Search results for "Computers in Earth Science"
showing 10 items of 323 documents
Well water quality in Latvia
1996
A total of 2500 water samples from drinking water shallow wells and boreholes in rural areas of Latvia were collected. The samples were analyzed for 20 parameters. Well waters in Latvia can be characterized by a high content of organic (humic) substances. Mean values for analyzed water parameters are: 0.17 mg/1 NH4, 0.016 mg/1 NO2, 2.90 mg/1 NO3, 0.028 mg/1 PO4, 25.53 mg/1 Cl, 0.12 mg/1 Fe, 7.4 pH, 784 μ/cm conductivity, 24 degrees in PtCo scale color, 7.5 mgequiv/1 total hardness. Comparison with water quality criteria adopted in the USA and European Communiy indicate that water quality is often unsatisfactory. For example, nitrate concentrations exceed standards in nearly 20% of the surve…
The abundance of Au, Pt, Pd, and the mode of heavy metal fixation in highly polluted sediments from the Rhine River near Mainz, West Germany
1984
The Au, Pt and Pd contents of the sediments of Ginsheimer‐Altrhine River, a channel of the Rhine river which drains one of the most industrialized regions of western Europe, have been determined by flameless atomic absorption spectrophotometry. The abundances of these noble metals range from 96–460 ppb Au; 734 ppb‐31 ppm Pt and 32 ppb‐4 ppm Pd. The extremely high concentrations, particulary those of Pt and Pd, are attributed to their use in industry and are due to the formation and concentration of metal‐organic complexes, mainly at the interface between an extremely reducing and an oxidizing aquatic environment. Differential thermal analyses of the polluted sediments in comparison to the p…
Geomatic applications tourban park in palermo
2015
Over the last few years topographical techniques have developed an exponential trend towards simplifying and speeding, both survey operations and analysis of data collected reaching at the same time ever higher levels of accuracy. Among the technologies that are increasingly taking the field in this context is part of the Mobile Mapping System (MMS) that, on any mobile platform, combines sensors and measurement systems designed to provide a 3D position of the platform and, at the same time, capable to acquire geographic data without the aid of control points on the ground. The study reported concerns the verification of the reliability metrics and a qualitative MMS in order to evaluate its …
The impact of noise on the population of an urban centre in Valencia (Spain)
1997
Acoustic contamination in residential areas is a generalized problem. This paper reports the results of a survey trying to evaluate this contamination in the historical center of Valencia and about its effects upon that district's residents. A total of 700 residents in 11 different neighbourhoods of the city of Valencia were interviewed; at the same time environmental noise was determined at 225 different points within the area of study. In the historical center of Valencia, there exists an important problem of environmental noise and the daily levels clearly exceed the recommended limits.
Benchmark study of undrained triaxial testing of Opalinus Clay shale: Results and implications for robust testing
2021
Triaxial testing of argillaceous rocks and shales is significantly more challenging than conventional rock mechanical testing. The challenges are mainly related to the very low permeability of these geomaterials, and their sensitivity to exposure of atmosphere and brines, which induces variations of water content, suction and effective stress. There are currently no international standards to guide service laboratories for robust testing procedures for shales. A benchmark study of undrained triaxial testing was therefore initiated with three leading service laboratories in shale testing, performing 13 tests and using two different methods of establishing sample saturation prior to deformati…
Mapping a-priori defined plant associations using remotely sensed vegetation characteristics
2014
Abstract Incorporation of a priori defined plant associations into remote sensing products is a major challenge that has only recently been confronted by the remote sensing community. We present an approach to map the spatial distribution of such associations by using plant indicator values (IVs) for salinity, moisture and nutrients as an intermediate between spectral reflectance and association occurrences. For a 12 km 2 study site in the Netherlands, the relations between observed IVs at local vegetation plots and visible and near-infrared (VNIR) and short-wave infrared (SWIR) airborne reflectance data were modelled using Gaussian Process Regression (GPR) (R 2 0.73, 0.64 and 0.76 for sali…
Impact of the terrestrial reference frame on the determination of the celestial reference frame.
2022
Currently three up-to-date Terrestrial Reference Frames (TRF) are available, the ITRF2014 from IGN, the DTRF2014 from DGFI-TUM, and JTRF2014 from JPL. All use the identical input data of space-geodetic station positions and Earth orientation parameters, but the concept of combining these data is fundamentally different. The IGN approach is based on the combination of technique solutions, while the DGFI is combining the normal equation systems. Both yield in reference epoch coordinates and velocities for a global set of stations. JPL uses a Kalman filter approach, realizing a TRF through weekly time series of geocentric coordinates. As the determination of the CRF is not independent of the T…
Carbon Budget and Molecular Structure of Natural Organic Matter in Bank Infiltrated Groundwater
2021
Groundwater : : journal of the Association of Ground-Water Scientists and Engineers, a division of the National Ground Water Association (2021). doi:10.1111/gwat.13087
Neighborhood Characteristics, Alcohol Outlet Density, and Alcohol-Related Calls-for-Service: A Spatiotemporal Analysis in a Wet Drinking Country
2017
Alcohol outlets have been associated with different social problems, such as crime, violence, intimate partner violence, and child maltreatment. The spatial analysis of neighborhood availability of alcohol outlets is key for better understanding of these influences. Most studies on the spatial distribution of alcohol outlets in the community have been conducted in U.S. cities, but few studies have assessed this spatial distribution in other countries where the drinking culture may differ. The aim of this study was to analyze the spatiotemporal distribution of alcohol outlets in the city of Valencia, Spain, and its relationship with neighborhood-level characteristics, as well as to examine t…
Predicting Earthquake-Induced Landslides by Using a Stochastic Modeling Approach: A Case Study of the 2001 El Salvador Coseismic Landslides
2023
In January and February 2001, El Salvador was hit by two strong earthquakes that triggered thousands of landslides, causing 1259 fatalities and extensive damage. The analysis of aerial and SPOT-4 satellite images allowed us to map 6491 coseismic landslides, mainly debris slides and flows that occurred in volcanic epiclastites and pyroclastites. Four different multivariate adaptive regression splines (MARS) models were produced using different predictors and landslide inventories which contain slope failures triggered by an extreme rainfall event in 2009 and those induced by the earthquakes of 2001. In a predictive analysis, three validation scenarios were employed: the first and the second …