E. Jarauta

Soil moisture regimes under different land uses were observed and modeled in a representative forest basin in the Catalonian Pre-Pyrenees, more specifically in the Ribera Salada catchment (222.5 km2). The vegetation cover in the catchment consists of pasture, tillage and forest. A number of representative plots for each of these land cover types were intensely monitored during the study period. The annual precipitation fluctuates between 516 and 753 mm, while the soil moisture content oscillates between 14 and 26% in the middle and low lying areas of the basin, and between 21 and 48% in shady zones near the river bed, and in the higher parts of the basin. Soil moisture and rainfall are controlled firstly by altitude, with the existence of two climatic types in the basin (sub-Mediterranean and sub-alpine), and further, by land use. Two models were applied to the estimated water moisture regimes: the Jarauta Simulation Newhall model (JSM) and the Newhall simulation model (NSM) were fo...

The classical statistical study of the wind speed in the atmospheric surface layer is made generally from the analysis of the three habitual components that perform the wind data, that is, the component W-E, the component S-N and the vertical component, considering these components independent. When the goal of the study of these data is the Aeolian energy, so is when wind is studied from an energetic point of view and the squares of wind components can be considered as compositional variables. To do so, each component has to be divided by the module of the corresponding vector. In this work the theoretical analysis of the components of the wind as compositional data is presented and also the conclusions that can be obtained from the point of view of the practical applications as well as those that can be derived from the application of this technique in different conditions of weather.

BibliografiaAnàlisi matemàtica d'una variable presenta un conjunt de temes que s'inclouen a la majoria dels programes de les assignatures de matemàtiques de primer curs universitari, i que es poden agrupar en quatre parts: fonaments, funcions, càlcul diferencial i càlcul integral. Està dirigit a estudiants i, per això, s'ha escrit amb un esquema didàctic, tenint en compte els aspectes acadèmics dels nous plans d'estudis, i ha estat pensat per servir de complement de les explicacions de classe, ja que permet fer lectures a diferents nivells. Per això, conté nombrosos exemples i exercicis i una guia de referències bibliogràfiques per a cada capítol

El presente trabajo constituye la segunda parte de 'El Sistema Alimentario Global: I - Definicion de un espacio' (2014). Los objetivos de esta segunda parte son: (1) ilustrar y desarrollar la aplicacion del modelo formulado en el trabajo anterior, (2) definir indices cuantitativos que permitan posicionar y caracterizar comparativamente el sistema alimentario desde una perspectiva global y (3) formular conclusiones en base al estudio cuantitativo realizado y los indices definidos. En esta segunda parte se aplica el modelo formulado en la parte I al estudio de un espacio agroalimentario, la Europa mediterranea, concretado en cuatro paises: Espana, Francia, Grecia e Italia. El estudio se lleva a cabo con datos correspondientes a 12 variables agrupadas en los cuatro ejes conceptuales del modelo. Para cuantificar la posicion relativa para cada variable y cada pais, se define la denominada ratio de posicion (RP) basada en la transformacion CLR (centered log-ratio transformation) d...

Los autores desarrollan su modelos de sistema alimentario global, pesentado conceptualmente en anteriores publicaciones, basado en cuatro ejes basicos (disonibilidad, economia, politica y saber) dandole una estructura compresnbile, abierta y en la que se la plica una metodologia matematica que permite conocer la evolucion de los parametros y su prospectiva. Para ello, en el presente trabajo se pasa de los conceptos cualitativos a los cuantitativos. Cada eje se descompine, en tres subejes dando un total de 12, que identifican aspectos especificos de los pirimarios y que definen en este espacio las actividades y conceptos fundmentales del sistema agroalimentario y de tal forma que puedan seguir desarrollandose sus contenidos en aspectos de aun mas detalle, en un desarrollo fractal de base tetraedica. Para cada subeje se propone un primer parametro de evaluacion en base a valores en unidades, obtenibles en unidades de tiempo, habitualmente anos, de datos fiables publicados y compatible...

Analisi matematica d'una variable: fonaments i aplicacions presenta un conjunt de temes inclosos en la majoria dels programes de les assignatures de calcul de primer curs universitari, que es poden agrupar en quatre parts: fonaments, funcions i limits, calcul diferencial i calcul integral. Ha estat concebut com a text de suport a l'activitat docent del professorat i serveix de complement i referencia a les explicacions que es fan a classe; aixi, doncs, s'estructura d'acord amb un esquema didactic, tenint en compte els aspectes academics dels plans d'estudis reformats, i admet lectures a diferents nivells. Conte molts exemples i exercicis resolts i que es proposen a l'estudiant, com tambe unes referencies bibliografiques comentades al final de cada capitol.

La aplicacion del modelo simulativo de f. Newhall (1976) a series de datos climaticos, del area meridional de Lleida, produce la aparicion generalizada del regimen de humedad USTIC. Tal resultado es incoherente con las caracteristicas de los suelos del clima de esta comarca y ha motivado la elaboracion de un nuevo modelo simulativo del regimen de humedad de los suelos, cuyas caracteristicas principales son: - considerar varios tipos de perfil de suelo. - posibilidad de utilizar datos de precipitacion diaria o mensual. - tiene en cuenta la infiltracion real del agua de lluvia. - tiene en cuenta las caracteristicas de los suelos para modelizar los procesos de infiltracion y evapotranspiracion. - coinciden muy satisfactoriamente los resultados experimentales con los obtenidos mediante el modelo. El modelo simulativo propuesto da como resultado que el regimen de humedad de los suelos del area meridional de Lleida es XEREIC-I y ARIDIC en los de menos capacidad de retencion de agua. __________________________________________________ Lack of irrigation water in southern Lleida (north-east of Spain) restricts the possibilities of an intensive use of soils. To better this situation we need a good information about soil moisture contents, Esther in the present situation or in a future implantation of some irrigation methods. The present research has been developed from 1984 to 1988. Its first aim has been to study the soil moisture contents in the above mentioned area during these years . The soil moisture contents has been determined in order to establish the real situation of the moisture control section; from twenty-two initial control points we selected two representative ones. The second aim has been to determine the moisture regimes of soils in the above mentioned area in order to determine its classification as Soil Taxonomy (USDA 1975) is concerned, to avoid the problems that arose from the fact of not knowing whether the regime was Aridic or not. In this research, Franklin Newhalls simulation model (1976) has been proved inadequate when applied in a semiarid zone like the studied. Therefore we propose a new simulation model for the soil moisture regimes with the following main properties: (1) possibility of using daily or monthly precipitation data; (2) possibility of taking account the efficiency of infiltration of rainfall water: (3) possibility of using the model soil profiles of different available water capacity; (4) it takes into account local soils and local whether properties; (5) it allows knowing the state of the moisture control section each day during each year of the studied series (7) it is very easy to use in a Personal Computer with MS-DOS operating system. Finally, there is a great coincidence between the experimental mentioned results and the estimation obtained by applying the model proponed in this work. Therefore, the soil moisture regimes in southern Lleida are Xeric and Aridic in soils with lower available water capacity, opposite to Ustic regime obtained by applying the F. Newhalls model.

El projecte consta de dues parts. La primera EVAM (Eina Virtual per a l’Autoaprenentatge de les Matemàtiques) és un conjunt de material interactiu accesible via Web per tal de consolidar i ampliar els coneixements de matemàtiques de l’estudiant. El projecte fa referència a temes de matemàtiques que majoritàriament, l’estudiant ha vist abans d’entrar a la Universitat, però l’experiència ens demostra que el nivell real està, en general, lluny del nivell teòric desitjable. Pels càlculs interactius s’utilitza la plataforma WIRIS. La segona part, que hem anomenat BASICMATWEB, es tracta d’una Web d’ensenyament i autoaprenentatge en xarxa de les Matemàtiques, amb uns continguts que, en general, són els que habitualment s’imparteixen a les assignatures de Matemàtiques del primer curs de les titulacions de la UPC. Per a cada tema hi ha uns resums dels conceptes il•lustrat amb exemples diversos i complementat amb problemes i exercicis que es poden resoldre amb càlculs interactius usant l’eina...

Aeolian energy is currently a viable alternative to traditional energies. Several studies have been made to design and to build Aeolian parks for power provision of small, medium or great levels of consumption. In order to determine the viability of parks’ locations, statistical studies in situ are made measuring the wind speed during long periods of time with expensive material to the approximated height of the nose of the aero generator. This paper aims to establish a mathematical relation, based on empirical data, between parameters of the Weibull distribution at different heights in the atmospheric superficial layer, to reduce the price of cost and to improve decision making.

Environmental pollution by heavy metals is a red-hot issue. It is being studied from many points of view, as it is not only an environmental problem but also a public health matter. The effect of pollution by heavy metals can be assessed directly, that is measuring heavy metal concentration in soils, or using indirect methods, that is measuring heavy metal contents on living beings of regional ecosystem, in particular on plants. One of the organisms that have proved to be the most faithfully and useful to do so are moss. So, taking moss samples and measuring their heavy metal contents, we can study heavy metal environmental pollution. The aim of this work is to show the use of geostatistical tools in environmental pollution analysis applied to a case study of environmental pollution by heavy metals in Ukraine (Polissia zone: Rivne , Zhytomyr, Kyiv and Chernigiv regions). To do so, two different information in that zone are available: on one hand, measures of heavy metal concentratio...

The main goal of this paper is to go some steps further to improve the understanding and manageability of air quality. Quality of atmospheric air in large cities is a matter of great importance because of its impact on the environment and on the health of the population. Recently, measures restricting access of private vehicles to the centre of large cities and other measures to prevent atmospheric air pollution are currently topical. The knowledge of air quality acquires special relevance to be able to evaluate the impact of those great social and economic measures. There are many indices to express air quality. In fact, quite every country has its own, depending on the main pollutants. In general, all indices ignore the compositional nature of the concentrations of air pollutants and do not apply methods of Compositional Data Analysis and have some other weak points such as leak of standardized scale. Therefore, the methodology used is founded on Compositional Data Analysis. The a...

Earth science studies deal in general with multivariate, regionalized, observations, which may be compositional, or not. Frequently, it is of interest to know whether those data have to be divided into different populations, a task usually performed by cluster analysis. This problem cannot be studied with traditional methods because samples are not independent. In that case, an extension of Ward's clustering method to spatially dependent samples can be used. This methodology is based on a generalized Mahalanobis distance, which uses the covariance and cross covariance (or variogram and cross-variogram) matrices. In its original version, the method was iterative and tedious, as it was necessary to re-estimate the spatial covariance structure at each step. In this work, we stay within the same theoretical framework, but we improve the methodology using the Fast Fourier Transform (FFT) method to find the covariance structure. Thus, we obtain a generalization to many compositional v...

An important problem in the geosciences is the estimation or prediction of regionalized compositions. In fact, it is usual to deal with data such as percentages, concentrations, ppm,...., and use them to estimate values in other locations. Compositional data have been regarded as difficult to work with because of the so-called constant sum constraint. Following Aitchison (1986), any meaningful statement about a composition can be expressed in terms of logratios, but those transformations, and their backtransformations, are not always easy to deal with. The aim of this paper is to compare results obtained applying different methodologies developed in geostatistics, with samples of compositional data from a bauxite deposit in Halimba II (Hungary). Firstly, a classical geostatistics study is done using raw data; secondly applying two wellknown transformations in compositional data analysis: additive logratio (ALR) and centered logratio (CLR); thirdly, the Fast Fourier Transform (FFT) m...

One of the most important aspects associated with transformations of compositional data, consists of establishing the analytical expression of the data transformation and, specially, the inverse transformation; in that case, once data of the simplex have been transformed in elements of the ordinary Euclidian space to proceed to its treatment (for example, kriging), apply to them the back transformation that allows to obtain again the corresponding elements in the simplex. Compositional data transformations more commonly applied up to now, are the additive logratio transformation (ALR) and the centered logratio transformation (CLR), both defined by J. Aitchison. Recently it was established by J. J. Egozcue and others (2003), a new compositional data transformation, named isometric logratio (ILR), with the purpose of having an orthonormal basis of reference in the simplex. The proposed expression for the calculation of the data transformation and the inverse transformation are really ...

Energy resources are very important for any kind of society. The energy consumed in the world comes from various sources. The time series data can be considered from the compositional point of view. Two groups can be considered: widespread (fossil, nuclear and hydraulics) and the modern renewable. In this paper the evolution of world energy system is studied, applying a model based on first order simplicial linear ordinary differential equations. The matrix of data is used to fit the parameters of a compositional model based on the integral form of the system expressed on ilr-coordinates (balances) of compositions. Groups are studied separately and a projection of the evolution of the proportions of the different sources of energy in the future is presented.

Egozcue, JJ, Barceló-Vidal, C., Martín-Fernández, JA, Jarauta-Bragulat, E., Díaz-Barrero, JL and Mateu-Figueras, G.(2011) Elements of Simplicial Linear Algebra and Geometry, in Compositional Data Analysis: Theory and Applications (eds V. Pawlowsky-Glahn and A. ...

ABSTRACT General systems are frequently decomposable into parts and these parts can evolve in time or space, a frequent occurrence in the field of Geosciences. In most cases, fitting models to forecast future states of the system is a goal of the analysis. Modelling interactions between parts may also be of common interest. The system can be analysed from different points of view; the traditional one consists in modelling each part of the system in time. Alternatively, modelling the evolution of the parts as proportions is proposed herein and attention is centred on the compositional evolution. The compositions are expressed in orthogonal coordinates (ilr) and then modelled using first-order differential equations with constant coefficients. Simple models are shown to be very flexible, including many of the standard growth curve models. The models are fitted using regression techniques on the integrated coordinates. The use and interpretation of these differential models is illustrated with several examples: a simulated example; urban waste in Catalonia (Spain); oil production and reserves; and growth of a luzonite crystal.

Page 1. Computers & Geosciences 27 (2001) 887–889 Short Note Modifications to KB2D program in GSLIB to allow use of tabulated covariances calculated with fast Fourier transform method $ Carme Hervada-Salaa,*, Eusebi Jarauta-Bragulatb a Dep. ...

BibliografiaAnàlisi matemàtica d'una variable presenta un conjunt de temes que s'inclouen a la majoria dels programes de les assignatures de matemàtiques de primer curs universitari, i que es poden agrupar en quatre parts: fonaments, funcions, càlcul diferencial i càlcul integral. Està dirigit a estudiants i, per això, s'ha escrit amb un esquema didàctic, tenint en compte els aspectes acadèmics dels nous plans d'estudis, i ha estat pensat per servir de complement de les explicacions de classe, ja que permet fer lectures a diferents nivells. Per això, conté nombrosos exemples i exercicis i una guia de referències bibliogràfiques per a cada capítol

NOTA: Hi ha un fe d'errates sobre l'article. Vegeu: Fe d'errates: Bases de dades de disponibilitat alimentària: llacunes estadístiques i propostes de millora”: [Quaderns Agraris, 46 (juny 2019), 129-138]”La disponibilitat d’aliments per a la població humana («fam zero») és un dels disset Objectius de Desenvolupament Sostenible (ODS) aprovats el 2015 per l’Organització de les Nacions Unides (ONU). La complexitat de la solució del problema de la manca d’aliments per a la població humana mundial exigeix dades fiables a fi de desenvolupar polítiques i estratègies adequades. Tradicionalment s’ha relacionat la producció fotosintètica (agricultura, ramaderia de pastura, pesca, etc.) amb la disponibilitat alimentària, però, atès que una part d’aquesta producció es destina al mercat global d’energia (biocombustib...

El projecte consta de dues parts. La primera EVAM (Eina Virtual per a l’Autoaprenentatge de les Matemàtiques) és un conjunt de material interactiu accesible via Web per tal de consolidar i ampliar els coneixements de matemàtiques de l’estudiant. El projecte fa referència a temes de matemàtiques que majoritàriament, l’estudiant ha vist abans d’entrar a la Universitat, però l’experiència ens demostra que el nivell real està, en general, lluny del nivell teòric desitjable. Pels càlculs interactius s’utilitza la plataforma WIRIS. La segona part, que hem anomenat BASICMATWEB, es tracta d’una Web d’ensenyament i autoaprenentatge en xarxa de les Matemàtiques, amb uns continguts que, en general, són els que habitualment s’imparteixen a les assignatures de Matemàtiques del primer curs de les titulacions de la UPC. Per a cada tema hi ha uns resums dels conceptes il•lustrat amb exemples diversos i complementat amb problemes i exercicis que es poden resoldre amb càlculs interactius usant l’eina...

El projecte consta de dues parts. La primera EVAM (Eina Virtual per a l’Autoaprenentatge de les Matemàtiques) és un conjunt de material interactiu accesible via Web per tal de consolidar i ampliar els coneixements de matemàtiques de l’estudiant. El projecte fa referència a temes de matemàtiques que majoritàriament, l’estudiant ha vist abans d’entrar a la Universitat, però l’experiència ens demostra que el nivell real està, en general, lluny del nivell teòric desitjable. Pels càlculs interactius s’utilitza la plataforma WIRIS. La segona part, que hem anomenat BASICMATWEB, es tracta d’una Web d’ensenyament i autoaprenentatge en xarxa de les Matemàtiques, amb uns continguts que, en general, són els que habitualment s’imparteixen a les assignatures de Matemàtiques del primer curs de les titulacions de la UPC. Per a cada tema hi ha uns resums dels conceptes il•lustrat amb exemples diversos i complementat amb problemes i exercicis que es poden resoldre amb càlculs interactius usant l’eina...

Soil Sci. Soc. Am. J. 75:2011 Posted online 18 Apr. 2011 doi:10.2136/sssaj2010.0307 Received 11 Aug. 2010. *Corresponding author (jordi.comas-angelet@upc.edu). © Soil Science Society of America, 5585 Guilford Rd., Madison WI 53711 USA All rights reserved. No part of this ...

Egozcue, JJ, Jarauta-Bragulat, E. and Díaz-Barrero, JL (2011) Calculus of Simplex-Valued Functions, in Compositional Data Analysis: Theory and Applications (eds V. Pawlowsky-Glahn and A. Buccianti), John Wiley & Sons, Ltd, Chichester, UK. doi: 10.1002/ ...