Hydrogeology of Nazret
| dc.contributor.advisor | Yirgu, Gezahegn (PhD) | |
| dc.contributor.author | Ameneshoa, Woldu | |
| dc.date.accessioned | 2018-07-11T13:14:49Z | |
| dc.date.accessioned | 2023-11-09T14:09:58Z | |
| dc.date.available | 2018-07-11T13:14:49Z | |
| dc.date.available | 2023-11-09T14:09:58Z | |
| dc.date.issued | 1994-06 | |
| dc.description.abstract | The study area is found in the southern part of the northern sector of the Main Ethiopian Rift some 97 km southeast of the capital. It covers a surface area of about 370 sq.km. Elevation varies from below 1600 m.a.s.l. to more than 1970 m.a.s.l .. More than 70% of the area represents low lying flat land with slop~ of.1 to 10%. The area is covered by various igneous rocks which are products of volcanism_that spanned from Pliocene to Recent, and also by Quaternary sediments. The volcanics include; ignimbrites, basaltic flows, rhyolitic flows and domes, unwelded tuffs, pumice and ash deposits. Lacustrine sediments, alluvium and colluvium represent the non-volcanic deposits in the area. Mean annual rainfall of 822.53 mm and mean annual temperature of 21'C characterize the study area. According to water balance study over the small sub-catchment at the centre of the area, generally about 49% of the mean annual rainfall is lost through evapotranspiration. While about 20% is available for runoff and the remaining about 30% is accounted for infiltration to the ground. The main aquifers in the area are coarse grained lacustrine and alluvial sediments, pyroclastic rocks (cinders, volcanic sand and pumice), and weathered or fractured volcanic rocks mainly basalts and also somtimes ignimbiites From the pumping test data, 'analyes permeabities and transmissivities of rocks have been foundto vary: from O. 50 to 78.50 mid and 14.73 to 1355.20 m2/d respectively specific capacity also ranges from 0.26 to 9.13 mJ/hr/m. High permeability values are observed for the aquifers in the southern part of the area. The pumping test analyses also shol1ed that there is a recharge from AI1ash river to the aquifers at Melka Hida well field. Depth to groundwater level ranges from fel" meters in the southern part of the area to more than 170 meter in its northern part. From the groundwater contour, it can be observed that the general groundwater flow is to the south in the deeper aquifers. In the shallow aquifer zone (that is , southern part of the study area) groundwater flows towards Awash river in locally different directions from both sides of the river. The chemical analyses result showed that the ~Taters of the area are mainly bicarbonate type varying from sodiumbicarbonate to calcium-bicarbonate ones. The analyses also showed that there is high fluoride concentration above the acceptable limit for drinking in the groundwaters. Potential places for groundwater in the area are restr icted to its southern part. The remaining part is of limi ted potential not only due to 1011 permeabili ties of aquifers but also due to large depth to groundwater level. Finally, it seems that conjunctive use of groundwater and surface water from Awash river is the only solution to meet future water demand of the town and of its surrounding. | en_US |
| dc.identifier.uri | http://10.90.10.223:4000/handle/123456789/8105 | |
| dc.language.iso | en | en_US |
| dc.publisher | Addis Ababa Universty | en_US |
| dc.subject | Nazret | en_US |
| dc.title | Hydrogeology of Nazret | en_US |
| dc.type | Thesis | en_US |