Impacto de las pistas forestales en medios frágiles mediterráneos. El caso del Turó de Burriach (Maresme Barcelona- España)

[Resumen] Con el presente estudio se pretende evaluar el impacto producido por la apertura de una pista forestal en la comarca del Maresme (Barcelona), concretamente en la zona del Turó de Burriach. A esta zona se le atribuyeuna dinámica erosiva muy baja, principalmente por el alto grado de protección del suelo. Lo que se pretende es demostrar que al desmantelar este manto protector, la dinámica aumenta considerablemente, produciéndose una rápida degradación del medio. Para ello, se hará en primer lugar, un análisis de como incide el clima sobre este medio y en segundo lugar, se evaluará el grado de degradación a través de un análisis de la erosión hídrica.[Abstract] With this paper we want to value the impact produced by the way construction in the Maresme region (Barcelona), concretely at the Burriach Hill area. In this area the erosion dinamic is very low, because of the good soil protection. In this way we pretend to demonstrate that the erosion is higher when the vegetation is dismantled, producing a fast land degradation. To get it, in a first time we will do a climate inf1uence analysis, and in a second moment we will value the degradation level using a hidrological erosion analysi

Mean temperature evolution on the Spanish mainland 1916-2015

An analysis of the evolution of annual and seasonal mean temperatures on the Spanish mainland (western Mediterranean basin) was carried out, using the new MOnthly TEmperature Dataset of Spain century (MOTEDAS-century) data set. This data set was developed by combining archives from the National Meteorological Agency and newly digitised legacy data from the Annual Books published between 1916 and 1949. Both the annual and seasonal regional mean temperature series experienced increasing trends during the study period. However, the in-crement was neither constant in time (monotonic) nor homogeneous between seasons. Four main periods were identified in the annual mean regional series. The first 3 corresponded to those previously confirmed in global temperature series (rise-pause-rise); a second pause or hiatus was also detected at the end of the period of analysis. The seasonal regional series followed specific patterns: Winter mean temperature only increased in the second rising period, autumn in the first and spring and summer during the 2 rising periods. Also, negative trends were found in extended areas in the first pause in spring, and to a lesser extent in summer. From the middle of the 1980s, the trends in annual and seasonal mean values were not significant up until 2015. Furthermore, spatial variations were found in the significance of the trends, revealing regional differences in the intensity of warming through the seasons. In comparison with other versions of secular mean temperature series developed for the Spanish mainland, MOTEDAS-century seems to better capture the spatial variability

Spatial variability of maximum and minimum monthly temperature in Spain during 1981–2010 evaluated by correlation decay distance (CDD)

The spatial variability of monthly diurnal and nocturnal mean values of temperature in Spain has been analysed to evaluate the optimal threshold distance between neighbouring stations that make a meteorological network (in terms of stations’ density) well representative of the conterminous land of Spain. To this end, the correlation decay distance has been calculated using the highest quality monthly available temperature series (1981–2010) from AEMet (National Spanish Meteorological Agency). In the conterminous land of Spain, the distance at which couples of stations have a common variance above the selected threshold (50 %, r Pearson ~0.70) for both maximum and minimum temperature on average does not exceed 400 km, with relevant spatial and temporal differences, and in extended areas of Spain, this value is lower than 200 km. The spatial variability for minimum temperature is higher than for maximum, except in cold months when the reverse is true. Spatially, highest values are located in both diurnal and nocturnal temperatures to the southeastern coastland and lower spatial variability is found to the inland areas, and thus the spatial variability shows a clear coastland-to-inland gradient at annual and monthly scale. Monthly analyses show that the highest spatial variability in maximum and minimum temperatures occur in July and August, when radiation is maximum, and in lowland areas, (<200 m o.s.l.), which coincide with the mostly transformed landscapes, particularly by irrigation and urbanization. These results highlight local factors could play a major role on spatial variability of temperature. Being maximum and minimum temperature interstation correlation values highly variable in Spanish land, an average of threshold distance of about 200 km as a limit value for a well representative network should be recommended for climate analyses,

Variability of maximum and minimum monthly mean air temperatures over mainland Spain and their relationship with low-variability atmospheric patterns for period 1916–2015

The analysis of monthly air temperature trends over mainland Spain during 1916–2015 shows that warming has not been constant over time nor generalized among different months; it has not been synchronous for maximum and minimum air temperatures; and it has been heterogeneous in space. Temperature rose during two characteristic pulses separated by a pause around the middle of the 20th century in some months. In other months, only the second rising period is identified, or no warming can be found. In all months, and both for maximum and minimum air temperatures, a stagnation of the increasing trend is observed in the last two decades of the study period. High spatial variability exists in trend signal and significance, and two contrasting temporal patterns of advance over the study area are identified for maximum and minimum air temperatures. These patterns can be related to prevalent flow directions and relief disposition with respect to the flows associated with low-variability meteorological patterns North Atlantic Oscillation (NAO) and Western Mediterranean Oscillation (WEMO). The results show that warming is a complex phenomenon at regional and sub-regional scales that can only be analysed using high-spatial-resolution data and considering global and local factors

La Potencialidad Oculta de los Recubrimientos

Nowadays the growth of technological materials in the form of thin lms, layers, or coatings, still remains like one of the topics of greatest vitality, in both the scientic and technological environment. These technological materials already are in various applications of the dierent products that we use on our daily basis. However, how technology on coatings can help the country's productive sector?. We briey describe this hidden potential of coatings through this communication to help close the gap between the knowledge production in the academy and the work tools that the Peruvian industry sector needs to improve the quality of its nal products.Hoy en día, el crecimiento de materiales tecnológicos en forma de películas delgadas, capas o recubrimientos, sigue siendo uno de los temas de mayor vitalidad, tanto en el entorno cientíco como tecnológico. Estos materiales tecnológicos ya se encuentran en diversas aplicaciones de los diferentes productos que utilizamos a diario. Sin embargo, ¿cómo la tecnología en recubrimientos puede ayudar al sector productivo del país? Describimos brevemente este potencial oculto de los recubrimientos a través de esta comunicación para ayudar a cerrar la brecha entre la producción de conocimiento en la academia y las herramientas de trabajo que el sector industrial peruano necesita para mejorar la calidad de sus productos nales

Rapid probe of the nicotine spectra by high-resolution rotational spectroscopy

Nicotine has been investigated in the gas phase and two conformational forms were characterized through their rotational spectra. Two spectroscopic techniques have been used to obtain the spectra: a new design of broadband Fourier transform microwave (FTMW) spectroscopy with an in-phase/quadrature- phase-modulation passage-acquired-coherence technique (IMPACT) and narrowband FTMW spectroscopy with coaxially oriented beam-resonator arrangement (COBRA). The rotational, centrifugal distortion and hyperfine quadrupole coupling constants of two conformers of nicotine have been determined and found to be in N-methyl trans configurations with the pyridine and pyrrolidine rings perpendicular to one another. The quadrupole hyperfine structure originated by two 14N nuclei has been completely resolved for both conformers and used for their unambiguous identification. © 2011 the Owner Societies

High-resolution spatio-temporal analyses of drought episodes in the western Mediterranean basin (Spanish mainland, Iberian Peninsula)

The purpose of this research was to identify major drought events on the Spanish mainland between 1961 and 2014 by means of two drought indices, and analyze the spatial propagation of drought conditions. The indices applied were the standardized precipitation index (SPI) and the standardized evaporation precipitation index (SPEI). The first was calculated as standardized anomalies of precipitation at various temporal intervals, while the second examined the climatic balance normalized at monthly scale, incorporating the relationship between precipitation and the atmospheric water demand. The daily meteorological data from Spanish Meteorological Archives (AEMet) were used in performing the analyses. Within the framework of the DESEMON project, original data were converted into a high spatial resolution grid (1.1 km2) following exhaustive quality control. Values of both indices were calculated on a weekly scale and different timescales (12, 24 and 36 months). The results show that during the first half of the study period, the SPI usually returned a higher identification of drought areas, while the reverse was true from the 1990s, suggesting that the effect from atmospheric evaporative demand could have increased. The temporal propagation from 12- to 24-month and 36-month timescales analyzed in the paper seems to be a far from straightforward phenomenon that does not follow a simple rule of time lag, because events at different temporal scales can overlap in time and space. Spatially, the propagation of drought events affecting more than 25% of the total land indicates the existence of various spatial gradients of drought propagation, mostly east–west or west–east, but also north–south have been found. No generalized episodes were found with a radial pattern, i.e., from inland to the coast

Variaciones temporales de las tendencias en la serie de temperatura de inglaterra central

Variations in trend rates of annual values of the Central England Temperature series (CET) over the period 1659-2017 were analysed using moving windows of different length, to identify the minimum period in which the trend expresses a climate signal not hidden by the noise produced by natural variability. Trend rates exhibit high variability and irregular shifting from positive to negative values unless very long window lengths (of 100 years or more) are used. In general, as the duration of the length of the temporal window analysed increases, the absolute range of the trend rates decreases and the signal-to-noise (S/N) ratio increases. The relationship between the S/N ratio and the window length also depended on the total length of the series, so high S/N values are achieved faster when shorter time series are considered. This prevents suggesting a minimum window length for undertaking trend analyses. A comparison between CET and the average continental series in the Berkeley Earth Surface Temperature (BEST) database in their common period (17532017) repeats the patterns described for 1659-2017, although the average values of the rates, ranges and the “threshold period” in years change, and are more variable in CET than in BEST. Analysis of both series suggests that the recent warming started early and can be linked to the recovery of temperatures after the Little Ice Age. This process has characterised by progressively increasing trend rates, but also includes periods of deceleration or even negative trends spanning less than 50 years. The behaviour of the two long-term temperature records analysed agrees with a long-term persistence (LTP) process. We estimated the Hurst exponent of the CET series to be around 0.72 and 0.8, which reinforces the LTP hypothesis. This implies that the currently widespread statistical framework assuming a stationary, short-memory process in which departures from the norm can be easily assessed by monotonic trend analysis should not be accepted for long climatic series. In brief, relevant questions relative to the recent evolution of temperatures such as the distinction between natural variability and departures from stationarity; attribution of the causes of variability at different time scales; determination of the shortest window length to detect a trend; and other similar ones have still not been answered and may require adoption of an alternative analytical framework

Arc-parallel vs back-arc extension in the Western Gibraltar arc : is the Gibraltar forearc still active?

Extremely tight arcs, framed within the Eurasia-Africa convergence region, developed during the Neogene on both sides of the western Mediterranean. A complex interplate deformation zone has been invoked to explain their structural trend-line patterns, the shortening directions and the development of back-arc basins. Updated structural and kinematic maps, combined with earthquake data covering the complete hinge zone of the western Gibraltar arc help us to explore the mode of strain partitioning from 25My ago to present. During the Miocene, the strain partitioning pattern showed arc-perpendicular shortening in the active orogenic wedge -assessed from the radial pattern of tectonic transport directions- accompained by subhorizontal stretching. Structures accommodating stretching fall into two categories on the basis of their space distribution and their relationships with the structural trend-line pattern: i) arc-parallel stretching structures in the external wedge (mainly normal faults and conjugate strike-slip faults); and ii) extensional faults developed in the hinterland zone in which transport directions are centripetal towards the Alborán back-arc basin. Pliocene to Recent deformational structures together with focal solutions from crustal earthquakes (n=167; 1.