8 research outputs found
Spatial distribution of daily rainfall in the Region of Alicante
El análisis de la precipitación diaria es un tema de gran interés en España. La importancia de este tipo de análisis deriva sobre todo del hecho de que las precipitaciones torrenciales constituyen uno de los mayores riesgos ambientales en el litoral mediterráneo ibérico. En este trabajo se analiza la concentración temporal diaria de la precipitación, a partir del cálculo del Ãndice de concentración pluviométrico (CI), a una escala de detalle –la provincia de Alicante–, y la situación sinóptica de una muestra de dÃas con precipitaciones torrenciales en la citada provincia. Los resultados obtenidos pueden resumirse en: 1) Una elevada concentración pluviométrica en el área de la capital y, sobre todo, en la parte septentrional de la provincia, donde el 30 % de los dÃas lluviosos aportan el 75 % del total anual; 2) la importancia de los episodios torrenciales consecuencia de una depresión aislada en niveles altos (DANA) o «gota frÃa»; y 3) la utilidad del Ãndice (CI) para la planificación territorial y la mitigación del riesgo en el área mediterránea de estudio.The analysis of daily precipitation has a great interest for Spain. This type of analysis is important because torrential rainfall is one of the most critical natural risk in the Iberian Mediterranean coast. In this paper the daily concentration of rainfall, by means of the Concentration Index (CI), in the province of Alicante, as well as the synoptic situation of a sample of days with heavy precipitation in the same province, are analysed. The results can be summarized as follows: 1) A high concentration of rainfall in the capital area and, especially, in the northern part of the province, where the 30% of rainy days account for much as 75% of the annual total; 2) torrential rainfall events as a result of isolated cold depression at high tropospheric levels (DANA), or cut-off low; and 3) the usefulness of the CI for the territorial planning in the study area.Este trabajo ha sido posible gracias a la financiación por el Ministerio de Ciencia e Innovación del proyecto CGL2011-29263-C02-01, 2012-2014, el Instituto Agronómico Mediterráneo de Zaragoza (IAMZ), el apoyo del Grup de ClimatologÃa (2009 SGR 443) y la beca FPI de que disfruta el primer autor
Progrès méthodologiques dans l´analyse de la concentration journalière desprécipitations en Espagne peninsulaire
The daily concentration of the precipitation in 32 meteorological stations in peninsular Spain by means of the Concentration Index (Martin-Vide, 2004) and similar indexs using 5 and 10 mm classes, and the corresponding Gini’s indexs, has been analysed. The maps for the period 1951-2010, as well as for the subperiods 1951-1980 and 1981-2010, have been compared. Finally, the changes in the daily concentration of the precipitation between the first and the second  subperiods are studied.En el presente trabajo, partiendo del Ãndice de concentración diaria de la precipitación de Martin-Vide (2004), basado en clases de 1 mm de longitud, se analiza la concentración de la precipitación en 32 observatorios de la España peninsular con Ãndices similares usando clases de 5 y de 10 mm, asà como con los Ãndices de Gini construidos con las mismas longitudes de clase. Se comparan los mapas resultantes para el perÃodo 1951-2010 y los subperÃodos 1951-1980 y 1981-2010. Finalmente, con los Ãndices citados se analizan las variaciones en la concentración diaria de la precipitación al pasar del primer al segundo subperÃodo.Le présent travail a pour objectif l’analyse à partir de l’indice de concentration quotidienne des précipitations de Martin-Vide (2004), basé sur des classes de 1 mm de longueur, la concentration des précipitations de 32 observatoires d’Espagne péninsulaire avec des indices similaires de 5 et 10 mm, ainsi que les indices de Gini construits avec les mêmes longueurs. Nous comparons les cartes qui en résultent pour la période 1951-2010 et sous-périodes de 1951-1980 et de 1981-2010. Enfin, avec les indices indiqués, on analyse les  variations de la concentration quotidienne des précipitations allant du premier à la deuxième sous-période
Spatial distribution of the daily precipitation concentration index in Algeria
In this paper, the spatial and temporal distribution of the daily precipitation concentration index (CI) in Algeria (south Mediterranean Sea) has been assessed. CI is an index related to the rainfall intensity and erosive capacity; therefore, this index is of great interest for studies on torrential rainfall and floods. Forty-two daily rainfall series based on high-quality and fairly regular rainfall records for the period from 1970 to 2008 were used. The daily precipitation CI results allowed the identification of three climate zones: the northern country, characterized by coastal regions with CI values between 0.59 and 0.63; the highlands, with values between 0.57 and 0.62, except for the region of Biskra (CI D0.70); and the southern region of the country, with high rainfall concentrations with values between 0.62 and 0.69
Rainfall distribution and trends of the daily precipitation concentration index in northern Morocco: a need for an adaptive environmental policy
A national priority at the Moroccan level is to understand the spatiotemporal rainfall irregularity to anticipate suitable strategies for water and agriculture management. The most northern mountainous region shows intense sensitivity to extreme hydroclimatic hazards which may compromise the future of socioeconomic acceleration and further weaken environmental balances. However, planning and decision making require accurate data, on a detailed scale and with good spatial distribution which is not the case in several south-Mediterranean countries where rainfall data and/or well- established hydro-meteorological network is lacking. In this paper, abundant rain gauge measurements combined with time-series open data (1958-2015) were used to study the rainfall variability. Results show an annual rainfall increase trend since 1996 with frequent, intense and abundant rains causing violent torrents and floods. This humid trend alter- nates with short but severe dry periods. Spatial distribution shows a rainfall increase from eastern to western area and from the coastal plains to high mountains. Based on a continuous daily rainfall dataset (from 1988 to 2012) from six scat- tered stations, it appears that the pattern of heavy and extreme wet days takes the form of an irregular interannual cycle. Trends of the annual precipitation daily concentration indicate a significant positive trend in the center than in the East of the study area. Considering these observations, a review of water needs/obligations priorities seems crucial so that a new conscious and adaptative environmental policy would approve new procedures for a sustainable management
Análisis de la concentración diaria de la precipitación en la Cuenca del Mediterráneo Occidental
[spa] El análisis de la precipitación diaria es un tema de gran interés en el litoral de la cuenca del Mediterráneo occidental. El interés por este tipo de análisis viene justificado por la presencia de los mayores riesgos ambientales en el Mediterráneo occidental. En esta tesis se analiza la concentración diaria de la precipitación entre 1952-2010, a partir del cálculo de los valores de la concentración diaria CI1, CI5, CI10 e IG1 de la precipitación, y la correlación entre ellos en diferentes periodos. En segundo lugar, se calcula la variación de la concentración diaria de la precipitación entre los subperiodos 1951-1980 al 1981-2010. En tercer lugar, se presenta la distribución espacial de los cuatro Ãndices citados anteriormente. En el cuarto lugar, se analizan las tendencias de la concentración de la precipitación diaria anualmente y la situación sinóptica de los años extremos en cuanto a la concentración diaria de la precipitación en el periodo 1970-2010. Los resultados obtenidos pueden resumirse como; una elevada concentración pluviométrica en la costa mediterránea francesa y la franja oriental de la España peninsular, con valores del IG1 y del CI1 que superan en varios observatorios 0,70 y llegan a aproximarse en alguno a 0,73 (el 25 % de los dÃas más lluviosos aporta hasta el 82 % del total pluviométrico), como se confirma, la existencia de un cambio significativo del Ãndice CI1 anual de la precipitación diaria en el litoral de la cuenca del Mediterráneo occidental durante los últimos 60 años. Finalmente, se concluye que un CI alto se relaciona notablemente con una frecuencia ciclónica (C) alta y una frecuencia anticiclónica (A) baja y viceversa
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 (25.6Â % 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
Spatial distribution of the daily precipitation concentration index in Algeria
In this paper, the spatial and temporal distribution of the daily precipitation concentration index (CI) in Algeria (south Mediterranean Sea) has been assessed. CI is an index related to the rainfall intensity and erosive capacity; therefore, this index is of great interest for studies on torrential rainfall and floods. Forty-two daily rainfall series based on high-quality and fairly regular rainfall records for the period from 1970 to 2008 were used. The daily precipitation CI results allowed the identification of three climate zones: the northern country, characterized by coastal regions with CI values between 0.59 and 0.63; the highlands, with values between 0.57 and 0.62, except for the region of Biskra (CI D0.70); and the southern region of the country, with high rainfall concentrations with values between 0.62 and 0.69