Changes in annual, June-September and March-May rainfall and rainy days herein (defined as a day with rainfall greater than 1 mm) have been analysed based on 11 key stations located in different climatic zones of Ethiopia over the common period . The progressive Mann-Kendall trend test shows that there is no trend in the annual rainfall total, the seasonal rainfall total or rainy days over central, northern and northwestern Ethiopia in the period . In contrast, the annual and the June-September total rainfalls for the eastern (Jijiga, 137 mm/decade), southern (Negele, 119 mm/decade) and southwestern (Gore 257 mm/decade) stations show a significant decline since about 1982. Correlation analysis shows that the decline of rainfall in eastern, south and southwestern Ethiopia is caused by the corresponding persistent warming of the South Atlantic Ocean over the period approximately from 1986 to 2002. The sea-surface temperature (SST) over the tropical eastern Pacific Ocean is not significantly correlated with the main rainfall of the semi-arid lowland areas of eastern, southern, and southwestern Ethiopia, except at marginal zones in transition to the Ethiopian Highlands.June-September rainfall over the Ethiopian Highlands is positively correlated to the equatorial east Pacific sealevel pressure and the southern oscillation index, and negatively correlated to SST over the tropical eastern Pacific Ocean as expected, confirming again that warm El Niño-southern oscillation episodes are associated with below-average June-September rainfall over the Ethiopian Highlands.
This paper assesses recent changes in extremes of seasonal rainfall in Ethiopia based on daily rainfall data for 11 key stations over the period 1965–2002. The seasons considered are Kiremt (‘main rains', June–September) and Belg (‘small rains', February/March–May). The Mann-Kendall and linear regression trend tests show decreasing trends in the Kiremt and the Belg extreme intensity and maximum consecutive 5-day rains over eastern, southwestern and southern parts of Ethiopia whereas no trends are found in the remaining part of Ethiopia. In general, no trends are found in the yearly maximum length of Kiremt and Belg dry spells (days with rainfall below 1 mm) over Ethiopia
Ethiopia has a complex topography, diversified climate, and immense water resources. The spatiotemporal variability of the water resources is characterized by multi-weather systems rainfall of the country. Most of the river courses become full and flood their surroundings during the three main rainy months (June-August). West-flowing rivers (Abay, Baro-Akobo, Omo-Gibe, and Tekeze) receive much rainfall unlike the northeast-(Awash) and east-flowing rivers (Wabishebele and Genale-Dawa) which receive normal to low rainfall. Although it needs further detailed investigation, according to the current knowledge, the country has about 124.4 billion cubic meter (BCM) river water, 70 BCM lake water, and 30 BCM groundwater resources. It has a potential to develop 3.8 million ha of irrigation and 45,000 MW hydropower production. This chapter discusses and presents the water resources of Ethiopia and the different challenges faced by the water sector to contribute to the economic development.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.