KNH-UoN Ethics and Research Committee

Kenya is classified as a water-scarce country with per capita water being below the global benchmark of 1,000 cubic meters. In 2005 the estimated per capita was about 647 cubic meters for all uses. This scarcity is expected to worsen by 2025 when per capita is projected to be about 235 cubic meters. This poses a serious threat to socio-economic development, the integrity of national ecosystems and the quest to achieve the Vision 2030. There is therefore urgency to investigate and understand the available freshwater resources and water dynamics so as to formulate informed policy. This study targets the Nyanzian trough in the neighborhood of the freshwater Lake Victoria. This region faces a lot of water challenges related to water quantity, water quality deterioration, transboundary water issues and perennial flooding.

To counter the challenges, we need to improve our understanding of the water cycle since it is one of the key elements of scientific information necessary for developing policies toward a sustainable management of freshwater resources. Water supplies in the area come from various sources including surface water, shallow and deep wells.

The aim of this study is to investigate the groundwater characteristics using suitable environmental isotope techniques in order to establish the links between groundwater and the surface water for better exploitation strategy. It will investigate and demonstrate if there is any link between the lake water and the boreholes and if water mining is occurring in some regions within the basin.

This study also aims to answer local hydrologic questions about the aquifers through studies with pumping tests and stable isotopes. Specifically, of interest is the amount of dispersion in the deeper aquifer, its degree of hydraulic connectivity, and whether there are signs of younger, shallow groundwater intrusion. On a regional scale, we would like to know what the age and recharge rates of groundwater are at depth, thus allowing the estimates of groundwater flowlines and their changes with shifting deep groundwater usage.

The study will explore the near-surface processes of the land phase of the hydrologic cycle (surface and shallow subsurface processes) in particular the movement of water near the earth's land surface, the physical and the chemical interactions with earth materials accompanying that movement.
Flow system analysis and tracer hydrology will be used to evaluate the water resources within the basin.

This will involve determination of the characteristics of the natural groundwater flow field, flow systems and hydrogeochemical facies analysis of water samples. The definition of the facies and classification of water types in the basin including identification of groundwater origin will be undertaken during this study.

Different methods of analyses and assessment of hydrological flow systems will be used including hydro-chemical and tracer hydrological approaches to delineate flow systems and understanding flow patterns in the Basin. The use of tracer techniques will illustrate the flow pathways, residence times of the water, the hydraulic properties of flow systems, and the mixing of different water compartments if any.

It is envisaged that through this study the general use and acceptance of hydrogeochemical proxies and by extension, isotope methodologies into the mainstream hydrology and water resources management in Kenya will be adopted since isotope techniques may provide, among others, adequate information on recharge conditions, quality and age of groundwater. It may also unravel the role groundwater dynamics contributes to the Lake Victoria waters and to the flooding in the Basin.

One way of dealing with urban floods is to ignore them. In many countries, Kenya included, neither the people nor the authorities want to take the danger due to urban floods seriously, partly due to large recurrent intervals of most urban floods. It may also be that the risk due to floods are taken for granted, given the many dangers and problems confronted with in people’s daily lives (Van Westen, C.J., 2000 ).
To effectively reduce the impacts of floods in our cities, including Nairobi, they must be managed before they turn into disaster. The primary objectives of sustainable urban drainage system can be considered to be the protection of life, property, the community and the environment. The process comprises a series of well-known stages, which begins with urban drainage evaluation. The second stage involves the evaluation, selection and implementation of flood reduction measures, and the establishment of enforcement procedures. This stage links urban flood management to emergency planning and management that are subsequent stages of the process. Preparedness, response and recovery are the three principal stages within emergency planning and management. The final stage in the flood management process is the feedback stage, where post-event appraisal of mitigation measures and other phases are evaluated (Starosolszky, O., and Melder O.M., 1990).
The sustainable urban drainage management process is open to institutional arrangements and policies, political economy and the technological environment. These influences exert both positive and negative forces on the drainage management thereby making it either effective or ineffective. The nature of hazardous environment need not be overemphasized because it determines the need for management. To make the process smooth, public cooperation is needed.

Throughout the world, prospecting for gemstone deposits is largely a primitive operation that does not involves scientific or systematic methods. In Taita Taveta district, most gemstones deposits are still found either by luck, or by direct visual inspection of outcrops or of the soil surface. However a wide range of methods are available to the prospector.

Prospecting methods include geological mapping, systematic eluvial test pitting, geophysical and geochemical prospecting. Remote sensing can also be used. It is important to understand perfectly the geological characteristics of gemstone deposits in order to be able to select the most efficient methods. In Taita Taveta, the combination of direct mapping, spectroradiometry, and soil geochemistry enables to delineate lithologies favourable to some gemstone deposits. On a local scale, computerised treatment of data obtained from systematic test pitting can assist in identifying possible secondary deposits, and to locate primary deposits.

The aim of this study was to investigate the detailed geology, the geochemistry and the mineralogy associated with the mafic and the ultramafic intrusives of the Mozambique Belt, eastern Kenya. To achieve this, a detailed geological mapping and sampling of the intrusives was done followed by laboratory analysis. The significance of the study was to highlight the nature, relative age and genesis of the intrusives and the potential for economic mineralization.

This study has revealed that the intrusive rocks and the regional foliation trends are inter-related suggesting that the intrusives developed in vertical structures during regional metamorphism. The elongated shapes of the bodies and their alignment with the enclosing regional structural grain of the gneisses suggest compressional deformation during the regional Mozambique Belt Orogeny. This is considered as evidence for at least a synorogenic emplacement of these intrusive rock bodies.
The mafic and the ultramafic rocks represent a range of differentiated rocks from fairly primitive magma (Mg-number = 79) to highly fractionated magma (Mg-number = 36). However, the fact that the rocks are intrusive brings out the possibility that none of them may represent parental magma composition. The magmas have undergone modification by crystal fractionation processes either in high-level magma chambers or during ascent from their mantle source regions. The gradual composition change in the feldspars, olivine and the pyroxenes is from high- to low-temperature members of their respective solid-solution series. This outlines the crystallization sequence.

The whole rock chemical analysis shows that rocks rich in magnesium oxide are also rich in chromium and nickel and those rich in potassium oxide are also rich in rubidium and barium in conformity with the rules of partitioning. This implies that they originated from one parent magma. The rocks show iron enrichment trend and have high nickel and low aluminium oxide contents. This chemical evidence supports a tholeiitic magma affinity for the intrusive rocks.
An attempt is made to construct the mineralogy of the gabbros based on the mineral chemistry. This has revealed that they are composed of magnesium-rich olivine (chrysolite) with approximately 80% forsterite. The pyroxene is both magnesium and calcium rich and has an enstatite molecular percentage of about 18%. It is an orthopyroxene (bronzite) in the enstatite-ferrosilite solid-solution series. The plagioclase feldspars show a range of composition from about 90-20% anorthite. This
range shows that the magma crystallized slowly. Crystallization over a wide temperature has resulted in the formation of alkali feldspars and other minor constituents.

Economically, the area has the potential for base metals. Chromium and nickel are present in concentrations higher than that found in average igneous rocks. Further geophysical work is recommended to reveal some more information in terms of the possibilities of economic deposits in this project area. Some of the pegmatite, particularly those near Muthanthara contains small needles of beryl. The beryl is blue green in colour but not of gem quality.

Throughout history man has been attracted to the land adjacent to rivers. The soil is normally fertile, there is a constant water supply, it is a cheap means of transportation etc. Settlements along or beside rivers are however hazardous. Once in a while, the rivers may overflow their banks and inundate the built up areas resulting in damage to crops and property, and sometimes loss of life as well.

Netherlands is worldly renown for its fight against floods. Therefore other countries can emulate a lot. The study tried to investigate the flood control and management practices in the Netherlands, and the feasibility of applying some of the methods to a developing country like Kenya.

From the study, the importance of good institutional framework is exemplified. A clear definition of flood management policy is essential if a country is to establish and maintain adequate arrangements to deal with floods.

In identifying what options are available as elements of national policy, it is useful to study all aspects of hazard management, namely; prevention (mitigation), preparedness, response and recovery. As one African saying goes, prevention is better than cure. But due to the social-economic constraints and engineering feasibility problems, some mitigation measures are beyond the reach for many developing countries. Therefore structural mitigation measures are not the most cost-effective methods for solving flood problems. The best methods are non-structural since they involve little costs and are more sustainable. Preparedness, response, and recovery must be covered in national policy to the best possible extent through government decrees, statements, legislation, regulations and other means.