Determination of the Thresholds of the Climatic Classification According to the Discharges in the Upper Senegal River Basin

Source:
By:Cheikh Faye

DOI: https://doi.org/10.30564/jgr.v5i1.4088

Abstract:

Floods are the most common type of natural disaster in the world and one of the most damaging. Changes in weather conditions such as precipitation and temperature result in changes in discharge. To better understand the floods and eventually develop a system to predict them, we must analyze in more detail the flow of rivers. The purpose of this article is to analyze the discharges in the upper Senegal River Basin by focusing on determining the limits of the climatic classification according to past discharges. The daily discharges from May 1, 1950 to April 30, 2018 were chosen as the study period. These flow data have been grouped into annual discharges and classified as very wet, moist, medium, dry and very dry each year.Then, the flow data were divided into two seasons or periods each year:high water and low water. The statistical variables used in this study are the average, the standard deviation, the coefficient of variation and the skewness. The results of the climate classification that corresponds to a log-normal distribution indicate a total of 17 years classified as averages (25% of the series), 14 classified as wet (20.6%), 29 classified as dry (42.6%) and 8 classified as very wet (11.8%), very dry classifications being nil.Seasonal analysis showed that the months of the high water period, such as September, had the highest flow, and the period of low water, such as May,had the lowest flow. The results of the flow analysis were then compared with changes in rainfall. The results obtained show similar climatic classifications between rainfall and flow in the basin.

References:

[1] Baldassarre, G.D., Uhlenbrook, S., 2011. Is the Current Flood of Data Enough? A Treatise of Research for Improvement of Flood Modeling. Wiley Online Library.DOI:https://doi.org/10.1002/hyp.8226. [2] EM-DAT, 2011. OFDA/CRED International Disaster Database, Universite Catholique de Louvain, Brussels, http://www.cred.be/emdat. [3] Ruppert, S., 2019. Stream Flow Analysis of the Big Sioux River Just South of Brookings, South Dakota.Electronic Theses and Dissertations. 3269. https://openprairie.sdstate.edu/etd/3269. [4] UN-ISDR Scientific and Technical Committee,2009. Reducing disaster risks through science:issues and actions. United Nations Office for Disaster Risk Reduction (UNDRR). pp. 23. [5] Fu, G., Charles, S.P., Viney, N.R., Chen, S., Wu, J.Q.,2007. Impacts of climate variability on stream-flow in the Yellow River. Hydrological Processes: An International Journal. 21(25),3431-3439. [6] Ma, Z., Kang, S., Zhang, L., Tong, L., Su, X., 2008.Analysis of impacts of climate variability and human activity on streamflow for a river basin in arid region of northwest China. Journal of Hydrology.352(3-4),239-249. [7] Sow AA, 2007: The hydrology of south-eastern Senegal and its Guinean-Malian borders: the Gambia and Faleme basins, Doctoral thesis of letters and human sciences, UCAD, FLSH, Department of Geography,1232 p. (In French) [8] Faye C., 2013: Assessment and integrated management of water resources in a context of hydroclimatic variability: case of the Faleme watershed. Doctoral thesis, Cheikh Anta Diop University of Dakar, 309 p.(In French) [9] Faye C., 2017: A comparative evaluation of the sequences of water stress and drought by indicators and by time scales in the Bafing basin upstream of Manantali. Geographical Space and Moroccan Society (Number 19), pp. 171 to 188. (In French) [10] Faye C., Diop E. S. and Mbaye I., 2015a: Impacts of climate change and development on the water resources of the Senegal River: characterization and evolution of the hydrological regimes of natural and managed sub-watersheds. Belgeo, 4, 1-22. (In French) [11] Tropica Environnemental Consultants, 2008: EIES Pipeline Eaux Faleme SMC, Public hearing report within the framework of the environmental impact study of the project to install and operate a water pumping pipe from La Faleme to the Sabodala Mining Company mine. 176 p. (In French) [12] Ali, A., Lebel, T., Amami, A., 2008. Signification et usage de l'indice pluviométrique au Sahel. Sécheresse. 19(4), 227-235. [13] Niang A.J., 2008: Morphodynamic processes, indicators of the state of desertification in the southwest of Mauritania. Multisource analysis approach. Doctoral thesis, University of Liège (Belgium), 286 p. (In French) [14] Robson, S.G., Stewart, M., 1990. GeoHydrologic Evaluation of the Upper Part of the Mesaverde Group Northwestern Colorado. U.S. Geological Survey,Water-Resources Investigation Report.90-4020,25. [15] OMVS, FEM / Senegal River Basin Project, 2008:Strategic Action Plan for the Management of Priority Environmental Problems in the Senegal River Basin,Final version, 133 p. (In French) [16] Michel P., 1973: The basins of the Senegal and Gambia rivers: Geomorphological study.ORSTOM Memoirs n ° 63-3tomes, 752 p. (In French) [17] Rochette C., 1974. Hydrological monograph of the Senegal river. Coll. Same. ORSTOM, 1442 p. (In French) [18] Hubert P., Carbonne J.P., Chaouche A., 1989: Segmentation of hydrometeorological series.Application to series of precipitations and flows of West Africa.Journal of Hydrology, 110,349-367. (In French) [19] Dione O., 1996: Recent climatic evolution and river dynamics in the high basins of the Senegal and Gambia rivers. Doctoral thesis, Université Lyon 3 Jean Moulin, 477 p. (In French) [20] Nicholson, S.E., Some, B., Kone, B., 2000. An analysis of recent rainfall conditions in West Africa, including the rainy seasons of the 1997 E1 Nino and the 1998 La Nina years. Journal of Climate. 13,2628-2640. [21] Ardoin-Bardin S., 2004: Hydroclimatic variability and impacts on the water resources of large hydrographic basins in the Sudano-Sahelian zone. Doctoral thesis Univ. Montpellier II. 440 p. (In French) [22] Faye C., 2015: Characterization of low water: the lasting effects of the rainfall deficit on low water levels and drying up in the Bakoye basin. Spaces and Societies in Change (Special Issue), 109-126. (In French) [23] Faye, C., Sow, A.A., Ndong, J.B., 2015b. Study of rainfall and hydrological droughts in tropical Africa:characterization and mapping of drought by indices in the upper basin of the Senegal river.Physio-Geo -Physical Geography and Environment. 9, 17-35. (In French) [24] Yamane, T., 1967. Statistics – An Introductory Analysis, Second Edition; Harper & Row Publisher. pp.1-126. [25] Kenton, W., 2018. Variability; What is Variability.Investopedia https://www.investopedia.com/terms/v/variability.asp Last Updated: June 28, 2018, Accessed on April 1, 2019. [26] Faye, C., 2018. Analysis of drought trends in Senegalese coastal zone on different climatic domains(1951-2010). Annals of the University of Oradea, Geography Series/Analele Universitatii din Oradea, Seria Geografie, 28(2), 231-244. [27] Faye, C., Mendy, A., 2018. Climate variability and hydrological impacts in West Africa: Case of the watershed of The Gambia (Senegal). Environmental and Water Sciences, Public Health & Territorial Intelligence. 2(1), 54-66. (In French) [28] Faye C., 2017: Variability and trends observed on the average monthly, seasonal and annual flows in the Faleme basin (Senegal), Hydrological Sciences Journal - Journal des sciences hydrologiques, 62 (2), 259 to 269. (In French) [29] Kouassi AM, Assoko AVS, Kouakou KE, Dje KB,Kouame KF, Biemi J., 2017: Analysis of the hydrological impacts of climate variability in West Africa:case of the Bandama watershed in Côte d’Ivoire ,Larhyss Journal, 31, 19-40. (In French) [30] Sighomnou D., 2004: Analysis and redefinition of climatic and hydrological regimes in Cameroon:prospects for the evolution of water resources. State Doctorate Thesis, University of Yaoundé 1, Department of Earth Sciences, 291 p. (In French) [31] Goula, B.T.A., Savane, I., Konan, B., Fadika, V.,Kouadio, G.B., 2005. Comparative study of climatic variability impact on water resources of N’zo and N’zi watersheds in Côte d’Ivoire - Sciences & Nature. 2(1), 10-19. (In French) [32] Ali, A., Lebel, T., 2009. The Sahelian standardized rainfall index revisited. Int. J. Climatol. 29,1705-1714. [33] Ouoba A.P., 2013: Climate change, vegetation dynamics and peasant perception in the Burkinabè Sahel. Single Doctorate Thesis, University of Ouagadougou (Burkina Faso), 305 p. (In French) [34] Ozer, P., Hountondji, Y., Laminou, M. O., 2009.Evolution of rainfall characteristics in Eastern Niger from 1940 to 2007. Geo-Eco-Trop, 33, 11-30. [35] Faye, C., 2014. Method of statistical analysis of morphometric data: correlation of morphometric parameters and influence on the flow of sub-basins of the Senegal river. Five Continents. 4(10), 80-108. (In French) [36] IPCC, 2007. Intergovernmental Panel on Climate Change, 2007 Climate Change eport.Contribution of Working Groups I, II and III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Geneva, Switzerland, 103 p. Ali A. and Lebel T., 2009:The Sahelian standardized rainfall index revisited. International Journal of Climatology.29(12),1705-1714. (In French) [37] Kane, A., 2002. Floods and floods in the lower valley of the Senegal river. Integrated management of tropical flood zones, IRD Éditions. 197-208. (In French) [38] Abashiya, M., Abaje, M., Iguisi, I.B., Bello, E.O.,Sawa, A.L., Amos, B.A., Musa, B.B., 2017. Randall characteristics and occurrence of floods in Gombe metropolis, nigeria abashiya. Ethiopian Journal of Environmental Studies & Management. 10(1), 44-5