Now showing items 34-53 of 80

    • Error in radar-derived soil moisture due to roughness parameterization: an analysis based on synthetical surface profiles 

      Lievens, Hans; Vernieuwe, Hilde; Álvarez-Mozos, Jesús Upna; Baets, Bernard de; Verhoest, Niko E. C. (MDPI, 2009)   Artículo / Artikulua  OpenAccess
      In the past decades, many studies on soil moisture retrieval from SAR demonstrated a poor correlation between the top layer soil moisture content and observed backscatter coefficients, which mainly has been attributed ...
    • Estimated and real durability of unfired clay bricks: Determining factorsand representativeness of the laboratory tests 

      Seco Meneses, Andrés Upna; Urmeneta, Pablo; Prieto Cobo, Eduardo Upna; García, Beñat; Miqueleiz, Luis (Elsevier, 2016)   Artículo / Artikulua  OpenAccess
      This paper presents an analysis of the representativeness of the main laboratory tests and the real dura-bility of earth-based construction materials. For this study, a natural marl soil, mixed with different per-centages ...
    • Evaluación de la aplicabilidad de la teledetección radar a la estimación de la humedad superficial del suelo en cuencas agrícolas 

      Álvarez-Mozos, Jesús Upna (2006)   Tesis doctoral / Doktoretza tesia  OpenAccess
      En esta tesis doctoral se aborda el tema de la estimación de la humedad superficial del suelo mediante teledetección radar. La humedad superficial del suelo es una variable que interviene en multitud de procesos que tienen ...
    • Evaluación de la producción de sedimentos y calidad de las aguas en cuencas agrarias de Navarra 

      Giménez Díaz, Rafael Upna; Casalí Sarasíbar, Javier Upna; Díez Beregaña, Javier Upna (Universidad de La Rioja, 2012)   Artículo / Artikulua  OpenAccess
      The Government of Navarre (Spain) established a series of experimental watersheds on different sites of its territory in order to assess the impact of the agricultural activities on the environment. Hydrological/meteorological ...
    • Evaluación multitemporal de métodos de corrección topográfica mediante el uso de imágenes sintéticas multiespectrales 

      Sola Torralba, Ion Upna; Álvarez-Mozos, Jesús Upna; González de Audícana Amenábar, María Upna; Torres Escribano, José Luis Upna (Asociación Española de Teledetección, 2014)   Artículo / Artikulua  OpenAccess
      En este trabajo se presentan los resultados de la evaluación multitemporal de varios métodos de corrección topográfica (TOC), cuya bondad se determina de forma cuantitativa mediante el uso de imágenes sintéticas multiespectrales ...
    • Evaluation of 2D models for the prediction of surface depression storage using realistic reference values 

      Giménez Díaz, Rafael Upna; Mezkiritz Barberena, Irantzu; Campo-Bescós, Miguel Upna; Álvarez-Mozos, Jesús Upna; González de Audícana Amenábar, María Upna; Martínez de Aguirre Escobar, Alejandro Upna; Casalí Sarasíbar, Javier Upna (Wiley, 2016)   Artículo / Artikulua  OpenAccess
      Depression storage (DS) is the maximum storage of precipitation and runoff in the soil surface at a given slope. The DS is determined by soil roughness that in agricultural soils is largely affected by tillage. The direct ...
    • Evaluation of a gully headcut retreat model using multitemporal aerial photographs and digital elevation models 

      Campo-Bescós, Miguel Upna; Flores Cervantes, J. H.; Bras, R. L.; Casalí Sarasíbar, Javier Upna; Giráldez Cervera, Juan Vicente (American Geophysical UnionWiley, 2013)   Artículo / Artikulua  OpenAccess
      A large fraction of soil erosion in temperate climate systems proceeds from gully headcut growth processes. Nevertheless, headcut retreat is not well understood. Few erosion models include gully headcut growth processes, ...
    • Evaluation of mechanical tomato harvesting using wireless sensors 

      Arazuri Garín, Silvia Upna; Arana Navarro, Ignacio Upna; Jarén Ceballos, Carmen Upna (MDPI, 2010)   Artículo / Artikulua  OpenAccess
      The harvesting of processing tomatoes is fully mechanised and it is well known that during harvest, fruits are subjected to mechanical stress causing physical injuries, including skin punctures, pulp and cell rupture. Some ...
    • Evaluation of risk factors in fatal accidents in agriculture 

      Arana Navarro, Ignacio Upna; Mangado Ederra, Jesús Upna; Arnal Atarés, Pedro Upna; Arazuri Garín, Silvia Upna; Alfaro López, José Ramón Upna; Jarén Ceballos, Carmen Upna (Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), 2010)   Artículo / Artikulua  OpenAccess
      En el ámbito agrario se producen anualmente muchos accidentes mortales, no siendo todos ellos registrados oficialmente como accidentes laborales. El objetivo de esta investigación es comparar los datos reales y oficiales ...
    • Evaluation of surface roughness parameters in agricultural soils with different tillage conditions using a laser profile meter 

      Martínez de Aguirre Escobar, Alejandro Upna; Álvarez-Mozos, Jesús Upna; Giménez Díaz, Rafael Upna (Elsevier, 2016)   Artículo / Artikulua  OpenAccess
      Surface roughness crucially affects the hydrological and erosive behaviours of soils. In agricultural areas surface roughness is directly related to tillage, whose action strongly affects the key physical properties of ...
    • Evaluation of the improvement of streamflow prediction through the assimilation of remotely sensed soil moisture observations 

      Loizu Maeztu, Javier Upna (2017)   Tesis doctoral / Doktoretza tesia  OpenAccess
      El objetivo principal de esta tesis es evaluar si la asimilacion de datos de humedad superficial del suelo obtenidos mediante tecnicas de teledeteccion, en modelos hidrologicos es capaz de mejorar la prediccion de caudales ...
    • Evaluation of TOPLATS on three Mediterranean catchments 

      Loizu Maeztu, Javier Upna; Álvarez-Mozos, Jesús Upna; Casalí Sarasíbar, Javier Upna; Goñi Garatea, Mikel Upna (Elsevier, 2016)   Artículo / Artikulua  OpenAccess
      Physically based hydrological models are complex tools that provide a complete description of the different processes occurring on a catchment. The TOPMODEL-based Land-Atmosphere Transfer Scheme (TOPLATS) simulates water ...
    • Evaluation of topographic correction algorithms on satellite images 

      Sola Torralba, Ion Upna (2016)   Tesis doctoral / Doktoretza tesia  OpenAccess
      Este trabajo contribuye al previamente limitado conocimiento acerca del rendimiento de los métodos de corrección topográfica proponiendo una nueva metodología de evaluación basada en imágenes sintéticas. Esta nueva metodología ...
    • Factors controlling sediment export in a small agricultural watershed in Navarre (Spain) 

      Giménez Díaz, Rafael Upna; Casalí Sarasíbar, Javier Upna; Grande Esteban, Ildefonso Upna; Díez Beregaña, Javier Upna; Campo-Bescós, Miguel Upna; Álvarez-Mozos, Jesús Upna; Goñi Garatea, Mikel Upna (Elsevier, 2012)   Artículo / Artikulua  OpenAccess
      It is recognised that the hydrological and erosion processes in watersheds are very much conditioned by the (inter)action of a number of variables. This paper covers a 15-year period of studying those factors that have ...
    • Gully geometry: what are we measuring? 

      Casalí Sarasíbar, Javier Upna; Giménez Díaz, Rafael Upna; Campo-Bescós, Miguel Upna (European Geosciences UnionCopernicus Publications, 2015)   Artículo / Artikulua  OpenAccess
      Much of the research on (ephemeral) gully erosion comprises the determination of the geometry of these eroded channels, especially their width and depth. This is not a simple task due to uncertainty generated by the wide ...
    • Hallazgo de treintaiséis nuevas estelas de Navarra 

      Ukar Muruzábal, Jesús Upna (Gobierno de Navarra. Institución Príncipe de Viana, 1993)   Artículo / Artikulua  OpenAccess
      El presente estudio describe el hallazgo de 31 nuevas estelas de Navarra.
    • Hydrological signatures based on event runoff coefficients in rural catchments of the Iberian Peninsula 

      Taguas, Encarnación V.; Nadal-Romero, Estela; Ayuso, José L.; Casalí Sarasíbar, Javier Upna; Cid, Patricio; Dafonte, Jorge; Canatário-Duarte, Antonio; Ferreira, Carla S.S.; Giménez Díaz, Rafael Upna; Giráldez, Juan V.; Gómez-Macpherson, Helena; Gómez, Jose A.; González-Hidalgo, J. Carlos; Lana Renault, Noemí; Lucía, Ana; Mateos, Luciano; Pérez, Rafael; Rodríguez-Blanco, M. Luz; Schnabel, Susanne; Serrano-Muela, M. Pilar; Taboada-Castro, M. Mercedes; Taboada-Castro, M. Teresa; Zabaleta, Ane (Wolters Kluwer, 2017)   Artículo / Artikulua  OpenAccess
      Hydrological signatures are indices that help to describe the behavior of catchments. These indices can also be used to transfer information from gauged to ungauged catchments. In this study, different approaches were ...
    • Influence of surface roughness measurement scale on radar backscattering in different agricultural soils 

      Martínez de Aguirre Escobar, Alejandro Upna; Álvarez-Mozos, Jesús Upna; Lievens, Hans; Verhoest, Niko E. C. (IEEE, 2017)   Artículo / Artikulua  OpenAccess
      Soil surface roughness strongly affects the scattering of microwaves on the soil surface and determines the backscattering coefficient (σ 0 ) observed by radar sensors. Previous studies have shown important scale issues ...
    • Influence of surface roughness sample size for C-band SAR backscatter applications on agricultural soils 

      Martínez de Aguirre Escobar, Alejandro Upna; Álvarez-Mozos, Jesús Upna; Lievens, Hans; Verhoest, Niko E. C.; Giménez Díaz, Rafael Upna (IEEE, 2017)   Artículo / Artikulua  OpenAccess
      Soil surface roughness determines the backscatter coefficient observed by radar sensors. The objective of this letter was to determine the surface roughness sample size required in synthetic aperture radar applications and ...
    • Influence of surface roughness spatial variability and temporal dynamics on the retrieval of soil moisture from SAR observations 

      Álvarez-Mozos, Jesús Upna; Verhoest, Niko E. C.; Larrañaga, Arantzazu Upna; Casalí Sarasíbar, Javier Upna; González de Audícana Amenábar, María Upna (MDPI, 2009)   Artículo / Artikulua  OpenAccess
      Radar-based surface soil moisture retrieval has been subject of intense research during the last decades. However, several difficulties hamper the operational estimation of soil moisture based on currently available ...