Physico Chemical Properties of Cow Milk Produced and Marketed in Dire Dawa Town, Eastern Ethiopia

The present study is primarily aimed at assessing the physico chemical properties of cow milk samples sold by dairy farms and milk vendors in Dire Dawa Town. A total of 30 cow milk samples were collected and examined. The mean values for pH, specific gravity, titratable acidity, protein, fat, total solids and solids-not-fat contents of milk samples collected from dairy farms were 6.627±0.135, 1.030±0.001, 0.165±0.022% lactic acid, 3.42±0.139%, 3.862±0.412%, 12.575±0.635% and 8.75±0.301% respectively. However, the corresponding values for milk vendors were 6.43±0.062, 1.025±0.001, 0.195±0.009% lactic acid, 3.274±0.083%, 3.85±0.284%, 12±0.572% and 8.15±0.308%. On the other hand, the respective values for pasteurized milk were 6.65±0.070, 1.031±0.0007, 0.15±0.014% lactic acid, 3.05±0.098%, 3.7±0.141%, 10.8±0.282% and 7.1±0.141% respectively. Significant differences (p<0.05) were found for the values of total solids, solids not-fat and protein between the sources of milk samples. The present study showed that dairy farm milk producers and milk vendors follow poor milk handling practices. Keywords: Fat, PH, Protein, Raw milk, Pasteurized milk

WEAP-MODFLOW dynamic modeling approach to evaluate surface water and groundwater supply sources of Addis Ababa city

The integration between WEAP and MODFLOW models coupled via LinkKitchen helps to create a dynamic link between surface water and groundwater supply sources of Addis Ababa city. Possible impacts of natural and anthropogenic stresses on surface water reservoirs volume and groundwater storage have been assessed through water supply scenario analysis. Besides, contrary to other surface water hydrological models, the unique nature of WEAP adds water demand assessment by simulating Addis Ababa city near future water demand coverage under three population projection scenarios. The water demand projections of Addis Ababa city indicates 100% water demand coverage will not be achieved for high (4.6%), medium (3.8%) and low (2.8%) population growth rate projections, even with all the emerging and planned water supply projects start production up until 2025. Supply scenario projections indicate, as surface water reservoirs are highly sensitive to climate change and variability, the city groundwater supply sources will be noticeably affected by the emerging and planned groundwater supply expansion schemes. If groundwater abstraction continues to reach to zero unmet demand, more than 30-meter groundwater level decline can be registered in 2025. To foresee the combined effect of both natural and anthropogenic stresses on Addis Ababa city water supply sources, best case (considering conditions which improve Addis Ababa city water supply) and worst case (considering conditions stressing Addis Ababa city water supply) scenarios were tested. The best case scenario results zero unmet water demand in Addis Ababa city in most wet months of future projection years up to 2025, with likely decline of about 6 meter on the groundwater level. The worst case scenario to the contrary shows, Addis Ababa city water demand coverage will potentially be reduced to a maximum of 35% in 2025, with seasonal and annual variability. The dynamic link between surface water reservoirs and groundwater supply sources helps to gain insight into the potential consequences of continuously changing natural and anthropogenic conditions on Addis Ababa city water supply sources. Consequently, the significant predicted near future pressure on Addis Ababa city surface water and groundwater supply clearly indicate planning and developing alternative water supply sources outside of the boundary (Upper Awash basin) where the city is located should be immediately started in order to endure the pressure from the ever increasing demand. Otherwise, not only Addis will continue suffering unmet water demand for the years to come, but also the water supply sources will be severely impacted. Nonetheless, wherever the water supply sources, minimizing water loss, recycling and improving water use efficiency should be given at most priority

REVIEW OF HYDROGEOLOGY OF TEKEZE RIVER BASIN: IMPLICATIONS FOR RURAL AND URBAN WATER SUPPLY IN THE REGION

This paper reviews the available published and unpublished data on the geology, hydrology and hydrogeology of the Tekeze River Basin (trb) with the aim to better conceptualize the hydrodynamics of the basin and its implications on the water resources potential for the development of rural and urban water supply system.  The work also highlights some of the knowledge gaps to fully understand the hydrogeology of the basin and proposes better scientific approach that will lead to the understanding of the movement and occurrence of groundwater in the complex river basin. The trb constitutes different rock types with ages ranging from Precambrian to Quaternary. These rocks are affected by different sets of faults, folds and lineaments with different orientations. The groundwater occurrence and flow is strongly controlled by the geomorphology, geological structures, type of rock and their hydraulic characteristics. The major aquifers in the basin are the Trap Basalts, the Antalo Limestone Formation, the Adigrat Sandstone and Quaternary sediments. An increase in permeability in shales and marls is observed due to the presence of dolerite dykes and sills. The Neoproterozoic basement rocks and associated intrusive bodies, and the Paleozoic sediments are characterised by shallow and localised aquifers. In many places the igneous intrusive bodies act as aquicludes. The major faults and associated drag folds in the basin form favourable conditions for groundwater recharge and groundwater localisation irrespective of lithology

Groundwater Recharge under Changing Landuses and Climate Variability: The Case of Baro-Akobo River Basin, Ethiopia

Impacts of landuse/landcover changes coupled with climate variability are well felt in areas of pristine environments like the dominantly high rainforest covered Baro-Akobo river basin of Ethiopia that form the Sobbat River system. Recharge is one of the hydrologic components to be influenced by induced anthropogenic changes. Quantifying and understanding changes in recharge and related hydrologic parameters help to properly manage the water resources and protect such vulnerable hydro-ecosystems. Among the various recharge estimation methods, WetSpass model is used for its capability to estimate recharge by coupling surface-subsurface water balances. It is also used to simulate yearly or seasonal averages of groundwater recharge, evapotranspiration and runoff that help to understand the basin’s hydro ecosystems dynamics. Modeling is done for the entire river basin of Baro-Akobo, taking into account landuse/landcover changes, varying climate and other physical parameters over the past four decades. Simulation results are validated using previous estimates, empirical methods using data from monitoring wells and isotope measurements. Bias corrected Climate Forecast System Reanalysis (CFSR) data are used to fill gaps in data scarce areas and to generate potential evapotranspiration. Field measurements, secondary data and fifteen months long three hourly well monitoring data are used to determine seasonal depth fluctuations of the groundwater. Landuse/landcover change of three periods, 1973 to 2014, and planned large scale development activities are used as inputs to see induced corresponding changes in the hydro-ecosystem. The simulated result showed small increase in runoff and despite the increase in temperature, there is a decrease in total evapotranspiration and significant increase in recharge in the recent period. The simulated result is also in line with the hydrogeologic characteristics of the basin making it a basin with low recharge as compared to basins in the central and eastern parts of the country. Coupled with other hydrological and hydrogeological characteristics of the basin, the result helps to understand the reason for finding large volume of surface flow entering the Machar wetlands and eventually reaching the White Nile from a relatively small watershed. Keywords: Land use- Land cover; Recharge; climate variability; WetSpass; Geolog

Resilience of rural groundwater supplies during drought in Ethiopia

As a result of climate change, sub-Saharan Africa, is expected to experience more frequent and extreme droughts, contributing to greater water insecurity. Droughts affect the reliability, quantity and quality of water available, potentially undermining recent gains in drinking water access and making it difficult to extend services. Ethiopia, in particular, is highly vulnerable to drought. Since 1965, Ethiopia has experienced 15 severe droughts affecting more than 65 million people and causing serious economic damage. Most recently, in 2015 and 2016, Ethiopia suffered a harsh drought, linked to El Nino, which forced more than 10 million people to rely on emergency aid due to crop and water supply failures. During the 2015-16 drought significant effort was made to monitor and understand the performance and use of rural water points. Drawing on two recently published studies we demonstrate that with adequate monitoring and maintenance rural groundwater points can deliver a consistent and safe water supply during drought. The first study monitored a total of 5196 water points (hand-pumps, motorized boreholes, springs, open-sources) and the success of a maintenance programme, every week for 12 weeks in early 2016. Enumerators used questionnaires on mobile phones to gather quantitative and qualitative data from those responsible for water points. The second study involved monitoring 51 groundwater points (hand-pumps, springs, hand-dug wells) over an 18 month period. Water sources were equipped with water level loggers and water was tested monthly for Thermo-tolerant Coliforms (TTCs). All sources were put under considerable strain during drought. Most demand was placed on motorised boreholes in lowland areas. Increases in functionality for motorised boreholes, as a result of the maintenance programme, lagged behind those of hand-pumped boreholes. More complex technologies have longer downtimes due to a lack of appropriate and/or accessible maintenance skills. Real time-monitoring and effective information flow helped facilitate responsive and proactive maintenance of infrastructure, and ensured demand was spread across a larger infrastructure portfolio reducing pressure on individual sources during the drought. Water level monitoring showed that shallow boreholes equipped with handpumps recovered quickly from daily abstraction. Recovery rates of hand-dug-wells and springs was longer. All sources were contaminated during the rains marking drought cessation but boreholes were least affected. We conclude that prioritising access to groundwater via multiple improved sources and a portfolio of technologies, such as hand-pumped and motorised boreholes, supported by responsive and proactive maintenance, increases rural water supply resilience to drought and climate change

Performance of rural water supplies during drought in Ethiopia

During the El Nino drought in Ethiopia in 2015-16 significant efforts were made to monitor the performance of rural water points. Using data from 5196 water points we demonstrate that with adequate monitoring and maintenance, groundwater sources deliver reliable water supply during drought. Our results have implications for resilient water supply across rural sub Saharan Africa

Groundwater potential mapping using GIS and remote sensing with multi-criteria decision-making in Shinile sub-basin, eastern Ethiopia

The main challenge for water resources development as well as food security in arid and semi-arid regions of Ethiopia is the hydroclimatic variability. Groundwater resources are largely the main sources of water supply in such regions, alleviating the pressure of hydroclimatic variability on water resources. The present study delineated the potential groundwater zones in the Shinile sub-basin by using geospatial techniques. The criteria used were: geology, geomorphology, slope, soil, lineament density, drainage density, land use land cover, topographic wetness index, topographic roughness index, and rainfall. The relative weights were given by the analytic hierarchy process. A validation was done using the area under the curve (AUC=0.941) of the receiver operating curve (ROC) from borehole data. The study region was partitioned to low, moderate, and high potential groundwater zones having respectively 1.5%, 43%, and 55% of the total area. The high potential areas are concentrated in the central part where alluvial and lacustrine sediment is the dominant geologic unit. The validation results suggest that the geospatial identification of groundwater potential zones effectively performed well in the study area. This study is very important for water management experts as well as for stakeholders and policymakers in the study region

Regional-scale interactions between groundwater and surface water under changing aridity: evidence from the River Awash Basin, Ethiopia

Relationships between surface waters and groundwaters at basin scales are rarely investigated but have important implications for water resource development and management. Here, we integrate evidence from geochemical tracers and piezometry to advance understanding of regional-scale, groundwater-surface water interactions in the River Awash Basin of Ethiopia. Hydrological characteristics are consistent with those observed in other semi-arid and arid basins where rivers are predominantly losing and act as a source of recharge rather than as a sink for groundwater discharge. Further, regional groundwater flow originating from the highlands exits the catchment rather than discharging to the riverine drainage. Consequently, groundwater abstraction from several regional-scale aquifers in the lowlands is not expected to impact river flow. However, salinity presents a major threat to irrigation and water supply. We identify critical areas for managing inflows, water use, wetlands and water quality that have significant implications for water security across the basin

A Hidden Crisis? Findings from research into borehole failure in Ethiopia, Malawi and Uganda.

Poor functionality of rural water points continues to be a problem which plagues the sector. In this webinar we discuss some of the main results from the second phase of the UPGRO Hidden Crisis Project which has been examining the issue in Ethiopia, Uganda and Malawi. After a brief overview of the project we report the results of 18 months of detailed fieldwork undertaking a forensic analysis of 150 failing waterpoints across the 3 countries sharing lessons from what we found of the physical factors contributing to poor performance and lessons about community management