

Soil Organic Carbon mapping of partially vegetated agricultural fields with imaging spectroscopy     

Harm Bartholomeus  Lammert Kooistra  Antoine Stevens  Martin van Leeuwen  Bas van Wesemael  Eyal Ben-Dor  Bernard Tychon 《International Journal of Applied Earth Observation and Geoinformation》2011

Soil Organic Carbon (SOC) is one of the key soil properties, but the large spatial variation makes continuous mapping a complex task. Imaging spectroscopy has proven to be an useful technique for mapping of soil properties, but the applicability decreases rapidly when fields are partially covered with vegetation. In this paper we show that with only a few percent fractional maize cover the accuracy of a Partial Least Square Regression (PLSR) based SOC prediction model drops dramatically. However, this problem can be solved with the use of spectral unmixing techniques. First, the fractional maize cover is determined with linear spectral unmixing, taking the illumination and observation angles into account. In a next step the influence of maize is filtered out from the spectral signal by a new procedure termed Residual Spectral Unmixing (RSU). The residual soil spectra resulting from this procedure are used for mapping of SOC using PLSR, which could be done with accuracies comparable to studies performed on bare soil surfaces (Root Mean Standard Error of Calibration = 1.34 g/kg and Root Mean Standard Error of Prediction = 1.65 g/kg). With the presented RSU approach it is possible to filter out the influence of maize from the mixed spectra, and the residual soil spectra contain enough information for mapping of the SOC distribution within agricultural fields. This can improve the applicability of airborne imaging spectroscopy for soil studies in temperate climates, since the use of the RSU approach can extend the flight-window which is often constrained by the presence of vegetation.  相似文献   

A Dutch multi-date land use database: Identification of real and methodological changes     

Gerard W. Hazeu  Arnold K. Bregt  Allard J.W. de Wit  Jan G.P.W. Clevers 《International Journal of Applied Earth Observation and Geoinformation》2011

Land cover and land use are important information sources for environmental issues. One of the most important changes at the Earth's surface concerns land cover and land use. Knowledge about the location and type of these changes is essential for environmental modeling and management. Remote sensing data in combination with additional spatial data are recognized as an important source of information to detect these land cover and land use changes.  相似文献   

Climate change,theory of planned behavior and values: a structural equation model with mediation analysis     

Aysel Tikir  Bernard Lehmann 《Climatic change》2011,104(2):389-402

An online survey about climate change was conducted 2008/2009 among all university members (N = 3541). Using the Theory of Planned Behavior and Cultural Theory within a structural equation modeling approach, one main goal was to explain climate-friendly behavioral intentions and the underlying psychological processes comprehensively and to show the interdependencies between both approaches. The model explained 72% of the variance in Intentions to use public transport. Attitude towards public transport (beta = 0.67, p < .001) most strongly influenced Intentions followed by Subjective Norms (beta = 0.23, p < .001). In turn, Attitudes and Norm were explained by the value types Egalitarian, Individualist and Fatalist (24% and 14% respectively). These value types are mediated through Attitudes and Subjective Norms. Recommendations regarding the support of climate friendly behavior are formulated.  相似文献   

Climatic consequences of gradual desertification in the semi-arid area of Northeast Brazil     

Dayana Castilho de Souza  Marcos Daisuke Oyama 《Theoretical and Applied Climatology》2011,103(3-4):345-357

The climatic impacts of gradual desertification in the semi-arid area of Northeast Brazil (SANEB) were evaluated using the MM5 regional model. Simulations for the rainy season of SANEB (March, April, and May) were performed. Desertification simulations were grouped into three numerical runs: total (all SANEB covered by desert), partial (desert areas placement based on future environmental degradation scenarios for SANEB), and random desertification (desert areas placed randomly within SANEB). Total desertification led to a pronounced and significant precipitation reduction in large parts of SANEB. Climatic impacts of partial desertification were guided by the southward expansion of desert areas. For intermediate desertification extensions, a dipole pattern with precipitation reduction (increase) in the northern (southern) areas of SANEB was found. Random desertification led to climatic impacts spread over the whole SANEB. In both partial and random desertification, a quasi-linear precipitation reduction was found as desertification extension increases.  相似文献   

Influence of coupling on atmosphere, sea ice and ocean regional models in the Ross Sea sector, Antarctica   总被引：1，自引：0，他引：1  

Nicolas C. Jourdain  Pierre Mathiot  Hubert Gallée  Bernard Barnier 《Climate Dynamics》2011,36(7-8):1523-1543

Air–sea ice–ocean interactions in the Ross Sea sector form dense waters that feed the global thermohaline circulation. In this paper, we develop the new limited-area ocean–sea ice–atmosphere coupled model TANGO to simulate the Ross Sea sector. TANGO is built up by coupling the atmospheric limited-area model MAR to a regional configuration of the ocean–sea ice model NEMO. A method is then developed to identify the mechanisms by which local coupling affects the simulations. TANGO is shown to simulate realistic sea ice properties and atmospheric surface temperatures. These skills are mostly related to the skills of the stand alone atmospheric and oceanic models used to build TANGO. Nonetheless, air temperatures over ocean and winter sea ice thickness are found to be slightly improved in coupled simulations as compared to standard stand alone ones. Local atmosphere ocean feedbacks over the open ocean are found to significantly influence ocean temperature and salinity. In a stand alone ocean configuration, the dry and cold air produces an ocean cooling through sensible and latent heat loss. In a coupled configuration, the atmosphere is in turn moistened and warmed by the ocean; sensible and latent heat loss is therefore reduced as compared to the stand alone simulations. The atmosphere is found to be less sensitive to local feedbacks than the ocean. Effects of local feedbacks are increased in the coastal area because of the presence of sea ice. It is suggested that slow heat conduction within sea ice could amplify the feedbacks. These local feedbacks result in less sea ice production in polynyas in coupled mode, with a subsequent reduction in deep water formation.  相似文献