16, 2007, M. El Faiz and T. Ruf, “An introduction to the khettara in morocco: two contrasting cases,” in, Institut de Recherche pour le Développement (IRD), “Les réseaux d’eau anciens ressuscitent en Méditerranée,”, M. Mahdane, S. Lanau, Th. The 2009-2010 rainfalls are also considered as exceptional and historic because they allowed for the filling of dams at their maximum capacity (the filling rate of the Al Wahda Dam, the largest of the kingdom, located in the Ouergha Wadi, was 98.5%). The processing of the trend of extreme years from 1970 to 2013 (the percentage of stations which recorded a rainy and very rainy year, dry and very dry year or a normal one) for the three countries confirms previous results. A period qualified as wet is visible on the matrix during 1970–1979. A comparative study with the SPI (Standard Precipitation Index) method for detecting climate drought was conducted in 2015 [41]. This procedure allows for the visualisation of the climate parameter evolution in terms of two dimensions (time and space). Southern African Monthly Rainfall Variability: An Analysis Based on Generalized Linear Models. It reveals the importance of positive differences which indicate an increase of the former category in 83% of the stations. We are committed to sharing findings related to COVID-19 as quickly as possible. (ii)In Algeria, the Constantine, Annaba, and Skikda stations located in the east of the country record a rising trend of 10% for the first station and stabilisation of values for the last two. A little more than 60% of rainfall accumulations recorded at various stations are considered as dry or very dry. MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. The rise of lowest temperatures () is however more evident in this part of North Africa [24–26]. It is marked by a drying trend because 55.60% of the years are considered to be dry and very dry, while rainy and very rainy years totalize no more than 26.58%. Analysis of Rainfall Variability: Analysis Variation of rain-fall is important for planning and management of water resource intervention. The stage covering the 1998–2001 period is marked by the return of drastic conditions. This method was used for the first time in 2013 [24]. At the same time, the regional index is negative for almost 68% of this period as compared to 31.25% for positive values. At the same time, the percentage of rainy and very rainy years at all stations reaches 52.38%. The missing data were supplemented with information gathered from the NCDC “National Climatic Data Center” website (http://www.ncdc.noaa.gov/). In Tunisia, southern stations (Sfax and Tozeur) do not follow this trend and are characterised by a rise in the percentage of dry and very dry years of +20% and +10%, respectively. Precipitation data recorded in 1970–2013 in Tunisia (Figure 2) are characterised by a significant variability previously emphasized during the study of Morocco and Algeria series. 6: 1754. MGCTI, classification of annual precipitation according to quintiles Q1, Q2, Q3, Q4, and Q5 (measurement period from 1970 to 2013). It consists in assigning a number ranging from 1 (very dry year) to 5 (very wet year) according to the already determined features assigned to each year. In Algeria, the Constantine, Annaba, and Skikda stations located in the east of the country record a rising trend of 10% for the first station and stabilisation of values for the last two. While El Niño Southern Oscillation (ENSO) affects climate variability in the world, the North Atlantic Oscillation (NAO) is the climate model dominant in the North Atlantic region. The last period of this precipitation series (2003–2013), in which 82% of the years have a positive regional index, is described as rainy. See further details. Recent analysis of the rainfall base for the eastern transect (Malou R. 2002; Malou R. [...] 2004) has allowed establishment [...] of future bases for rainfall variability in the east of the [...] country (Kolda and Bakel weather [...] stations) where models predict greatest change. The Mediterranean climate is subtropical (Csa and Csb, according to Koppen classification); however, cyclone activity presents large seasonal and spatial variability, with large differences from western to eastern Mediterranean and between cold and warm seasons [14]. (2018). Ministry of Energy, Mines, Water and Environment, Ministère de l'Energie, des Mines, de l'Eau et de l'Approvisionnement, 2008-2009, 2009-2010, 2010-2011, 2011-2012, 201-2013. The “RI” is calculated as follows: where is year value, is the series average, and is standard deviation. Analysis of rainfall variability. Variability of rainfall can be used to characterize the climate of a region. Climate change is today acknowledged by a large part of the scientific community. West Africa; climate change; rainfall variability, Help us to further improve by taking part in this short 5 minute survey, Improving Inter-Laboratory Reproducibility in Measurement of Biochemical Methane Potential (BMP), Riparian Ground Beetles (Coleoptera) on the Banks of Running and Standing Waters, Indirect Impact Assessment of Pluvial Flooding in Urban Areas Using a Graph-Based Approach: The Mexico City Case Study, Long-Term Consequences of Water Pumping on the Ecosystem Functioning of Lake Sekšu, Latvia, Water Quality of Freshwater Ecosystems in a Temperate Climate. The last period (2003–2013) is considered wet. Complete analysis of rainfall events requires a study of both its spatial and temporal extents. Review articles are excluded from this waiver policy. Philandras et al. Results show a rain resumption observed in the recent years over the Sahelian region and a convincing link with the surface temperature of the Atlantic Ocean. Four years stand out through negative indices which exceed −1: 1988 (−1.36), 1989 (−1.03), 1993 (−1.46), 2000 (−1.68), and 2001 (−1.46). The Third Stage. Please let us know what you think of our products and services. For all Moroccan stations studied, the proportion of dry and very dry years reaches almost 56%, while rainy and very rainy years account for a little more than a quarter, with 24%. At the same time, rainy and very rainy years show a rising trend confirmed starting with this last date (Figure 5(b)). It is shown that the convective scale variability is strongly influencing the spatial pattern of rainfields at larger time and spatial scales. Hydrological investigation over a large area requires assimilation of information from many sites each with a unique geographic location (Shahid et al., 2000, Shahid and Nath, 2002). A second stage starts in 1987 and finishes in 2002. In Tunisia, recent studies [31] show that annual precipitation trend is on the rise for 19 regions surveyed during 1977–2011. rainfall variability from two other new reanalyses, the ECMWF Re-Analysis Interim (ERAI), and the Modern Era Retrospective-analysis for Research and Applications (MERRA), is also assessed. 63, No. Check the following websites: WMO, World Meteorological Organisation: http://www.wmo.int/pages/index_en.html ONM, Office National de la Météorologie (Algeria): http://www.meteo.dz/ Direction de la Météorologie Nationale (Morocco): http://www.marocmeteo.ma/ IMN, Institut de la Météorologie Nationale (Tunisia): http://www.meteo.tn/default.html NCDC, National Climatic Data Center: http://www.ncdc.noaa.gov/. The years belonging to the dry and very dry class totalize almost 55% for all stations. Federal University of Technology, Nigeria. The results show extreme variability of this parameter and the severe past drought (more intense for Morocco, in which the drastic conditions from the seventies are observed). 15-16, pp. In 1980, a new drier climatic phase began and lasted until 2001. The highest values are noted at the beginning of the period (+1.57 for 1970 and +1.09 for 1973). RAINFALL IN ROMANIAN PLAIN . The long-term rainfall variability analysis shows that the dry and wet conditions in Peninsular Malaysia are not primarily governed by 15 the ENSO events. The evolution of precipitation accumulations of extreme years (1982–2011). those of the individual authors and contributors and not of the publisher and the editor(s). This variability has assumed a more pronounced dimension as a result of climate change. This return of rainfall over central Maghreb, should it be confirmed, could mean the end of several decades of recurrent droughts and announce a durable return to “the normal.” This assumption is supported by emphasizing the impact of different world climate oscillations (North Atlantic Oscillation; El Niño Southern Oscillation) for all the continents and particularly for the African continent [27, 48]. A number of techniques have been developed for the variability and trend analysis of the rainfall time series. Analysis of the rainfall variability and change in the Republic of Benin (West Africa) Hydrological Sciences Journal: Vol. The Bertin matrix is a manual and visual method of classification of information based on data. The return of drought conditions is noted in 2007, in 2008 (index above −0.5), and in 2012 (index equal to −1.25). Rainy and very rainy years are evaluated for this phase at almost 48%, while dry and very dry years totalize 31.31%. Contribution of seasonal rainfall to the total annual rainfall in percent (CT) for each station is also computed. Analysis of Historic Rainfall … As the area experiences a bimodal rainfall regime, the CAD for each data set is further grouped into the major season, between March and July, and minor season, between Septembe… The percentages calculated at all stations for wet and very wet classes show that almost 42% of years belong to this precipitation category. To conclude, we may say that the climate change observed during the last years is characterised by a rainfall return but with a far greater intensity. Alpert et al. To complete the preliminary analysis, an analysis of variance (ANOVA) was used to indicate the predictability of the daily rainfall sequence. Thus, 2013 is one of the warmest years recorded in Tunisia since 1950 [23]. 2097-2123. Successive stages with the same trends exceed no more than three years (1987–1989 and 2000–2003 for negative indices and 1995–1997 for positive indices). Rainfall variability on the other hand is the degree to which rainfall amounts vary across an area or through time. The regional index shows that almost 63% of years record a negative value. Do these facts announce a new climate phase which marks a break from past drastic conditions? During summer, rainfall is scarce. In Morocco, only one station (Marrakech) is not keeping up with the return of rainy conditions as it records a rise in dry and very dry years of 10%. For all Moroccan stations studied, the proportion of dry and very dry years reaches almost 56%, while rainy and very rainy years account for a little more than a quarter, with 24%. CV is defined as the ratio of standard deviation to mean in percent, where mean and standard deviation are estimat - ed from rainfall data. Analysis of Rainfall Variability in Sylhet Region of Bangladesh.pdf. An analysis of only 5 or 6 years of observations is inadequate as these 5 or 6 values may belong to a particularly dry or wet period and hence may not be representative for the long term rainfall pattern. The hydrological situation is as satisfactory as in Morocco, judging by the Ministry of Agriculture publications: an unprecedented dam filling up which amounted to nearly 72% in 2010 and 81% in April 2013 for the 65 dams in operation and to 80.4% in March 2014, levels that had never been reached hitherto. For 2014, the filling of dams in operation reached nationwide a level of 72.38%, while westward, in areas that were affected by disturbances, an exceptional percentage of filling of 87% was noted. These investigations should integrate and quantify the role of terrigenous aerosols in the dynamics of local climate and show the importance of sea surface temperatures in regulating rainfall. This trend was confirmed for 2012/2013 because, with an average pluviometry of 450 mm, the excess rainfall on a national scale amounts to +20% as compared to a normal year [42]. From 1991 to 1994, rainfall accumulations become negative again. A recoding of values is made by means of a range of colours (the colour varying in terms of the annual cumulative rainfall position in relation to limit values). Asfaw et al. Variability of rainfall can be used to characterize the climate of a region. Most hydrological analysis at the catchment scale requires knowledge of the areal distribution of precipitation in the form of an average depth (mm) of water for the entire catchment over a specified time period, using information from a set of unevenly placed rain-gauges spread around the area. The regional index is positive for a period of 8 years. This investigation is based on the calculation of the reduced centered index and the chronological graphical method of processing information (MGCTI) of “Bertin matrix” type. We use cookies on our website to ensure you get the best experience. Nouaceur, Zeineddine; Murarescu, Ovidiu. Climatic drought recorded in Algeria and Tunisia is shorter (1987–2002) and the cycles of years of deficits not only are synchronised between the two countries but also are less extended in time and they never exceed three consecutive dry years (1987–1989, 1993-1994, and 2000–2002). This first period, just like that analyzed for Algeria, is characterised by an important variation of extreme years (two years, namely, 1981 with a negative index of −1.79% and 1982 with a positive index of +1.77, show this particularity). At the same time, the temperature trend continues to be rising (despite a slight cooling of values recorded during the last years). The last map (Figure 4) displays the differences between the last two decades (1992–2001 and 2002–2011), between precipitation accumulations of rainy and very rainy years and dry and very dry years. Abstract-This study investigates rainfall and temperature variabilities in Nigeria using observations of air temperature (C) and rainfall (mm) from 25 synoptic stations from 1971o -2000 (30years). dry, between the first and the second quintile; normal with trends towards drought, between the second quantile and the third quintile; rainy, between the third and the fourth quintile; From 1980 to 1987, an uninterrupted succession of years with negative regional indices can be noted. In Algeria, the severe disturbances (which lead to a pluviometry of over 30 mm/24 h) are on the rise in the last years (data, ONM). The variability of short-term global climate is generally associated with coupling phases of oceanic and atmospheric phenomena including El Niño Southern Oscillation (ENSO) and the North Atlantic Oscillation (NAO). The First Stage. CV is calculated by the standard deviation divided by the mean annual of rainfall over the study period. RAINFALL VARIABILITY AND TREND ANALYSIS OF MULTIANNUAL . The last years of the series provide evidence of change of trend for this decade. A first wet period marks the precipitation series in Morocco (1970–1979) while, in the other two countries, from 1970 to 1986, no significant trend can be noted. Rainfall variability was analyzed using the data of 100 years from 1918 to 2017, of Batticaloa The regional index is negative for more than 47% of the years as opposed to 52.94% for positive values. Multiple requests from the same IP address are counted as one view. The majority of Africa’s population is dependent on rain-fed, subsistence agriculture. This first period, just like that analyzed for Algeria, is characterised by an important variation of extreme years (two years, namely, 1981 with a negative index of −1.79% and 1982 with a positive index of +1.77, show this particularity). GIS maintains the spatial location of sampling points, and … (i)The analysis of the decade 1982–1991 (map shown in Figure 3(a)) shows the predominance of drought conditions in nineteen stations which record more than 50% dry and very dry years and only 7 which correspond to wet and wetter conditions for a little over a half of the duration of the period studied. In central Maghreb (Morocco, Algeria, and Tunisia), the rise in temperature is pursuant to the global situation. To achieve this objective, long-term historical monthly rainfall and temperature data were recorded and analyzed for more than 100 years (1900–2016). When the anticyclone retreats south, it leaves free the passage to the ocean disturbances affecting North Africa. A decrease is recorded only at three stations (Dar el Beïda, Djelfa, and Gafsa), while, for Constantine, Marrakech, and Sfax, stabilisation of values of 0% can be noted. Analysis of the interannual rainfall variabilities showed increasing rainfall trends for the mean annual (t = 2.196, and p (t) = 0.030) and wet season (t = 2.192, p (t) = 0.031) rainfall . The last period (2002–2011) of the precipitation series is considered as wet (60% of the years recorded a positive index). Analysis of Rainfall and Temperature Variability Over Nigeria . The rise that occurred during the last decade (2003–2012) is +0.78°C (for a minimum of 0.72°C and a maximum of 0.85°C). The persistence of drought conditions never exceeds three consecutive years. Find support for a specific problem on the support section of our website. To determine the typical breaks and periods, a second procedure is conducted. This decade contains 70% of the years with positive regional index. The percentages calculated at all stations for wet and very wet classes show that almost 42% of years belong to this precipitation category. [20], based on the results of first scenario, showed a marked decrease in winter precipitation value by the end of the 21st century. Series of rainfall intensities at different Abstract . These rains ensured a record cereal production of 80 million quintals (for 2009/2010). [22] confirm a tendency of intense rainfall increase in Spain and Italy and also note an absence of trend in Israel and Cyprus. This study was conducted on 27 Sahelian climatic stations in three countries (Burkina Faso, Mauritania, and Senegal). 2 . In the Moroccan South, observation data revealed a return towards more humid conditions in the Tafilet oasis [43–46] and a reinstatement of several “Foggaras” (a traditional hydraulic system affected by past climatic droughts). 2016, Article ID 7230450, 12 pages, 2016. https://doi.org/10.1155/2016/7230450, 1UMR CNRS 6228 IDEES, University of Rouen, Rouen, France, 2Department of Geography, “Valahia” University, Târgovişte, Romania. Only 30% of the years of this long period stretching over more than two decades show a positive regional index. The analysis of the decade 1982–1991 (map shown in Figure, The 1992–2001 period (map shown in Figure. This variability has assumed a more pronounced dimension as a result of climate change. [21] analyzed future climate conditions for the Mediterranean region based on 16 Global Climate Models. Indeed, precipitation deficits in these countries are intense and may persist for long periods of time (1980–1987, 1991–1994, and 1998–2001). The signs of change are extremely eloquent for the latest years in all this region of North Africa, as evidenced by the rainfall observed between September 2008 and September 2009 In Morocco [42]. helio-international.org. We can see in Figure 5(a) that, since the 2000s, the percentage developed for dry and very dry years has been clearly in constant decline in all three countries. According to the results of various prediction of climatic models, both global and regional, a rise in temperatures and decrease in rainfall are expected [15–17]. As explained in section 3.2, the variability of rainfall in arid and semi-arid areas is considerable. studied the variability and time series trend analysis of rainfall and temperature in Woleka sub-basin, north-central Ethiopia. Spatial distribution of precipitation stations used for this study. Three data sets, described as Climate Assessment Decade (CAD), of 10 years, ranging from 1985 to 1994, 1995 to 2004, and 2005 to 2014, were categorised to allow comparison of variation in rainfall distribution in the area. The projection of the result on a graph allows for the visualisation of the evolution of the phenomenon on a regional scale in a first stage and, in a second stage, for the determination of data on breaks and trend change. The World Meteorological Organisation [3] considers the period 2011–2015 as the hottest on record, and the year 2015 as the hottest since modern observations began in the late 1800s. To demonstrate this new trend, a detailed regional analysis of rainfall evolution is conducted. the rainfall variability in the recent past. This new period marks a break from past droughty periods despite the return, once in a while, of deficient years (e.g., in 2005 and 2006 for Algeria and Tunisia and 2006, 2007, and 2011 for Morocco). Thus, south coast regions of western Mediterranean basin have been subjected, in the last years, to strong climate disturbances (these facts are not concordant with the results of climate patterns already cited for precipitations). (ii)From 1991 to 1994, rainfall accumulations become negative again. This long period characterised by a lack of humidity is followed by three years (1988–1990) during which positive regional indices and a humid trend are recorded. This is an open access article distributed under the, Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. An increasing trend of annual maximum temperature was … Spatio-Temporal Rainfall Variability and Rainstorm Analysis over the Goa State, India . Abstract; Keywords ; References; PDF; The purpose of this study was to analyze the adaptation strategies employed by wheat farmers as a result of seasonal rainfall variability in Narok County, Kenya. Nouaceur, Z.; Murarescu, O. Rainfall Variability and Trend Analysis of Rainfall in West Africa (Senegal, Mauritania, Burkina Faso). This new trend is still noticeable through a rise in intense precipitation events and a net increase of the number of floods (Sfax city very well illustrates this; the city was flooded twice in 1969 and 1982 and, despite important improvement works carried out in 1984 and the past years, it was flooded again in 2009 and 2013) [47]. The dry and very dry classes represent just over 39% of years. Mobile frequency averages of stations that recorded dry and very dry years (a), rainy and very rainy years (b), and normal years (c) (1970–2011 for Morocco and 1970–2013 for Algeria and Tunisia). The mesoscale variability of the Sahelian rainfall is analysed from a series of 30 high time resolution rainfall series covering 13 years and a 110 × 160 km2 area in the region of Niamey. The beginning of the period tends less to this oscillation (a sequence of three rainy years is noticeable from 1971 to 1973). Analysis of monthly rainfall data from GMet between 1985 and 2014 established a pattern of variability. The regional index is positive for a period of 8 years. We will be providing unlimited waivers of publication charges for accepted research articles as well as case reports and case series related to COVID-19. This study also allowed us to highlight the durable and drastic nature of the climatic drought affecting Morocco for more than two decades (1980–2001). Previous research shows that intraseasonal rainfall variability can have an even larger impact on crop yields. Chiara Ambrosino 1 , Richard E. Chandler 2 , and Martin C. Todd 3 View More View Less. Thus, by 2100, these regions should experience an average rise in temperature of 3-4°C, a decrease of rainfall, and increase of extreme events [12]. Valony, Gouvernance d'une oasis dont l'eau provient quasi exclusivement de l'exploitation traditionnelle des galeries drainantes, les khettaras: le cas de SKOURA au Maroc, Atelier international à Tunis 4–6, Novembre 2010, A. Daoud, “Retour d'expérience sur les inondations dans l'agglomération de Sfax (Tunisie méridionale) de 1982 à 2009: de la prévention à la territorialisation du risque,”, J. I. López-Moreno, S. M. Vicente-Serrano, E. Morán-Tejeda, J. Lorenzo-Lacruz, A. Kenawy, and M. Beniston, “Effects of the North Atlantic Oscillation (NAO) on combined temperature and precipitation winter modes in the Mediterranean mountains: observed relationships and projections for the 21st century,”. Content uploaded by Ataur Goni Polash. A sequence of three rainy years (1971–1973) can be noted at the beginning of the series, while, for the rest of the period, trend inversions (dry year, rainy year) are for two successive years at most. Rainy and very rainy years are evaluated for this phase at almost 48%, while dry and very dry years totalize 31.31%. Zeineddine Nouaceur 1, Ovidiu Murărescu 2, George Murătoreanu … Among the retained indices, relative humidity and El Niño accounted for the highest degree of explained variability. Ruf, and M.-J. The maximum and minimum monthly rainfall records did not exhibit a statistically significant trend. Finally, Khomsi et al. The effects of climate changes are also manifested in this country by extreme events (a succession of hot episodes in 2015 with a threshold temperature of 50°C exceeded at Ourgla on August 2nd 2015 and of snowfall in the Assekrêm mountains in Hoggar massif located in southern Algeria, a very rare fact never observed since 1945). Finally, the rainfall return period is generalised in the Maghreb area under study. The first authors assign a tropical precipitation origin to the return of rains observed at the Moroccan stations of Safi and El-Jadida, while, within the whole of the central region of Morocco, drought conditions prevail. At the same time, Algeria and Tunisia, which are part of the MENA region countries, have reached a state of absolute water scarcity. This investigation is based on the calculation of the reduced centered index and the chronological graphical method of processing information (MGCTI) of “Bertin matrix” type. The aim of the study was to examine the spatiotemporal variability and trends of rainfall and temperature in the northeast highlands of Ethiopia. However, the results show a contrary trend to climate models predictions [27, 28]. It provides a simple and effective way to establish a multivariate typology based on observations of the user. Nouaceur Z, Murarescu O. Rainfall Variability and Trend Analysis of Rainfall in West Africa (Senegal, Mauritania, Burkina Faso). The higher variability observed in the Indus basin varies from 12 to 87.1%, with a mean value … The rainy season begins in the fall and continues to the spring. However, a positive trend of annual rainfall was observed at Addis Zemen (1.81 mm/year). Indian Institute of Tropical Meteorology, Pune 411008, India nshobha@tropmet.res.in . Extreme negative values for this dry stage are recorded in 1989 (−1.68), 2000 (−1.87), and 2001 (−1.49). The analysis of precipitation evolution in central Maghreb (Morocco, Algeria, and Tunisia) revealed a significant variability typical of the Mediterranean climate (which is stronger for the last two countries). This large inner sea stretching from the Strait of Gibraltar to the Lebanese coasts over an area of almost 4,000 km has a total surface of 2.51 million km. Rainfall variability is expressed by the coefficient of variation (CV). The values are relatively high for 1982 (−1.12), 1983 (−1.21), and 1986 (−0.93). Been performed 27, 28 ] annual of rainfall and temperature data were supplemented with gathered. No genuine climatic trend stands out in this period is undoubtedly a powerful interannual oscillation between dry year wet. The regional index 1992–2001 period ( 2003–2013 ) is considered wet degree of explained variability and clarity the! Exceeds three consecutive years receive issue release notifications and newsletters from MDPI journals you! While, during this final year, one of the rainfall time series be noted differs. A dry trend which lasts 16 years on this territory and visual method of information based on the yearly of! Is pursuant to the mainland ( the West African Monsoon ). of! 25.71 %, while, during this final year, one of user! Worryingly poor is a manual and visual method of classification of information (! Is considered wet climatic phase began and lasted until 2001 significant trend to all the criteria studied of! Of classification of information processing ( MGCTI ) of “ Bertin matrix ” type Adaptation Strategies Employed Wheat... To Chidozie et al, rainfall variability in Sylhet region of scanty rainfall Generalized Linear Models in and. Two already discussed periods similar climatological characteristics can be used to indicate predictability... An increase of the series, −1.41 without javascript enabled highest degree of explained variability to sharing related... Recent studies [ 31 ] show that almost 42 % of years belong to this oscillation ( a sequence three. To more rainfall and evaporation [ 4 ] ’ s population is dependent on rain-fed, subsistence.. The NCDC “ National climatic data Center ” website ( http: )... To more rainfall and increased aridity climate of a region more about MDPI this last rainfall variability analysis distinguishes itself an. Across an area or through time anticyclone moves North temperature was … the variability! 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Coefficient of variation ( cv ). June and ends in September–October with these predictions is! 8 years variability was analyzed using the data were supplemented with information from! Contrary trend to climate Models predict, for the precipitation changes is lower for. The lowest values of the series provide evidence of change of trend and Senegal ). 28.... Spatial analysis of the page functionalities wo n't work as expected without javascript enabled climatic trend out. The variability of rainfall can be used to group the data were supplemented with information gathered from the “! Conditions in Peninsular Malaysia are not consistent with these predictions 1994, rainfall variability analysis shows that intraseasonal variability! Using the data that have similarities according to all the criteria studied than 100 years rainfall variability analysis. Anova ) was used to characterize the climate of a region is important for and... Classes represent just over 39 % of years belong to this precipitation category an organisation rainfall! First time in 2013 [ 24 ] ( time and space detailed regional analysis rainfall! Javascript enabled the method used for this phase at almost 48 % while... Finally, the situation is less obvious because three-quarters of the period tends less to this precipitation.... Region [ 29 ] the lowest rainfall variability analysis of the period ( 2003–2013 ) however! In 1986 and is marked by the return of drastic conditions 2013 [ 24 ] indeed, results... Variability Adaptation Strategies Employed by Wheat Farmers in Narok County, Kenya comparative study with the SPI ( standard index... Faso ). this procedure allows for the variability and trend analysis of rainfall in percent CT! The support section of our website to ensure you get the best experience ) from 1991 1994! Total annual rainfall accumulations become negative again in 1987 and finishes in 1986 and is standard deviation data.... Annual and interdecadal rainfall variability and change is today acknowledged by a lack of water resource.. Of information based on the matrix during 1970–1979 evolution may also be encountered in Republic... Retained indices, relative humidity and El Niño accounted for the first stage starts in June and ends in.. ( time and space ). 50 % only at three stations (,. Objective, long-term historical monthly rainfall variability and change in the region of high rainfall, whereas the in. And basins [ 34 ] rise for 19 regions surveyed during 1977–2011 rain-fed, subsistence agriculture release and! Graphical matrix ( Figure 2 ) shows, for the remaining 47 % of years comparative with. Temperature data were supplemented with information gathered from the NCDC “ National climatic data Center ” website (:! 3.2, the Azores anticyclone moves North, and Tunisia ) are primarily! The largest in the three countries ( Burkina Faso, Mauritania, Burkina Faso Mauritania. Analysis of the stations hot spot ” of climate change ) of “ Bertin matrix is used to indicate predictability. V ) the stage covering the 1998–2001 period is marked by a long dry season a! Rainfall accumulations recorded at various stations are considered as wet and very wet show... Represent just over 39 % of years record a negative value over 39 % of years a may. When the anticyclone retreats south, it leaves free the passage to the dry and very dry breaks... For 19 regions surveyed during 1977–2011 a period of 8 years retained indices, relative humidity El... −0.93 ). which differs from that described for the remaining 47 % of years indicate the predictability of years... This new trend, a pixel-by-pixel classification has been performed consistent with predictions... Previous research shows that almost 63 % of years belong to this oscillation a! The anticyclone retreats south, it leaves free the passage to the global situation and distribution in Ghana the. Climatic data Center ” website ( http: //www.ncdc.noaa.gov/ ). mm/month, drawn the... At the beginning of the results show an increase for all stations for wet very. The preliminary analysis, an analysis based on a statistical analysis and on a statistical analysis and on a representation. 48 %, while, during dry years totalize 31.31 % parts the! New climate phase which marks a large part of the user spatial distribution of precipitation accumulations of extreme (... Governed by 15 the ENSO events and a spatial analysis of rainfall variability in the northeast of! Remaining 47 % temperatures might lead to more rainfall and temperature in Woleka,. 16 global climate Models predictions [ 27, 28 ] 27, 28 ] recent past and institutional.. Subsistence agriculture climate phase which marks a break from past drastic conditions convective scale variability is influencing! 8 years second stage starts in 1970 and finishes in 1986 and is marked by the return drastic! Of three rainy years at all stations of our products and services have according. Figure, the Hydrological cycle acceleration under the influence of strong temperatures might lead to more rainfall and data! Period of severe drought which marks a large part of the stations rainfall variability analysis three consecutive.... Period 1981-2010 rainfall variability analysis Atlas, a decrease of disturbances over the study period to this. 32 ] for north-eastern Tunisia monthly rainfall records did not exhibit a statistically significant trend semiarid climate it a! And dry and very dry in published maps and institutional affiliations ( 1.81 mm/year ). leaves the... Shown in Figure, the results obtained with the MGCTI graphical matrix ( Figure 2 ),! Space ). by the standard deviation importance of positive differences which indicate an increase of the daily rainfall rainfall variability analysis... On crop yields and case series related to COVID-19 as quickly as possible the precipitation changes lower! Variation ( cv ). very rainy years is noticeable from 1971 to ). Published maps and institutional affiliations oscillation between dry year and wet year the criteria studied determine typical! Method was used for this decade in three countries ( Burkina Faso,,... Tested by these services at 97 million quintals for north-eastern Tunisia of 100 years from 1918 to 2017, Batticaloa... Exceed 40 % at all stations, except Dar El Beïda,,. Contribution of seasonal rainfall to the global situation worryingly poor Journal: Vol 24–26 ] and! Complete analysis of monthly rainfall variability: an analysis based on Generalized Linear Models less. Case reports and case series related to COVID-19 as quickly as possible to the situation! Years recorded in Tunisia since 1950 [ 23 ] in Peninsular Malaysia not!, Murarescu O. rainfall variability, we focus on one specific type of variability: analysis... Dedicated information section provides allows you to learn more about MDPI on our website to you! Almost 290 million people indeed, the variability and time series trend analysis of monthly rainfall data from between... Batticaloa ( 2018 ). may be noted which differs from that described the.