Orbital-scale climate forcing of grassland burning in southern Africa.

This is the final version of the article. Available from the publisher via the DOI in this record.Although grassland and savanna occupy only a quarter of the world's vegetation, burning in these ecosystems accounts for roughly half the global carbon emissions from fire. However, the processes that govern changes in grassland burning are poorly understood, particularly on time scales beyond satellite records. We analyzed microcharcoal, sediments, and geochemistry in a high-resolution marine sediment core off Namibia to identify the processes that have controlled biomass burning in southern African grassland ecosystems under large, multimillennial-scale climate changes. Six fire cycles occurred during the past 170,000 y in southern Africa that correspond both in timing and magnitude to the precessional forcing of north-south shifts in the Intertropical Convergence Zone. Contrary to the conventional expectation that fire increases with higher temperatures and increased drought, we found that wetter and cooler climates cause increased burning in the study region, owing to a shift in rainfall amount and seasonality (and thus vegetation flammability). We also show that charcoal morphology (i.e., the particle's length-to-width ratio) can be used to reconstruct changes in fire activity as well as biome shifts over time. Our results provide essential context for understanding current and future grassland-fire dynamics and their associated carbon emissions.We thank Linda Rossignol for picking the foraminifera for carbon radiometric dating, Olivier Ther for XRF analysis, Marie-Hélène Castera and Muriel Georget for laboratory assistance, V. Hanquiez for extracting bathymetric data, Thibault Caley for providing the East African monsoon regression model data, Lydie Dupont for sharing the pollen data of cores GeoB1711 and MD96-2048, and Louis Scott for providing Wonderkrater’s charcoal data. This research was funded by European Research Council Advanced Grant TRACSYMBOLS 249587. The postdoctoral position of A.-L.D was funded by this project

Por la salud mental

En Colombia se han realizado el Estudio de Salud Mental y Consumo de Sustancias psicoactivas, de 1993 (2) y el Estudio de 1997 (1), que suministran información epidemiológica sobre las enfermedades mentales. Los resultados no son comparables debido a que se utilizaron escalas de medición y clasificación de enfermedades diferentes. En el estudio realizado en 1993 se pueden resaltar los siguientes hallazgos (1): La morbilidad sentida fue de 7.9%. La utilización de los servicios de salud mental aumenta con la edad, en especial en el grupo de 50 a 60 años, con un 6.8% de asistencia.  Al disminuir la estabilidad económica y el estrato social aumenta la percepción de la angustia.  La prevalencia de depresión clínica fue de 25.1% y de ansiedad 9.6% siendo mayor en mujeres que en hombres. • La población entre 12-24 años es la que presenta mayor intento de suicidio, con una prevalencia total de 4.5%

Qualités psychométriques du Consumer satisfaction questionnaire (CSQ-8) et du Helping alliance questionnaire (HAQ) [Psychometric properties of the Consumer Satisfaction Questionnaire (CSQ-8) and the Helping Alliance Questionnaire (HAQ)].

BACKGROUND: This study was based on data from a quality of care assessment survey conducted in 2011 in outpatient polyclinics of the Vaud Canton in Switzerland, comprising questionnaires completed by 568 children over the age often and 672 parents of children of all ages. The objective of this study was to evaluate the psychometric qualities of the eight-item French versions for children of the Helping Alliance Questionnaire (HAQ) and the Consumer Satisfaction Questionnaire (CSQ-8) to allow formal validation and clinical application of these tools in the context of French-speaking child psychiatry. METHODOLOGY: Responses from children over the age often to the HAQ and CSQ-8 questionnaires were submitted to confirmatory factorial analysis (CFA) for ordinal data to verify their good fit with the original long versions. Construct validity (correspondence between scores on the scales and other external criteria considered to evaluate similar concepts) of the child questionnaires was tested by Spearman's correlation with the parents' responses and their feeling of being reassured or in agreement with respect to the first visit, and with the perception of the help provided by individual and family interviews. RESULTS: CFA showed an acceptable fit with the one-dimensional model of the original scales, both for the HAQ and the CSQ-8. Significant positive correlations of the scales with the parents' responses and with other convergent external criteria confirmed the good construct validity. CONCLUSIONS: These psychometric analyses provide a basis for the validation and clinical application of the abridged French versions of the HAQ and CSQ-8 in quality of care assessment in child psychiatry

Control genético del carácter número de frutos por planta y sus componentes en un cruzamiento dialélico entre cultivares de tomate "chonto", lycopersicon esculentum mill

Se realizó el análisis genético del carácter número de frutos por planta y sus componentes utilizando un cruzamiento dialélico entre siete cultivares de tomate "chonto" (Ángela Gigante, Licapal- 21, Raminho, Olho Roxo, 1258, 1465, y 1507). El análisis genético-estadístico se efectuó utilizando la metodología desarrollada por Hayman (1954 a, 1954b). No se detectó evidencia de epistasis para ninguno de los caracteres estudiados y los datos experimentales se ajustaron al modelo aditivo-dominante. La acción génica aditiva y no aditiva participaron en forma conjunta y significativa en la expresión de los caracteres número de frutos por planta y número de inflorescencias por planta. Solamente la acción génica no aditiva participó en forma significativa en la expresión del carácter número de frutos por inflorescencia. Se detectó la presencia de sobredominacia en los tres caracteres estudiados. Se pudieron estimar los límites de selección para el carácter número de frutos por planta (34.12 y 3.15) y para el carácter número de frutos por inflorescencia (4.37 y 0.29) para padres completamente dominantes y recesivos, respectivamente. Para el carácter número de inflorescencias por planta, no fue posible estimarlos debido a la baja correlación presentada entre el grado de dominacia y el valor medio de los progenitores.Genetic analysis for fruits per plant, clusters per plant and fruits per cluster characters was carried out using a diallel crossing between seven "chonto" tomato cultivars (Angela Gigante, Licapal- 21, Raminho, Olho Roxo, 1258, 1465 and 1507). Was made a genetic- statistic analysis using the methodology developed by Hayman (1954 a, 1954b). There was no evidence of epistasis in any of characters studied and the experimental data are adjusted to the additive-dominant model. Additive gene action and non-additive gene action participate jointly and highly significant manner, in the fruits per plant, and clusters per plant characters expression. Fruits per cluster character is conditioned mainly by the non-additive gene action. It is detected the presence of sobredominance in three studied characters. It's could estimate selection lirnits to the fruits per plant (34.12 and 3.15) and to the fruits per cluster (4.37 and 0.29). For cluster per plant character, it was not possible to estimate them because of low correlation showed between dominance degree and mean value of character

Mar Menor lagoon (SE Spain) chlorophyll-a and turbidity estimation with Sentinel-2

Mar Menor is a Mediterranean Coastal lagoon with high environmental and social value, but has suffered important episodes of contamination in recent years due to heavy rains, sediment dragging and polluting substances mainly from agriculture as well as the entry of mining waste, causing an increase in eutrophication. Water quality variables such as chlorophyll-a concentration [Chl-a] and turbidity, can be studied through its optical properties by remote sensing techniques. In this work, a methodology is proposed for monitoring [Chl-a] and the turbidity of the Mar Menor using Sentinel-2 images. For this purpose, an extensive database of both variables was used consisting of data taken on different dates between 2016 and 2019 at 12 points of Mar Menor. The images were atmospherically corrected using Case 2 Regional Coast Color Processor (C2RCC) version for turbid waters (C2X) to obtain the water surface reflectance. Then several arithmetic relations between database and reflectance bands used in the bibliography for [Chl-a] and turbidity were analyzed. Comparing the results of each one of these relations with the in situ data, decided that the best index for [Chl-a] estimation is the relation (R560 + R705)/ (R560 + R665) with an RMSE = 2.6 mg/m3 and a NRMSE = 9.1 % and for turbidity R705*R705/R490 with an RMSE = 1.5 NTU and a NRMSE= 10.9 %. Finally, by applying these relationships on different dates, thematic maps of [Chl-a] and turbidity of Mar Menor were obtained. One of these images was some days after September 2019 torrential rains, in which a considerable [Chl-a] and turbidity increase was observed

Neuroactive Steroids in Hypoxic–Ischemic Brain Injury: Overview and Future Directions

Hypoxic–ischemic brain injury is a number one cause of long-term neurologic disability and death worldwide. This public health burden is mainly characterized by a decrease in oxygen concentration and blood flow to the tissues, which lead to an inefficient supply of nutrients to the brain. This condition induces cell death by energy depletion and increases free radical generation and inflammation. Hypoxic–ischemic brain injury may occur in ischemic-stroke and over perinatal asphyxia, being both leading causes of morbidity in adults and children, respectively. Currently, there are no effective pharmaceutical strategies to prevent the triggering of secondary injury cascades, including oxidative stress and metabolic dysfunction. Neuroactive steroids like selective estrogen receptor modulators, SERMs, and selective tissue estrogenic activity regulators, STEARs, exert several neuroprotective effects. These encompass mitochondrial survival, a decrease in reactive oxygen species, and maintenance of cell viability, among others. In this context, these neurosteroids constitute promising molecules, which could modify brain response to injury. Here we show an updated overview of the underlying mechanisms of hypoxic–ischemic brain injury. We also highlight the neuroprotective effects of neurosteroids and their future directions

Effect of Biodiversity Changes in Disease Risk: Exploring Disease Emergence in a Plant-Virus System

The effect of biodiversity on the ability of parasites to infect their host and cause disease (i.e. disease risk) is a major question in pathology, which is central to understand the emergence of infectious diseases, and to develop strategies for their management. Two hypotheses, which can be considered as extremes of a continuum, relate biodiversity to disease risk: One states that biodiversity is positively correlated with disease risk (Amplification Effect), and the second predicts a negative correlation between biodiversity and disease risk (Dilution Effect). Which of them applies better to different host-parasite systems is still a source of debate, due to limited experimental or empirical data. This is especially the case for viral diseases of plants. To address this subject, we have monitored for three years the prevalence of several viruses, and virus-associated symptoms, in populations of wild pepper (chiltepin) under different levels of human management. For each population, we also measured the habitat species diversity, host plant genetic diversity and host plant density. Results indicate that disease and infection risk increased with the level of human management, which was associated with decreased species diversity and host genetic diversity, and with increased host plant density. Importantly, species diversity of the habitat was the primary predictor of disease risk for wild chiltepin populations. This changed in managed populations where host genetic diversity was the primary predictor. Host density was generally a poorer predictor of disease and infection risk. These results support the dilution effect hypothesis, and underline the relevance of different ecological factors in determining disease/infection risk in host plant populations under different levels of anthropic influence. These results are relevant for managing plant diseases and for establishing conservation policies for endangered plant species

Identifying the determinants of perceived quality in outpatient child and adolescent mental health services from the perspectives of parents and patients.

This cross-sectional survey adopting a multiple-informant perspective explores the factors that influence perceived quality (i.e., therapeutic alliance and satisfaction) in an outpatient setting within child and adolescent mental health services (CAMHS). A total of 1433 participants (parents, n = 770, and patients, n = 663) attending or having attended (drop-out) outpatient units participated in the study. The outcome measures were satisfaction (Client Satisfaction Questionnaire) and the therapeutic alliance (Helping Alliance Questionnaire). The determinants of these quality indicators were socio-demographic variables (e.g., age, gender, and mother's socio-economic status), factors related to the extent of difficulties (number of reasons for the consultation, number of people who referred the child to the CAMHS), the approach to treatment at outset (agreeing to the consultation, feeling reassured at the first appointment), the organizational friendliness (secretary, waiting room, waiting time for the first appointment) and the organization of the therapy (frequency of sessions, time for questions, change of therapist). The approach to treatment at outset, accessibility by phone, satisfaction with the frequency of the sessions and having enough time for questions were the factors that consistently explain the quality indicators from both perspectives (patients and parents). In contrast, the socio-demographic variables as well as the extent of difficulties and factors related to the organizational friendliness and the organization of the therapy (frequency of sessions, change of therapist) were not related to the quality indicators. This study identifies key determinants of the quality indicators from the perspective of patients and parents that should be considered to improve CAMHS care quality. First appointments should be carefully prepared, and clinicians should centre care on the needs and expectations of patients and parents

Fire severity estimation in southern of the Buenos Aires province, Argentina, using Sentinel-2 and its comparison with Landsat-8

[EN] Assessment of rural fire severity is fundamental to evaluate fire damages and to analyze recovery processes in a low-cost and efficient way. Burnt areas covering shrubs and grasslands were estimated in more than 30,000 km2 in Argentina from December 2016 to January 2017. The study area presented in this work is located in the South of the Buenos Aires province, and it covers a semiarid area with the presence of xerophilous shrubs and grasslands. This is one of the most abundant ecosystem in Central and Southern Argentina. Field campaigns were carried out over the area affected by the fire in order to georreference the burnt plots and characterized the fire severity in 5 levels. The objective of this work is to analyze the feasibility of new satellites Sentinel-2 for fire studies, as well as provide a comparison to Landsat-8 derived results, because this mission has been one of the most used in it. Pre-fire and postfire Sentinel-2 and Landsat-8 imagery were used to analyze different band combinations to compute a Normalized Difference Spectral Index (NDSI), as well as the difference of this index before and after the fire (dNDSI). Results show a significant correlation (R2 =0.72 and estimation error of 0.77) between dNDSI derived from Sentinel-2 and the severity levels obtained in the field campaign using bands 8a and 12 (NIR and SWIR), the same bands as used in the Normalized Burn Ratio (NBR). Moreover, results derived from Sentinel-2 are better than results derived from Landsat-8 (R2 =0.63 and estimation error of 0.92). Furthermore, it is observed that the correlation is improved when Sentinel-2 bands 6 and 5 (located in the Red-Edge region) are considered (R2 =0.74 and estimation error of 0.76). An inverse correlation has been observed between the recovery of vegetation four months after the fire and the fire severity level.[ES] Conocer la severidad de los incendios rurales es imprescindible para evaluar daños y analizar los procesos de recuperación en forma económica y eficaz. Entre diciembre de 2016 y enero de 2017 se quemaron más de 30.000 km2 de arbustos y pastizales en Argentina. El incendio estudiado en este trabajo, localizado en el sur de la provincia de Buenos Aires, corresponde a una zona semiárida con predominio de arbustales xerófilos y pastizales, siendo este ecosistema muy abundante en la zona centro y sur de Argentina. A partir de campañas de campo en el área afectada por este incendio, se georreferenciaron zonas quemadas y se caracterizó la severidad del fuego en 5 niveles. El objetivo de este trabajo es analizar la potencialidad de los nuevos satélites Sentinel-2 para el estudio de incendios, comparándolo con Landsat-8, pues esta misión ha sido una de las más usadas en ello. A partir de imágenes Sentinel-2 y Landsat-8 antes y después del incendio, se han analizado todas las posibles combinaciones de bandas de ambos satélites en índices espectrales de diferencia normalizada (NDSI), así como la diferencia de esos valores antes y después del incendio (dNDSI). Los resultados muestran una significativa correlación (R2 =0,72 y error de estimación de 0,77) del dNDSI obtenido con Sentinel-2 con los niveles de severidad obtenidos en la campaña de campo usando las bandas 8a y 12 (del NIR y del SWIR), que coinciden con las bandas del Normalized Burn Ratio (NBR) mejorando respecto a Landsat-8 (R2 =0,63 y error de estimación de 0,92). Además se observa que la correlación mejora todavía más usando las bandas 6 y 5 de Sentinel-2 localizadas en la región del Red-Edge (R2 =0,74 y error de estimación de 0,76). Se ha observado una correlación inversa entre la recuperación de la vegetación cuatro meses después del incendio y el nivel de severidad del incendio.Delegido, J.; Pezzola, A.; Casella, A.; Winschel, C.; Urrego, EP.; Jimenez, JC.; Soria, G.... (2018). Estimación del grado de severidad de incendios en el sur de la provincia de Buenos Aires, Argentina, usando Sentinel-2 y su comparación con Landsat-8. Revista de Teledetección. (51):47-60. doi:10.4995/raet.2018.8934SWORD476051Botella-Martínez, M. A., Fernández-Manso, A. 2017. Study of post-fire severity in the Valencia region comparing the NBR, RdNBR and RBR indexes derived from Landsat 8 images. Revista de Teledetección, 49, 33-47. https://doi.org/10.4995/raet.2017.7095Bran, D., Cecchi, G., Gaitan, J., Ayesa, J., Lopez, C. 2007. Efecto de la severidad de quemado sobre la regeneración de la vegetación en el Monte Austral. Revista Ecología Austral, 17(1), 123-132.Cabrera, A. 1951. Territorios fitogeográficos de la República Argentina. Boletín de la Sociedad Argentina de Botánica. IV, N° 1 - 2.Casas, R., Irurtia, C., Michelena, R. 1978. Desmonte y habilitación de tierras para la producción agropecuaria en La República Argentina. Suelos, 157. Buenos Aires, Argentina.Cecchi, G. A., Krofpl, A.I., Kugler, N. et al., 2006. Principales gramíneas forrajeras perennes del monte. EEA Valle Inferior Convenio INTA - provincia de Río Negro.Chuvieco, E. 2002. Teledetección Ambiental. Ed. Ariel Ciencia, Barcelona, España.Chuvieco, E., Riaño, D., Danson, F. M., Martin, P. 2006. Use of a radiative transfer model to simulate the postfire spectral response to burn severity. Journal of Geophysical Research, 111(G4). https://doi.org/10.1029/2005JG000143.Cocke, A. E., Fulé, P. Z., Crouse, J. E. 2005. Comparison of burn severity assessments using Differenced Normalized Burn Ratio and ground data. International Journal of Wildland Fire, 14(2), 189-198. https://doi.org/10.1071/WF04010Delegido, J., Verrelst, J., Meza, C. M., Rivera, J. P. Alonso, L., Moreno, J. 2013. A red-edge spectral index for remote sensing estimation of green LAI over Agroecosystems. European Journal Agronomy, 46, 42-52. https://doi.org/10.1016/j.eja.2012.12.001Delegido, J., Meza, C.M., Pasqualotto, N., Moreno, J. 2016. Influencia del ángulo de observación en la estimación del índice de área foliar (LAI) mediante imágenes PROBA/CHRIS. Revista de Teledetección, 46, 45-55. https://doi.org/10.4995/raet.2016.4612Delegido, J., Pezzola, A., Casella, A., Winschel, C., Urrego, E. P., Jiménez-Muñoz, J. C., Soria, G., Sobrino, J. A., Moreno, J. 2017. Potencialidad de índices de severidad de incendios utilizando Sentinel2 y su análisis comparativo con Landsat8 para la cartografía en los incendios rurales en el Sur de la provincia de Buenos Aires (Argentina) 2016- 2017. XVII Congreso de la Asociación Española de Teledetección. Murcia, 3 al 7 octubre 2017.De Santis, A., Chuvieco, E. 2007. Burn severity estimation from remotely sensed data: Performance of simulation versus empirical models. 2006. Remote Sensing of Environment, 108, 422-435. https://doi.org/10.1016/j.rse.2006.11.022Diaz-Delgado, R., Lloret, F., Folliott, P. F. 2003. Influence of fire severity on plant regeneration by means of remote sensing imagery. International Journal of Remote Sensing, 24, 1751-1763. https://doi.org/10.1080/01431160210144732ESA. 2017. ESA's Sentinel Satellites. Available online: http://www.esa.int/Our_Activities/Observing_the_ Earth/Copernicus/Sentinel-2/Facts_and_figures (acceso el 31 de marzo de 2017)Escuin, S., Navarro, R., Fernandez, P. 2008. Fire severity assessment by using NBR (Normalized Burn Ratio) and NDVI (Normalized Difference Vegetation Index) derived from LANDSAT TM/ETM images. International Journal of Remote Sensing, 29(4), 1053-1073. https://doi.org/10.1080/01431160701281072Fernández-Manso, A., Fernández-Manso, O., Quintano, C. 2016. SENTINEL-2A red-edge spectral indices suitability for discrimination burn severity. International Journal of Applied Earth Observation and Geoinformation, 50, 170-175. https://doi.org/10.1016/j.jag.2016.03.005Fernández-Manso, A., Fernández-Manso, O., Quintano, C., Marcos, E., Calvo, L. 2017. Utilización de las imágenes Sentinel-2 para cartografía de área quemada. Congreso AET, Murcia 3-7 Octubre 2017.Ghermandi, L., Gonzalez, S., Lescano, M., Oddi, F. 2013. Effects of fire severity on early recovery of Patagonian steppes. International Journal of Wildland Fire, 22, 1155-1062. https://doi.org/10.1071/WF12198González, S. 2002. El Banco de semillas como estrategia de regeneración postfuego en un pastizal del Noroeste de la Patagonia. Tesis de Licenciatura, Universidad Nacional del Comahue, S.C. de Bariloche, Argentina.González, S. 2011. Estrategias de regeneración postfuego en pastizales del noroeste patagónico: un enfoque experimental, PhD thesis, Centro Regional Universitario Bariloche, Argentina.González-Alonso, F., Merino-De-Miguel, S., RoldánZamarrón, A., García-Gigorro, S., Cuevas, J. M. 2007. MERIS Full Resolution data for mapping level-of-damage caused by forest fires: the Valencia de Alcántara event in August 2003. International Journal of Remote Sensing, 28:3-4, 797-809. https://doi.org/10.1080/01431160600979115Key, C. H., Benson, N. 2005. Landscape assessment: ground measure of severity, the Composite Burn Index; and remote sensing of severity, the Normalized Burn Ratio. En FIREMON: Fire Effects Monitoring and Inventory System. Lutes, Duncan C.; Keane, Robert E.; Caratti, John F.; Key, Carl H.; Benson, Nathan C.; Sutherland, Steve; Gangi, Larry J. 2006. Gen. Tech. Rep. RMRS -GTR-164-CD. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research StationKröpfl, A., Cecchi, G., Villasuso, N., Rossio, E., Pelotto, J. 2005. Manual de especies silvestres del monte Rionegrino. Estación Experimental Agropecuaria Valle Inferior - Centro Universitario Regional Zona Atlántica (UNC). Ediciones INTA, Argentina.Lamberto, S. 1987. Vegetación natural. En: Evaluación expeditiva del recurso suelo y uso y cobertura de la tierra en el sur de la provincia de Buenos Aires. Informe técnico N° 28. Secretaria de Agricultura, Ganadería y Pesca. Instituto Nacional de Tecnología Agropecuaria. Estación Experimental Agropecuaria Hilario Ascasubi. Bahía Blanca, Argentina.López-García, M. J., Caselles, V. 1991. Mapping burns and natural reforestation using Thematic Mapper data. Geocarto International, 1, 31-37. https://doi.org/10.1080/10106049109354290Martínez, S., Chuvieco, E., Aguado, I., Salas, J. 2017. Burn severity and regeneration in large forest fires: an analysis from Landsat time series. Revista de Teledetección, 49, 17-32. https://doi.org/10.4995/raet.2017.7182Montorio, R., Pérez, F., García, A., Vlassova, L., de la Riva, J. R. 2014. La severidad del fuego: Revisión de conceptos, métodos y efectos ambientales. En: José Arnáez, Penélope González-Sampériz, Teodoro Lasanta y Blas L. Valero Garcés (eds.). Geoecología, cambio ambiental y paisaje: homenaje al profesor José María García Ruiz. Logroño: Instituto Pirenaico de Ecología (CSIC): Universidad de La Rioja, España.NASA, National Aeronautics and Space Administration. 2017. https://landsat.gsfc.nasa.gov/landsat-datacontinuity-mission/Navarro, G., Caballero, I., Silva, G., Parra, P., Vázquez, A., Caldeira, R. 2017. Evaluation of forest fire on Madeira Island using Sentinel-2A MSI imagery. International Journal of Applied Earth Observation and Geoinformation, 58, 97-106. https://doi.org/10.1016/j.jag.2017.02.003Nicora, M. G. 2014. Actividad eléctrica atmosférica en Sudamérica. Tesis Doctoral. Facultad de Ciencias Astronómicas y Geofísicas La Plata, Buenos Aires.Quintano, C., Fernández-Manso, A., FernándezManso, O. 2018. Combination of Landsat and Sentinel-2 MSI data for initial assessing of burn severity. International Journal of Applied Earth Observation and Geoinformation, 64, 221-225. https://doi.org/10.1016/j.jag.2017.09.014Roldán-Zamarrón, A., Merino-de-Miguel, S., GonzálezAlonso, F., García-Gigorro, S., Cuevas, J. M. 2006. Minas de Riotinto (south Spain) forest fire: Burned area assessment and fire severity mapping using Landsat 5-TM, Envisat-MERIS, and Terra-MODIS postfire images. Journal Geophysical Research, 111, G04S11. https://doi.org/10.1029/2005JG000136Van Der Werf, G. R., Randerson, J. T., Giglio, L., Van Leeuwen, T. T., Chen, Y., Rogers, B. M., Mu, M., Van Marle, M.J.E., Morton, D.C., Collatz, G.J., Yokelson, R.J., Kasibhatla, P. S. 2017. Global fire emissions estimates during 1997- 2016. Earth System Science Data, 9(2), 697-720. https://doi.org/10.5194/essd-9-697-2017Vanzolini, J., Pezzola, A., Iurman, D., Vasicek J., Cantamutto, M. 2017. Reporte de la recorrida en las áreas afectadas por fuego en Villarino y Patagones. Informe técnico. Estación Experimental Agropecuaria INTA Hilario Ascasubi. Argentina

Turbidity and Secchi disc depth with Sentinel-2 in different trophic status reservoirs at the Comunidad Valenciana

[ES] En los estudios de calidad de aguas por teledetección, uno de los principales indicadores es la transparencia o turbidez del agua. La transparencia puede ser medida in situ mediante la profundidad del disco de Secchi (SD), y la turbidez con un turbidímetro. En las últimas décadas se han utilizado diferentes relaciones entre bandas de diferentes sensores obtenidas por teledetección para la estimación de estos parámetros. En este trabajo, a partir de datos de campo obtenidos a lo largo de 2017 y 2018 en embalses de la cuenca del Júcar con gran variedad de estados tróficos, se han calibrado diferentes índices y bandas para poder estimar la transparencia a partir de imágenes Sentinel-2 (S2). A las imágenes S2 nivel L1C tomadas en el mismo día que los datos de campo, se les han aplicado tres métodos de corrección atmosférica desarrollados para aguas: Polymer, C2RCC y C2X. A partir de los espectros de S2 obtenidos y de los datos de campo de SD se ha observado que el menor error se obtiene con las imágenes corregidas con Polymer y un ajuste potencial del cociente de reflectividades en las bandas azul y verde (R490/R560), que permiten la estimación de SD con un error relativo del 13%. También el método C2X presenta buen ajuste con el mismo cociente de bandas, aunque un error mayor, presentando la corrección C2RCC la peor correlación. Se ha obtenido también la relación entre SD (en m) y turbidez (en NTU), lo que proporciona un método operativo para la estimación de la turbidez con S2. Se muestra, además, la relación para los diferentes embalses entre el SD y la concentración de clorofila-a, sólidos en suspensión y materia orgánica disuelta.[EN] Transparency or turbidity is one of the main indicators in studies of water quality using remote sensing. Transparency can be measured in situ through the Secchi disc depth (SD), and turbidity using a turbidimeter. In recent decades, different relationships between bands from different remote sensing sensors have been used for the estimation of these variables. In this paper, several indices and spectral bands have been calibrated in order to estimate transparency from Sentinel-2 (S2) images from field data, obtained throughout 2017 and 2018 in Júcar basin reservoirs with a great variety of trophic states. Three atmospheric correction methods developed for waters have been applied to the S2 level L1C images taken at the same day as the field data: Polymer, C2RCC and C2X. From the spectra obtained from S2 and the SD field data, it has been found that the smallest error is obtained with the images atmospherically corrected with Polymer and a potential adjustment of the reflectivities’ ratio of the blue and green bands (R490/R560), which allow the estimation of SD with a relative error of 13%. Also the C2X method presents good adjustment with the same bands ratio, although with a greater error, while the correction C2RCC shows the worst correlation. The relationship between SD (in m) and turbidity (in NTU) has also been obtained, which provides an operational method for estimating turbidity with S2. The relationship for the different reservoirs between SD and chlorophyll-a concentration, suspended solids and dissolved organic matter, is also shownEste trabajo ha sido posible gracias al Proyecto ESAQS del Programa Prometeo para grupos de investigación de excelencia de la Conselleria d’Educació, Investigació, Cultura i Esport (GVPROMETEO2016-132) de la Generalitat Valenciana.Delegido, J.; Urrego, P.; Vicente, E.; Sòria-Perpinyà, X.; Soria, J.; Pereira-Sandoval, M.; Ruiz-Verdú, A.... (2019). Turbidez y profundidad de disco de Secchi con Sentinel-2 en embalses con diferente estado trófico en la Comunidad Valenciana. 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