scholarly journals Relationships between the distribution of Galba truncatula (Gastropoda: Lymnaeidae) climatic conditions and the altitude of municipalities in Haute Vienne (France)

2018 ◽  
Vol 54 ◽  
pp. 19
Author(s):  
Gilles Dreyfuss ◽  
Philippe Vignoles ◽  
Daniel Rondelaud
Keyword(s):  
Retrospective Study ◽  
Habitat Type ◽  
Acid Soils ◽  
Climatic Conditions ◽  
Annual Rainfall ◽  
Mean Annual Temperature ◽  
Galba Truncatula ◽  
Mean Annual Rainfall ◽  
The Mean

A retrospective study on 7407 populations of Galba truncatula found in the department of Haute Vienne for 37 years (1970–2006) was carried out to determine if altitude and climate on acid soils had an effect on the distribution of populations and the characteristics of their habitats. Out of a total of 13 478 water points surveyed in 179 municipalities, the overall frequency of snail populations was 54.9% but varied with the habitat type and the municipality on which these water points are located. The frequency of snail populations significantly decreased when the mean altitude of municipalities or their mean annual rainfall increased. Conversely, this frequency significantly increased with increasing mean annual temperature. The characteristics of habitats were analysed for 6281 populations in relation to the mean altitude of municipalities. The area of G. truncatula habitats and the density of overwintering snails per m2 of habitat significantly decreased with increasing altitude. On the acid soils of Haute Vienne, the distribution of G. truncatula populations is closely related to the altitude and climatic conditions of municipalities.

scholarly journals Determination of zones at risk for fasciolosis in the department of Haute-Vienne, central France: a retrospective study on natural infections detected in 108,481 Galba truncatula for 37 years

Parasite ◽  
2017 ◽  
Vol 24 ◽  
pp. 55 ◽  
Author(s):  
Philippe Vignoles ◽  
Daniel Rondelaud ◽  
Gilles Dreyfuss
Keyword(s):  
At Risk ◽  
Retrospective Study ◽  
Fasciola Hepatica ◽  
Natural Infection ◽  
Acid Soils ◽  
Annual Rainfall ◽  
Mean Annual Temperature ◽  
Climatic Data ◽  
Galba Truncatula ◽  
Mean Annual Rainfall

A retrospective study on the natural infection of Galba truncatula by Fasciola hepatica was carried out in the French department of Haute-Vienne to determine whether there are areas at risk for fasciolosis. Adult snails included in this analysis came from samples collected from pastures on 259 farms and from 121 wild watercress beds between 1970 and 2006. Fasciola hepatica infection rates were examined in relation to altitude and climatic data (mean annual rainfall, mean annual temperature) of each municipality. In a total of 108,481 snails collected in 151 municipalities, the overall prevalence of infection was 3.8% but varied according to the municipalities from which samples were taken (from 1% to 7.4%). The prevalence of F. hepatica infection in snails significantly decreased when the mean altitude of municipalities or their mean annual rainfall increased. However, this prevalence significantly increased with increasing mean annual temperatures. Studying the prevalence of infection in these snails makes it possible to delineate zones at risk for fasciolosis on the acid soils of Haute-Vienne. The risk of infection for livestock would be greater in areas of Haute-Vienne below 400 m above sea level and would gradually decrease when the altitude of the land increases.

scholarly journals Recent Rainfall Variability Over a Dryland Ecosystem of North Western India

2021 ◽  
Author(s):  
DIVYA SAINI ◽  
PANKAJ BHARDWAJ ◽  
Omvir Singh
Keyword(s):  
Rainfall Variability ◽  
Climatic Conditions ◽  
Annual Rainfall ◽  
Western India ◽  
Positive Trend ◽  
North West ◽  
North East ◽  
Mean Annual Rainfall ◽  
The Mean ◽  
North Western

Abstract In this study, an attempt has been made to examine the recent rainfall variability by means of daily rainfall data of 33 well spread stations over dryland ecosystem of Rajasthan in north western India during 1961-2017. For trend analysis, Mann-Kendall, Sen’s slope estimator and simple linear regression test have been used (at 95% confidence level). The results have shown a high interannual variability in rainfall occurrence varying from 277 mm (in year 2002) to 839 mm (in year 1975) with mean of 583 mm over this dryland ecosystem. Most of the rainfall deficit years have occurred with El-Nino years. The mean annual rainfall has shown a marginal non-significant upward trend over the ecosystem. The station-wise mean annual rainfall has revealed a significant rising trend over Barmer, Churu, Ganganagar, Jaisalmer and Pratapgarh stations. Interestingly, three year running average has shown a cyclic pattern of rainfall over dryland ecosystem under the changing climatic conditions. The spatial pattern has exhibited that the mean annual rainfall decreases from east and south east (more than 850 mm) to west and north west (less than 400 mm), which is mainly associated with the presence of Aravalli Mountains spreading north east to south west in central Rajasthan. Remarkably, majority of stations positioned in western parts of dryland ecosystem have shown increasing rainfall trends, whereas some stations located in eastern parts have recorded a non-significant declining trend. The magnitude of significant rising trend has varied from 5.34 mm/year (Pratapgarh station) to 2.17 mm/year (Jaisalmer station). Also, the frequency of heavy rainfall events has shown a positive trend with significant increasing trends over Bharatpur, Jaisalmer and Pratapgarh stations, whereas Bundi station has shown significant decreasing trend.

scholarly journals Secular variation in rainfall and intensity–frequency–duration curves in Eastern Australia

2013 ◽  
Vol 4 (3) ◽  
pp. 244-251 ◽  
Author(s):  
Yi-Ru Chen ◽  
Bofu Yu ◽  
Graham Jenkins
Keyword(s):  
Global Warming ◽  
Secular Variation ◽  
Rainfall Intensity ◽  
Storm Runoff ◽  
Annual Rainfall ◽  
Mean Annual Temperature ◽  
Mean Annual Rainfall ◽  
Eastern Australia ◽  
The Mean

Rainfall intensity–frequency–duration curves are used extensively for storm runoff estimation. It is generally assumed that rainfall intensity would increase with global warming irrespective of the underlying changes to rainfall. This study analyzed rainfall and temperature from six sites in Eastern Australia. Two non-overlapping 30-year periods with the greatest difference in the mean annual rainfall were selected at each of the six sites to test for significant changes in the mean annual temperature and rainfall. Changes in the mean rainfall intensity for different frequencies of occurrence and storm durations for each site were also analyzed. Temperature has increased at all sites, and significantly at five out of the six sites. The mean annual rainfall has significantly changed between the two non-overlapping periods at the sites with the exception of Cairns (latitude – 16.87° south). The changes in rainfall intensity for longer durations (≥1 h) positively correlate with changes in the mean annual rainfall. There is evidence to suggest that the 6 min rainfall intensity would increase irrespective of the changes in the mean annual rainfall.

Effects of geographical and climatic factors on cystic echinococcosis in south-western Iran

2020 ◽  
Vol 94 ◽  
Author(s):  
A. Jamshidi ◽  
A. Haniloo ◽  
A. Fazaeli ◽  
M.A. Ghatee
Keyword(s):  
Land Cover ◽  
Cystic Echinococcosis ◽  
Geographical Information Systems ◽  
Climatic Factors ◽  
Weather Conditions ◽  
Climatic Conditions ◽  
Geographical Information ◽  
Annual Rainfall ◽  
Mean Annual Temperature ◽  
Western Iran

Abstract Cystic echinococcosis (CE) is caused by the larval form of Echinococcus granulosus that can cause serious health and economic problems in the endemic foci. CE is globally distributed in various climatic conditions from circumpolar to tropical latitudes. Iran is an important endemic area with a spectrum of weather conditions. The aim of this study was to determine the effects of geo-climatic factors on the distribution of livestock CE in south-western Iran (SWI) in 2016 to 2018. Data of livestock CE were retrieved from veterinary organizations of four provinces of SWI. The geo-climatic factors, including mean annual temperature (MAT), minimum MAT (MinMAT), maximum MAT (MaxMAT), mean annual rainfall (MAR), elevation, mean annual evaporation (MAE), sunny hours, wind speed, mean annual humidity (MAH), slope, frost days and land cover, were analysed using geographical information systems (GIS) approaches. The statistical analysis showed that MAR, frost days, elevation, slope and semi-condensed forest land cover were positively and MAE, MAT, MaxMAT, MinMAT and salt and salinity land cover were negatively correlated with CE occurrence. MAE was shown to be a predictive factor in the stepwise linear logistic regression model. In short, the current GIS-based study found that areas with lower evaporation were the main CE risk zones, though those with lower temperature and higher rainfall, altitude and slope, especially where covered with or in close proximity of semi-condensed forest, should be prioritized for consideration by health professionals and veterinarians for conducting control programmes in SWI.

A Practical Method for Estimating Rainfall Rate Frequencies Directly from Climatic Data

1958 ◽  
Vol 39 (9) ◽  
pp. 469-472 ◽  
Author(s):  
S. L. Russak ◽  
J. W. Easley
Keyword(s):  
Signal Transmission ◽  
General Relation ◽  
Practical Method ◽  
Rainfall Rate ◽  
Annual Rainfall ◽  
Climatic Data ◽  
Mean Annual Rainfall ◽  
Hourly Rainfall ◽  
The Mean ◽  
Complete Frequency

In evaluating the environmental limitations on microwave signal transmission, it was necessary to determine the occurrence of rainfall rates for a number of regions in different parts of the world. Clock-hourly precipitation data were used where available. Where these data were not available, a known empirical technique was employed which correlates clock-hourly rainfall at individual rates to a climatological index. This index uses parameters which are almost universally obtainable—namely, mean annual rainfall and number of days with measurable rain. In the course of this work, the authors found a more general relation between clock-hourly rainfall rate frequencies and the climatological index. Using this relation, rainfall frequencies at any rate are obtained directly from a linear equation and two nomograms. It is also possible to synthesize the complete frequency distribution of rainfall rates and obtain, as a check, the mean annual rainfall. Examples, supplemented by illustrations, are given in the development of this technique and its utilization.

THE MEAN ANNUAL RAINFALL OF MOUNT KENYA

Weather ◽  
1966 ◽  
Vol 21 (2) ◽  
pp. 48-49 ◽  
Author(s):  
B. W. Thompson
Keyword(s):  
Annual Rainfall ◽  
Mean Annual Rainfall ◽  
The Mean

scholarly journals Recent Trends in the Daily Rainfall Regime in Southern West Africa

Atmosphere ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 741 ◽  
Author(s):  
Francis Nkrumah ◽  
Théo Vischel ◽  
Geremy Panthou ◽  
Nana Ama Browne Klutse ◽  
David C. Adukpo ◽  
...  
Keyword(s):  
West Africa ◽  
Rainy Season ◽  
Daily Rainfall ◽  
Annual Rainfall ◽  
Large Set ◽  
Mean Intensity ◽  
Mean Annual Rainfall ◽  
Recent Trends ◽  
The Mean ◽  
Climate Events

Extreme climate events, either being linked to dry spells or extreme precipitation, are of major concern in Africa, a region in which the economy and population are highly vulnerable to climate hazards. However, recent trends in climate events are not often documented in this poorly surveyed continent. This study makes use of a large set of daily rain gauge data covering Southern West Africa (extending from 10° W to 10° E and from 4° N to 12° N) from 1950 to 2014. The evolution of the number and the intensity of daily rainfall events, especially the most extremes, were analyzed at the annual and seasonal scales. During the first rainy season (April–July), mean annual rainfall is observed to have a minor trend due to less frequent but more intense rainfall mainly along the coast of Southern West Africa (SWA) over the last two decades. The north–south seasonal changes exhibit an increase in mean annual rainfall over the last decade during the second rainy season (September–November) linked by both an increase in the frequency of occurrence of rainy days as well as an increase in the mean intensity and extreme events over the last decade. The study also provides evidence of a disparity that exists between the west and east of SWA, with the east recording a stronger increase in the mean intensity of wet days and extreme rainfall during the second rainy season (September–November).

PHYSICAL AND BIOTIC FACTORS AFFECTING EUXOA SPECIES ABUNDANCE IN WESTERN NORTH AMERICA: A REGRESSION ANALYSIS

1971 ◽  
Vol 103 (9) ◽  
pp. 1217-1235 ◽  
Author(s):  
D. F. Hardwick ◽  
L. P. Lefkovitch
Keyword(s):  
Regression Analysis ◽  
North America ◽  
Sample Size ◽  
Annual Rainfall ◽  
Mean Annual Temperature ◽  
Residual Variance ◽  
Biotic Factors ◽  
Western North America ◽  
Factors Affecting ◽  
Mean Annual Rainfall

AbstractIn an attempt to evaluate the importance of physical and biotic factors affecting the distribution of species of the cutworm genus Euxoa, a multivariate regression analysis, as based on a light-trapping survey in western North America, has been conducted. The possible contributory factors have been grouped into four major categories relating to geography, habitat, period of flight, and sample size. Sample size is a composite value reflecting both suitability of habitat and suitability of weather conditions at the time the sample was taken. Geographic factors considered were latitude, altitude, and longitude; habitat factors were mean annual temperature, mean July temperature, mean January temperature, mean annual rainfall and plantform; factors relating to period of flight were calendar date, mean temperature on date of sample, photoperiod, and the phenological date. Except for photoperiod, the variables listed were considered in a quadratic as well as a natural function in the regression analysis. With the number of species of Euxoa as the dependent variable and the factors listed above as the independent variables a total reduction of 76.0% in the residual variance was obtained. When only four variables, sample size, mean annual temperature, mean annual rainfall, and phenological date were employed in a similar regression analysis, however, a reduction of 68.7% in the residual variance was obtained. On the basis of present evidence, it appears that temperature and rainfall are primary factors governing the abundance of species of Euxoa in a given habitat.

scholarly journals The Geographical Distribution of the Mean Annual Rainfall of Wales and Monmouthshire: Discussion

1909 ◽  
Vol 33 (3) ◽  
pp. 305
Author(s):  
Dr. Strahan ◽  
Dr. Mill ◽  
Baldwin Latham ◽  
George Bransby Williams
Keyword(s):  
Geographical Distribution ◽  
Annual Rainfall ◽  
Mean Annual Rainfall ◽  
The Mean
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