ALGUNAS REFLEXIONES Y EJEMPLOS DEL VALOR DE LA PERCEPCIÓN AMBIENTALEN LA PLANIFICACIÓN TERRITORIALY DE ACTIVIDADES

La percepción ambiental, es decir, cómo se percibe o se siente el medio ambiente (a partir del individuo inserto en él), tiene un notable interés psicológico y sociológico, pero también constituye una herramienta útil de análisis de la realidad para la planificación territorial y la programación de actividades. Aunque los resultados que la percepción suministre puedan, en ocasiones, discrepar abiertamente de la realidad, sirven al gestor y al planificador en la toma de decisiones adecuadas para la colectividad en sus relaciones con el marco físico

Meteorological drought lacunarity around the world and its classification

The measure of drought duration strongly depends on the definition considered. In meteorology, dryness is habitually measured by means of fixed thresholds (e.g. 0.1 or 1 mm usually define dry spells) or climatic mean values (as is the case of the standardised precipitation index), but this also depends on the aggregation time interval considered. However, robust measurements of drought duration are required for analysing the statistical significance of possible changes. Herein we climatically classified the drought duration around the world according to its similarity to the voids of the Cantor set. Dryness time structure can be concisely measured by the n index (from the regular or irregular alternation of dry or wet spells), which is closely related to the Gini index and to a Cantor-based exponent. This enables the world’s climates to be classified into six large types based on a new measure of drought duration. To conclude, outcomes provide the ability to determine when droughts start and finish. We performed the dry-spell analysis using the full global gridded daily Multi-Source Weighted-Ensemble Precipitation (MSWEP) dataset. The MSWEP combines gauge-, satellite-, and reanalysis-based data to provide reliable precipitation estimates. The study period comprises the years 1979–2016 (total of 45 165 d), and a spatial resolution of 0.5∘, with a total of 259 197 grid pointsThis research has been supported by the European Research Council (RESCCUE (grant no. 700174)) and the Spanish Ministry of Science, Innovation and Universities (grant no. CGL2017-83866-C3-2-R). We are grateful for the support provided by the RESCCUE project, which received funding from the European Research Council under the European Union's Horizon 2020 research and innovation programme (grant agreement no. 700174). We also wish to acknowledge the support received from the Spanish projects CGL2017-83866-C3-2-R and Climatology Group 2017 SGR 1362. We appreciate the interest in our research shown by the Water Research Institute of the University of Barcelona and by the Department of Algebra, Geometry and Topology of the Complutense University of MadridS

Future Projection of precipitation changes in the Júcar and Segura River Basins (Iberian Peninsula) by CMIP5 GCMs Local Downscaling

The basins of the Júcar and Segura rivers, on the Mediterranean coast of the Iberian Peninsula, present a special water problem and are of particular interest regarding climate change. These basins are very vulnerable to a possible scenario of decreasing water resources. Recent studies on historic rainfall since 1955 have indicated an ongoing loss of precipitation in their headwaters, especially in the case of the Júcar river. The aim of the present study is to perform climate projections for the precipitation variable for several future periods (2021-2040, 2051-2070, 2081-2100) and emission scenarios (RCPs 4.5, 8.5) within the Júcar and Segura River Basin authorities. For this purpose, a set of CMIP5 global models have been used, as well as the CDRD-HR-EIP-1955-2016 database, as a source of local observed information. This database comprises nearly 900 precipitation series in both basins and has been used in recent studies to determine historic trends of change in these basins. A statistical downscaling of the global models for all available observed series has been applied using the LARS-WG method. The results, although variable according to the CMIP5 model used, show the continuation of the patterns of precipitation change in the future, as already observed in the historical series. The results also predict a clear reduction in precipitation in the long term. However, torrential rainfall tends to increase in the coastal areas in relation to that observed in the short-term predictions. These results, due to their high spatial resolution, are of great interest for their use in small-scale hydrological and spatial planning (regional and local), which is one of the current challenges of climate modeling

CONCENTRAÇÃO DIÁRIA DA PRECIPITAÇÃO NA BACIA DO ALTO IGUAÇU, PARANÁ, BRASIL - CONCENTRATION INDEX OF RAINFALL IN THE UPPER BASIN IGUAÇU, PARANÁ, BRAZIL

A Bacia do Alto Iguaçu/Paraná, localizada no sul do Brasil, encontra-se exposta a riscos derivados das inundações, sobretudo nos meses de verão (dezembro, janeiro e fevereiro). Durante este período a bacia experimenta precipitações convectivas associadas a sistemas frontais juntamente com o aquecimento local. Además, as precipitações convectivas estão associadas com a entrada de umidade procedente do norte do Brasil. Dada a sua concentração e seu grande volume total, o conhecimento da precipitação em escala diária é essencial para o planejamento e gestão da bacia. Em particular, a compreensão dos padrões de precipitação diária torna-se essencial para o planejamento e gestão do território, assim como para a conservação dos recursos naturais. Com base no conhecimento da área de estudo, este trabalho utiliza o índice de concentração da precipitação (CI) para determinar os potencias impactos da precipitação diária. O índice foi aplicado para 18 estações meteorológicas com dados homogeneizados de qualidade, para o período de 1980 a 2010. Os valores foram calculados considerando os totais e a sazonalidade, com o intuito de verificar possíveis variações. Os valores do índice de concentração, foram altos durante o outono e inverno, já durante a primavera e o verão, apresentaram-se moderados.ABSTRACTThe Upper Iguaçu Basin/Paraná, located in the South of Brazil, is exposed to flood risk, mainly during summer months (December, January and February). During this period, the basin undergoes convective precipitation associated with frontal systems with local heating. Besides that, the convective precipitation is related to the moisture entrance from the North of Brazil. Given its concentration at time and large total volume, the knowledge of the resolution of daily rainfall is very important. Particularly, the comprehension of the daily rainfall patterns is essential for planning and management of land and to the conservation of natural resources. Based on area knowledge, this paper uses the concentration index (IC) to determine the potential impacts of daily rainfall. The index was applied in 18 meteorological stations within homogenized quality for the period 1970-2010. The values were calculated considering the the total amount and the sazonality, with the purpose of check possible variations.The values of the Concentration Index were high during fall and winter, and during summer and spring it reveals to be moderate

Upper-Level Mediterranean Oscillation index and seasonal variability of rainfall and temperature

The need for early seasonal forecasts stimulates continuous research in climate teleconnections. The large variability of the Mediterranean climate presents a greater difficulty in predicting climate anomalies. This article reviews teleconnection indices commonly used for the Mediterranean basin and explores possible extensions of one of them, the Mediterranean Oscillation index (MOi). In particular, the anomalies of the geopotential height field at 500 hPa are analyzed using segmentation of the Mediterranean basin in seven spatial windows: three at eastern and four at western. That is, different versions of an Upper-Level Mediterranean Oscillation index (ULMOi) were calculated, and monthly and annual variability of precipitation and temperature were analyzed for 53 observatories from 1951 to 2015. Best versions were selected according to the Pearson correlation, its related p-value, and two measures of standardized error. The combination of the Balearic Sea and Libya/Egypt windows was the best for precipitation and temperature, respectively. The ULMOi showed the highest predictive ability in combination with the Atlantic Multidecadal Oscillation index (AMOi) for the annual temperature throughout the Mediterranean basin. The best model built from the indices presented a final mean error between 15% and 25% in annual precipitation for most of the studied area

Tendencias recientes observadas en la evaporación en España y su posible relación con las variaciones de la radiación solar en superficie (1985-2010)

Ponencia presentada en: VIII Congreso de la Asociación Española de Climatología celebrado en Salamanca entre el 25 y el 28 de septiembre de 2012.[ES]Existe un creciente interés sobre las causas de las tendencias de la evaporación observadas en diferentes regiones del planeta. En este trabajo se analizan las tendencias recientes de la evaporación potencial en España durante el periodo 1985-2010 a partir de registros mensuales homogeneizados de evaporímetros de tanque (21 series que inician sus observaciones en los 1980) y Piché (71 series, muchas de más de 60 años). Los resultados muestran una ausencia de cambios significativos de la evaporación en tanque durante el período 1985-2010.[EN]There is growing interest on the causes of evaporation trends observed in different regions of the planet. This paper analyses recent trends in potential evaporation in Spain over the 1985-2010 period from monthly homogenised records both for pan evaporation measurements (21 series that start in the 1980s) and for Piché atmometers (71 series, most of them with more than 60 years of data). Despite of increasing solar radiation during the period 1985-2010, results show no significant trends in pan evaporation over the period 1985-2010.Esta investigación ha sido financiada por el Ministerio Economía y Competitividad, a través de los proyectos NUCLIERSOL (CGL2010-18546) e HIDROCAES (CGL2011-27574-C02-02). El segundo autor está financiado por una beca postdoctoral Beatriu de Pinós de la Generalitat de Catalunya (2009 BP-A 00035)

A component-based approximation for trend detection of intense rainfall in the Spanish Mediterranean coast

Rainfall behavior is a fundamental issue in areas with scarce and irregular amounts, such as the Spanish Mediterranean region. We identified 12 spatial patterns that characterized 899 torrential precipitation events (≥150 mm in 24 h) that occurred in the 3,537 rainy precipitation series in the period 1950-2020. Three of these components--eastern and ESE--showed positive and significant trends in their accumulated volumes. We then characterized the mean synoptic causes of the 10 most intense events in each component at both mean sea-level pressure and 500 hPa geopotential height, and also the integrated water-vapor transport between 1,000 and 300 hPa. We found a clear spatial distribution of the pluviometric effects related to unstable atmospheric situations (such as troughs and cut-off lows), and also to SW-SE advection fluxes that brought moist air from the Western Mediterranean. In particular, torrential rainfall in the Balearic Islands related more to E-NE advections than to southeastern ones. We also determined that the major parts of these components occurred in early autumn, especially in September and October. We expect these findings to help our understanding of the processes leading to catastrophic situations along the Spanish Mediterranean coast and to lead to improvements in early alert systems and management plans

Definition of a temporal distribution index for high temporal resolution precipitation data over Peninsular Spain and the Balearic Islands: the fractal dimension; and its synoptic implications

Precipitation on the Spanish mainland and in the Balearic archipelago exhibits a high degree of spatial and temporal variability, regardless of the temporal resolution of the data considered. The fractal dimension indicates the property of self-similarity, and in the case of this study, wherein it is applied to the temporal behaviour of rainfall at a fine (10-min) resolution from a total of 48 observatories, it provides insights into its more or less convective nature. The methodology of Jenkinson & Collison which automatically classifies synoptic situations at the surface, as well as an adaptation of this methodology at 500 hPa, was applied in order to gain insights into the synoptic implications of extreme values of the fractal dimension. The highest fractal dimension values in the study area were observed in places with precipitation that has a more random behaviour over time with generally high totals. Four different regions in which the atmospheric mechanisms giving rise to precipitation at the surface differ from the corresponding above-ground mechanisms have been identified in the study area based on the fractal dimension. In the north of the Iberian Peninsula, high fractal dimension values are linked to a lower frequency of anticyclonic situations, whereas the opposite occurs in the central region. In the Mediterranean, higher fractal dimension values are associated with a higher frequency of the anticyclonic type and a lower frequency of the advective type from the east. In the south, lower fractal dimension values indicate higher frequency with respect to the anticyclonic type from the east and lower frequency with respect to the cyclonic type

Évolutions de la concentration des précipitations journalières sur les littoraux du bassin méditerranéen occidental (1951-2010)

In this paper, the nonparametric MANN-KENDALL test is used to detect the trends of the annual values of the daily precipitation concentration index (CI1) recorded in the coastal areas of the western Mediterranean Sea. Daily series of 45 meteorological observatories distributed in a relatively uniform way to the coastal lands of the western Mediterranean Sea and the Balearic Islands, Corsica, Sardinia and Sicily of the period of 60 years (1951-2010) were analyzed. The results reveal significant changes of the annual concentration index (CI1) of the daily precipitation for the complete period and two sub-periods of 30 years studied (1951-1980 and 1981-2010). Over the full period, ten stations out of thirty show a significant positive evolution of the index and only two significant negative developments. The same trend is evident in the sub-period 1981-210 (25.6 % of stations with significant positive developments). But the lack of homogeneity of the results does not lead to the conclusion of a general change in the distribution of daily rainfall