A Comparative Analysis of Phytovolume Estimation Methods Based on UAV-Photogrammetry and Multispectral Imagery in a Mediterranean Forest

Management and control operations are crucial for preventing forest fires, especially in Mediterranean forest areas with dry climatic periods. One of them is prescribed fires, in which the biomass fuel present in the controlled plot area must be accurately estimated. The most used methods for estimating biomass are time-consuming and demand too much manpower. Unmanned aerial vehicles (UAVs) carrying multispectral sensors can be used to carry out accurate indirect measurements of terrain and vegetation morphology and their radiometric characteristics. Based on the UAV-photogrammetric project products, four estimators of phytovolume were compared in a Mediterranean forest area, all obtained using the difference between a digital surface model (DSM) and a digital terrain model (DTM). The DSM was derived from a UAV-photogrammetric project based on the structure from a motion algorithm. Four different methods for obtaining a DTM were used based on an unclassified dense point cloud produced through a UAV-photogrammetric project (FFU), an unsupervised classified dense point cloud (FFC), a multispectral vegetation index (FMI), and a cloth simulation filter (FCS). Qualitative and quantitative comparisons determined the ability of the phytovolume estimators for vegetation detection and occupied volume. The results show that there are no significant differences in surface vegetation detection between all the pairwise possible comparisons of the four estimators at a 95% confidence level, but FMI presented the best kappa value (0.678) in an error matrix analysis with reference data obtained from photointerpretation and supervised classification. Concerning the accuracy of phytovolume estimation, only FFU and FFC presented differences higher than two standard deviations in a pairwise comparison, and FMI presented the best RMSE (12.3 m) when the estimators were compared to 768 observed data points grouped in four 500 m2 sample plots. The FMI was the best phytovolume estimator of the four compared for low vegetation height in a Mediterranean forest. The use of FMI based on UAV data provides accurate phytovolume estimations that can be applied on several environment management activities, including wildfire prevention. Multitemporal phytovolume estimations based on FMI could help to model the forest resources evolution in a very realistic way

Análisis de la producción de sedimentos en una cuenca con un sistema de información geográfica. El sistema Cubillas-Colomera

[ES] En este trabajo se analiza la producción de sedimentos en las cuencas de los ríos Cubillas y Colomera, afluentes del río Genil, que tienen los embalses conectados. Para ello se ha aplicado la ecuación universal de pérdida de suelo sobre las celdillas de una gran retícula en la que se han dividido las cuencas, abordando el estudio en un sistema de información geográfica. La circulación de sedimentos se basa en los coeficientes de entrega definidos en función del tiempo de viaje por la superficie de la cuenca, propuesta por Dickinson y Rudra (1990) en el modelo GAMES, adaptándola en algunos aspectos al método propuesto. Una vez validado el modelo, mediante la comparación de los resultados obtenidos con los recogidos en la bibliografía, y ante la imposibilidad de realizar una correcta calibración del mismo al no existir datos experimentales suficientes, se ha realizado un análisis de sensibilidad con el propósito de estimar el nivel de error introducido en los resultados del modelo, ante variaciones de su parámetro principal. Finalmente, se han simulado diferentes situaciones para localizar las zonas más susceptibles de mejora con diferentes prácticas de conservación, concluyéndose que el método estima bien los niveles erosivos de las cuencas, y las cantidades de sedimento aportadas a sus respectivos embalses. Además se ha determinado el valor umbral del llamado factor de cubierta por encima del cual es preferible un cambio de manejo del suelo frente a la protección directa de cauces fluviales, para disminuir el sedimento recibido por los embalses.Carvajal Ramírez, F.; Giráldez Cervera, JV. (2000). Análisis de la producción de sedimentos en una cuenca con un sistema de información geográfica. El sistema Cubillas-Colomera. Ingeniería del Agua. 7(3):225-236. https://doi.org/10.4995/ia.2000.2845SWORD22523673Ascough J.C., Baffaut C., Nearing M.A. y Liu B.Y. 1997. The WEPP Watershed model: I. Hydrology and Erosion. Trans. ASAE 40: 921-933.Bosque J. 1992. Sistemas de Información Geográfica. Rialp. MadridBurrough P.A. y McDonnell R.A. 1998. Principles of Geographical Information Systems. Oxford. University Press, Oxford.Chaves H.M.L. y Nearing M.A. 1991. Uncertaintity analysis of the WEPP soil erosion model. Trans. ASAE 34:2437-2444.Chow V.T., Maidment L.W. y Mays L.W. 1988. Applied Hydrology. McGraw Hill, Nueva York.DBA Systems Inc., U.S. Army corps engineers. Construction engineering research laboratory. 1991. GRASS (Geographical Resources Analysis Support System). User manual.De León A. 1989. Caracterización agroclimática de la provincia de Granada. M.A.P.A., Madrid.Dickinson W.T. y Rudra R.P. 1990. Games: The Guelph model for evaluating effects of agricultural management systems on erosion and sedimentation. User's manual. Versión 3.01. University of Guelph. School of engineering. Technical Reports 126-86.Environmental System Research Institute Inc. 1992. ARC/INFO Users guide. Nueva York.Foster G.R y Weissmeier W.H. 1974. Evaluating irregular slopes for soil loss prediction. Trans. ASAE 17: 305-309.Foster G.R. y Meyer L.D. 1975. Mathematical simulation of upland erosion by fundamental erosion mechanism. USDA-ARS-S-40: 190.Govers, G. Y Desmet P.J.J. 1995. A procedure for Calculation of the LS-Factor for USLE-Type Models on Topographically Complex Ladscape Units. Procedings de Joint European Conference and Exhibition on Geographical Information. Netherlands, 26-31 de marzo de 1995.Govindaraju R.S. 1995. Non-dimensional analysis of a physically based rainfall-runoff-erosion model over steep slopes. J. Hydrol. 173: 327-341.Hrissanthou, V. 1990. Application of a sediment routing model to a middle european watershed. Water Resour. Bull. 26: 801-810.IARA. 1986. Estudio Hidrológico de Andalucía. Consejería de Agricultura y Pesca. Junta de Andalucía.ICONA. 1982. Mapa de fenómenos de erosión hídrica en España (Península y Baleares). E 1/100000. Dirección General de Medio Ambiente e ICONA. Madrid.ICONA. 1987. Mapa de estados erosivos. Cuenca Hidrográfica del Guadalquivir. Instituto Nacional para la Conservación de la Naturaleza. MAPA Madrid.Janson M.B. 1982. Land erosion by water in different climates. UNGI Rapport Nr 57. Uppsala University.Lane L.J. Nearing M.A. 1989. USDA-Water Erosion Prediction Project: Hillslope profile model documentation. USDA-Agricultural Research Service.Lane L.J., Shirley E.D. y Singh V.P. 1988. Modelling erosion on hillslopes. En: Modelling Geomorphological Systems. Anderson M.G. ed. John and Sons.Masa M. 1996. Control de la evolución de los sedimentos en el embalse de Cubillas (Granada). Actas de las V Jornadas Españolas de Presas. Comité Nacional Español de Grandes Presas. Valencia.McCool D.K., Brown L.C., Foster G.R., Mutchler C.K. y Meyer L.D. 1987. Revised slope steepness factor for the universal soil loss equation. Trans. ASAE 30: 1387-1396.McCuen, R.H. y Snyder, W.M. 1986. Hydrologic Modeling. Prentice Hall, Englewood Cliffs.Meyer L.D. y Weischmeier W.H. 1969. Mathematical simulation of the process of soil erosion by water. Trans. ASAE 12: 754-758.Moore, I.D. y Burch, G.J. 1986. Physical Basis of the Length-slope Factor in the Universal Soil Loss Ecuation. Soil Sci. Soc. Am. J. 50: 1294-1298.Morgan R.P.C., Morgan D.D.V., y Finney H.J. 1984. A predictive model for the assessment of soil erosion risk, J. Agric. Engng. Res. 30: 245-253.Morgan, R.P.C., Quinton J.N., Smith R.E., Govers G., Poesen J.W.A., Auerswald K., Chisci G., Torri D., Styczen M.E. y Folly A.J.V. 1998. The European soil erosion model (EUROSEM): documentation and user guide. Silsoe College. Cranfield University. http://www.silsoe.cranfield.ac.uk/eurosem/euro3.htmPérez A. y Prieto P. 1980. Memoria explicativa de los mapas de suelos y vegetación de la provincia de Granada. C.S.I.C. Estación experimental del Zaidín. Granada.Renard K.G., Foster G.R., Weesies G.A., McCool D.K. y Yoder D.C. 1997. Predicting Soil Erosion by Water: A guide to conservation planning with the Revised Universal Soil Loss Erosion (RUSLE). USDA Agr. Hbk. nº 703.Rose C.W. 1985. Develops in soil erosion and deposition models, Advances in Soil Science. Vol. 2. Springer-Verlag.Sander G.C., Hairsine P.B., Rose C.W., Cassidy D., Parlange J.Y., Hogarth W.L. y Lisle I.G. 1996. Unsteady soil erosion model, analytical solutions and comparison with experimental results. J. Hydrol. 178: 351-367.Servicio Geográfico del Ejército. 1991. Mapa militar de España escala 1/50000. Hojas nº 1009, 1010, 991, 992, 969, 970. Madrid.Singh V.P. 1989. Hydrologic systems. Watershed Modeling. Volumen II. Prentice Hall, Englewood Cliffs.Simons D.B. y Sentürk F, 1992. Sediment transport technology. Water Resources Publication, Littleton.Stocking, M., C. Kalabane, y H. Elwell, 1988. An inproved methodology for erosion mapping. Geogr. Anal. 70A: 169-180.Williams J.R. 1975a. Sediment-yield prediction with Universal Ecuation using runoff energy factor. En: Present and prospective technology for predicting sediment yields and sources. ARS-S-40, USDA-Agricultural Research Service: 244-252.Williams J.R. 1975b. Sediment routing for agricultural watersheds. Water Resour.Bull. 11: 965-974.Williams J.R. 1977. Sediment delivery ratios determined with sediment and runoff models. IAHS, 122: 168-178.Wischmeier W.H. y D.D. Smith. 1958a. Predicting rainfall erosion losses from cropland east of the Rocky Mountains, USDA, Agr. Hbk. 282.Wischmeier W.H. y D.D. Smith. 1958b. Rainfall Energy and Its Relation to Soil Loss. Am. Geophys. Union Trans. 39:285-291.Wischmeier W.H. y D.D. Smith. 1978. Predicting rainfall erosion losses -a guide to conservation planning. USDA, Agric. Hbk. nº 537.Woolhiser D.A., R.E. Smith y D.C. Goodrich. 1990. KINEROS, a kinematic runoff and erosion model. USDA-ARS-7

Composición y producción de 8 temas de música electrónica a partir de sonidos concretos, técnicas de manipulación y síntesis sonora

Maestro (a) en MúsicaPregrad

Use of UAV-Photogrammetry for Quasi-Vertical Wall Surveying

In this study, an analysis of the capabilities of unmanned aerial vehicle (UAV) photogrammetry to obtain point clouds from areas with a near-vertical inclination was carried out. For this purpose, 18 different combinations were proposed, varying the number of ground control points (GCPs), the adequacy (or not) of the distribution of GCPs, and the orientation of the photographs (nadir and oblique). The results have shown that under certain conditions, the accuracy achieved was similar to those obtained by a terrestrial laser scanner (TLS). For this reason, it is necessary to increase the number of GCPs as much as possible in order to cover a whole study area. In the event that this is not possible, the inclusion of oblique photography ostensibly improves results; therefore, it is always advisable since they also improve the geometric descriptions of break lines or sudden changes in slope. In this sense, UAVs seem to be a more economic substitute compared to TLS for vertical wall surveying

Editorial for Special Issue “UAV Photogrammetry and Remote Sensing”

The concept of Remote Sensing as a way of capturing information from an object without making contact with it has, until recently, been exclusively focused on the use of earth observation satellites [...

Diagnóstico del estado actual y planteamiento de escenarios financieros que permitan que “el Hotel” mejore sus procesos y continúe en la industria hotelera del centro de Bogotá

Trabajo de Síntesis AplicadaEl siguiente proyecto aborda el diagnóstico realizado al proceso Técnico y proceso comercial, llevados a cabo en el hotel ubicado en el Centro de Bogotá, Colombia; con el fin de establecer escenarios financieros; los cuales conduzcan a que este Hotel mejore sus procesos y continúe con sus puertas abiertas en la industria Hotelera.INTRODUCCIÓN 1. GENERALIDADES 2. MARCO TEORICO Y CONCEPTUAL 3. METODOLOGIA Y PRESENTACION DE RESULTADOS 4. DISCUSION DE RESULTADOS CONCLUSINES BIBLIOGRAFÍAEspecializaciónEspecialista en Análisis y Administración Financier

UAV Photogrammetry Accuracy Assessment for Corridor Mapping Based on the Number and Distribution of Ground Control Points

Unmanned aerial vehicle (UAV) photogrammetry has recently emerged as a popular solution to obtain certain products necessary in linear projects, such as orthoimages or digital surface models. This is mainly due to its ability to provide these topographic products in a fast and economical way. In order to guarantee a certain degree of accuracy, it is important to know how many ground control points (GCPs) are necessary and how to distribute them across the study site. The purpose of this work consists of determining the number of GCPs and how to distribute them in a way that yields higher accuracy for a corridor-shaped study area. To do so, several photogrammetric projects have been carried out in which the number of GCPs used in the bundle adjustment and their distribution vary. The different projects were assessed taking into account two different parameters: the root mean square error (RMSE) and the Multiscale Model to Model Cloud Comparison (M3C2). From the different configurations tested, the projects using 9 and 11 GCPs (4.3 and 5.2 GCPs km−1, respectively) distributed alternatively on both sides of the road in an offset or zigzagging pattern, with a pair of GCPs at each end of the road, yielded optimal results regarding fieldwork cost, compared to projects using similar or more GCPs placed according to other distributions

Estimation of Productivity in Dryland Mediterranean Pastures: Long-Term Field Tests to Calibration and Validation of the Grassmaster II Probe

The estimation of pasture productivity is of great interest for the management of animal grazing. The standard method of assessing pasture mass requires great effort and expense to collect enough samples to accurately represent a pasture. This work presents the results of a long-term study to calibrate a Grassmaster II capacitance probe to estimate pasture productivity in two phases: (i) the calibration phase (2007–2018), which included measurements in 1411 sampling points in three parcels; and (ii) the validation phase (2019), which included measurements in 216 sampling points in eight parcels. A regression analysis was performed between the capacitance (CMR) measured by the probe and values of pasture green matter and dry matter (respectively, GM and DM, in kg ha−1). The results showed significant correlations between GM and CMR and between DM and CMR, especially in the early stages of pasture growth cycle. The analysis of the data grouped by classes of pasture moisture content (PMC) shows higher correlation coefficients for PMC content >80% (r = 0.775; p 80% showed a good approximation between GM or DM measured and GM or DM predicted (r = 0.959; p 80%

Supply Chain Management y Logística en la Empresa "Argos S.A."

Mediante el desarrollo del informe ejecutivo se puede apreciar la importancia que tiene conocer a nuestros clientes internos y externos mediante la ejecución y aplicación de las entrevistas; con la finalidad de mejorar dentro de la empresa los servicios, calidad y resultados en la producción. Nuestro fin es relacionar los conceptos y procesos en Supply Chain, Logística y Competitividad Global Gestión de Inventarios, almacenes, Logística de aprovisionamiento, Gestión de Transportes y Procesos logísticos en Distribución. Se tuvo en cuenta las 4 unidades temáticas del curso, logrando aplicar estos conocimientos a través de la metodología del trabajo colaborativo. En el desarrollo del curso fue escogida una empresa por el grupo de los estudiantes la cual fue CEMENTOS ARGOS, la cual escogimos como producto a investigar logrando el objetivo final mediante cada una de las fases: identificar, mejorar y dar a conocer los procesos logísticos que se llevan en ella y poder presentar hoy este informe llevado a buen término logrando las expectativas de esta fase proyecto final.Through the development of the executive report you can appreciate the importance of know our internal and external clients through the execution and application of the interviews; with the purpose of improving services, quality and results within the company in the production. Our goal is to relate the concepts and processes in Supply Chain, Logistics and Global Competitiveness Inventory Management, Warehouses, Logistics Procurement, Transport Management and Logistic Processes in Distribution. It was taken in account the 4 thematic units of the course, managing to apply this knowledge through the collaborative work methodology. In the development of the course a company was chosen by the group of students which was CEMENTOS ARGOS, which we chose as a product to be investigated, achieving the final objective through each of the phases: identify, improve and publicize the processes logistics that are carried in it and be able to present today this report brought to fruition achieving the expectations of this final project phase

Plan de ordenación y manejo de la cuenca del río Aburra -Antioquia, Colombia.

La formulación del POMCA, se desarrolló siguiendo la metodología propuesta en la Guía técnico científica desarrolla por el IDEAM, la cual comprende las fases de Aprestamiento, Diagnóstico, Prospectiva, Formulación, Seguimiento y Control. La conexión entre la situación ambiental actual y los escenarios de futuro se construye en la fase de Formulación por medio de Lineamientos de política, líneas estratégicas, Programas y Proyectos, los cuales serán implementados y vigilados por las autoridades ambientales