Bio

DR. OPERE ALFRED OWUOR CV

Publications


2018

WAMBUI, MBOTEBETH, Opere A, GITHAIGA JOHNM, Karanja FK.  2018.  Assessing the Impacts of Climate Variability and Climate Change on Biodiversity in Lake Nakuru, Kenya. Bonorowo Wetlands. 8(1):13-24. Abstractassessing_the_impacts_of_climate_variability_and_climate_change_on_biodiversity_in_lake_nakuru_kenya.pdfSMUJO (smujo.id)

Wambui MB, Opere A, Githaiga MJ, Karanja FK. 2017. Assessing the impacts of climate variability and climate change on biodiversity in Lake Nakuru, Kenya. Bonorowo Wetlands 1: 13-24. This study evaluates the impacts of the raised water levels and the flooding of Lake Nakuru and its surrounding areas on biodiversity, specifically, the phytoplankton and lesser flamingo communities, due to climate change and climate variability. The study was to review and analyze noticed climatic records from 2000 to 2014. Several methods were used to ascertain the past and current trends of climatic parameters (temperature, rainfall and evaporation), and also the physicochemical characteristics of Lake Nakuru (conductivity, phytoplankton, lesser flamingos and the lake depth). These included time series analysis, and trend analysis, so the Pearson’s correlation analysis was used to show a relationship between the alterations in lake conductivity to alterations in population estimates of the lesser flamingos and the phytoplankton. Data set extracted from the Coupled Model Intercomparison Project Phase 5 (CMIP5) (IPCC Fifth Assessment Report (AR5) Atlas subset) models were subjected to time series analysis method where the future climate scenarios of near surface temperature, rainfall and evaporation were plotted for the period 2017 to 2100 (projection) for RCP2.6 and RCP8.5 relative to the baseline period 1971 to 2000 in Lake Nakuru were analysed. The results were used to evaluate the impact of climate change on the lesser flamingos and phytoplankton abundance. It was noticed that there was a raise in the mean annual rainfall during the study period (2009 to 2014) which brought the increment in the lake’s surface area from a low area of 31.8 km² in January 2010 to a high of 54.7 km² in Sept 2013, indicating an increment of 22.9 km² (71.92% surface area increment). Mean conductivity of the lake also lessened leading to the loss of phytoplankton on which flamingos feed making them to migrate. A strong positive correlation between conductivity and the lesser flamingo population was noticed signifying that low conductivity affects the growth of phytoplankton and since the lesser flamingos depend on the phytoplankton for their feed, this subsequently revealed that the phytoplankton density could be a notable predictor of the lesser flamingo occurrence in Lake Nakuru. There was also a strong positive correlation noticed between phytoplankton and the lesser flamingo population which confirms that feed availability is a key determining factor of the lesser flamingo distribution in the lake. It is projected that there would be an increment in temperatures, rainfall and evaporation for the period 2017 to 2100 under RCP2.6 and RCP8.5 relative to the baseline period 1971 to 2000 obtained from the Coupled Model Intercomparison Project phase 5 (CMIP5) multi-model ensemble. As a result, it is expected that the lake will further increment in surface area and depth by the year 2100 due to increased rainfall thereby affecting the populations of the lesser flamingos and phytoplankton, as the physicochemical factors of the lake will alter as well during the projected period.
Keywords: Biodiversity, climate change, Lake Nakuru, Kenya

Muthuwatta, L, Sood A, McCartney M, Silva NS, Opere A.  2018.  Understanding the Impacts of Climate Change in the Tana River Basin, Kenya. Proceedings of the International Association of Hydrological Sciences. 379:37-42. Abstractunderstanding_the_impacts_of_climate_change_in_the_tana_river_basin_kenya.pdfProceedings of the International Association of Hydrological Sciences

In the Tana River Basin in Kenya, six Regional Circulation Models (RCMs) simulating two Representative Concentration Pathways (RCPs) (i.e., 4.5 and 8.5) were used as input to the Soil and Water Assessment Tool (SWAT) model to determine the possible implications for the hydrology and water resources of the basin. Four hydrological characteristics – water yield, groundwater recharge, base flow and flow regulation – were determined and mapped throughout the basin for three 30-year time periods: 2020–2049, 2040–2069 and 2070–2099. Results were compared with a baseline period, 1983–2011. All four hydrological characteristics show steady increases under both RCPs for the entire basin but with considerable spatial heterogeneity and greater increases under RCP 8.5 than RCP 4.5. The results have important implications for the way water resources in the basin are managed. It is imperative that water managers and policy makers take into account the additional challenges imposed by climate change in operating built infrastructure.

Ngaina, JN, Muthama NJ, Mwalichi IJ, Owuor OA.  2018.  Towards Mapping Suitable Areas for Weather Modification in East Africa Community. Journal of Climatology & Weather Forecasting. 6(1) AbstractOMICS International

In order to map suitable areas for weather modification in East Africa Community (EAC), investigations were performed to determine spatio-temporal variability and relationship of aerosol, clouds and precipitation during March- April-May (MAM) and October-November-December (OND). Principal Component Analysis (PCA), Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) and Multivariate Regression Analysis (MRA) were used. Identification of near homogeneous zones of Aerosol Optical Depth (AOD), Fine Mode Fraction (FMF), Cloud Top and 3B42 Tropical Rainfall Measuring Mission (TRMM) yielded 13 (14), 20 (18), 11 (10) and 16 (17) significant Principal Components (PCs) for MAM (OND) with explained variance greater than 57%. Aerosols and clouds had positive relationship with precipitation in areas with strong factor loadings. MRA indicated independence of variables used and normality in the model residuals. Backward trajectory analysis indicated differences in origins of transported particles in the atmosphere with strong vertical mixing inlands with mixed aerosols resulting due to mountain blocking systems accounted for enhanced rainfall. Enhanced rainfall was attributed to highly varied AOD and unaffected FMF in the atmosphere. Locations east and west EAC with mean temperatures greater than -10°C were unsuitable for cloud seeding while central EAC region along the great rift-valley and coastal Tanzania exhibited optimal temperatures suitable for cloud seeding. Successful precipitation enhancement will increase available fresh water sources and thus alleviate existing and projected water stress.

Siderius, C, Gannon KE, Ndiyoi M, Opere A, Batisani N, Olago D, Pardoe J, Conway D.  2018.  Hydrological response and complex impact pathways of the 2015/2016 El Niño in Eastern and Southern Africa. Earth's Future. 6(1):2-22. Abstract

The 2015/2016 El Niño has been classified as one of the three most severe on record. El Niño teleconnections are commonly associated with droughts in southern Africa and high precipitation in eastern Africa. Despite their relatively frequent occurrence, evidence for their hydrological effects and impacts beyond agriculture is limited. We examine the hydrological response and impact pathways of the 2015/2016 El Niño in eastern and southern Africa, focusing on Botswana, Kenya, and Zambia. We use in situ and remotely sensed time series of precipitation, river flow, and lake levels complemented by qualitative insights from interviews with key organizations in each country about awareness, impacts, and responses. Our results show that drought conditions prevailed in large parts of southern Africa, reducing runoff and contributing to unusually low lake levels in Botswana and Zambia. Key informants characterized this El Niño through record high temperatures and water supply disruption in Botswana and through hydroelectric load shedding in Zambia. Warnings of flood risk in Kenya were pronounced, but the El Niño teleconnection did not materialize as expected in 2015/2016. Extreme precipitation was limited and caused localized impacts. The hydrological impacts in southern Africa were severe and complex, strongly exacerbated by dry antecedent conditions, recent changes in exposure and sensitivity and management decisions. Improved understanding of hydrological responses and the complexity of differing impact pathways can support design of more adaptive, region‐specific management strategies.

2017

Karuri, HW, Olago D, Neilson R, Njeri E, Opere A, Ndegwa P.  2017.  Plant parasitic nematode assemblages associated with sweet potato in Kenya and their relationship with environmental variables. Tropical Plant Pathology. 42(1):1-12. AbstractSpringerLink

Sweet potato is one of the most important staple food crops consumed in Kenya and throughout Africa but yields are greatly reduced by plant parasitic nematodes (PPN). The aim of this study was to determine the prevalence of PPN in Kenyan sweet potato fields and their relationship with soil and climatic variables. Soil samples were collected from sweet potato fields in Busia, Teso, Kisii, Embu and Makueni counties. Thirteen nematode genera were identified across the five counties with Meloidogyne, Pratylenchus and Rotylenchus being the most prevalent. There was a significant (P <0.05) relationship between PPN abundance and sodium, calcium and iron. Canonical correspondence analysis of climatic variables revealed that the relationship between rainfall and nematode genera was significant (P <0.05) while maximum and minimum temperatures were not significant. This description of PPN assemblages associated with sweet potato in Kenya and their relationship with environmental variables provides a starting point from which appropriate nematode management strategies can be implemented.

Omwoyo, AM, Muthama NJ, Opere A, Onwonga R.  2017.  Simulating Streamflow in Response to Climate Change in The Upper Ewaso Ngiro Catchment, Kenya. Journal of Climate Change and Sustainability. 1(2):12-29. Abstract

The study simulated streamflow response under changing climate for Ewaso Ngiro river in Upper Ewaso
Ngiro Catchment (UENC), using Soil and Water Assessment Tool (SWAT). Data from National Centre
for Meteorological research (CNRM) model of Co-Ordinated Regional Downscaling Experiment
(CORDEX) was used to generate climate change scenarios (temperature and rainfall) for representative
concentration pathway (RCP) 4.5 and 8.5 from 2021-2080 relative to the baseline 1976-2005. SWAT
model was set up using historical daily rainfall and temperature data, soils, Digital Elevation Model and
land cover map, and calibrated against observed streamflow. Decreasing trend in historical rainfall and
streamflow was observed while increasing trend was observed for temperature. Projections indicated
increasing trend in temperature in both RCPs, with RCP 8.5 having higher increase (1.1-2.60 C) than
RCP 4.5 (1.0-1.70 C). Rainfall was found to increase from March-November, and decreased in
December-February in all scenarios. Change in total annual rainfall ranged from 0.1-18.5% in 20212050
and 1.2-18.7% in 2051-2080, which corresponded to increase in streamflow of 20.9-23.6% and
21.2-28.2% respectively. Streamflow in March-May decreased (-26 to -10%) in all scenarios and
increased in June-February (9-114%). This was found contrary to streamflow patterns simulated in
neighboring catchments where studies indicate increasing streamflow trend in March-May. Streamflow
response was found to be sensitive to changes in rainfall, thus emphasis should be put on water
conservation and catchment management including protection of headwater forests through agroforestry,
afforestation and reforestation.
Key words: Climate change, Streamflow, Simulation, Upper Ewaso Ngiro Catchment

2016

Rwigi, S, Muthama NJ, Opere A, Opijah FJ.  2016.  Assessment of Potential Changes in Hydrologically Relevant Rainfall Statistics over the Sondu River Basin in Kenya Under a Changing Climate. J. Meteorol. 9:2-12. AbstractJ. Meteorol

Scenarios of past, present and intermediate future climates for Sondu River basin were analysed in this study to evaluate the potential changes in hydrologically relevant rainfall statistics that are likely to be observed by the middle of this century as a result of climate change. These climate scenarios were developed by applying dynamical downscaling of the relatively course resolution climate scenarios simulated by the fourth generation coupled Ocean-Atmosphere European Community Hamburg Model (ECHAM4) using the Providing Regional Climates for Impacts Studies (PRECIS) modelling system. The regional climate scenarios, which were available at a daily time-step and a spatial grid resolution of 0.5˚ over the Eastern Africa region, were matched to the Sondu river basin in the western region of Kenya. The possible hydrological impacts of climate change were assessed by applying the scenarios in a daily time-step hydrological model. The analysis of hydrologically relevant rainfall statistics focussed on determining changes in rainfall patterns and the likely hydrological implications to the basin. The results indicated that more rainfall is projected for the region in the immediate and intermediate future in form of increased seasonal rainfall during the December-January-February (DJF), March-April-May (MAM) and September-October-November (SON) seasons resulting from increased number of days of rainfall and higher probabilities of a wet day following a dry day in a month. Based on these scenarios, the combination of the wetter antecedent conditions and the more rain days in a month will result in more surface runoff being generated which will not only have implications on the water balance but also the water quality in the basin.

Key Words: climate change, climate scenarios, climate modelling, climate downscaling, Sondu Basin, Kenya

Andang’o, HA, Ouma JO, Muthama NJ, Opere AO, Hezron A’o A.  2016.  Investigating the Homogeneity of Monthly Rainfall Records in Kenya. J. Meteorol. 9:48-54.. Abstractinvestigating_the_homogeneity_of_monthly_rainfall_records_in_kenya.pdfJ. Meteorol

Homogenization of climate data is of major importance because non-climatic factors make avail-able data unrepresentative of the actual climate variation, and thus the conclusions of climatic and hydrological studies are potentially biased. A great deal of effort has been made to develop proce-dures to identify and remove non-climatic in-homogeneities. This paper first reviews several widely used statistical techniques then applies statistical simulation approach to precipitation data from different monitoring stations located in Kenya (1950-2006).
Analyses were carried out on several rainfall series in the 12 climatic zones of Kenya. The results of both the Standard Normal Homogeneity Tests (SNHT) and the Buishand Range Test (BR) tests show that, at the 5% significance level, the monthly series have statistically significant trend.
Findings from the Standard Normal Homogeneity Test (SNHT) showed that all the monthly rain-fall records from the selected synoptic stations were useful and hence could be used for any further analysis. From the Buishand Range (BR) Test done, seven out of the twelve stations were useful while the rest of the stations were doubtful. From the results of the Tests performed it is clear that the Buishand Range (BR) Test was able to detect breaks at the beginning middle and the end of the series. This method was thus recommended for homogeneity testing.
Promising results from the case study open new research perspectives on the homogenization of the Kenyan climate data time series.

Rwigi, SK, Muthama JN, Opere AO, Opijah FJ, Gichuki FN.  2016.  imulated Impacts of Climate Change on Surface Water Yields over the Sondu Basin in Kenya . International Journal for Innovation Education and Research. 4(8):160-172. AbstractInternational Journal for Innovation Education and Research

Potential impacts of climate change on surface water yields over the Sondu River basin in the western region of Kenya were analysed using the Soil and Water Assessment Tool (SWAT) model with climate input data obtained from the fourth generation coupled Ocean-Atmosphere European Community Hamburg Model (ECHAM4) using the Providing Regional Climates for Impacts Studies (PRECIS) model. Daily time step regional climate scenarios at a spatial grid resolution of 0.44˚ over the Eastern Africa region were matched to the Sondu river basin and used to calibrate and validate the SWAT model. Analysis of historical and projected rainfall over the basin strongly indicated that the climate of the area will significantly change with wetter climates being experienced by 2030 and beyond. Projected monthly rainfall distribution shows increasing trends in the relatively dry DJF and SON seasons while showing decreasing trends in the relatively wet MAM and JJA seasons. Potential changes in water yields resulting from climate change were computed by comparing simulated yields under climate change scenarios with those simulated under baseline conditions.

There was evidence of substantial increases in water yields ranging between 88% and 110% of the baseline yields by 2030 and 2050 respectively. Although simulated water yields are subject to further verification from observed values, this study has provided useful information about potential changes in water yields as a result of climate change over the Sondu River basin and in similar basins in this region

Keywords: Simulated Impacts; Climate Change; Water Yields; Sondu Basin; Kenya

WAMBUI, MBOTEBETH, Opere A, Gathiga JM, Karanja FK.  2016.  ASSESSING THE IMPACTS OF CLIMATE VARIABILITY AND CLIMATE CHANGE ON BIODIVERSITY IN LAKE NAKURU, KENYA, 23-11-2016. , Nairobi: University of Nairobi AbstractDepartment of Meteorology

Hydrological systems are potentially very sensitive to changes in climate. Recently, attention has been mainly drawn to the rising global temperatures; however, over the past century, human livelihoods have substantially been directly affected by changes in the regional hydrological balance. Lake Nakuru is one example of a hydrological system which has seen its water levels increasing since September 2010 during the beginning of the short rains making it the first lake in the Rift Valley bursting its banks, leading to decreased electrical conductivity levels as a result of water dilution. All flamingos left the lake, initially settling in the Lake Oloidien a small alkaline lake south of Lake Naivasha and Lake Bogoria. The increased water levels led to change in aquatic life and biodiversity, including submersion of habitats adjoining the lake and have therefore had major ecological implications on the lake and its environs.
This study, therefore, assesses the impacts of the increased water levels and the flooding of Lake Nakuru and its surrounding areas on biodiversity, specifically, the phytoplankton and lesser flamingo communities, owing to climate change and climate variability. The study focused on reviewing and analysing observed climatic records from 2000 to 2014, obtained from the Kenya Meteorological Department, especially temperature, precipitation and evaporation of Lake Nakuru in order to assess how climate variability and climate change has contributed to the increased lake levels, monitoring and reviewing information on the state of past and present records of the lesser flamingo and phytoplankton communities of Lake Nakuru was undertaken, with the data sets obtained from the Kenya Wildlife Service and National Museums of Kenya database. Several methods were employed in order to determine the past and current trends of climatic parameters (temperature, precipitation and evaporation), and also for the physicochemical characteristics of Lake Nakuru (conductivity, phytoplankton, lesser flamingos and the lake depth). These included time series analysis, trend analysis and the Pearson's correlation analysis was used to correlate the changes in lake conductivity to changes in population estimates of the lesser flamingos and the phytoplankton. Data set extracted from the Coupled Model lntercomparison Project Phase 5 (CM1P5) (IPCC Fifth Assessment Report (AR5) Atlas subset) models were subjected to time series analysis method where the future climate scenarios of near surface temperature, precipitation and evaporation were plotted for the period 2017 to 2100 (projection) for RCP2.6 and RCP8.5 relative to the baseline period 1971 to 2000 in Lake Nakuru were analysed. The results were used to assess the impact of climate change on the lesser flamingos and phytoplankton abundance.
It was observed that there was an increase in the mean annual precipitation during the study period (2009 to 2014) which caused the increase in the lake's surface area from a low area of 31.8 km2 in January 2010 to a high of 54.7 km2 in Sept 2013, indicating an increase of 22.9 km2 (71.92% surface area increase). Mean conductivity of the lake also decreased leading to the loss of phytoplankton on which flamingos feed causing them to migrate. A strong positive correlation between conductivity and the lesser flamingo population was observed implying that low conductivity affects the growth of phytoplankton and since the lesser flamingos depend on the phytoplankton for their feed, this subsequently demonstrated th&t the phytoplankton density could be a significant predictor of the lesser flamingo occurrence in Lake Nakuru. There was also a strong positive correlation observed between phytoplankton and the lesser flamingo population which confirms that feed availability is a key determining factor of the lesser flamingo distribution in the lake.
It is projected that there would be an increase in temperatures, precipitation and evaporation for the period 20 I 7 to 2100 under RCP2.6 and RCP8.5 relative to the baseline period 1971 to 2000 obtained from the Coupled Model Intercomparison Project phase 5 (CMIP5) multi-model ensemble. As a result, it is expected that the lake will further increase in surface area and depth by the year 2 I 00 due to increased precipitation thereby affecting the populations of the lesser . flamingos and phytoplankton, as the physicochemical factors of the lake will change as wel I during the projected period.
Recommendation.s that can be taken to contribute to the country's biodiversity resources, specifically in Lake Nakuru through climate change mitigation and appropriate adaptations have been provided. They include: In order to assess the variability in climate, continuous monitoring and analysing meteorological parameters in the lake basin is suggested; government policy on illegal water abstractions and massive afforestation of indigenous trees need to be enforced in order to enhance precipitation regularity so as to sustainably utilize and manage Lake Nakuru 's waters; Climate vulnerability assessments need to be carried out in order to come up with mitigations and adaptations measures unique to Lake Nakuru basin to inform the measures that need to be taken in order to minimize the negative impacts of climate vulnerability/change, and exploit the beneficial ones.

2015

Kirui, JW, Muthama JN, Opere AO, Ngaina JURI:N.  2015.  Influence of climate change on smallholder dairy productivity: A case of Kosirai, Kenya, and Namayumba, Uganda. Academe Research Journals. Abstractngaina_influence_of_climate_change_on_smallholder_dairy_productivity.pdf

Climate change influences dairy productivity in East Africa through impacts on fodder production and supply, livestock disease outbreak and water availability for livestock. This study assessed the influence of climate change on smallholder dairy farming in Kosirai, Nandi District of Kenya and Namayumba in Wakiso District of Uganda, in support of climate-smart agricultural practices. Observed (1973-2009) and model output (1950-2100) climate data comprising rainfall, minimum and maximum temperature and household survey were used. A simple random sampling technique, time series analysis, and descriptive statistics were used to achieve the objectives of the study. Mean rainfall in the two sites had progressively decreased over the last ten years. Conversely, there was a systematic rise in both the minimum and maximum temperature, both in historical and projected period in the two sites.

The weather variables namely rainfall, maximum and the minimum temperature had a positive correlation with fodder production and supply. Likewise, milk production that mainly depended on rainfed forages also correlated with the supply of feeds. There was increased milk production and supply during the wet season as compared to the dry spells. Climate change was linked to the emergence and rise of both the vector born and viral diseases in the two sites. There was a significant rise in outbreaks of foot and mouth disease and tick-borne diseases in Namayumba area. In Kosirai, there was an increase in outbreaks of tick-borne. The study recommended that dairy farmers be empowered to prepare effectively to climate change through adaptation and mitigation of the effect of extreme climate change. Farmers should also invest in the production and conservation of fodder for their dairy production.

Gateri, MW, Alfred OPERE, Wilson GITAU, Ndiwa NGAINAJ.  2015.  Domestic rainwater harvesting: a case study in Embu County, Kenya. Africa Journal of Physical Sciences. 2(1):50-59. Abstractdomestic_rainwater_harvesting_a_case_study_in_embu_county_kenya.pdfAfrica Journal of Physical Sciences

This study assessed probable water that could be harvested during rainy seasons over Embu County of Kenya. Monthly rainfall data was obtained from Kenya Meteorological Department while percentage distribution of household by household size, main roofing material, number of rooms in the main dwelling and per capita volume of water required was sourced from Kenya Integrated Household Budget of Survey (KIHBS). Minimum water demand per household was computed based on KIHBS. Kenya National Bureau of Statistics (KNBS) 2009 population census was used to determine population and number of occupants in the main dwelling. Embu County receives bimodal rainfall during March-April-May (MAM) and October-November-December (OND). Rainfall is highly variable with 8190 and 7490 litres of harvested water during MAM and OND season respectively expected to last for approximately 43 days (MAM) while 39 days (OND) and thus not sufficient to satisfy minimum water demand levels for Embu population. The total potential harvestable water during MAM and OND accounted for 45.4 % and would go a long way in meeting water demands in the region. Notably, harvestable water was being used to supplement natural sources of water. Therefore, enhanced water harvesting during rainy season could provide an alternate source of domestic water.

Ngaina, JN, Opere A, Ininda JM, Muthama N.  2015.  Aerosol-Cloud Interactions in Deep Convective Clouds Over Equatorial East Africa. AGU Fall Meeting Abstracts. AbstractThe SAO/NASA Astrophysics Data System

Deep convective clouds (DCCs) associated with tropical convection, are significant sources of precipitation in Equatorial East Africa. The DCCs play a fundamental role in hydrological and energy cycle. Weather Research and Forecasting (WRF) model with detailed bin-resolved microphysics are used to explore the diurnal variation of DCCs under maritime/clean and continental/polluted conditions. The sign and magnitude of the Twomey effect, droplet dispersion effect, cloud thickness effect, Cloud Optical Depth (COD) susceptibility to aerosol perturbations, and aerosol effects on clouds and precipitation is evaluated. Twomey effect emerges as dominant in total COD susceptibility to aerosol perturbations. The dispersion effect is positive and accounts for 3-10% of the total COD susceptibility at nighttime, with greater influence on heavier drizzling clouds. The cloud thickness effect is positive (negative) for a moderate/heavy drizzling (light thickness) clouds. The cloud thickness effect results in 5-22% of the nighttime total cloud susceptibility. Cloud microphysical properties and accumulated total precipitation show a complex relationship under varied aerosol conditions. The mean of core updraft and maximal vertical velocity increased (decreased) under low (high) CCN scenarios. Overall, the total COD susceptibility ranges from 0.28-0.53 at night; an increase in aerosol concentration enhances COD, especially with heavier precipitation and in a clean environment. During the daytime, the range of magnitude of each effect is more variable owing to cloud thinning and decoupling. The ratio of the magnitude of cloud thickness effect to that of the Twomey effect depends on cloud thickness and base height in unperturbed clouds while the response of precipitation to increase in aerosol concentration was non-monotonic.

2014

Ngaina, J, Muthama N, Ininda J, Opere A, Mutai B.  2014.  Towards precipitation enhancement through cloud seeding in Kenya. Global Meteorology. 3:7-13. Abstract

The study investigated potential of enhancing precipitation through cloud seeding during October-November-December (OND) season. Rainfall, cloud top temperature (CTT), aerosol optical depth (AOD) and wind data were used. Short-Cut Bartlett correlation, composite wind and time series analysis, and HYSPLIT backward trajectory analysis were used to achieve
the objectives of study. Precipitation showed decreasing patterns with peaks between pentad 65 and 68. Delineated dry years (18) exceeded wet years (9). Low level winds were predominantly north-easterly during dry years characterized by continental trajectory. AOD values increased in all stations during dry year with aerosol load being higher in areas characterized by depressed rainfall. Pollutants suspended 1000 above mean sea level (AMSL) originated from Arabian and India subcontinent and pollutants suspended below 1000 AMSL were predominantly south easterly during wet years originated from Western Indian Ocean and characterized by maritime trajectory. Mean CTT during dry/wet years were positve over coastal areas while central, Rift-valley and Lake Victoria basin
showed negative values, indicating presence of seedable conditions and thus potential cloud seeding to enhance rainfall and alleviate existing water stress.

J.N, N, J.N M, A.O O, J.M I, C.K N’etich, V. O, B.K M.  2014.  Potential of harvesting atmospheric water over urban cities in Kenya. International Journal of Physical Sciences. 2(5):69-75. AbstractInternational Journal of Physical Sciences

Most urban areas in Kenya are facing water crisis due to rapid population growth, industrialization and climate change. This study investigates potential of harvesting water from fog and air humidity over urban cities in Kenya. Daily air temperature, dew point temperature, wind direction and speed were used. Parameters including atmospheric water vapor pressure, saturated vapor pressure and the absolute and relative humidity of the atmosphere were derived. Air temperatures ranged between 18.2 and 27.6°C in urban areas. Mean annual foggy days was higher at Jomo Kenyatta International Airport (JKIA) with a maximum of 17 foggy days compared to other stations. However, mean annual harvesting days was higher at Moi International Airport (MIA) with a maximum of 350 days. Based on device efficiency of 10%, stations in Nairobi city (JKIA/Dagorretti Corner/Wilson Airport) indicated maximum water harvesting potential of 3.2/1.4/2.9 litres/m2/day in direction d6 (225 -270°) while Kisumu station showed highest potential of harvesting water (2.2 litres/m2/day) in direction d5 (180-225°). In Mombasa, the MIA and Lamu stations showed potential of harvesting 4.4 litres/m2/day and 3.9 litres/m2/day in direction d6 and d5 respectively. Based on monthly distribution of potential monthly water, harvesting from fog and air humidity was classified into either coastal or non-coastal/continental regions. The urban cities in Kenya have high potential of water harvesting from fog and air humidity presenting an alternative sustainable low cost approach to augmenting available fresh water sources and alleviating existing water stress. This will enable achievement of Kenya’s long term development footprint (Vision 2030) and Millennium Development Goals.

Ndiwa, NGAINAJ, James N, Francis M, Kipkoech MB, Owuor OA.  2014.  Flood Forecasting over Lower Nzoia Sub-Basin in Kenya. Africa Journal of Physical Sciences. 1(1):25-31. Abstractflood_forecasting_over_lower_nzoia_sub-basin_in_kenya.pdfAfrica Journal of Physical Sciences

Real time flood forecasting is one of the most effective non- structural measures for flood management. In this study, Ensemble Kalman Filter (EnKF) is used with Probability Distributed Moisture model (PDM) to forecast flood events over Nzoia sub-basin. The performance of four variations of EnKF (state updating, parameter updating, dual (state parameter) and dual (parameter-state) updating) were evaluated using the Root Mean Square (RMSE) and Coefficient of Efficiency (CoE) for 1, 3, 6, 9 and 12-hour lead time forecasts. In 1EE01 gauging station, RMSE and CoE values was 30m3/s and 0.70 while 1EF01 station had RMSE and CoE values of 50m3/s and 0.82 respectively. For the state variables, standard deviation of 1.1, 0.32, 0.21 and 0.05 were found for recharge, surface storage, groundwater storage and storage respectively while for the PDM parameters, standard deviation of 4.0, 0.2 and 0.2 were found for maximum store capacity, exponent of recharge function and ground recharge time respectively. Parameter updating performed better in terms of RMSE and CoE and thus potential of improving flood forecasting to enable management of flood related risk on real time basis over the sub-basin.
Key Words: Discharge, rainfall, Ensemble Kalman Filter, flood forecasting, rainfall-runoff model.

2013

Opere, A.  2013.  Floods in Kenya. Developments in Earth Surface Processes. : Elsevier B.V. Abstract

The vulnerability of a water resource system to climate change is a function of a number of physical features and social characteristics. The physical features associated with maximum vulnerability of water resources in a region include the marginal hydrologic and climatic regime; high rates of sedimentation leading to reduction of reservoir storage; topography and land-use practices that promote soil erosion and flash flooding conditions; and deforestation, which allows increased surface run-off, increased soil erosion and more frequent significant flooding. Coupled with these factors, the social characteristics that increase vulnerability of water resources include poverty and low income levels that prevent long-term planning and provision at the household level, lack of water control infrastructures, inadequate maintenance and deterioration of existing infrastructure, lack of human capital skills for system planning and management, lack of appropriate and empowered institutions, absence of appropriate land-use planning and management, and high population densities and other factors that inhibit population mobility. Of all the relevant factors in climate, precipitation is the main cause of disasters in flooding, water pollution, soil erosion, dam breaks and water-related disease outbreaks among others. Floods increase vulnerability of society and thereby perpetuate and increase the incidence of poverty.

Opere, A.  2013.  SMR 207: Fundamentals of Cloud Physics and Atmospheric Pollution. , Nairobi: University of Nairobi

2012

Opere, A, Oludhe C, Omondi P.  2012.  Resource Guide on Climate Change Science. , Nairobi: Department of Meteorology, University of Nairobi, KE AbstractIDRC Digital Library

AfricaAdapt is is an independent bilingual network (French/English) focused exclusively on Africa. The Network’s aim is to facilitate the flow of climate change adaptation knowledge for sustainable livelihoods between researchers, policy makers, civil society organizations and communities who are vulnerable to climate variability and change across the continent. In many cases, the abundance of resources has led to confusion and misinformation surrounding climate change issues. This resource guide provides selected resource materials and links that specifically target non-climate experts.

Muthama, NJ, W.B. Masieyi, R. E O, Opere AO.  2012.  Survey on the Utilization of Weather Information and Products for Selected Districts in Kenya. J Meteorol Rel Sci. 6:51–58. AbstractUniversity of Nairobi Research Archive

This study summarizes the results of a pilot survey on utilization of weather information and products for selected districts in Kenya and the response of users to Kenya Meteorological Department’s (KMD) weather products on how members of the public obtain, perceive, use, and value weather services. Questionnaires were used to conduct sample surveys on three distinct populations comprising of general public, enterprises and public officials. The survey (288 respondents were interviewed in June 2007) indicated that people use weather information for a variety of activities ranging from crop farming to road transport. Most people identified crop-farming as the activity most vulnerable to weather. Majority of people indicated that they are willing to spend money on weather information, including value added products an indication that KMD should add value to its products and services. The overall assessment of KMD’s performance in terms of provision of weather information was rated as above average. The results from this survey suggest that there is need for KMD to brand its products. The effective dissemination and awareness of the availability and use of weather information should be promoted through a partnership between KMD and local media. Most respondents feel that the government should put in place policies on monitoring, processing and dissemination of weather information with more emphasis on dissemination. Regulatory measures are also necessary and critical in the development of new weather information dissemination strategies.

Yanda, P, Wandiga S, Kangalawe R, Opondo M, Olago D, Githeko A, Downs T, Robert Kabumbuli, Opere A, Githui F, Kathuri J, Olaka L, Apindi E, Marshall M, Ogallo L, Mugambi P, Kirumira E, Nanyunja R, Baguma T, Sigalla R, Achola P.  2012.  Climate, Malaria and Cholera in the Lake Victoria Region: Adapting to Changing Risks. Climate Change and Adaptation. : Routledge Abstract

In the East African countries, malaria is ranked as the primary cause of morbidity and mortality in both children and adults. It causes about 40,000 infant deaths in Kenya each year; in Uganda annual cases of malaria range between 6 to 7 million, with 6500 to 8500 fatalities, and in Tanzania the annual death toll is between 70,000 and 125,000 and accounts for 19 per cent of health expenditure (De Savigny et al, 2004a and b). In the case of cholera, the first epidemic in Africa was reported as far back as 1836 (Rees, 2000). Major outbreaks were next reported in 1970 and affected West Africa (Guinea), the horn of Africa (Ethiopia, Somalia and Sudan) and Kenya (Waiyaki, 1996). The most severe cholera outbreak on the African continent was in 1998, accounting for more than 72 per cent of the global total number of cholera cases and acutely affecting the Democratic Republic of Congo, Kenya, Mozambique, Uganda and the United Republic of Tanzania. Cholera outbreaks in East Africa have been reported to the World Health Organization (WHO) since 1972. In the Lake Victoria region of East Africa both malaria and cholera are common, with malaria endemic in the lowlands and epidemic in the highland areas and cholera endemic in the basin since the early 1970s (Rees, 2000).

Opere, A.  2012.  THE IMPACT OF NATURAL DISASTERS, DUE TO ENVIRONMENTAL CHANGE, ON THE LIVELIHOOD OF THE LAKE VICTORIA BASIN, 2004. , Nairobi: University of Nairobi AbstractWebsite

The major forms of disasters include: Droughts, Floods, Terrorism, Landslides, HIV/AIDS and disease epidemics, Transport accidents, Fires/industrial hazards and pollution. There are other extreme outbreaks of diseases, such as cholera, malaria, typhoid and meningitis, which have become threats as a result of HIV/AIDS. The focus of this paper is on the natural disasters, which are rampant within the lake Victoria basin and are related to extreme weather and climate events such as droughts, floods and strong winds, among others. Extreme weather and climate events influence the welfare of the society and entire economy of the country with droughts and floods having the highest adverse effects. The sectors that experience the immediate effects include agriculture, health, and water resources among others.

NAFUNA, TERESAM, Waweru PW, Kimathi BM, Njiru LN, Osuala TM, Osiemo MR, Orucho MN, Koimur S, Mwenje SN, Njeru FM, Okoola RE, Ininda JM, Mugo RM, Ombaka EO, Muthama NJ, Manene MM, Mutai BK, Ang’u C, Opere AO, Nzioka JM, Ouma JO, Andang’o HA, Kimani, P.M; Kimani JM, Kimani NM.  2012.  Challenges Faced By Kenya Sugar Board In Implementing Strategy On Service Delivery To Sugar Cane Millers In Kenya. AbstractUniversity of Nairobi

A company's strategy is management's action plan for running the business and conducting its operations. Strategy on service delivery is thus an important element of this management process. For global business market acceleration, business must respond to customers faster than ever with value added products and services, while they struggle to maintain temporary competitive advantage. The study was guided by the main objective which was to identify the challenges of implementation of strategy on service delivery by Kenya Sugar Board to Sugar Millers and to determine possible solutions to these Challenges. It utilized a case study on the Kenya Sugar Board. The target population was the managerial personnel at KSB and a total of eight representatives (one from eight sugar factories). Primary data was collected by the use of interview guide.

2011

Opere, A, Olago D, Chidumayo E, Osman-Elasha B.  2011.  Climate Change Processes and Impacts. Climate Change and African Forest and Wildlife Resources. :18-33. AbstractAfrican Forest Forum

Climate change is expressed as deviations from a regional climatology determined by analysis of long-term measurements, usually over a period of at least 30 years, or the normally experienced climate conditions and a different, but recurrent, set of climate conditions over a given region of the world (IPCC, 1998). Climate change may also refer to a shift in climate, occurring as a result of human activities (Wigley, 1999). Changing climate is expected to continue in the 21st century in response to the continued increasing trend in global green house gas (GHG) emissions (IPCC, 2007a), stimulating three main responses: technical and livelihood adaptations by affected communities, mitigation actions that sequester GHGs or reduce fossil fuels dependence, and formal international dialogue on the scope and correction of this now rapidly emerging threat to human existence.

Climate change scenarios for Africa include higher temperatures across the continent estimated to be increasing by 0.2°C per decade (Elagiband Mansell, 2000) and more erratic precipitation with slight increase in ecozones of eastern Africa and moist forest ecozones of West Africa and sustainable declines in the productivity in the Sahel and the ecozones of southern, Central and North Africa (Stige et al., 2006). This projection is in part reinforced by changes in rainfall over the last 60 years that has declined by up to 30% (Sivakumar et al ., 2 0 05 ), with the greatest negative impacts felt in Alfred Opere, Daniel Olago, Emmanuel Chidumayo and Balgis Osman-Elasha the Sahel of West Africa (Nicholson et al., 2000; Hulme et al., 2001).

Opere, A, Olago D, Chidumayo E, Osman-Elasha B.  2011.  PROCESSUS ET IMPACT DU CHANGEMENT CLIMATIQUE. FORETS, FAUNE SAUVAGE ET CHANGEMENT CLIMATIQUE EN AFRIQUE. , Sweden: Traduit de l’Anglais par: New Alliance Publishers. Abstractforets_faune_sauvage_et.pdf

me des déviations de la climatologie régionale déterminée par l'analyse desmesures à long terme, généralement surune période d'au moins 30 ans, ou aux conditions climatiques normalement vécues,
et un ensemble différent mais récurrent de conditions climatiques sur une région donnée du monde (IPCC, 1998). Le changement climatique peut également se référer à une altération du climat, survenue suite aux activités humaines (Wigley, 1999). Le changement climatique devrait se poursuivre au cours du 21ème siècle comme une conséquence de la tendance croissante des émissions de GES (IPCC, 2007a), stimulant trois principales réponses: les adaptations techniques et celles des moyens de subsistance par les communautés affectées, les mesures d'atténuation qui permettent de séquestrer les GES ou de réduire la dépendance aux combustibles fossiles, et le dialogue international formel sur la portée et la correction de cette menace émergente et désormais pressante pour l’humanité. Les scénarios de changement climatique pour l'Afrique comprennent des températures plus élevées sur tout le continent, estimées pour croître à un taux de 0,2°C par décennie (Elagib et Mansell, 2000) et des précipitations plus aléatoires avec une augmentation légère dans les éco-zones de l'Afrique orientale et éco-zones forestières humides de l'Afrique occidentale, puis des baisses durables de productivité dans le Sahel et dans les éco-zones du sud, du centre et du nord de l'Afrique (Stige et al., 2006). Cette projection est en partie renforcée par les changements dans les rythmes pluviométriques au cours des 60 dernières années, qui ont diminué de près de 30% (Sivakumar et al, 2005), avec les plus grands effets négatifs ressentis dans le Sahel et l’Afrique de l'Ouest (Nicholson et al, 2000; Hulme et al, 2001).

Opere, AO.  2011.  Hydrologic analysis for river Nyando using SWAT. Hydrol. Earth Syst. Sci. Discuss.. 8:1765-1797.opere_hess-abstract.pdf

2010

Gina Ziervogel, Opere A.  2010.  Integrating Meteorological and Indigenous Knowledge-based Seasonal Climate Forecasts for the Agricultural Sector. CCAA learning paper, 1. Abstractintegrating_meteorological_and_indigenous_knowledge-based_seasonal_climate_forecasts_for_the_agricultural_sector.pdfIDRC Digital Library

Extreme climatic events, such as droughts and floods, as well as changes in the mean climate, have a direct
effect on crops and livestock and, thus, people’s livelihoods. Food security is at risk, particularly in sub-saharan Africa where local production remains largely rain-fed. Given that climate variability is likely to increase with increasing greenhouse gas emissions, it is more important than ever to understand how this variability can be managed to reduce the negative consequences.

The impact is already significant. In Malawi, for example, as a result of the 2002 drought, approximately 5 million people needed emergency food aid, which took a long time to be delivered. A similar situation occurred in Niger in 2004–2005 when approximately 2.5 million people — or a fifth of the population — was in need of food rations (UNDP 2007). In 2009, approximately 3.8 million people in Kenya required food aid because of the prolonged drought (FEWS Net 2010). In 2006, sub-Saharan Africa accounted for 13% of the world’s population and 25% of the undernourished people in the developing world (FAO 2006).

O, DROPEREALFRED.  2010.  OPEN AND DISTANT LEARNING MATERIALS WRITTEN & REVIEWED: 1. SMR 103: Quantitative methods & Computer Applications I 2. SMR 309: Hydrometeorology I 3. SMR 307: Thermodynamics & Cloud Physics. University of Nairobi. : A Matimba, M Oluka, B Ebeshi, J Sayi, Bolaji, J Del Favero , C Van Broeckhoven, AN Guanta Abstract
Oral infection with Herpes Simplex Virus (HSV) is a frequent and well documented complication in immunosuppressed individuals including patients on immunosuppressive medication. We report the development of severe oral infection with HSV type 1 in a 34 year old woman with type 1 diabetes mellitus and end stage renal disease (ESRD) following cadaveric renal transplantation at the Western General Hospital, Edinburgh. The role of acyclovir in therapy and chemoprophylaxis is discussed.
Wandiga, SO, Opondo M, Olago D, Githeko A, Githui F, Marshall M, Downs T, Opere A, Yanda PZ, Kangalawe R, Kabumbuli R, Kirumira E, Kathuri J, Apindi E, Olaka L, Ogallo L, Ouma G, Oludhe C, Mugambi P, Sigalla R, Nanyunja R, Baguma T.  2010.  Vulnerability to Epidemic Malaria in the Highlands of Lake Victoria Basin: The Role of Climate Change/Variability, Hydrology and Socio-economic Factors. Grignon, F., and Marpeu, H., (eds), L. : A Matimba, M Oluka, B Ebeshi, J Sayi, Bolaji, J Del Favero , C Van Broeckhoven, AN Guanta Abstract

Oral infection with Herpes Simplex Virus (HSV) is a frequent and well documented complication in immunosuppressed individuals including patients on immunosuppressive medication. We report the development of severe oral infection with HSV type 1 in a 34 year old woman with type 1 diabetes mellitus and end stage renal disease (ESRD) following cadaveric renal transplantation at the Western General Hospital, Edinburgh. The role of acyclovir in therapy and chemoprophylaxis is discussed.

2009

Willems, P, Ogira PN, Mutua F, Abdo G, Kabubi J, Fahmi AH, Sonbol M, Lotfy A, Kimaro TA, Mkhandi S, Opere A, Ibrahim YA, Kizza M, Tadesse L, Motaleb AM, Farid S, Zaki A, Al-Weshah R.  2009.  Regional Flood Frequency Analysis for the River Nile Basin. Mededelingen der Zittingen van de Koninklijke Academie voor Overzeese Wetenschappen. 55(4):555-570. AbstractLirias

Regional differences have been investigated in the probabilities of high and low river flow extremes along the river Nile basin in eastern Africa. This has been done on the basis of statistical extreme value analysis applied to about one hundred flow gauging stations spread over the basin. The statistical analysis results have been combined with physical sub-basin characteristics such as topography and land use. The research has been conducted within the framework of the FRIEND/Nile project, which focuses on regional hydrology research cooperation between the main Nile countries (Egypt, Sudan, Ethiopia, Kenya, Tanzania, Uganda) and the Flemish universities. The high- and low-flow statistics developed can be used in water engineering and civil engineering design applications. Of equal importance are the supratechnical research outputs, among which enhancement of water-related transboundary research cooperation in the Nile region. During the course of the project, trust among the researchers and water managers from the different Nile countries gradually increased, data sharing enhanced, and politically sensitive issues (on transboundary water sharing) became debatable.

DANIEL OLAGO_1, ALFREDOPERE_2 JUSTUSBARONGO_1&.  2009.  Holocene palaeohydrology, groundwater and climate change in the lake basins of the Central Kenya Rift. , Nairobi: Department of Meteorology, University of Nairobi
Opere A.O., Mkhandi, WSP.  2009.  Homogeneity testing for peak discharge in catchments in the equatorial Nile basins. Journal of Meteorology and Related Sciences. 3(3):13-20.

2008

O, DROPEREALFRED.  2008.  UNEP 2008. Beekman H.E., Abu-Zeid K., Afouda A., Hughes S., Kane A., Kulindwa K.A., Odada E.O., Opere Alfred., Oyebande L. and Saayman, I.C. : . University of Nairobi. : A Matimba, M Oluka, B Ebeshi, J Sayi, Bolaji, J Del Favero , C Van Broeckhoven, AN Guanta Abstract
Oral infection with Herpes Simplex Virus (HSV) is a frequent and well documented complication in immunosuppressed individuals including patients on immunosuppressive medication. We report the development of severe oral infection with HSV type 1 in a 34 year old woman with type 1 diabetes mellitus and end stage renal disease (ESRD) following cadaveric renal transplantation at the Western General Hospital, Edinburgh. The role of acyclovir in therapy and chemoprophylaxis is discussed.

2007

O, DROPEREALFRED.  2007.  Methodology for Flood Risk scenarios for Burundi. Workshop on WFP & ICPAC Consultant mission on . University of Nairobi. : A Matimba, M Oluka, B Ebeshi, J Sayi, Bolaji, J Del Favero , C Van Broeckhoven, AN Guanta Abstract
Oral infection with Herpes Simplex Virus (HSV) is a frequent and well documented complication in immunosuppressed individuals including patients on immunosuppressive medication. We report the development of severe oral infection with HSV type 1 in a 34 year old woman with type 1 diabetes mellitus and end stage renal disease (ESRD) following cadaveric renal transplantation at the Western General Hospital, Edinburgh. The role of acyclovir in therapy and chemoprophylaxis is discussed.
O, DROPEREALFRED.  2007.  Water Resources Vulnerability to Environmental Change in Eastern Africa sub-region . Join Africa-Asia workshop on Water Resources Vulnerability to Environmental Change, a UNEP draft report, Huahin, Thailand; 16-18 October 2007. University of Nairobi. : A Matimba, M Oluka, B Ebeshi, J Sayi, Bolaji, J Del Favero , C Van Broeckhoven, AN Guanta Abstract
Oral infection with Herpes Simplex Virus (HSV) is a frequent and well documented complication in immunosuppressed individuals including patients on immunosuppressive medication. We report the development of severe oral infection with HSV type 1 in a 34 year old woman with type 1 diabetes mellitus and end stage renal disease (ESRD) following cadaveric renal transplantation at the Western General Hospital, Edinburgh. The role of acyclovir in therapy and chemoprophylaxis is discussed.
O, DROPEREALFRED.  2007.  Ndetei, C.J. , Opere, A.O. and Mutua F.M. (2007): Flood frequency analysis in Lake Victoria basin based on tail behaviour of distributions. Journal of KMS, vol., pp.44-54. ISSN 1995-9834.. University of Nairobi. : A Matimba, M Oluka, B Ebeshi, J Sayi, Bolaji, J Del Favero , C Van Broeckhoven, AN Guanta Abstract
Oral infection with Herpes Simplex Virus (HSV) is a frequent and well documented complication in immunosuppressed individuals including patients on immunosuppressive medication. We report the development of severe oral infection with HSV type 1 in a 34 year old woman with type 1 diabetes mellitus and end stage renal disease (ESRD) following cadaveric renal transplantation at the Western General Hospital, Edinburgh. The role of acyclovir in therapy and chemoprophylaxis is discussed.
O, DROPEREALFRED.  2007.  Water Resources Vulnerability to Environmental Change in Eastern Africa sub-region: Workshop on Africa. University of Nairobi. : A Matimba, M Oluka, B Ebeshi, J Sayi, Bolaji, J Del Favero , C Van Broeckhoven, AN Guanta Abstract
Oral infection with Herpes Simplex Virus (HSV) is a frequent and well documented complication in immunosuppressed individuals including patients on immunosuppressive medication. We report the development of severe oral infection with HSV type 1 in a 34 year old woman with type 1 diabetes mellitus and end stage renal disease (ESRD) following cadaveric renal transplantation at the Western General Hospital, Edinburgh. The role of acyclovir in therapy and chemoprophylaxis is discussed.

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