Impact of pumping for Irrigation on Groundwater Potential (The Case of Eastern Part of Guraghe Zone)
| dc.contributor.advisor | Mohammed, Mebruk (PhD) | |
| dc.contributor.author | Banda, zekarias | |
| dc.date.accessioned | 2018-07-20T11:12:42Z | |
| dc.date.accessioned | 2023-11-11T08:33:02Z | |
| dc.date.available | 2018-07-20T11:12:42Z | |
| dc.date.available | 2023-11-11T08:33:02Z | |
| dc.date.issued | 2015-07 | |
| dc.description.abstract | In the eastern part of Guraghe, bounded by Meki and Weja River, Irrigation practice increases using pumping technology. This alarming increasing of pumping groundwater for irrigation purpose has resulted in:-The reduction of groundwater potential in the groundwater basin and dry up of streams, rivers nearby. Such aggressive groundwater abstraction will result conflicts between the users of groundwater and rivers. Thus it is vital to understand the impact of such groundwater abstraction on its availability and decide on the optimum abstraction rate. To assess the impact of groundwater abstraction in its availability and nearby rivers a 3D conceptual groundwater model is created. This conceptual model consists of the catchment divide in the west (guraghe High Mountain) and two adjacent rivers (Weja and Meki rivers). The catchment divide is taken as a hydraulic –Neumann-boundary and the two adjoin rivers are taken as dirichelet- boundary. The bottom and groundwater surface is between these boundaries is taken as a flux-boundary. Whereby the top ground takes recharge while the bottom is taken as a no-flow boundary. The four different geological strictures found are consider as different hydro geologic settings where by hydraulic conductivity is assigned as a trial value, to make sure that the hydraulic heads collected in 94 hand dug wells in the study area are estimated reasonably. The above conceptual model is used as an input of TAGSAC software whereby the model area is decertified in to 22301 nodes and 21710 triangular prism elements of 200mx200mx200m all the 94 inventoried wells were represented by nodes. Thiesson polygon based on rainfall distribution is also used as an input but with a reduced rate to represent the effective recharge. The four different geologic setting were also represented by the finite elements generated, so that different hydraulic conductivity is given to each of the four geologic settings. The model is calibrated with, 8.74m, 7.45m, 0.83 RMSE, ME and R2 values respectively. After calibration the impact of pumping is analyzed by assigning the current groundwater abstraction rate 21,186,913m3/year to the nodes representing the impact zone. The result clearly shows that the region of influence reaches the existing perennial river. Thus the current trend of pumping will result in drying up of these rivers. To come up with optimum pumping rate trial values were given to the model area representing the pumping site. An optimum pumping rate of 16,666,214m3/year would minimize the impact of pumping on the adjacent rivers. Keywords: Groundwater, Guraghe Zone, Numerical modeling, Optimum pumping rate, TAGSAC | en_US |
| dc.identifier.uri | http://etd.aau.edu.et/handle/12345678/9565 | |
| dc.language.iso | en | en_US |
| dc.publisher | Addis Ababa University | en_US |
| dc.subject | Groundwater | en_US |
| dc.subject | Guraghe Zone | en_US |
| dc.subject | Numerical modeling | en_US |
| dc.subject | Optimum pumping rate | en_US |
| dc.subject | Tagsac | en_US |
| dc.title | Impact of pumping for Irrigation on Groundwater Potential (The Case of Eastern Part of Guraghe Zone) | en_US |
| dc.type | Thesis | en_US |