Influencia de la ganadería en la evolución del riesgo de incendio en función de la vegetación en un área de montaña: el ejemplo del valle de Borau (Pirineo aragonés)

The study concerns the impact of livestock on the fire-risk evolution in Borau valley (Pyrenees) between 1957 and 2000. The risk has grown considerably due to an increase in pine woods and scrub areas because of land abandonment and livestock extensification. The decrease in livestock pression has been crucial in the potential firerisk increase. The decline of stay sheep and the extensification of their shepherding areas have been the most important factors in the process.Se ha estudiado la influencia de la ganadería en la evolución del riesgo de incendio en función de la vegetación en el valle de Borau (Pirineo aragonés) entre 1957 y 2000. Se ha comprobado que el riesgo ha aumentado considerablemente a lo largo del periodo estudiado como consecuencia del incremento de los bosques de coníferas y de la vegetación arbustiva, fruto del abandono de campos de cultivo y de la extensificación ganadera. El descenso de la presión ganadera ha intervenido de forma determinante en el incremento del potencial riesgo de incendio. El factor más importante ha sido el retroceso del ganado lanar estante y la extensificación de sus áreas de pastoreo

Temporal variability of the urban heat island in Zaragoza (Spain)

We analyse the temporal intensity and variability of the urban heat island (UHI) in the city of Zaragoza (Spain), and assess the role of wind as an important atmospheric conditioning factor. Based on the time data provided by the city’s urban mesoscale meteorological network, the temperature difference between two observatories, one urban (Plaza Santa Marta) and one located on the outskirts of the urban area (Ciudad Deportiva), was calculated for the 2015-2020 period. The results indicate that the temperature in the city centre is very frequently 1º or 2ºC higher than in the surroundings, sometimes even more than 8ºC higher. The UHI is more intense in summer (an average of 2.5ºC per hour) than in winter (an average of 2.2ºC per hour) and more intense during the night than during the day. The maximum UHI value is reached in calm atmospheric situations; however, this value is very limited with winds over 10 km/h and it practically disappears with wind speeds over 50 km/h.En este artículo se analiza la intensidad y la variabilidad temporal de la isla de calor urbana (ICU) de la ciudad de Zaragoza (España) y se evalúa la acción del viento como importante factor atmosférico condicionante de la misma. A partir de los datos horarios proporcionados por la red meteorológica urbana de mesoescala de la ciudad, se calculó la diferencia de temperatura entre dos observatorios, uno urbano (Plaza Santa Marta) y otro en las afueras del área urbana (Ciudad Deportiva), en el periodo 2015-2020. Los resultados indican que la temperatura en el centro de la ciudad es, con mucha frecuencia, 1º o 2ºC más elevada que en el entorno, y en ocasiones ha llegado a superar los 8ºC. La ICU es más intensa en verano (promedios horarios de 2,5ºC) que en invierno (promedio de 2,2ºC) y es más intensa durante la noche que durante el día. El valor máximo de la ICU se alcanza en situaciones de calma atmosférica; en cambio, se debilita claramente con vientos de más de 10 km/h y llega prácticamente a desaparecer con velocidades superiores a 50 km/

Islas de calor y confort térmico en Zaragoza durante la ola de calor de julio de 2015

En este trabajo se analiza la isla de calor y la isla de sequedad del verano del año 2015 a partir de la red de sensores de temperatura y humedad existentes en la ciudad y su entorno inmediato. Asimismo, se evalúa la incidencia de la ciudad sobre las temperaturas y la humedad durante la intensa ola de calor del mes de julio, y se caracteriza el régimen de confort a partir del índice de confort térmico THI, de Thom.This paper analyzes both the heat island and the island of dryness of the summer of 2015 from the network of temperature and humidity sensors existing in the city and its surroundings. Furthermore, we evaluate the incidence of the city within the temperatures and humidity during the intense July heat wave. Finally, we characterized the thermal comfort index from the thermal comfort index THI, Thom.Este trabajo ha sido posible gracias a los proyectos 909.338/2014 Patrones temporales y espaciales de la temperatura urbana de Zaragoza, y 943.674/2013 Clima y masas forestales del término municipal de Zaragoza en el contexto del cambio global, financiados por la Agencia de Medio Ambiente y Sostenibilidad del Ayuntamiento de Zaragoza. Ha contado también con la ayuda del Gobierno de Aragón y Fondo Social Europeo al grupo de investigación “Clima, agua y cambio global” de la Universidad de Zaragoza

The state of art of the drought studies in Spain

Póster elaborado para el WCRP Workshop on Drought Predictability and Prediction in a Changing Climate celebrado en Barcelona del 2 al 4 de marzo de 201

Características espaciales del clima en La Rioja modelizadas a partir de sistemas de información geográfica y técnicas de regresión espacial

21 páginas[ES] En este trabajo se modeliza la distribución espacial de algunas variables climáticas en el conjunto de La Rioja mediante sistemas de información geográfica y técnicas de regresión espacial. El resultado de los modelos son cartografías digitales a una resolución temporal mensual y espacial de 100 metros. Las cartografías tienen la ventaja de ser objetivas y automáticas, mejorando aproximaciones anteriores basadas en criterios expertos. Los modelos han permitido llevar a cabo una caracterización muy precisa del clima de La Rioja. Se presentan, a escala estacional y anual, los principales patrones espaciales del clima de La Rioja, incluyendo la precipitación, temperaturas, evapotranspiración y balance hídrico.[EN] The spatial distribution of climate variables in La Rioja is modelled by means of geographical information systems and advanced spatial regression techniques. Application of models allows to obtain monthly digital maps of precipitation, temperature, evapotranspiration and water balance at a spatial resolution of 100 m. The maps are objective and they are obtained automatically using numerical methods. This approach improves previous maps based on subjective manual mapping. The maps allow to obtain accurate approximation to the average climate characteristics in La Rioja and to determine their spatial patterns.Este trabajo ha contado con el apoyo de los siguientes proyectos de investigación: CGL2005-04508/BOS (financiado por el Ministerio de Educación y Ciencia), PIP176/2005 (financiado por el Gobierno de Aragón), y “Programa de grupos de investigación consolidados” (BOA 48 of 20-04- 2005), también financiado por el Gobierno de Aragón. Agradecer al Instituto Nacional de Meteorología la cesión de los datos utilizados en este trabajo.Peer reviewe

Trends in drought intensity and variability in the middle Ebro valley (NE of the Iberian peninsula) during the second half of the twentieth century

12 páginas, 9 figuras, 3 tablas.-- El documento en word es el post-print del artículo.Here we analyse trends in drought magnitude in the middle Ebro valley, a semi-arid area of the Iberian Peninsula, between 1951 and 2000. A significant increase in the severity of drought was identified from 1951 to 2000, and principal components analysis revealed three general patterns of drought evolution. Trend analysis of these patterns indicated that trend is significant only in northern areas (p < 0.01). Trends in drought variability were also analysed; a positive trend was recorded between 1951 and 2000. However, the overall results show a high degree of spatial variability. We show that this variability is determined by several geographic/topographic factors, mainly the distance to the Mediterranean Sea and the Bay of Biscay, water bodies that regulate the origin and direction of air masses and flows. It should also be noted that spatial variability of drought was detected because we used a dense database. Our results indicate that at the sub-regional level, drought patterns should be studied using a large amount of empirical data, since spatial variability may be relevant.The authors want to acknowledge financial support from the projects BSO2002-02743 and CGL2005-04508=BOS (Financed by Ministerio de Educaci ón y Ciencia, Spain and FEDER), and ‘‘Programa de grupos de investigaci on consolidados’’ (grupo Clima, Cambio Global y Sistemas Naturales, BOA 48 of 20-04-2005), financed by Aragón Government.Peer reviewe

Early prediction of crop production using drought indices at different time-scales and remote sensing data: application in the Ebro Valley (north-east Spain)

8 páginas.-- El documento en word es la versión post-print del autor.This Letter shows the results of early crop prediction from combined use of AVHRR-NDVI data and drought indices at different time-scales. The study was carried out in an agricultural municipality located in the Middle Ebro valley, one of the most arid regions in Europe. The methodology proposed here has allowed the prediction of wheat and barley production in February, four months before harvest. Moreover, the predictive models created have explained 88% and 82% of the temporal variability of wheat and barley production, respectively. This procedure could be very useful for managing crop production at a municipal level. Moreover, insurance companies could take advantage of the early prediction of crop losses, which are very frequent in this drought-affected area.Peer reviewe

Comparison of regression techniques for mapping fog frequency: application to the Aragón region (northeast Spain)

28 páginas,, 4 tablas, 7 figuras. The definitive version is available at: http://www3.interscience.wiley.com/journal/4735/homeWe compare different spatial interpolation techniques in mapping the monthly frequency of fogs in the Aragón region (northeast Spain). The local and spatially complex nature of the fogs makes them more difficult to map than other climatic variables such as precipitation and temperature. We found clear seasonal differences in the quality of the obtained maps. The localized nature of spring and summer fogs, mainly restricted to valley bottoms in mountainous areas, gives rise to several limitations. The modelling of fog frequency is more complex than that of other climate variables; to improve the model predictions, it is necessary to consider topographic variables that simulate the terrain structure. Moreover, the highly complex nature of the relationship between fog frequency and terrain means that simple linear models perform poorly in accounting for the role of geographic and topographic variables in determining the spatial distribution of fog frequency. The inclusion of non-linear relationships between fog frequency and terrain variables in the models following a general additive model (GAM) procedure leads to an improvement in model performance because the flexibility of GAMs enables the inclusion of non-linear relationships and the generation of response-curve shapes that detail the exact relationship between the dependent variable and predictors throughout the entire range of the variable.This work has been supported by the following research projects: CGL2005-04508/BOS (financed by the Spanish Commission of Science and Technology and FEDER), PIP176/2005 (financed by the Aragón Government), and “Programa de grupos de investigación consolidados” (BOA 48 of 20-04-2005), also financed by the Aragón Government.Peer reviewe