Les saisons, les années et les périodes sèches et humides au Portugal durant la dernière période séculaire
Détermination des périodes sèches et humides au XXe siècle communes à quatre stations météorologiques portugaises dont les séries ont été considérées homogènes. Relation avec des indices zonaux et méridiens de la circulation. - (DBF)
Etude de la fréquence, de la sévérité et de la persistance des épisodes climatiques secs et humides dans la période 1931-75. Les anomalies sèches sont plus fréquentes dans le New Mexico et le Texas ouest alors que les anomalies humides sont plus
fréquentes dans l'Illinois et l'Iowa. Les périodeshumides sont plus nombreuses mais plus courtes que les périodes sèches typiquement longues.
Vertikalne zmeny relativnej vlhkosti vzduchu v Tatrach a vo Vychodnych Alpach. (Vertical changes of relative air humidity in the Tatra Mts and in the Eastern Alps)
As the basis the term measurements of relative air humidity in the Tatra Mts and in the Eastern Alps for a 1951-1970 period the characteristics of air humidity are analysed. The results gained enable laying out three characteristic zones. (MS).
Predicting landslides from rainfall in a humid, sub-tropical region
Topography, geology and a humid, sub-tropical climate make the Durban region on the east coast of South Africa particularly prone to sliding mass movements. Records of individual landslides and landslide events between 1970 and 1990 were compared
with 22 rainfall variables calculated for the same period. Correlation coefficients demonstrated statistically significant relationships between annual and wet season landslide frequencies and maximum 3-day and maximum monthly wet season rainfall, whereas
precipitation for shorter and longer periods was unrelated.
Organisation et dynamique de la végétation d'une zone humide, aménagement et utilisation agricole pendant la période 1961-1989
Action anthropique ; Agriculture ; Bretagne ; Dynamique des populations ; France ; Géographie de l'Europe ; Ille-et-Vilaine ; Milieu humide ; Phytosociologie ; Utilisation du sol ; Végétation
Geomorphology and sedimentology of the Toro Amarillo alluvial fan in humid tropical environment, Costa Rica
Caractéristiques géomorphologiques et sédimentologiques du cône alluvial Toro Amarillo situé dans un milieu tropical humide. De courtes périodes actives sont séparées par de longues périodes inactives caractérisées par l'érosion météorique des
Drainage density and network evolution in the humid tropics: evidence from the Seychelles and the Windward Islands
fonction des caractéristiques des précipitations et des propriétés hydrauliques du sol. 2) Etude de l'évolution du réseau de drainage dans un milieu tropical humide en comparant les réseaux de drainage à différentes périodes (Historique jusqu'à Pléistocène).
A partir des données des Iles au Vent et des Iles Seychelles, étude des caractéristiques des réseaux hydrographiques des pays tropicaux humides. 1) Etude des variations de la densité de drainage entre et dans les régions tropicales humides en
Greatest lake period and its palaeo-environment on the Tibetan Plateau
by the last highest lake shorelines. They are several even ten times larger than that at present. The occurence of maximum areas of lakes marked the very humidperiod on the Plateau and was also related to the stronger summer monsoon during that period.
The greatest lake period means that the lakes are in the stage of their maximum areas. As the paleolake shorelines are widely distributed in the lake basins on the Tibetan Plateau, the lake areas during the greatest lake period may be inferred
Les AA. prennent à contrepied l'opinion généralement admise jusqu'ici de l'existence de périodeshumides au Sahara nord-occidental jusque vers 20 000 ans BP, établie sur la foi de datations au C 14 sur des dépôts carbonatés. Selon eux, ces mesures
Hydrologie ; Islande ; Marais ; Milieu humide ; Palse ; Pergélisol ; Périglaciaire ; Végétation ; Zone froide
Bog ; Cold area ; Humid environment ; Hydrology ; Iceland ; Palsa ; Periglacial features ; Permafrost ; Vegetation
The effects of the changed hydrological conditions on 5 palsas were monitored over a period of 5 years. All the palsas increased in height. A core through one palsa showed that while it was formed by segregation ice, the observed height increases
Soil pipes and their role in runoff generation and chemical denudation in a humid tropical catchment in Dominica
Numerous soil pipes are reported from a small catchment in an area of kandoid (kaolin-rich) soils and 2375 mm annual rainfall in the humid tropical volcanic island of Dominica West Indies, contributing at least 14-16 % of streamflow. The principal
flow perennially and showed little response to daily rainfalls of up to 43 mm during the monitoring period.
The timing of alluvial sedimentation and floodplain formation in the lowland humid tropics of Ghana, Sierra Leone and western Kalimantan (Indonesian Borneo)
Temporal patterns in floodplain genesis and alluvial sedimentation in lowlands tropical rain forest zones of Ghana, Sierra Leone and western Kalimantan (Indonesian Borneo) based upon 14C age determinations are described. The AA. propose that periods
of more frequent episodes of accelerated floodplain erosion and reconstitution, channel morpho-sedimentary activity and alluvial accumulation (1) are responses to interstadial and interglacial periods of higher precipitation following intervening periods
of cooler and drier conditions; and (2) may be synchronous during the last 60 ka throughout the African and Asian inner humid lowland tropics.
Période 1850-1980. Variabilité interannuelle forte et permanente, surtout depuis 1930. Oscillations pluviométriques de période décennale, s'intégrant à de grandes phases : humide (jusqu'en 1885), puis sèche à dominante chaude (1886-1950), enfin
increased with decreasing soil moisture following each of the 12 precipitation events. Using a two-way indicator species analysis (TWINSPAN), the soil moisture measurement periods following each event were classified into 3 discrete groups : humidperiods
, moderate periods, and dry periods. For the humidperiods, the total variance of soil moisture that could be explained by redundancy analysis was more consistent than those of the moderate and dry periods. For the humidperiods on the first axis, soil
thickness was the main significant factor, and the topographic wetness index, slope position and aspect were also significant environmental factors. For the moderate and dry periods, however, the effect of aspect on soil moisture decreased, whereas
atmospheric humidity over the North Atlantic from satellite based pictures in the visible spectrum)
3477 vertical humidity distributions measured at 8 ships on the North Atlantic within a period of 2 years were used, together with satellite-based pictures on the visible spectral region, to find out relations for the determination of data
of atmospheric humidity from satellite-based imagery. (HL).
A model is tested basing on radiocarbon dated field evidence from various river systems. Conclusions on palaeoclimatic periodshumid as today and more humid than at present within the Namib as well as more arid than at present in the hinterland
are deduced from geomorphic findings. The arranged relief types themselves came into existence only as a result of climatic changes. Only locally effective palaeoclimatic events can be separated readily from regionally effective ones. More humid than
at present of the last-mentioned periods happened > 34 ka BP, > 16 ka BP, and 5-1 ka BP within the Namib itself.