Assessment of Groundwater Quality for Drinking Purpose in Guya Village Its Surrounding Area, Tigray, Northern Ethiopia

This paper assesses the groundwater chemistry and evaluates its quality for drinking use in the area using groundwater chemistry analysis method and compare with International water quality standards in Guya area (157.015 km2) in Tigray, northern Ethiopia. Chemical composition of the water varies widely depending up on climate and hydrology in a specific drainage area, which contributes a seasonal influence .Among drainage area, composition is mostly depend on geology. Depth integrated groundwater sampling was applied to collect the water samples from two Bore hole, four springs as well as Three shallow wells.The dominant cations concentration in the area are mainly are Mg2+, Ca2+, Na+, K+ where the dominant anions are HCO3-, CO32-, SO42- and Cl-.  The groundwater type in the area is generally classified in to Mg-K-HCo3-Cl, K-Ca-HCo3-Cl , K-Na-Mg-HCo3-Cl ,K-Mg-Cl-HCo3, Na-K-Mg-HCo3-Cl,  Na-K-Mg-HCo3 and  K-Na-Mg-HCo3-Cl. Physically and chemically, the groundwater in the area is suitable for drinking purpose but, from hardness point of view ther groundwater need to be soften as far as the drinking purpose is concerned Keywords: Groundwater, Drinking, Suitability, Quality, Guya, Ethiopi

Aquifers Characterization and Productivity in Ellala Catchment, Tigray, Northern Ethiopia

This paper assesses the aquifer characteristics and productivity nature of different rocks and sediments using geological and hydrogeological methods in Ellala catchment (296.5km2) in Tigray, northern Ethiopia. The catchment consists of limestone (29.91%), intercalation of limestone-shale-marl (27.90%), dolerite dykes and sills (21.85%) and recent sediments (20.33%). Compared to rocks, the sediment due to lack of both extensive areal coverage and thickness, its water-bearing capability is almost negligible. Aquifers developed in the different rocks are mainly due to secondary processes such as weathering, fracturing and karstification. The degree of variations in the groundwater productivity is mainly linked with the variations in the effect of these processes in the respective rock. Hydrodynamic analyses of the aquifers reveal that in the limestone aquifer hydraulic conductivity is ranging from 0.046 to 4.65 m/day with a mean value of 1.44 m/day and transmissivity is ranging from 2.38 to 93.02 m2/day with a mean value of 32.58 m2/day; in the intercalated limestone-shale-marl aquifer hydraulic conductivity is ranging from 0.87 to 70.13 m/day with a mean value of 10.11 m/day and transmissivity is ranging from 17.88 to 645.7 m2/day with a mean value of 163.41 m2/day; and in the dolerite aquifer hydraulic conductivity is ranging from 1.67 to 108.86 m/day with a mean value of 59.32 m/day and transmissivity is ranging from 57.63 to 307 m2/day with a mean value of 142.71 m2/day. Based on these determined transmissivity values of different aquifers and geomorphological setup of the catchment, the potentiality degree of the aquifers of the catchment range from moderate to negligible. The negligible potentiality aquifer is found covering steep slopes and topographically high areas, whereas aquifers that have moderate to weak degree of potentiality are found occupying flat to rugged topography of the catchment.Keywords: Groundwater, Aquifer, Ellala catchment, Hydraulic conductivity, Transmissivity, Ethiopia

Application of GIS and Remote Sensing for Land Use and Land Cover Change in Kilite Awulalo, Tigray Ethiopia

This study examines the application of GIS and Remote Sensing in mapping Land Use and Land Cover change in Kilite Awulalo Woreda, Eastern Tigray Zone from 1972 to 2014. For this study, LANDSAT images of 1972 (Landsat-1 MSS); 1984 (Landsat-5 TM); 2000 (Landsat-7 ETM+) and 2014 (Landsat-8 OLI_TIRS) were used and analyzed using Arc GIS 10.1 and Erdas Imagine 13. Supervised classification scheme was used to classify the images. Under land use and land cover categories Agriculture land, Settlement land, Grazing land, Forest land, Bush land, Water bodies and Bare/stony land were studied. The result shows that Bush land was decreased from 1972 to 2014 which is 1972 (58007.88 hectare), 1984 (47900.79 hectare), 2000 (45000.1 hectare) and 2014 (40573.53 hectare) and forested land was decreased from the year 1984 (21706.65 hectare) to 2014 (11916.6 hectare). Agriculture and settlement area was increased from the year 1972 to 2014. Agriculture was increasing 13138.92, 20856.78, and 23000.09 to 30402.27 hectares from the year 1972, 1984, 2000 and 2014 respectively