Reconstitution de données climatiques pour l’Algérie du Nord : application des réseaux neuronaux

Abstract

le contexte actuel de changement climatique et de pre ´servation de la biodiversite´, l'appre ´ciation de la vulne ´rabilite ´des e ´cosyste `mes naturels et de leur capacite ´d'adaptation figurent parmi les principales pre ´occupations au niveau mondial (GIEC, 2007). Cette e ´valuation des e ´cosyste `mes ne ´cessite la disponibilite ´de donne ´es climatiques, ce qui est souvent rendu difficile par la faible densite ´voire l'absence de stations me ´te ´orologiques notamment, au niveau des zones de montagnes. Dans le cadre d'une e ´tude des relations climat-ve ´ge ´tation de l'Alge ´rie du Nord, nous avons eu recours a `l'interpolation des donne ´es climatiques. Cette ope ´ration a pour but de reconstituer, a `partir du re ´seau me ´te ´orologique existant (269 stations utilise ´es), les donne ´es climatiques au niveau des sites e ´chantillonne ´s (1035 releve ´s phytoe ´cologiques). Nous pre ´sentons ici, l'application d'une me ´thode d'interpolation automatique dite, me ´thode des re ´seaux neuronaux, qui se caracte ´rise par une grande souplesse de non-line ´arite ´, ainsi que par sa capacite ´de reconstitution d'une information a `partir d'indices partiels et mal de ´finis tel que c'est le cas des donne ´es fournies par le re ´seau me ´te ´orologique. Pour proce ´der a `la reconstitution des donne ´es climatiques, nous utilisons les variables explicatives, longitude, latitude et altitude, les variables a `expliquer e ´tant la pluviosite ´et les tempe ´ratures. Pour de ´finir la meilleure approche, la calibration du re ´seau a e ´te ´teste ´e sur les parame `tres climatiques pris globalement ou isole ´ment, pour l'ensemble de la zone d'e ´tude et par secteur ge ´ographique. Les re ´sultats de l'interpolation sont exprime ´s a `travers une cartographie des parame `tres climatiques, re ´alise ´e automatiquement par le logiciel MapInfo 8.0. La fiabilite des re ´sultats obtenus par cette me ´thode est appre ´cie ´e a `travers la re ´alisation de cartes des erreurs d'estimation par comparaison a `des donne ´es de re ´fe ´rence.

Chemical Variability and Biological Activities of Essential Oils of Micromeria inodora (Desf.) Benth. from Algeria

“…The differences can be explained by the nature of the soils of harvest localities. Calcareous soil‐humic rich in organic matter characterized areas 1 and 2 however the vegetation in area 2 is more existing in a climate vegetation (holm oak, Aleppo pine) with a dense undergrowth indicated that soil is rich in bases including Ca ++ , Mg ++ and K + . Rich‐mineral soils seem to further the production of essential oils of M .…”

Seroprevalence Assessment and Risk Factor Analysis of Toxoplasma gondii Infection in Goats from Northeastern Algeria

“…The comparison of research is challenging in this context. Our results imply that the prevalence identified in this study may be associated with suitable climatic conditions, because the four study provinces (Mila, Constantine, Guelma, and El Taref) have similar ecological patterns characterized by a wet period during most of the year [ 22 ] that are favorable for T. gondii oocyst formation and survival [ 5 ]. As a result, this region in Algeria has the greatest prevalence rate of the parasite in animals [ 21 ].…”

“…The region has a humid Mediterranean climate, with hot, dry summers and cold, wet winters. The annual rainfall is approximately 550 mm with a relative humidity of 70%, and the annual temperature varies between 8 °C and 24 °C [ 22 ]. Constantine is situated on a plateau at 698 m above sea level; the area has a humid climate with hot, dry summers and cold, moist winters and is characterized by an annual rainfall of 600 mm, an annual temperature range of 10 °C to 25 °C, and 60% annual relative humidity [ 22 ].…”

“…The annual rainfall is approximately 550 mm with a relative humidity of 70%, and the annual temperature varies between 8 °C and 24 °C [ 22 ]. Constantine is situated on a plateau at 698 m above sea level; the area has a humid climate with hot, dry summers and cold, moist winters and is characterized by an annual rainfall of 600 mm, an annual temperature range of 10 °C to 25 °C, and 60% annual relative humidity [ 22 ]. The territory of Guelma province is characterized by a sub-humid climate in the center and the north and a semi-arid climate towards the south.…”

“…El Taref province is located in the far northeast of Algeria, close to the Tunisian border. The climate is generally humid, with an important annual rainfall of 1000 mm, a high annual relative humidity of 77%, and an annual temperature ranging from 4 °C to 23 °C [ 22 ]. Livestock husbandry in these four provinces consists of a mixture of breeding cattle and small ruminants.…”