Evaluación de la pérdida de suelo en olivar a escala de microcuenca bajo distintos manejos de suelo

Los mecanismos de generación de escorrentía y pérdida de suelo han sido ampliamente estudiados en áreas semiáridas como Andalucía, aunque la mayoría de esfuerzos tanto en modelado como en medidas de campo han estado concentrados en escala de parcela, a pesar de sus limitaciones en la predicción hidrológica. Existen diversos estudios dedicados a la pérdida de suelo en olivar, todos ellos realizados sobre parcelas de un máximo de 200 m2 donde se analizan La incidencia del uso de olivar y/o el manejo del suelo correspondiente. Los resultados de estos estudios son diversos y, en algunos caso contradictorios, debido fundamentalmente a las distintas condiciones ambientales en las que se han realizado. Por consiguiente, parece adecuado ampliar la escala de estudio a unidades geomorfológicos no aisladas donde el número de fenómenos naturales que intervienen en la circulación de agua y sedimentos es mayor y más complejo que en las parcelas de ladera y donde los resultados responden mejor a las condiciones reales en las que tienen lugar. En este trabajo, se aborda el estudio de la erosión en dos microcuencas de aproximadamente 6 ha, sometidas a mínimo laboreo y a no laboreo con cubiertas. La primera parte, está dedicada a la análisis de su variabilidad intrínseca de las cuencas desde el punto de vista de la topografía y el suelo junto con las consideraciones derivadas del manejo. En ellas, se han localizado puntos donde lso procesos de erosión y depósito son evidentes para analizar las variables más influyentes en estos fenómenos, de manera que faciliten la interpretación de los valores de escorrentía y erosión. La segunda parte, está dedicada a la adquisición y análisis de datos que proporcionen información del balance hidrológico y las pérdidas de suelo a escala de microcuenca con los manejos correspondientes. Para ello, se ha diseñado e instalado una pequeña estación hidrológica en cada una de las cuencas de estudio de las cuales se han obtenido datos de precipitación, escorrentía y concentración de sedimentos en un ciclo de más de un año (2005-2006). Finalmente, en la última partes, se ha seleccionado un modelo de simulación de procesos hidrológicos y erosivos, AnnAGNPS (Annualized Agricultural Non Point Source), para su calibración y validación según los episodios registrados con el objeto de juzgar los resutlados del modelo así como su extrapolación a otros escenarios

Opportunities of super high-density olive orchard to improve soil quality: Management guidelines for application of pruning residues

Applying pruning residues in the lanes of olive groves has become a popular practice because it is economical and accrues benefits for soil and water management. This study presents an analysis of the impact of different rates of pruning residue on soil properties, in particular related with soil quality. Over 4 annual campaigns, chopped pruning residues used as a mulch were analyzed in terms of composition, coverage and moisture content to evaluate their effects on the amount of soil organic carbon (−10 cm and −20 cm) and CO2 emissions, temperature and moisture. The experiment was carried out in a super-intensive olive orchard in Cordoba (SE, Spain) and used four amounts of fresh pruning residue: 7.5 t ha⁻1(T1), 15.0 t ha⁻1 (T2) and 30.0 t ha⁻1 (T3), with a control T0 = 0.0 t ha1.Mulch mean leaf fraction was 46.0 ± 17.5% (±SD) and initial water content, 24.8 ± 8.6%. The mulching benefits for soil moisture were observed in amounts of pruning residue >7.5 t ha⁻1, which are only produced in super-intensive olive groves or in orchards with high tree densities. The low impact of the treatments on soil moisture was explained by the dramatic annual variations in residue moisture contents, caused by the regimes of high temperatures and rainfall-evapotranspiration deficits inherent to the Mediterranean Basin climate. Thus, the mulching capacity only resulted efficient when the residues were still humid in spring. In addition, 15.0 t ha⁻1 of pruning residues was the threshold to provide significant increases in soil organic carbon at depths of 0–20 cm. Thus, accumulating pruning residue in lanes at rates of over 15 t ha⁻1 (T2 and T3) is more convenient than a uniform distribution with lower amounts, due to the low mineralization rates occurring during warm seasons and the larger inputs of OM increasing the annual balance of SOC

The use of immersive virtual worlds in the improvement of competencies of team work, creativity and innovation

El Plan de Innovación Docente 2015-2016 de la Universidad de Córdoba tenía entre sus líneas prioritarias tanto el trabajo en competencias (línea 1), como el fomento de la enseñanza virtual (línea 10) y la tutorización del alumnado (línea 12). En este contexto, nuestro trabajo ha aplicado y evaluado el uso de mundos virtuales inmersivos para la mejora del manejo de herramientas virtuales y competencias de trabajo en equipo, aspectos claves y transferibles al aprendizaje de cualquier disciplina. Así, se creó un escenario virtual inmersivo para reuniones de trabajo y se diseñaron unas actividades grupales que incluían un manual para el aprendizaje del manejo de avatares y su interacción en un grupo de trabajo en mundos inmersivos. Además se llevaron a cabo actividades tutoradas dirigidas a resolver dudas en grupo así como para definitivamente mejorar la creatividad en un contexto innovador y diferente. Estas sesiones se incluyeron dentro de las prácticas de la asignatura “Proyectos” del grado de Ingeniería Agroalimentaria y del Medio Rural. Los resultados de la evaluación de la experiencia a modo de encuestas diseñadas ad hoc para caracterizar la curva de aprendizaje del manejo de avatares y mundos inmersivos, puso de manifiesto el éxito y utilidad del proyecto cuyo material es reutilizable en futuras experiencias educativas.The Teaching Innovation Plan 2015-2016 of the University of Cordoba had among its priorities competency-based work (line 1), the promotion of virtual teaching (line 10) and tutoring students (line 12). In this context, the use of immersive virtual worlds has been applied to improve teamwork competencies and the management of virtual tools, both being important and transferable aspects to the learning of any discipline. Thus, an immersive virtual scenario was created to enable work meetings, and group activities were designed for learning the handling of avatars in working groups. In addition, tutored activities aimed at solving group doubts as well as definitely improving creativity in an innovative and different atmosphere. These sessions were included within the practices of the subject "Projects" of the degree of Agri-food Engineering and Rural Environment. The results of the evaluation of the experience -as an ad hoc survey designed to characterize the learning curve of the management of avatars and immersive worlds-, showed the success and usefulness of the project whose material is reusable in future educational experiences.Keywords: avatar; immersive worlds; teamwork; virtual teaching

Relationship of runoff, erosion and sediment yield to weather types in the Iberian Peninsula

Precipitation has been recognized as one of the main factors driving soil erosion and sediment yield (SY), and its spatial and temporal variability is recognized as one of themain reasons for spatial and temporal analyses of soil erosion variability. The weather types (WTs) approach classifies the continuumof atmospheric circulation into a small number of categories or types and has been proven a good indicator of the spatial and temporal variability of precipitation. Thus, themain objective of this study is to analyze the relationship betweenWTs, runoff, soil erosion (measured in plots), and sediment yield (measured in catchments) in different areas of the Iberian Peninsula (IP) with the aimof detecting spatial variations in these relationships. To this end, hydrological and sediment information covering the IP from several Spanish research teams has been combined, and related with daily WTs estimated by using the NMC/NCAR 40-Year Reanalysis Project. The results showthat, in general, a fewWTs (particularly westerly, southwesterly and cyclonic) provide the largest amounts of precipitation; and southwesterly, northwesterly and westerly WTs play an important role in runoff generation, erosion and sediment yield as they coincide with the wettest WTs. However, this study highlights the spatial variability of erosion and sediment yield in the IP according to WT, differentiating (1) areas under the influence of north and/or north-westerly flows (the north coast of Cantabria and inland central areas), (2) areas under the influence of westerly, southwesterly and cyclonic WTs (western and southwestern IP), (3) areas in which erosion and sediment yield are controlled by easterly flows (Mediterranean coastland), and (4) lastly, a transitional zone in the inland northeast Ebro catchment,wherewe detected a high variability in the effects ofWTs on erosion. Overall results suggest that the use of WTs derived fromobserved atmospheric pressure patterns could be a useful tool for inclusion in future projections of the spatial variability of erosion and sediment yield, as models capture pressure fields reliably

Appliying inmersive worlds for solving real problems of Agronomic and Forest Engineering and Enology

El Plan de Innovación Docente 2016-2017 de la Universidad de Córdoba planteaba en sus líneas prioritarias de proyectos el trabajo por competencias, las actividades académicamente dirigidas y la transferencia del conocimiento teórico a la práctica. En este contexto, se planteó desarrollar una serie de casos prácticos en un espacio virtual adaptado a las características de los mismos donde, a través de juegos de rol (en los que participaran no sólo los estudiantes sino profesionales del sector) los estudiantes organizados en grupos tendrían que resolver problemas y/o plantear y analizar sus posibles soluciones. Se presenta en el siguiente trabajo un proyecto colectivo donde diferentes escenarios prácticos y agentes involucrados en los temarios de asignaturas como Proyectos y Comercialización y Regulación de Mercados Agrarios comunes al Grado de Ingeniería Agroalimentaria y del Medio Rural, Ingeniería. Forestal y Enología fueron representados. En el primer caso, se propuso la elaboración y presentación de una licitación pública y en el segundo caso, la simulación de los actores de una subasta pública en una lonja. Entre los resultados del proyecto, se destacan los vídeos protagonizados por los alumnos reproduciendo las entrevistas reales y negociaciones de los agentes de la lonja o en el caso de la licitación, la preparación de los pliegos de una licitación por parte de los técnicos de un ayuntamiento, la elaboración de las plicas por parte de empresas licitadoras y la evaluación de las mismas por parte de la mesa de contratación. Además, los resultados de las encuestas a los estudiantes pusieron de manifiesto la importancia de este tipo de proyectos para mejorar la adquisición de conocimiento práctico de las asignaturas así como competencias de comportamiento y particularmente de tipo creativo.The Teaching Innovation Plan 2016-2017 of the University of Cordoba proposed in its priority lines of projects the work by competences, the academically directed activities and the transfer of theoretical knowledge to the practice. In this context, the development of a series of practical cases in a virtual space or role plays were proposed in which not only students but professionals of the sector participated. The students, organized in groups, had to solve problems and / or raise and analyze their possible solutions. We presented in the following work a collective project where different practical scenarios and agents involved in the subjects “Projects” and “Marketing and Regulation of Agrarian Markets” of the Degrees of Agri-food Engineering and Rural Environment, Forest Engineering and Oenology were represented. The first case was the preparation and the presentation of a public contract whereas in the second case, the simulation of the actors of a public auction was played. Among the results of the project, it is worth highlighting the videos played by the students reproducing the actual interviews and negotiations of the agents of the auction or in the case of the tender, the preparation of the bidding documents by the technicians of a town hall, the offers of the bidding companies and the evaluation of the same by the contracting table. In addition, the results of the student surveys showed the importance of this type of projects to improve the acquisition of practical knowledge of the subjects as well as behavioural competences and, particularly, of a creative type

Development and analysis of the Soil Water Infiltration Global database

In this paper, we present and analyze a novel global database of soil infiltration measurements, the Soil Water Infiltration Global (SWIG) database. In total, 5023 infiltration curves were collected across all continents in the SWIG database. These data were either provided and quality checked by the scientists who performed the experiments or they were digitized from published articles. Data from 54 different countries were included in the database with major contributions from Iran, China, and the USA. In addition to its extensive geographical coverage, the collected infiltration curves cover research from 1976 to late 2017. Basic information on measurement location and method, soil properties, and land use was gathered along with the infiltration data, making the database valuable for the development of pedotransfer functions (PTFs) for estimating soil hydraulic properties, for the evaluation of infiltration measurement methods, and for developing and validating infiltration models. Soil textural information (clay, silt, and sand content) is available for 3842 out of 5023 infiltration measurements ( ∼ 76%) covering nearly all soil USDA textural classes except for the sandy clay and silt classes. Information on land use is available for 76% of the experimental sites with agricultural land use as the dominant type ( ∼ 40%). We are convinced that the SWIG database will allow for a better parameterization of the infiltration process in land surface models and for testing infiltration models. All collected data and related soil characteristics are provided online in *.xlsx and *.csv formats for reference, and we add a disclaimer that the database is for public domain use only and can be copied freely by referencing it. Supplementary data are available at https://doi.org/10.1594/PANGAEA.885492 (Rahmati et al., 2018). Data quality assessment is strongly advised prior to any use of this database. Finally, we would like to encourage scientists to extend and update the SWIG database by uploading new data to it

Determining gully volume from straightforward photo-based 3D reconstruction

Geophysical Research Abstracts, Vol. 14, EGU2012-4597, 2012 In order to quantify soil loss through gully erosion, accurate measurements of gully volume are required. However, gullys are usually extended features, often with complex morphologies and are challenging to survey appropriately and efficiently. Here we explore the use of a photo-based technique for deriving 3D gully models suitable for detailed erosion studies. Traditional aerial and oblique close-range photogrammetry approaches have been previously used to produce accurate digital elevation models (DEMs) from photographs. However, these techniques require expertise to carry out successfully, use proprietry software and usually need apriori camera calibration. The computer vision approach we adopt here relaxes these requirements and allows 3D models to be automatically produced from collections of unordered photos. We use a freely available ‘reconstruction pipeline’ (http://blog.neonascent.net/archives/bundler-photogrammetry-package/) that combines structure-from-motion and multi-view stereo algorithms (SfM-MVS) to generate dense point clouds (millions of points). The model is derived from photos taken from different positions with a consumer camera and is then scaled and georeferenced using additional software (http://www.lancs.ac.uk/ staff/jamesm/software/sfm_georef.htm) and observations of some control points in the scene. The approach was tested on a ~7-m long sinous gully section (average width and depth ~2.4 and 1.2 m respectively) in Vertisol soils, near Cordoba, Spain. For benchmark data, the gully topography was determined with a terrestrial laser scanner (Riegl LMS-Z420i, with a cited range accuracy of 10 mm). 191 photos were taken with a Canon EOS 450D with a prime (fixed) 28 mm lens over a period of ~10 minutes. In order to georeference the SfM-MVS model for comparison with the TLS data, 6 control targets were located around the gully and their locations determined by dGPS. Differences between the TLS and SfM-MVS surfaces are dominated by areas of data gaps from either one of the techniques with some additional issues related to small amounts of vegetation on steep gully walls. The overall difference between the surfaces represents <2 % of the gully volume surveyed. This supports the viability of SfM-MVS as a useful tool for gully evaluations, capable of producing accurate DEMs at low cost

Comparing the accuracy of several field methods for measuring gully erosion

Most fi eld erosion studies in agricultural areas provide little information on the probable errors involved. Here, for the fi rst time, we compare the accuracy, time and cost of conventional and new methodologies for gully surveying, and provide a model to estimate the effort required to achieve a specifi ed accuracy. Using a terrestrial LiDAR survey of a 7.1-m-long gully reach as a benchmark data set, the accuracies of different measurement methods (a new 3D photo-reconstruction technique, total station, laser profi lemeter, and pole) are assessed for estimating gully erosion at a reach scale. Based on further fi eld measurements performed over nine gullies (>100 m long), a simulation approach is derived to model the expected volume errors when 2D methods are used at the gully scale. All gullies considered were located near Cordoba, Spain. At the reach scale, the fi eld measurements using 3D photo-reconstruction and total station techniques produced cross-sectional area error values smaller than 4%, with other 2D methods exceeding 10%. For volume estimation, photo-reconstruction proved similar to LiDAR data, but 2D methods generated large negative volume error (EV) values (<–13% for laser profi lemeter and pole). We show that the proposed error expressions derived from the model are in line with the reach-scale fi eld results. A measurement distance factor (MDF) is defi ned that represents the ratio between cross-section distance and the gully length, and thus refl ects relative survey effort. We calculate the required MDF for specifi ed values of EV, illustrating how MDF decreases with increasing gully length and sinuosity