Streamflow and Salt Flux in Seasonal Rivers: The Case of the Semi-Arid Tiva River Basin, Kenya

This paper presents the results of a study on the influence of streamflow variability on salinity, total dissolved solids (TDS) and conductivity in a semi-arid Tiva River Basin in Kenya. Measurements of salinity, TDS, conductivity and river discharges were undertaken in sampling stations by applying standard hydrologic methods. The mean and maximum river discharges for the sub-basins of the river ranged from 11 to 33 m3s-1 and from 118 to 210 m3s-1, respectively, with the peak river discharge at the main Tiva  branch being 270 m3s-1.  The study shows that there is a significant relationship between the variability of streamflow and the variability of salinity, conductivity and TDS in the river. The relationships between streamflow and salinity were best represented by power functions rather than linear regression functions. The relationships were negative so that the levels of salinity, conductivity and TDS decreased with an increase in river discharge.  Salinity, TDS and conductivity were also inversely correlated to turbidity. An increase in turbidity corresponded to a decrease in conductivity and hence salinity and TDS. The low conductivity at high streamflow conditions were attributed to the dilution effect of increased volume and also by the presence of high proportion of non-conductance organic and inorganic materials such sand and clay.  The highest TDS, conductivity and salinity values were measured during the low flow (baseflow) conditions and the concentrations were lowest during high streamflow conditions. It is postulated that the high concentrations were a result of high evapotranspiration and seepage of subterranean water from bank storage and groundwater aquifers, and that low concentrations were a result of dilution and flushing effect of high streamflow. Inter-subbasin variations in the levels of salinity were attributed to differences in landuses, lengths and sizes of the sub-basins. The effects of upstream irrigation were evident in one of the main sub-basins-Mwitasyano river where the highest salinity levels (max: 3.4%; mean 1.1%) were measured. The total salt flux from Upper Tiva river basin was estimated to be 100,344 tonnes.yr-1 with basin salt production rate of 27.87 tons.m-2.yr-1. This salt flux was attributed to the nature of the basement complex metamorphic rocks (e.g. Kankur limestone) through which the river drains. The influence of irrigation upstream was noted to be important in the Mwitasyano sub-basin that contributed 61% of the total salt load. The study emphasizes the need for water resources and agricultural development programmes in the semi arid Tiva River Basin to promote sustainable irrigation and landuse practices. It is suggested that construction of water reservoirs in the Tiva basin would help in controlling salinity levels in the river. Keywords: Tiva River; Salinity; Total Dissolved Solids (TDS); Streamflow; Salt fluxes; Keny

Bringing Romanticism into urban landscapes: how investment in parks and open green spaces helped revitalize the City of Chattanooga, TN

The romantic preservation movement is credited with helping preserve many parks and wilderness areas in the U.S.A. The philosophy behind romanticism espoused respect for nature and enhancement of its integrity as opposed to fear for nature and the attempts to conquer it. What if those same principles of reverence for nature and ecological integrity were integrated into urban landscapes? There is increasing recognition of the role of proximity to nature in enhancing the wellbeing and quality of life and thus an effort to enhance and bring back green infrastructures urbanized areas. Residents and visitors use such spaces for recreation, connection with nature and also for educational purposes. This research looks at the role of urban parks and other green infrastructures in the rebirth of the City of Chattanooga, TN, once the dirtiest city in America. Findings suggest that investment in environmentally-sensitive recreation amenities were pivotal in re-imaging the city

Seasonal river channel water exchange and implications on salinity levels in sand dams: Case of semi-arid Kitui Region, Kenya

This paper presents results of a study on the variations of salinity levels (and associated physico-chemical parameters) in sandbeds of seasonal rivers found in the semi-arid region of Kenya. The study sought to investigate the interaction between water in river sandbeds and bank storage and how this interaction influences salinity levels in sand dams and shallow wells in semi arid lands. The results of the study show that there is a significant relationship between water quality parameters in dry river sandbeds and the corresponding water quality parameters in shallow wells and sand dams. Within river sandbeds, the dry season salinity ranged from 0.9 to 12.8% while the wet season salinity ranged from 0.4 to 1.1%. The wet season total dissolved solids (TDS) concentrations ranged from 77.8 to 272 mgl-1. The dry season TDS concentrations were high ranging from 227 to 3,320 mgl-1. The wet season water conductivities were  however low ranging from 155.9 to 539 µS.cm-1 as compared to the dry season conductivities that were high ranging from 455 to 6,640 µS.cm-1. As compared to the river channel sandbeds, water in shallow wells and sand dams was characterized by relatively high levels of physico-chemical parameters with salinity ranging between 1.5% and 6.5% and TDS concentrations ranging from 396 to 1,680 mgl-1. The level of salinity in sand dams and shallow wells tends to be much higher than those in the stream channel sandbed. Also, within the river channel sand beds, the levels of salinity were mostly within the minimum allowable limit for drinking water except in extended drought periods. The relatively high salinity, TDS concentrations and conductivity were attributed to mineralization of water due to entrapment, ground water recharge and solubisation of minerals from soils. The study shows that the flow of water within sand bed matrix is characterized by low hydraulic conductivities and water fluxes and this has important implication on the salinity levels in sand beds of seasonal rivers.   Keywords: Sandy river channel; water exchange; bank storage; salinity; Kitui, Kenya

The Study of the Effects of Mau Catchment Degradation on the Flow of the Mara River, Kenya

There is growing concern however, regarding land degradation in the Mara River Basin in Kenya, particularly deforestation in the headwaters; that is affecting the natural resource base and the river flows. Scientific studies are required to advise on policy issues, and to plan appropriate mitigation measures in the basin. This study utilized remote sensing and geographical information system (GIS) tools, and hydrological and ground-truth studies to determine the magnitude of the land-use/cover changes in the Mara River Basin, and the effects of these changes on the river flows over the last 30 years. The results of the studies indicate that land-use/cover changes have occurred in the basin. In 1973, for example, rangelands (savannah, grasslands and shrublands) covered 10,989 km2 (79%) of the total basin area. The rangelands have now been reduced to 7,245 km2 (52%) by 2000. The forest areas have been reduced by 32% over the same period. These changes have been attributed to the encroachment of agriculture, which has more than doubled (203%) its land area over the same period. To investigate the effects of land cover change on river flow, stream flow was generated from derived land cover thematic maps of 1973 and 2000 using the same rainfall and evaporation data of 1983 to 1992 period. The  other  model  input  datasets  for  topography  and  soils  were  held  constant during the two runs. The differences in the generated hydrographs could only be associated to the changes in land cover, which was the only variable. The percentage difference between the mean annual stream flows of the two hydrographs was negligible at 0.01%. This study therefore  concludes  that  land  cover  changes  in  the  basin  have changed the day to day flow characteristics of the  Mara river but the annual flow volumes remain unaffected. There is need for urgent action to stem the land degradation of the Mara River Basin, including planning and implementing appropriate mitigation measures. Keywords: SWAT model, Mara River Basin, Hydrological Modelling, River Discharge

Sand Gradation in Seasonal Rivers and Their Suitability for Construction of Sand Dams in Kitui South, Kenya

This study was undertaken in Kitui South in Kitui County in the south eastern parts of Kenya. The main objective of the study was to develop a spatial model that can be used for selection of suitable sites for sand dam in Kitui South. The study also assessed the spatial variation of sand grain sizes and how these determines the suitability of sites for the sand dams. Data analysis was done using three approaches. The first approach involved the use of the Remote Sensing (RS) technique where data was preprocessed and analyzed using Erdas Imagine software and Geographical Information Systems (GIS) for spatial modelling. The distribution of sand particle-sizes was based on sieve analysis on the sand samples collected from seasonal rivers in the study area. The seasonal rivers that were investigated in this study included Mwila, Kakya, Wiitu, Nguni, Ngunyumu, Muvuko, Kanzilu, Masaa, Katiliku, Ngulungu, Nzeeu, Koma and Katitika. Statistical analysis was done to establish the relationships between the various spatial components affecting sand particle distribution. The results from the spatial model which integrated all factors shows that 16% of the studied sites along the seasonal rivers in Kitui South were fairly suitable for construction of sand dams while 79% were classified as suitable and 5% are categorized as very suitable. Several sites in the central and the entire eastern parts of Mutha Ward were found not suitable for sand dam construction due to poor conditions such as the lack of suitable sand particles, lack of bedrock exposure on the riverbeds, flat terrain, very shallow stream banks, and weak soils on the riverbanks. Suitable sites for sand dams were found on the western and central areas of Kitui South where production and high accumulation of coarse sands was observed along the seasonal rivers. The areas near Mutomo hills and the rocky areas in Ikanga wards were found to be characterized with few excellent sites for sand dams. The optimum accumulation of different grades of sand in the seasonal rivers was found on streams with slope of between 1.5 and 6% that were dominated with0 to 40% coarse sands, 0 to 30% fine gravels, 0 to 20% fine sands, and 20 to 80% medium sands. The accumulation of fine gravels was found to be closely related to the distribution of D30, D60 and D90sand particle-sizes (0.4-4mm) while accumulation of coarse sands showed good relationship with the distribution of the medium size sand (0.2-0.4mm). The accumulation of medium sands was equally high when the occurrence of coarse sands was minimal. Different grades of sand were found to be strongly influenced by the changes in the elevation of the stream especially with regard to the accumulation of the medium sands (r= 0.76) and coarse sands(r=0.75). Out of 80 investigated sites, 59% of them were dominated with uniform sands (Cu<3), 30% were intermediate sands and only 11% were well-graded sands (Cu>5). The study also found that86% of the sites along the seasonal streams were dominated with medium sands while 10% were dominated with fine sands and the rest (4%) dominated by coarse and gravelly sands. From the results this study concludes that 59% of the 80 sites that were investigated in this study have a high potential for providing suitable sites for sand dams in Kitui South. Keywords: Sand Dams; Particle Size Distribution; Hydrology; Water Management; Kitui South, Keny

The Impacts of Water Abstraction in Tropical Rivers: A Case of South West Upper Tana Basin, Kenya.

The study to determine the impacts of water abstraction in South West Upper Tana Basin which is part of the larger Upper Tana basin was undertaken in four major rivers, Thika, Kimakia, Kiama and Chania. Data for this study was obtained from the Kenya Meteorological department (KMD), Water Resources Management (WRA) and questionnaire surveys. The questionnaires were administered in the period between January 2018 and December 2018 to determine the impacts of water abstraction in both dry and wet seasons. Regression and correlation analysis was used to determine the nature and strength of relationships between different variables. The results of the study indicate that the main impacts of water abstraction are hydrological, environmental and socio-economic. The hydrological impacts include reduced water levels, changes in stream morphology, decreased turbidity and reduced siltation. Socio-economic impacts include increased income from crop production and conflicts while environmental impacts were mainly changes in riparian vegetation. The study established that the best combination of impacts of water abstraction in the South West Upper Tana Basin were changes in water turbidity, decline in water levels, improved crop yields, changes in channel morphology and siltation with a coefficient correlation r of 0.57 and coefficient of determination R2 of 0.52. To mitigate these impacts, there is a need for better enforcement of legislations on water abstraction and the monitoring of the river basins to curb water over-abstraction. Public awareness campaigns and involvement of stakeholders could also minimize these impacts. Keywords: Water abstraction, hydrological impacts, socio-economic impacts, environmental impacts, South West Upper Tana Basin (SWUT). DOI: 10.7176/JEES/9-5-08 Publication date:May 31st 201

An Assessment of the Spatial and Temporal variations of Groundwater quality in Yatta Plateau in Kitui County, Kenya

The study is primarily focused on the assessment of groundwater quality in the Yatta Plateau of Kitui County. The study focused on the spatial temporal distribution of key chemical parameters namely pH, TDS, Colour, Total hardness, Turbidity, Conductivity, Total alkalinity, Fluoride and Iron. Groundwater samples were collected four times from the six target boreholes found on the plateau in the period between March 2015 and March 2016. The sampling programme covered two dry seasons and two wet seasons. Key physicochemical parameters were analysed using standard laboratory methods. The water samples were analyzed at the Water Resources Management Authority (WARMA) Water Quality Testing Laboratory in Nairobi. The results of the study show that there is no direct relationship between rainfall and variations of groundwater quality in the Yatta plateau. The influence of water abstraction on water quality was also limited. The dominant influence on groundwater quality in the Yatta Plateau was found to be the geological characteristics of the area. It was however found that there was spatial-temporal variability in different groundwater quality parameters that were analysed. The study recommends integrated groundwater resources management including continuous water quality monitoring in the Yatta Plateau in Eastern Kenya. Key Words: Groundwater quality, physic-chemical parameters, spatial-temporal variability, Yatta Plateau, Keny

Financial Deepening And Economic Competitiveness In Kenya: The Strides To Being An Economic Power House

Economists have long held the view that financial deepening and economic development are closely intertwined. Kenya’s development blue print, Vision 2030, is anchored on this belief and aims to create a vibrant, globally competitive financial sector, envisioning Kenya as a leading financial centre in Eastern and Southern Africa. Using descriptive survey design, this study investigated the state of financial deepening in Kenya and how this enhances the country’s economic competitiveness. Data was collected from a key informant in the four largest banks by asset base that have subsidiaries/branches in other East African countries using a structured questionnaire. It focused on Mobile banking, Agency banking and credit referencing as indicators of financial deepening and established that Kenya has made remarkable strides in financial deepening, which has enhanced the country’s competitiveness through wider access of financial services, reduced operation and transaction costs, product diversification, superior customer experience and reduced loan default rates

A Survey of Supermarkets in Kakamega Town

Abstract Supplier quality management is one of the very many simple concepts that make a lot of sense to any well meaning organization. Unfortunately, implementing the concept is not very simple and over the years, companies have crumbled due to failure to master the best practices in supplier quality management. Practices such as measuring the performance of suppliers, engaging suppliers in quality management systems, supplier audits, supplier development, integration and competitive supplier selection are a great opportunity to improve organizational performance in terms of customer service delivery levels and operational costs reduction. However, it is worth noting that there are numerous challenges encountered in having such practices accepted by all the stakeholders. The purpose of this study was to determine the effect of supplier quality management on organizational performance, covering all the supermarkets in Kakamega town. The study employed a descriptive survey design and the study population was the procurement managers of the supermarkets. Data was collected using structured questionnaires which were administered by the researchers through a drop and pick technique and it was descriptively analyzed. The study also explored the potential integration of supplier quality management practices into an organization’s operations, focussing on the currently available applications. The study recommended that suppliers should maintain reliable records, errors to be identified early, supermarkets to decentralize their management structures, suppliers should conform to specifications and that senior level management should be fully committed especially in supplier development programmes so as to overcome the challenges faced in supplier quality management. Finally, suggestions for further research were given. Key words: Organizational performance, Supplier, Supplier Quality Managemen