Petrography and Geochemistry of the Rocks in Lodwar, Kenya and their Influences on Groundwater Quality

This paper evaluates the influence of rock chemistry on groundwater quality in the region of Lodwar County, Kenya. Rock geochemistry influences groundwater quality and the aquifer processes of an area. Therefore, this study used conventional petrography and geochemistry techniques to measure the mineralogical compositions of 69 rock samples. The geological study area comprised of quartzo-feldspathic gneiss and biotite gneiss of the Precambrian basement, as well as sedimentary Turkana Grits and Holocene sediments, Tertiary volcanics comprising nepheline phonolites and augite basalts, alluvial deposits along the banks of major Streams and laggas. Quaternary sands also blanket much of the area. The results demonstrate that that geological factors and processes have location-specific influence on groundwater quality. These should be considered in aquifer water-quality studies and supply development across Africa’s vast ASAL regions.

Hydrochemical and isotopic characteristics of the Lodwar Alluvial Aquifer System (LAAS) in Northwestern Kenya and implications for sustainable groundwater use in dryland urban areas

This paper assesses the Lodwar Alluvial Aquifer System (LAAS), a crucial resource to northwestern Kenya amid its drylands and unreliable surface water supply. The researchers aimed to study the aquifers hydrochemical and isotopic characteristics to better understand how to manage this groundwater system. Therefore, during the May 2018 wet season, they collected 112 water samples to establish isotopic compositions of rain, spring, surface water and groundwater. Understanding recharge sources and aquifer vulnerability of similar strategic aquifers can help scientists appropriately advise policymakers and the water community who develop sustainable water use, aquifer protection and conservation strategies. As well as providing insight in this regard, the study contributes scientific evidence of isotopic compositions of groundwater in the Horn of Africa.

Unbundling water and land rights in Kilifi County, Kenya a gender perspective

Feminist scholars have highlighted the importance of women’s land rights, and irrigation studies have explored the gendered relationships between land and water rights. However, less research has been conducted which assesses the relationship between water and land rights for domestic and productive purposes. Therefore, by collating community profiles, focus group discussions, interviews and survey data, this study explores women’s rights to land and water within rural communities in Kilifi County, Kenya. It provides interesting insight into the dynamics and negotiations of water access, including the social networks that affect how water transactions take place.

Multibranch Modelling of Flow and Water Quality in the Dhaka River System, Bangladesh: Impacts of Future Development Plans and Climate Change

The rivers of Dhaka, Bangladesh, suffer high levels of pollution from untreated sewage and industrial effluent. To address this, over the next 20 years, the government is planning to install 12 large Sewage Treatment Plants (STPs) across the Dhaka River System. This paper applies a water quality model to assess the efficacy of this planned investment. The model suggests that the STPs will improve water quality in the most densely populated areas of the city along the Turag and Buriganga rivers, and in some other parts of the city (Tongi Khal). However, future upgrades will be needed to improve dissolved oxygen levels more widely, due to predicted population growth. Policies to reduce industrial pollution should also be pursued.

Hydrologic Extremes in a Changing Climate: a Review of Extremes in East Africa

This review presents recent research on drivers and typologies of climate extremes across different East African geographies. Droughts and floods remain the major challenges of the region. There are improvements in forecasting these extremes, but further research is required to improve understanding of key drivers and improve information provision for risk-based decision-making.

Environmental isotopes (δ 18O–δ 2H, 222Rn) and electrical conductivity in backtracking sources of urban pipe water, monitoring the stability of water quality and estimating pipe water residence time

In this paper, environmental isotopes and electrical conductivity are used to investigate water quality variations in the urban piped water network of Addis Ababa, Ethiopia. The isotopic signature of the water allows the back-tracking of tap water to its source and also provides insights into pipe water residence time for groundwater-sources supplies. The tracers reveal that 50% of the city relies on groundwater, and that groundwater-sourced water supplies show the highest water quality instability. One important cause of water quality variation in the city is borehole stoppages and reconnection as a result of electricity cuts.

Evaluating the effects of geochemical and anthropogenic factors on the concentration and treatability of heavy metals in Awash River and Lake Beseka, Ethiopia: arsenic and molybdenum issues

This study assesses heavy metal and pollution sources within the Awash River Basin, in Ethiopia. In this region, significant urbanization and industrialization have caused pollutants to enter water bodies on a large scale. After finding high levels of heavy metals across surface water sampling stations, the study advocates for increased efforts towards water security within the Addis Ababa and Awash watershed region.

Evaluating the structures and arrangements of water institutions to include in-stream modeling for water quality management and control pollution: Insights from the Awash Basin, Ethiopia

In sub-Saharan regions, human activities are causing stream water quality to decline. This study assesses stream water quality issues in the Awash Basin of Ethiopia, identifying key sources of land-based pollutants. Applicable models with the capability of simulating the Awash streams are presented, and recommendations towards improved use of water quality modelling for development planning by Awash Basin institutions are made.

Information synthesis to identify water quality issues and select applicable in-stream water quality model for the Awash River basin in Ethiopia: A perspective from developing countries

In-stream water quality models can help prepare effective planning strategies to tackle problems with stream water quality and understand pollutant dynamics in stream systems. In this study, water quality issues in the Awash Basin were reviewed to select an applicable in-stream model to support local model practitioners in creating improvement in water quality management. QUAL2KW and INCA models are found more applicable for the present conditions, while the WASP model may be useful to conduct detailed analysis.

Assessing heavy metal contamination using biosensors and a multi-branch Integrated Catchment Model in the Awash River Basin, Ethiopia

The Awash River Basin in Ethiopia faces rising heavy metal concentrations due to poor wastewater management and loose enforcement of regulations around effluent discharge. Acute toxicity of surface and wastewater samples was measured using new molecular biosensor technology based on engineered luminescent bacteria. A multi-branch Integrated Catchment model (INCA) simulating tannery discharge under different treatment scenarios indicates that a 50% reduction in effluent concentrations could produce a 20 to 50% reduction in heavy metal concentration in the river over two years.

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