Abbay Journal of Water and Environmental Sciences

A Investigation of household drinking water quality in Dembia District, Tana Basin, Ethiopia

2025-12-31T13:40:59+00:00

Access to safe and adequate drinking water is essential for human health, yet many communities in developing countries, including Ethiopia, still depend on water that is not microbiologically safe. Even improved water sources can become contaminated due to poor source protection, improper handling, and unsafe household storage. This study assessed the physicochemical and microbiological quality of household drinking water sources within multiple-use water systems in Dembia District, northwestern Ethiopia. A total of 22 water points from rural and urban kebeles were randomly selected and evaluated through sanitary inspections and laboratory analyses following WHO guidelines. Most physicochemical parameters met guideline values, with iron concentrations below 0.3 mg/L, manganese below 0.4 mg/L, fluoride below 1.5 mg/L, and chloride below 250 mg/L in all sources, except for one hand-dug well that showed a higher chloride level (185 mg/L). In contrast, turbidity and microbial contamination were key concerns, particularly in rural areas. Total coliforms were detected in 18.1% of urban and 36.4% of rural water points, while fecal coliforms were present in 9.0% of urban and 22.7% of rural sources, indicating potential fecal contamination and related health risks. Overall, although chemical water quality was largely acceptable, the presence of coliform bacteria in several sources highlights the need for improved source protection, routine chlorination, and household-level water treatment to ensure safe drinking water.

Keywords: Drinking water quality; WHO guidelines; physicochemical parameters; Microbial contamination; rural water supply; Water sustainability

crop water productivity of maize under koga irrigation condition

2025-12-31T13:27:41+00:00

Water is a vital natural resource for human survival. The lack of freshwater is becoming a major problem for both general growth and ensuring food self-sufficiency. Water management techniques that focus on prudent water resource management are therefore essential. This study aimed to investigate the effects of deficit irrigation on yield, water productivity, and the reduction of blue water footprints, particularly with regard to different kinds of mulching. To examine the combined impact, deficit irrigation and mulching—a layer of organic or inorganic material placed to the soil's surface to improve aeration, retain moisture, and lower evaporation—were used. The field experiment was set up using a Randomized Complete Block Design (RCBD) with three replications. Treatments included three mulching techniques (no mulch, wheat straw mulch, and white plastic mulch) and four (DI) levels (0% (full irrigation), 20% (80% ETc), 40% (60% ETc), and 50% (50% ETc). The pan evaporation method was used to calculate the irrigation schedule. Using the R software, agronomic parameters were statistically examined using analysis of variance (ANOVA). These research' findings demonstrated the interaction effects of DI and mulch on yield, water productivity, and the reduction of blue water footprints. The treatment combination of DI level (50% ETc) and plastic mulch showed the least reduction in consumptive water footprint. The combination of full irrigation and no mulching resulted in the greatest reduction in blue water footprint (101.433). It indicates that the yield of maize at 80% ETc with a combination of plastic mulch treatment was 27.27% greater than at full irrigation (100% ETc) without mulch and 3.17% higher than the DI level of 60% ETc with plastic mulch, but the yield was not significantly affected. Consequently, this approach with plastic mulch was chosen by 60% of farmers. The water productivity results showed that a treatment with DI level of 50% ETc with plastic mulch was 128.9% higher than full irrigation (100%) with no mulch. The lowest marginal rate of return depth of irrigation 60%ETc with nm followed by depth of irrigation 80%ETc with nm. Plastic mulch with DI had showed better marginal rates of return.

Key words: mulch, DI, yield, water productivity, and water management

Spatial Heterogeneity and Fragmentation Trends of Ecosystem Services: The Case of Highland Watershed

2026-01-01T10:07:38+00:00

Landscape fragmentation and heterogeneity are poorly understood and acknowledged in the Ethiopian highlands. Land fragmentation has both direct and indirect relationship with productivity, water resource, sediment load and enviorment. This study aims to spatially characterize the state of heterogeneity and fragmentation of ecosystem services (ES) since 1957. The data were obtained from the aerial photograph and field data. Indices were used to analyse fragmentation and heterogeneity. A total of 1869 parcels were mapped using GPS. Average crop landholding size and number of parcels per household was 0.18 ha and 4.5, respectively. The density of cropland was 150 parcels/100 ha and of shrubland was one parcel/100ha. The highest number, density, dominance and smallest size were revealed for food providing land parcels. However, cultural service providing parcels are larger in size. The increase of demand and the different use rights for ESs caused to increase the heterogeneity of the land cover types. The analyses indicated that there has been an increasing trend of land fragmentation. Such condition deteriorates productivity of the resource base and diminishes benefits from the ESs. The study recommends research and policy tools (such as clustering similar land units) to limit further fragmentation and calls for more work on how fragmentation affects productivity, water, environment and land management decisions.

Removal of Chromium (VI) from Synthetic Wastewater Using Industrial Marble Waste

2026-01-15T10:26:10+00:00

Spatiotemporal Assessment of Pollution Levels in the Southern Gulf of Lake Tana

2026-01-01T10:07:35+00:00

This study investigates the spatial and seasonal patterns of pollution in the southern Gulf of Lake Tana, Ethiopia. Lake Tana plays a crucial role in supporting aquatic biodiversity and supplying water to surrounding communities; however, escalating human activities have raised concerns about its water quality. Through systematic sampling and analysis, the study assesses the distribution of pollutants and their seasonal and spatial variability. An integrated methodological framework combining GIS, remote sensing, and physicochemical water quality assessment was employed to provide a comprehensive understanding of pollution dynamics. The results show that dissolved oxygen concentrations recorded mean values ranging from 8.21 to 9.52 mg/L during both dry and wet seasons. Mean total dissolved solids ranged from 97.32 to 99.75 mg/L in the dry season and from 97.81 to 104.02 mg/L in the wet season, revealing a decreasing trend from near shore reference points toward the open lake with increasing horizontal distance. In contrast, turbidity values increased horizontally, rising from an average of 11.48 to 16.43 NTU. Phosphate concentrations exhibited marked seasonal and spatial variability, with mean values ranging from 9.43 to 9.53 mg/L in the dry season and from 0.64 to 1.22 mg/L in the wet season, indicating significant differences among sampling stations. Overall, the study demonstrates that the physicochemical characteristics of Lake Tana vary both spatially and seasonally, particularly in areas adjacent to the shoreline near Bahir Dar City, highlighting clear evidence of pollution impacts within the lake.

Keywords: Physicochemical parameters, Spatio-temporal variations, GIS, Lake Tana, pollution

Investigating reservoir sedimentation for two micro earth dams in the Ethiopian Highlands.

2026-01-01T10:07:31+00:00

Reservoirs serve multiple purposes, such as providing water for irrigation and domestic use, flood control, and hydropower generation. However, they are prone to sediment accumulation due to watershed erosion. Understanding erosion and sedimentation processes is essential to determine sedimentation rates and identify factors contributing to these issues. Various methods exist for estimating sediment delivery, and this study employed a bathymetric survey to assess sediment deposition and erosion in the Anjeb and Abrajit reservoirs. Additionally, RUSLE was used to simulate watershed sedimentation. The findings revealed significant differences in sediment impoundment between the reservoirs, with noticeable bathymetric changes due to sedimentation. Both reservoirs were found to be heavily silted before reaching their intended lifespans.

The RUSLE analysis estimated annual soil loss at 1374.71 t/km²/y for Abrajit and 1518.23 t/km²/y for Anjeb, much lower than the bathymetric results of 9362.29 t/km²/y and 12889.61 t/km²/y, respectively. The soil loss rates and spatial patterns align reasonably well with records and prior studies. In 2013 and 2021, Anjeb's capacities and sediment volumes were 1.0720 and 0.9534 Mm³, respectively, with an estimated live storage capacity loss of 0.119 Mm³. The long-term average annual sedimentation rate was 12,889.61 t/km²/y for Anjeb (8 years) and 9,362.29 t/km²/y for Abrajit (13 years). Bathymetric surveying revealed average annual storage losses of 11.12% for Anjeb and 4.5% for Abrajit.

Building strategic communication to “tell GERD Stories to the world”, Improving Ethiopian GERD Communication Strategy

2026-01-01T10:07:28+00:00

Strategic communication can play a critical role in helping to decrease negative externalities associated with the GERD dispute. Specifically, it is used to pinpoint barriers both externally and internally by telling the truth behind the construction of the dam and the negative role played in Egyptian diplomacy. The Egyptian highly used digital diplomacy to influence the course of the dispute. Egypt used campaign strategies to make their truth heard by the world in the form of propaganda. The joint plan of action used by Egyptians includes media diplomacy. This paper is mainly based on secondary data analysis of the available secondary information and newspaper articles, online articles, and academic literature

The “Water, Hydro-diplomacy and communication forum” formed to discuss various issues to have a clear understanding of GERD and a transboundary river issue is a good beginning. However, the effort has to go beyond this. Ethiopia has to use digital tactics to fruitfully introduce the truth to both the riparian countries and to the world through strategic communication using different media channels under the campaign “to tell GERD stories to the world". Additionally this article also found the importance of “GERD” day for the Ethiopian people to continue on this path with unwavering dedication, protecting the prosperity and legacy for generations to come

Wavelet Analysis of Hydroclimatic Teleconnections and Precipitation Variability over Ethiopia

2026-01-01T10:07:24+00:00

Atmospheric variables like precipitation and stream flow are significantly influenced by various climatic factors and large-scale atmospheric circulation patterns. Investigations into the variation of rainfall by different large-scale oceanic impacts are very fundamental for the economy and climatic maintenance of the country. The study examines the variability of precipitation over Ethiopia through the analysis of monthly and annual rainfall data at five stations in the north, east, west, south, and central parts of Ethiopia from 1987 to 2017 for 31 years. Standardized precipitation ratio (Ip) and wavelet analyses were applied to examine the spatiotemporal variability of precipitation and to determine the effect of oceanic fluctuations on rainfall variability. The calculated standard precipitation index (Ip) indicates the year-to-year variability of rainfall over Ethiopia, which lies between 3.2 and -2. The continuous wavelet technique applied to the yearly time series of precipitations over five stations in Ethiopia reveals short- and long-term periodicities like 2-3, 3-5, and 6â€“10 years at different time periods. The oceanic indices reveal long-term oscillations like 2-3, 3-5, 6â€“10, and 8â€“13 years over different time periods. The rainfall and oceanic fluctuations show similar periodicity in some parts of Ethiopia. Our analysis reveals that the northern part of Ethiopia is negatively affected by Nino-4 during 1992-2003 with a flood event (wet 2.5) around 2001, the southern part is negatively affected by NAO during 2009-2016 with a severe drought (dry -2) in 2014/2015, the western part is negatively affected by SOI during 1992-2005 with two severe droughts observed around 1994/1995 (dry -1.8) and 2003 (dry -2), the eastern part is negatively affected by MOI during 1995-2000 with a drought around 2000/2001, and the central part is negatively affected by Nino-4 during 2002-2010 with a drought (dry -1.3) around 2004/2005.

A Review of Water Footprints for Irrigated Vegetables under Conservation Agriculture in the Ethiopian Highlands.

2026-01-01T10:07:42+00:00

Water footprint (WF) accounting has the potential to provide crop water use metrics and can assist farmers to improve water uses. However, WFs for smallholder irrigated vegetables under conservation agriculture (CA) practices have not been accounted in the Ethiopian highlands. This research was conducted aiming to better understand the potential advantages of irrigated technologies for saving water in the sub-humid highlands. Results showed that the highest irrigation water saving (25%) was found under CA for overhead irrigation application on tomato in the dry period while the lowest water saving (9%) was found under CA compared with CT under Majipump drip system of onion. On the other hand, the evapotranspiration (ET) in the conventional tillage (CT) under the overhead irrigation, when compared with the CA, was in the ranges of 38-96% while the value is lowered to the range of 7-10% for drip irrigation. In the dry phase of vegetable production, blue WF in CA was reduced by about 1.7 times when compared with the CT while the green water was reduced by about 5.7 times when compared with the CT. In general, the total WF was about 2.2 times lower under the CA when compared with the CT.

Optimizing Water Conservation and Crop Yield: Evaluating the Blue Water Saving Potential of Deficit Irrigation and Mulching in the Nile Basin

2026-01-01T10:07:21+00:00

This study aims to investigate the potential water savings achieved through implementing deficit irrigation (DI) combined with mulching in the Nile Basin countries. The study analyzes the effects of blue water consumption and water footprint (WF) on various crops in the Nile basin countries. We utilized the AquaCrop-OS model to evaluate the effects of blue crop water use and water footprint of dominant crops. Changes in blue crop water use (CWU) varied between countries and crops, ranging from -34% to -1%. Yield varied in the simulations, with some decreases and some increases compared to the reference (R). The blue water footprint exhibited relative changes ranging from -47% to 35%. The changes in blue water footprint (measured in m³/y) resulting from deficit irrigation and mulching impacted production while maintaining a constant irrigation area. In South Sudan, for cotton, Deficit irrigation (DI1) resulted in a -12.5% relative decrease in blue WF compared to R. However, the reduction in blue WF was more significant (-37.2% relative decrease) when DI1M compared to R. Other countries also experienced varying reductions in blue WF for crops. These findings show the possibility of saving water while keeping production levels stable. In Egypt, DI1 resulted in an 8.0% reduction in blue WF compared to R. Combining DI1M led to a more significant reduction of 37.2%. This study provides useful information for water conservation decision-makers in the Nile Basin countries.