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The article informs that regular rainfall, violent storms leading to the destruction of crops by hail or flooding as in Cressier NE, major flooding of the sub-Jura lakes, had direct consequences on Ornithological chronicle for inhabitants of French-speaking Switzerland with Spring-summer and nesting 2021. It mentions about meteorological conditions of a year and specific events migratory blockages that influence the success of reproduction that marked presence of Cisticola juncidis.

Algeria, an arid to semi-arid country, is highly vulnerable to climate change. Rainfall is limited in the coastal zone, uncertain or even non-existent towards the South, and is particularly vulnerable to the negative effects of global warming. There is a downward trend in rainfall since 1975 and the rising phase is not yet ready to begin. The purpose of this work is to analyze the interannual variability of the rainfall time series of 17 stations in the Upper and Middle Cheliff watershed over the period 1972/73-2012/13 (42 years). The seven-year moving average method and non parametric statistical tests (Pettitt and Mann-Kendall) have been used to analyze these time series. This analysis shows the existence of a succession of wet (1972/73 to 1979/80) and dry (1979/80 to 2005/06) sequences common to 14 stations. The rupture date detected for the majority of the stations is between the end of the 1970s and the middle of the 1980s. Indeed, 6 stations out of 17 have a regular rainfall pattern, while the remaining 11 stations have a rainfall deficit that fluctuates between 16% and 29%. [ABSTRACT FROM AUTHOR]

Nitrogen (N) is essential for cereal production. The aim of this work is to study from the national statistics the evolution over time of nitrogen fertilizer use in wheat crop in Tunisia and to relate this consumption to wheat yields and to rainfall patterns. The results showed that wheat is the larger user of mineral nitrogen fertilizer in Tunisia with an average of 51300±19500 tons.N.yr-1 and an increase rate of 1600 tons.N.yr-1. Nitrogen is provided as diammonium phosphate (DAP) before seeding and then as ammonium nitrate during the crop cycle. The total amount of mineral nitrogen spread contributes significantly to the wheat grain yield (p<0.01). The spreading of ammonium nitrate is variable in quantity, frequency and date of application, and is highly influenced by annual climatic conditions, essentially the total amount of rainfall. A positive relationship (p<0.01) was observed between partial factor productivity for Nfertilizer and the rainfall during wheat growing cycle. [ABSTRACT FROM AUTHOR]

In the semi-arid Mediterranean climate of the Maghreb region, Algeria, the intensity and high variability of rainfall contribute to soil erosion that feeds the sediment load of the wadis, which, in turn, is a factor in the rapid silting-up of reservoirs. The temporal variability of solid and liquid flows, an important characteristic in Mediterranean regions, is the subject of this research, which focuses on the Wadi Bouhamdane in eastern Algeria. Since December 1987, the wadi flows—recorded by the gauging station (1105 km2) since September 1969—have been regulated by the Hammam Debagh Dam, located immediately upstream of the station (1070 km2). The study involved the treatment of a long time series of suspended sediment concentration and water flow data, together with daily water discharge data recorded at the dam site. A power function describing the relationship between the instantaneous suspended sediment loads and the instantaneous water flow was used to estimate daily suspended sediment discharge of two series (1969–1987 and 1995–2010), recorded, respectively, at the outlet of the basin (gauging station) and at the dam site. The results show a moderate mean annual specific suspended sediment flux (257 t km−2year−1), but high inter-annual variability characterizes the specific suspended sediment (TSS = 0.5 and 1396 t km−2year−1in 1996/97 and 2004/05, respectively), which increases significantly in the season of high streamflow. Thus, floods generate large quantities of sediment that represent a significant proportion of the annual total and monthly specific degradation throughout the basin. The comparative approach shows that the sediment flux estimated by concentration measurements at the wadi gauging station (0.22–0.29 hm3year−1) does not represent the entire volume of silting of the dam (0.98 hm3year−1on average), identified using bathymetry. This second method includes bedload and other inputs of sediment that are very difficult to measure. [ABSTRACT FROM AUTHOR]

Climate variability, non-optimal water resources management and increase of human pressure are three possible factors influencing runoff and water resources in semi-arid Algerian catchments, such as the Tafna catchment (western Algeria). This catchment is subject to a semi-arid climate. In addition to rainfall impact, we examine the influence of other factors, such as geology, topography and human activity, on the runoff variability in the Tafna catchment. For this purpose, to complement the rainfall and discharge series analysis, we considered baseflow and the baseflow index (BFI). The analysis was conducted for five sub-catchments of the Tafna basin, where daily rainfall and discharge series were available for the 1976–2006 period. In the analysis, we distinguished two domains defined from the topography: a high-altitude area and a plain area. According to their geological setting, the hydrological regime is different. High-altitude catchments have a larger baseflow and BFI than catchments in the plain. This may be related to the differences in lithology, as high-altitude catchments have a large area of karstic geological formations. No significant trends or step changes were found in the annual rainfall for the 1976–2006 period. We found a decrease in the mean annual discharge of two high-altitude discharge stations (significant at the 1% and 10% levels, respectively). A decreasing trend was also found for two high-altitude catchments and a plain catchment (significant at both the 1% and 5% level). The BFI decrease is only significant for one high-altitude catchment. This is evidence of a decrease in storage within high-altitude catchments. Runoff change in the Tafna catchment could therefore be related to other factors, such as human impact, rather than to rainfall change. [ABSTRACT FROM AUTHOR]

Abstract: The study area is the N’zi watershed, sub-watershed of the Bandama River (Ivory Coast). The N’zi watershed is located between longitudes 3°49′ and 5°22′ West and latitudes 6°00′ and 9°26′ North and covers an area of 35,500km2. This study aims to identify trends in the rainfall-runoff relationship by using a monthly conceptual model. The methodology has consisted on the one hand in highlighting the existence of interannual climate and hydrological variability by using the method of segmentation of Hubert, and on the other hand, in applying the crossed simulations method by using the GR2M model, over several 7-year sub-periods. The results of the application of the method of segmentation of Hubert have demonstrated the presence of a hydroclimatic variability in the N’zi watershed. The modifications of the climate and physical conditions of the flow resulted in a modification of the hydrological response of the watershed translated by a non-stationarity in the rainfall-runoff relation. [Copyright &y& Elsevier]

Flow gauge data - and even rainfall data - are quasi unavailable for small watersheds as those on which hill ponds are constructed. The objective of this paper is to present a regional statistical approach aiming at estimating the rainfall characteristics related to these small watersheds. The regional approach allows estimating the coefficient of variation of the average annual rainfall, choosing the statistical distribution of the interannual variability as well as estimating the maximal daily rainfall at different return periods; all of these statistics using mainly the average annual rainfall along with geographic characteristics of the hill ponds location and their watersheds. The methodology is applied in an area of 43 000 km2 in the North East of Algeria. The developed statistical relationships are robust and reliable as shown by cross validation checking, which allows using them for preliminary design purposes of hill ponds. [ABSTRACT FROM AUTHOR]

In this experimental work, we studied the mechanical behaviour of a short glass fibre reinforced polyamide frequently used in the automotive industry. In order to investigate the influence of glass fibre content, relative humidity and strain rate, we carried out uniaxial tensile tests on an unfilled polyamide and glass fibre reinforced polyamide with different weight fractions: 10, 20 and 30 wt%. Experimental results showed that the studied composite is a strain rate, moisture and fibre volume fraction dependant mechanical behaviour. The thermography infrared (IR) technique has been used to determine the change of the surface temperature at the surface of materials during tensile tests. The local deformation process can be identified and studied from the infrared thermal images. [ABSTRACT FROM AUTHOR]

This research analyzes the changes in extreme events in the Ouémé River basin and their impact on the socio-economic populations Basin to Ouémé Bonou. The methodology used consists of technical statistical data of the rainfall series 1951-2000. On this series, the maximum depth of precipitation in 24 hours was determined by the theory of large numbers. From the series of maximum depth rainfall indices such as average and the deviation from the mean were determined. Moreover, the vulnerability of human settlements to the maximum rainfall was assessed as a result of field investigations and use of the matrix of Leopold et al, 1971. Analysis of these data shows that the watershed of the river Ouémé had on the series 1951-2000 rainfall variability, marked by a high occurrence of extreme events. This situation leads to increased frequency of floods that cause major damage like ecosystem degradation, loss of crops and the decimation of livestock products box (poultry, goats, pigs). This weakens the economic fabric of the basin and therefore creates a context of food insecurity. In situations of extreme rainfall, people adopt proactive strategies and reactive, like early harvests, temporary migration of the crops to non-flooded plateaus and summary accommodations for the crops. [ABSTRACT FROM AUTHOR]

The present research studies the frequency and magnitude of extreme rainfall years with high rainfall variability that characterizes the study area since the 1970s. The data concern the high rainfall (daily, monthly, seasonal and annual) of four (4) stations from ASCNA-Cotonou and covering the period 1941-2000. The use of descriptive statistics (mean, quartile, etc.) and the frequency analysis, were used to process data collected. The results indicate that extreme rainfall years (surplus and deficits) are alternated with no apparent periodicity. In addition, the extreme rainfall was more frequent during the 1971- 2000 series of thirty especially during the rainy season in comparison to the 1941-2000 series. [ABSTRACT FROM AUTHOR]

Abstract: This study compares different methods used to estimate extreme rainfall quantiles in an area with a Mediterranean climate. The first method (M1) is based on a stochastic model of hourly rainfall, which provides hourly rainfall series. The cumulative distribution functions (cdf) of extreme rainfall over various durations are deduced from the simulations. The second method (M2) is a regional approach based on the construction of a regional cdf of maximum annual daily rainfall. In the third method (M3), an exponential cdf is fitted to observed rainfall at a given gauging station. The three methods are compared with their parameters calibrated locally using the information observed at a given gauge, and using regionalised parameters. Comparison of M1 and M2 showed good agreement, with only relatively small differences between the rarest quantiles, less than 20% for the 1000-year return period. These differences can be explained by the regionalisation of the parameters. With both methods, a heavy tail of the daily maxima annual rainfall cdf deviates from the exponential cdf. Moreover, the regionalisation of M1 and M2 is more robust than with M3, which is much more influenced by sampling uncertainties. [Copyright &y& Elsevier]

Abstract: A sample of 92 daily precipitation series was selected in the French Mediterranean region over the period 1945–2004, to study the stationarity of extreme events. The criticized series are used to define seven homogeneous climatic zones. For each one, regional series of daily peaks over threshold records are extracted from the raw data. A new adaptation of the Peak Over Threshold (POT) methodology is proposed for the search of nonstationarity. For that purpose, we suppose that the scale and occurrence parameters of the model are not constant, and linearly depend on time. This approach allows us to study the stationarity of both the occurrence and the intensity of extreme events, at the regional scale. The only statistically significant results concern an increase of the occurrence and intensity of extreme daily rains in the North of the Lozère ‘department’ (France) and the southern part of the Auvergne, as well as an increase of the intensity of extreme rainfalls in Languedoc-Roussillon. [Copyright &y& Elsevier]

In 1996, following torrential rains, a layer of clean sediments was deposited in the upstream part of the Saguenay Fjord. This layer acted as a damping layer between contaminated sediments and the Saguenay waters. It is important to collect information on the water–sediments interface, which is the site of exchanges between the sediments and the waters. Three oceanographical campaigns have allowed us to obtain the data on the velocity of the benthic currents and the properties of the surface sediments. The velocities have been obtained by means of two current meters located at 3 m from the bottom and by means of registered videos. These two types of measurements have given comparable results. The main information collected on the sediments were their water content, grain size, density, and the presence of benthic fauna. The distribution of the main biogenic structure, the tubes of polychetes, is related to the depth of the site and to the grain size of the sediments. For the surface layer, large variations of the water content were obtained during the field measurements. Tests with an axial tomodensitometer have revealed a large variation in the density of the sediments in the top 2.5 cm. [ABSTRACT FROM AUTHOR]

Abstract: This study deals with the daily precipitation occurrence during the rainy season in different locations in Congo-Brazzaville. The Markov-chain probability model has been used for defining probable dry and wet rainy sequences at each station, and transition probabilities between daily precipitations of two successive days. The main results are: in Congo, the dependence on the preceding day of the daily precipitations occurrence; the confirmation of two main climatic region (equatorial climate to the north and tropical wet to the south); the lack of coherence in the distribution of precipitations. To cite this article: G. Samba, M. Mpounza, C. R. Geoscience 337 (2005). [Copyright &y& Elsevier]

Abstract: One of the main stakes in hydrology is the characterization and the quantification of the human influence on the hydrological regime generally speaking, and on flood and inundations in particular. The improvement of the available knowledge in this matter is slow, due to a huge complexity. The social demand toward the scientists is however very high and insistent, since our modern societies have an aversion to be at risk, and do not accept any more the relative powerlessness of the structural developments against natural disasters. Since the main scientific question is very related to temporal and spatial scaling, a ‘management scale’ has to be defined, as well as a topology of the developments in the hydrographical network, together with a sufficient quantity of relevant hydrological measurements. Practically, the hydrological basin is preferred as appropriate object, both to characterize the social demand and to propose sustainable development strategies, but also to identify the variations on the hydrological processes governing river-flow routings and inundations due to these structural developments. The main difficulty comes from the huge diversity of these effects related to the spatial distribution of various developments and equipments, which makes any quantification complex. Moreover, the concerned physical processes are rather studied at small scales, and the related physically based models have troubles to balance, in a useful way, the global consistency of those results and the lack almost systematic of data to be fed in those parameters. More than that, these models give a poor evaluation of their internal uncertainty, are complicated to be operated, and still need to be calibrated. In this respect, and under the general constraint of climatic variability, the effects of hydraulic structures will be studied, based on operational examples, then the effects of the vegetal land cover and its variability on extreme discharges, and finally the consequences of the development of rural areas and of land-use management on floods and inundations. Lastly, some alternative land-development strategies will be proposed, which minimize their consequences on water regime generally speaking, and on floods and inundations in particular. To cite this article: P. Givone, C. R. Geoscience 337 (2005). [Copyright &y& Elsevier]

Many earlier studies have shown the very large spatial variability of rainfall in the Sahel at all time steps, from the event to the season. Often, the meteorological network in these countries is sparse, with one to five rain gauges per 10 000 km2. It is thus difficult to calculate accurate estimates of the mean rainfall over such a large area. To improve the knowledge of Sahelian systems and the spatial distribution of rainfall, a dense network was set up in an area of 16 000 km2 in southwestern Niger between 1991 and 1996. The aim was to calculate accurate rainfall spatial means over an area of 12 000 km2 at different time steps (from the season to the ten-day period). With the spatialisation method used (kriging), it was possible to calculate curves of estimation errors of mean rainfall versus the rain-gauge network density. Operational abacuses of the standard estimation error as a function of the spatial mean of rainfall and the network density are proposed. [Copyright &y& Elsevier]

In order to quantify the quality of the rainfall/discharge relationship across time-scales, we propose the use of both orthogonal wavelet multiresolution analysis and cross-correlation analysis. By using the two techniques together, it is possible to show, scale-by-scale, the influence of the input to the system (rainfall) on the response (discharge) of the aquifer and also to relate these results to the internal structure of the aquifer and to the degree of organisation of the karst drainage. An application of this method to three Pyrenean karsts is also shown. To cite this article: D. Labat et al., C. R. Geoscience 334 (2002) 551–556. [Copyright &y& Elsevier]

The isotopic content of rainfall was measured in Niamey (Niger) over a period of eight years (1992–1999). Seasonal distribution of rainy events depends on the monsoon movement over the region. At the beginning and at the end of the rainy season, low rainfall, high temperatures and low relative humidity favour isotopic enrichment. In the middle of the rainy season, heavy rainfall, low temperatures and relative humidity close to saturation lead to isotopically depleted contents because of the mass effect; moreover, in the case of low rainfall, marked vertical convective development favours high altitude condensation. How far the Intertropical Front moves north, determines the quality of the rainy season and influences the isotopic contents. Thus the isotopic contents of rainfall are good climatic indicators. To cite this article: J.-D. Taupin et al., C. R. Geoscience 334 (2002) 43–50 [Copyright &y& Elsevier]

This article discusses the epidemiology of Marssonina brunnea , a leaf parasite of cultivated poplars. The relationship between outbreaks of the disease and ripening of ascospores, and the release of conidia in spring was studied in the year 1972 and 1973 in the north and the east of France. Climatic conditions play an important role in the occurrence of primary infection. During the growing season, spores are released after each rainfall, but the number of spores trapped varies considerably. It is very high after heavy rainfall.