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Accueil du site → Master → Belgique → Geophysical Investigation of Groundwater Parameters in an Agricultural area (Abraha Atsbeha) and Leaking Micro-Dam Reservoir (Arato Dam) in Tigray Ethiopia

Universiteit Gent (2013)

Geophysical Investigation of Groundwater Parameters in an Agricultural area (Abraha Atsbeha) and Leaking Micro-Dam Reservoir (Arato Dam) in Tigray Ethiopia

GELENA Samuel Kebede

Titre : Geophysical Investigation of Groundwater Parameters in an Agricultural area (Abraha Atsbeha) and Leaking Micro-Dam Reservoir (Arato Dam) in Tigray Ethiopia

Auteur : GELENA Samuel Kebede

Université de soutenance : Universiteit Gent

Grade : Master of Science (MS) Physical Land Resources 2013

Résumé
The study areas are located in a semi-arid region in the northern part of Ethiopia, in Tigray Regional State. Tigray region is one of the most water stressed areas of the country. Hence, an intensive water resource development has a crucial role in the economic and social development of the region. In order to alleviate the problem of recurrent drought and to assure household food security, efforts are being made to use groundwater for irrigation and harvest surface water runoff in micro dams. However, the micro dams frequently face leakage problems. Hence, the main objective of this thesis is to investigate geological, hydrogeological and geophysical methods for groundwater of Mandae catchment (Abraha Atsbeha) and to analyse the leakage of Arato micro dam. The geological units found in the Abraha Atsbeha study area are metamorphic rocks, Edaga Arbi Tillite, Adigrat Sandstone, Antalo Limestone and Quaternary deposits. The geological units found in the Arato study area are Agula Shale, dolerite and Quaternary deposits. In order to understand the water quality of Abraha Atsbeha study area, 12 water samples were collected and analysed and results were compared with WHO drinking water standards. For most of the chemical constituents, water samples are within the safety standards, except for Ca2+ 67%, NO2- 25% and Mn2+, Fe2+ and NO3- < 10% of the samples fail to meet the standards. These values of NO2- and NO3- which are above WHO 2006 standards constitute health problems. However, Ca2+ and Fe2+ are only comfort problems, not health problems. Electrical resistivity technique was investigated to determine groundwater level and the aquifer thickness in Abraha Atsbeha study area and to determine leakage of Arato micro dam reservoir. A total of 23 electrical resistivity soundings (VES) and 11 electrical resistivity profilings (ERP) were conducted to understand vertical and lateral resistivity variation of Abraha Atsbeha study area subsurface. 8 VES and 6 ERP were conducted in Arato study area. The groundwater level is estimated from VES measurements and the results are compared with measured groundwater levels and have a sound relationship. The groundwater saturated thickness in the area is estimated and maximum aquifer thickness (104 m) is obtained at VES 7 in the central valley of Mandae catchment. Resistivity method is also used to identify the Arato micro dam reservoir leakage and the results show that excessive leakage of the micro dam is through weathered and fractured Agula Shale.

Source : Pedon 25 - Physical Land Resources - Universiteit Gent

Page publiée le 8 novembre 2015, mise à jour le 23 janvier 2018