Comunicacions a congressos (Química, Física i Ciències Ambientals i del Sòl)
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- ItemOpen AccessFactores de explotación que afectan a la composición de purín en cerdos de engorde(Asociación Interprofesional para el Desarrollo Agrario, 2011) Álvarez Rodríguez, Javier; Hermida, B.; Teira Esmatges, Maria Rosa; Boixadera Llobet, Jaume; Virgili Sanromà, Josep M.; Babot Gaspa, DanielThis study evaluated the effect of certain farming factors (period of year, feed to gain ratio and feed presentation system) on the slurry composition of growing-finishing pig farms (n=23). Feed to gain ration hardly affected chemical composition of slurry, whereas period of year only affected the organic matter content, which was lower in the hot than in the cold period. Likewise, feed presentation system showed a significant effect on some nutrient contents (organic matter, ammonium nitrogen and potassium), which were greater in wet/dry than in dry feeder type. These results highlight the importance of water and feed equipment on the excreta composition of fattening pigs.
- ItemOpen AccessHydraulic canals: can these have functions comparable to those of natural aquatic ecosystems?(Fundació Universitat de Lleida, 2014) Obrador, M.; Vericat Querol, Damià; Palau, Antoni
- ItemOpen AccessThe role of canals in transferring water and sediment during sediment sluicing operations in reservoirs(Fundació Universitat de Lleida, 2014) Béjar Maceiras, María; Vericat Querol, Damià; Batalla, Ramon J.; Palau, AntoniDams alter the continuity of sediment transport in rivers and, consequently, reservoirs experience siltation worldwide. In this paper we present a case study in which we describe how canals may play an important role in managing sediment sluicing operations in reservoirs. Water and sediment transport were monitored at 5 sections along 60 km of the River Segre downstream the Sant Llorenç de Montgai Dam; while bed mobility and in-channel sediment storage were assessed at 3 sites. Results indicate that canal intakes can be managed to control flow discharge and sediment conveyance. Canals located downstream reservoirs may be also used to reduce ecological impacts on riverbed during sediment sluicing from dams.
- ItemOpen AccessEffects of irrigation canals on the sustainability of the irrigated area: learning from the past from the Canal d'Urgell irrigated area(Fundació Universitat de Lleida, 2014) Pedrol, M.; Porta i Casanellas, Jaume
- ItemOpen AccessAplicaciones de software para gestión de canales(Fundació Universitat de Lleida, 2014) Mallol Casals, PilarLos sistemas de información geográfica permiten diseñar y poner a punto herramientas muy útiles para la gestión, puesto que registran y procesan datos gráficos y alfanuméricos del conjunto formado por canal y sus aprovechamientos. Las aplicaciones que se han presentado son ejemplos de los posibles desarrollos, con series históricas de datos y/o con de datos actuales, simular escenarios probables para evaluar los efectos o bien, elaborar análisis complejos con los datos recogidos. Las herramientas desarrolladas con estos sistemas resultan de gran utilidad para los equipos de gestión puesto que se desarrollan en interfaces de uso intuitivo, se pueden introducir datos y realizar consultas en línea el despacho o desde el campo a través de dispositivos móviles y recogen y operan con datos espaciales.
- ItemOpen AccessSeasonal water quality trends in the lower Segre river-derived channels (NE Spain)(Fundació Universitat de Lleida, 2014) Balasch Solanes, J. Carles (Josep Carles); Teira Esmatges, Maria Rosa; Pascual Díaz, M.A monthly sampling survey has been undertaken in the main agricultural and industrial channels derived from the Lower Segre River system (Eastern Ebro Basin, NE Spain) during 2009 and 2010. The monthly evolution of the chemical water quality has been monitored in 11 benchmark spots of the Canals d’Urgell, Auxiliar d’Urgell, Balaguer, Gerb, Hostal Nou, Cup, Aragó i Catalunya, and Serós channels. At the Canals d’Urgell system, the 2nd, 3rd and 4th derivations as well as the final stretch have been controlled. The goal of the survey is to assess physical, chemical and biological water properties with the objective of diagnosing its water quality status according to the Water Framework Directive (2000/60/CE) and to point out actions to improve this channel system.
- ItemOpen AccessNDVI from satellite images to estimate LiDAR-derived geometric and structural parameters in super-intensive almond orchards(2021) Martínez Casasnovas, José Antonio; Llorens Calveras, Jordi; Sandonís Pozo, Leire; Escolà i Agustí, Alexandre; Arnó Satorra, JaumeThe present work tries to bridge a gap about the estimation of geometric and structural orchard parameters (LiDAR-derived) from vegetation indices from satellites. The maximum height and width, the cross-sectional area and the porosity were measured along the rows in a super-intensive almond (Prunus dulcis) orchard every 0.5 m by means of a Velodyne VLP16 LiDAR sensor. These parameters were interpolated to the pixel centroids of PlanetScope and Sentinel-2 and correlated with the normalized difference vegetation index (NDVI) from both platforms. The highest correlations were obtained between the NDVI of PlanetScope images and the cross-sectional area of the almond trees (R=0.72) and with the maximum width of the cross-sections (R=0.71). The results can be useful to estimate important canopy geometric parameters for site-specific management of orchards.
- ItemOpen AccessAplicaciones de la teledetección en la caracterización de frutales y en la fertilización de cultivos extensivos(2021) Martínez Casasnovas, José Antonio; Arnó Satorra, Jaume; Daniele, Elisa; Escolà i Agustí, Alexandre; Sandonís Pozo, Leire; Llorens Calveras, Jordi; Rosell Polo, Joan Ramon; Uribeetxebarria Alonso de Armiño, Asier
- ItemOpen AccessMulti-beam LiDAR-derived data analysis for optimal canopy 3D monitoring in super-intensive almond (Prunus dulcis) orchards(2021) Llorens Calveras, Jordi; Alsina Tehàs, Albert; Arnó Satorra, Jaume; Martínez Casasnovas, José Antonio; Escolà i Agustí, AlexandreAn analysis of data obtained by a LiDAR sensor was carried out. The sensor uses 16 laser beams and was moved along super-intensive almond orchard alleyways to obtain a 3D point cloud. Different beam combinations were used to obtain three geometrical crop parameters: canopy height, width and cross-sectional area. The parameters were computed using a single central beam, a combination of the two outer beams and all 16 beams. The results showed statistically significant differences in width and cross-sectional area when using one, two or sixteen beams. The more the laser beams considered, the larger the canopy width and cross-sectional area. 28-33% larger width was obtained in comparison to the central beam whereas the cross-sectional area was doubled when all beams were considered.
- ItemOpen AccessEstimation of geometric and structural parameters in a super-intensive almond (Prunus dulcis) orchard from multispectral vegetation indices derived from UAV-based imagery(2021) Llorens Calveras, Jordi; Escolà i Agustí, Alexandre; Casañas, E.; Rosell Polo, Joan Ramon; Arnó Satorra, Jaume; Martínez Casasnovas, José AntonioCanopy geometric and structural parameters in a super-intensive almond (Prunus dulcis) orchard were estimated from multispectral vegetation indices from very high-resolution UAV images (0.07 m/pixel). As ground truth data, the canopy geometric and structural parameters were extracted from a 3D LiDAR point cloud. These data were summarized every 0.5 m along the tree rows. The vegetation indices CCCI, NDRE, NDVI, GNDVI and WDRVI were calculated and summarized at the same points as the LiDAR data. The highest correlations (R>0.70) were obtained between the NDVI and the maximum width and the cross-sectional area. The porosity was negatively correlated (R=-0.59) with the NDVI. This research opens the opportunity of using remotely sensed vegetation indices to estimate canopy geometric and structural parameters in addition to vigour for precise canopy management.
- ItemOpen AccessAnálisis del dosel foliar de setos olivo mediante LiDAR y su relación con la productividad y atributos de calidad del aceite(2022) Sandonís Pozo, Leire; Arnó Satorra, Jaume; Rufat i Lamarca, Josep; Villar Mir, Josep Ma.; Martínez Casasnovas, José Antonio; Pascual Roca, MiquelLa gestión del cultivo del olivo, particularmente en condiciones superintensivas, es clave para alcanzar la productividad y la calidad del aceite necesarias para mantener las expectativas económicas de las explotaciones. En este sentido, los sensores LiDAR (Light Detection And Ranging) pueden aportar la información necesaria para cuantificar las características geométricas y estructurales del dosel foliar de las plantaciones. El presente trabajo se ha realizado en una plantación comercial superintensiva de olivo, variedad “Arbequina”, en la que se diseñó un experimento con diferentes dosis de nitrógeno y de riego (desde condiciones deficitarias en diferentes períodos hasta riego completo), cruzado con dosis de N subóptimas y suficientes. Los resultados obtenidos del análisis LiDAR permiten estimar adecuadamente el volumen de los árboles y la porosidad del dosel, pudiendo relacionar estos indicadores con diversos e importantes atributos cuantitativos (producción, crecimiento vegetativo y frondosidad del seto), y cualitativos del aceite obtenido (MUFA, PUFA, estabilidad, polifenoles y esteroles).
- ItemOpen AccessAssessment of different N treatments in Hedgerow Almond Orchards by means of LiDAR point clouds(2022) Sandonís Pozo, Leire; Llorens Calveras, Jordi; Escolà i Agustí, Alexandre; Arnó Satorra, Jaume; Pascual Roca, Miquel; Martínez Casasnovas, José AntonioMonitoring of canopy status in fruit tree orchards allows better decisions in the canopy management, such as pruning or fertirrigation. LiDAR is an effective tool to acquire accurate 3D geometric and structural data, such as height, width, volume or canopy porosity, among others. In the present work, a super-intensive almond orchard (Prunus Dulcis) with 8 different N treatments (N50, N100, N150, NStop: N100 only in Fase I and with and without DMPSA nitrification inhibitor in 24 rows and 3 blocks, was scanned during three years (2019-21) in two different vegetative stages (after spring pruning and before harvesting) by means of a terrestrial LiDAR scanner. Canopy parameters such maximum height and width, cross section and porosity were summarized from the LiDAR 3D point cloud every 0.5 m along the almond tree hedgerows. A repeated measure mixed statistical model was applied to each parameter in order to assess the effect of the N treatments. The adjusted R2 ranged from 0.73 of the canopy width to 0.83 of the porosity. Canopy parameters and their main interactions with the different treatments were significantly differentiated. The N100+DMPSA treatment was the one favoring higher canopy development (higher cross sections and widths, and less porosity), while the NStop+DMPSA treatment was related to lower canopy development and higher porosity.
- ItemOpen AccessPlanetScope Vegetation Indices to Estimate UAV and LiDAR-derived Canopy Parameters in a Super-Intensive Almond Orchard(2022) Sandonís Pozo, Leire; Plata Moreno, José Manuel; Llorens Calveras, Jordi; Escolà i Agustí, Alexandre; Pascual Roca, Miquel; Martínez Casasnovas, José AntonioThe continuous monitoring of geometric and structural parameters is a key aspect in sustainable and accurate orchard management. Although LiDAR and UAV photogrammetry are widely used to measure canopy architecture, there is still a gap to bridge in the development of software to process this information. The present work tries to estimate the maximum height and width in a hedgerow fruit tree orchard from PlanetScope vegetation indices (NDVI and GNDVI). To analyze the correspondence between geometric parameters and the vegetation indices, LiDAR and UAV point clouds were acquired on two 2021 dates in a super-intensive almond orchard: after mechanical pruning (June) and before harvesting (September). The 3D point clouds were summarized every 0.5 m and the maximum width and height along the rows were calculated and interpolated by means of block kriging to the pixel centroids of the PlanetScope image. These maps were later classified using a k means algorithm in two classes. Results indicate that the NDVI was the best performing index in estimation of maximum height and width on the two analyzed dates. GNDVI obtained its best results in September, when vegetation was fully developed. In conclusion, these vegetation indices could be useful for monitoring canopy geometry in this type of orchard, in particular to decide about pruning intensity.
- ItemOpen AccessA new Leafiness-LiDAR index to estimate light interception in intensive olive orchards(2023-07) Sandonís Pozo, Leire; Martínez Casasnovas, José Antonio; Escolà i Agustí, Alexandre; Rosell Polo, Joan Ramon; Rufat i Lamarca, Josep; Pascual Roca, MiquelCanopy light interception constitutes an important yield limiting factor in high density olive orchards. However, its characterisation still implies laborious measurements. A new index, the Leafiness-LiDAR index (LLI), is presented as a LAI estimator. LLI combines LiDAR-derived parameters: Cross-Section and Leafiness from 3D point clouds. To validate the results, photosynthetically active radiation (PAR) measurements, canopy volume, yield and quality parameters were collected and analysed. LLI showed significant correlations both with PAR and canopy volume (r = 0.8) and quality parameters (r = -0.6). LLI may be useful as an early decision canopy monitoring tool in the framework of Precision Fructiculture.