144 resultados para Geographic information |Morphometric analysis
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Flood simulation studies use spatial-temporal rainfall data input into distributed hydrological models. A correct description of rainfall in space and in time contributes to improvements on hydrological modelling and design. This work is focused on the analysis of 2-D convective structures (rain cells), whose contribution is especially significant in most flood events. The objective of this paper is to provide statistical descriptors and distribution functions for convective structure characteristics of precipitation systems producing floods in Catalonia (NE Spain). To achieve this purpose heavy rainfall events recorded between 1996 and 2000 have been analysed. By means of weather radar, and applying 2-D radar algorithms a distinction between convective and stratiform precipitation is made. These data are introduced and analyzed with a GIS. In a first step different groups of connected pixels with convective precipitation are identified. Only convective structures with an area greater than 32 km2 are selected. Then, geometric characteristics (area, perimeter, orientation and dimensions of the ellipse), and rainfall statistics (maximum, mean, minimum, range, standard deviation, and sum) of these structures are obtained and stored in a database. Finally, descriptive statistics for selected characteristics are calculated and statistical distributions are fitted to the observed frequency distributions. Statistical analyses reveal that the Generalized Pareto distribution for the area and the Generalized Extreme Value distribution for the perimeter, dimensions, orientation and mean areal precipitation are the statistical distributions that best fit the observed ones of these parameters. The statistical descriptors and the probability distribution functions obtained are of direct use as an input in spatial rainfall generators.
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El presente estudio consiste en la elaboracin de un mapa del estado de tenencia de la tierra actual de la Zona Protectora y Parque Nacional Volcn Tenorio situado al norte de Costa Rica. A partir de este resultado cartogrfico se efectuarn estudios referentes al estado legal de las propiedades, al tipo de propiedad, a la ubicacin de las propiedades dentro del rea Silvestre Protegida y al evalo de los conflictos legales dentro de sta. Por otro lado, se analiza la cobertura de la tierra y el estado de conservacin. La metodologa utilizada se basa en el uso de Sistemas de Informacin Geogrfica y en la verificacin de la informacin mediante puntos GPS tomados al campo y su anlisis en la oficina. Los resultados muestran una reubicacin de los planos ms precisa y real que la indicada por el Catastro Nacional. Aunque las propiedades privadas son mayoritarias, el rea de estudio presenta en general un porcentaje alto de masa boscosa, mientras que en las zonas limtrofes se encuentra una fragmentacin del hbitat determinada por herbazales. Este estudio contribuye a una mejor gestin y conservacin del rea Protegida y es un avance en el ordenamiento territorial del pas.
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Relevant market definition is still a key element of economic analysis of competition in the gasoline market. It is particularly difficult to handle when competition is local and market power is geographically constrained like is the case in the gasoline market. We analyse how the application of the hypothetical monopolist or Small but Significant Non-Transitory Increase in Prices (SSNIP) test performs for defining isochrones using only information on prices and distance among competitors. We conclude that geographic information systems can be very successfully used to define more precisely relevant geographic market in the gasoline retailing. The application to the Spanish gasoline market concludes that geographic relevant market is composed by 5-6 minutes of travel time. Localised market power should be taken into account when analysing the adverse effects of mergers and entry regulations in gasoline retailing. Only drawing small enough isochrones will drive competition in local markets because it is just close rivals that compete effectively with each other.
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Anlisi de les funcions que desenvolupaven els diferents jaciments de la zona d'estudi: el riu Llobregat, com s'interrelacionaven, el perqu de la seva ubicaci, etc. S'espera que els nous usuaris de SIG assoleixin el que s'anomena pensament geogrfic.
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L'objectiu principal d'aquest treball s construir un sistema d'informaci geogrfica (SIG) que permeti l'anlisi de la relaci del llit del riu Llobregat amb la ubicaci dels jacimentsarqueolgics i les vies de transport del Baix Llobregat a l'poca romana.
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Resumo:
Aquest document ens acosta als sistemes d'informaci geogrfica donant-nos una definici de qu fan, descrivint qu sn els objectes geogrfics (entitats amb informaci geomtrica i temtica) i tractant de la problemtica de la seva representaci. Tamb ens mostra els passos que cal fer en un sistema d'informaci geogrfica, des de la introducci de les dades fins a la presentaci dels resultats, passant per la consulta i l'anlisi.
Resumo:
L'objectiu principal d'aquest Treball s construir un sistema d'informaci geogrfica (SIG) que permeti l'anlisi de la relaci del llit del riu Llobregat amb la ubicaci dels jaciments arqueolgics i les vies de transport del Baix Llobregat en l'poca romana.
Resumo:
Sistema d'Informaci Geogrfica que realitza un anlisi de la relaci del llit del Riu Llobregat amb la ubicaci dels jaciments arqueolgics i les vies de transport del Baix Llobregat en l'poca Romana.
Resumo:
L'objectiu del Treball s establir una relaci entre l'antic traat del riu Llobregat al seu pas per diverses poblacions de Catalunya enclavades a la Comarca del Baix Llobregat i els jaciments arqueolgics datats a l'poca romana amb la perspectiva de la utilitzaci de la via fluvial com element de transport.Per a l'anlisi de les ubicacions de les diferents entitats geogrfiques s'utilitza una eina de programariespecfica: Sistema d'Informaci Geogrfica (SIG) amb la qual es construir el nostre sistema dereferncia per extreure les conclusions oportunes.
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Aquest treball estudia la construcci d'un SIG que permet l'anlisi de la relaci del llit del riu Llobregat amb la ubicaci dels jaciments arqueolgics i les vies de transport del Baix Llobregat en l'poca romana.
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Concretament, l'objectiu principal d'aquest projecte s el de construir un sistema de Informaci Geogrfic que permeti l'anlisi de les diferents rutes i camins existents entre Tarraco (Tarragona) i St Bertrand de Comminges (Frana) passant per Ilerda (Lleida) amb l'objectiu de trobar el cam de mnim cost travessant els Pirineus.
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Anlisis de cinco plataformas, va navegador, para crear mapas y compartirlos.
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A novel test of spatial independence of the distribution of crystals or phases in rocksbased on compositional statistics is introduced. It improves and generalizes the commonjoins-count statistics known from map analysis in geographic information systems.Assigning phases independently to objects in RD is modelled by a single-trial multinomialrandom function Z(x), where the probabilities of phases add to one and areexplicitly modelled as compositions in the K-part simplex SK. Thus, apparent inconsistenciesof the tests based on the conventional joins{count statistics and their possiblycontradictory interpretations are avoided. In practical applications we assume that theprobabilities of phases do not depend on the location but are identical everywhere inthe domain of de nition. Thus, the model involves the sum of r independent identicalmultinomial distributed 1-trial random variables which is an r-trial multinomialdistributed random variable. The probabilities of the distribution of the r counts canbe considered as a composition in the Q-part simplex SQ. They span the so calledHardy-Weinberg manifold H that is proved to be a K-1-affine subspace of SQ. This isa generalisation of the well-known Hardy-Weinberg law of genetics. If the assignmentof phases accounts for some kind of spatial dependence, then the r-trial probabilitiesdo not remain on H. This suggests the use of the Aitchison distance between observedprobabilities to H to test dependence. Moreover, when there is a spatial uctuation ofthe multinomial probabilities, the observed r-trial probabilities move on H. This shiftcan be used as to check for these uctuations. A practical procedure and an algorithmto perform the test have been developed. Some cases applied to simulated and realdata are presented.Key words: Spatial distribution of crystals in rocks, spatial distribution of phases,joins-count statistics, multinomial distribution, Hardy-Weinberg law, Hardy-Weinbergmanifold, Aitchison geometry
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Floods are the natural hazards that produce the highest number of casualties and material damage in the Western Mediterranean. An improvement in flood risk assessment and study of a possible increase in flooding occurrence are therefore needed. To carry out these tasks it is important to have at our disposal extensive knowledge on historical floods and to find an efficient way to manage this geographical data. In this paper we present a complete flood database spanning the 20th century for the whole of Catalonia (NE Spain), which includes documentary information (affected areas and damage) and instrumental information (meteorological and hydrological records). This geodatabase, named Inungama, has been implemented on a GIS (Geographical Information System) in order to display all the information within a given geographical scenario, as well as to carry out an analysis thereof using queries, overlays and calculus. Following a description of the type and amount of information stored in the database and the structure of the information system, the first applications of Inungama are presented. The geographical distribution of floods shows the localities which are more likely to be flooded, confirming that the most affected municipalities are the most densely populated ones in coastal areas. Regarding the existence of an increase in flooding occurrence, a temporal analysis has been carried out, showing a steady increase over the last 30 years.
