ON THE RELATIONSHIP BETWEEN SATELLITE-BASED EVAPOTRANSPIRATION AND NORMALIZED DIFFERENCE VEGETATION INDEX, CASE STUDY: NAROK COUNTY OF KENYA

This study sought to unearth a possible relationship between evapotranspiration and Normalized Difference vegetation index (NDVI). Daily datasets of Evapotranspiration with a pixel resolution of 3km were sourced from the EUMETSAT’s Land Surface Analysis Satellite Application Facility (LSA-SAF). Twice monthly (NDVI) datasets were retrieved from the Moderate Resolution Imaging Spectro-radiometer (MODIS) which is housed by the TERRA satellite platform. The NDVI is at a pixel resolution of 250m. The two datasets were averaged accordingly using Climate Data Operators (CDO) to produce monthly values from January 2001 to October 2012. Using Grid Analysis and Display System (GrADs), data for a total of 36 grid locations were extracted from the two datasets at a uniform spatial increment of 0.1˚ covering an estimated area of 3600Km2 within Narok County. Scatter plots showed that in most locations, there existed a positive linear relationship between the two datasets with 80% of the grid locations considered confirming this analogy. Pearson correlation analysis was performed between the two datasets. Only a few locations showed non-significant correlations at the 95% confidence level. The results therefore pointed to a conclusion that the two datasets can be used interchangeably for various agro-meteorological applications. However, the Root Mean Square Error (RMSE) computed between the two datasets for each of the considered grid locations was large. It’s therefore advised that one should exercise caution in using the 2 datasets interchangeably. One of the factors that might have contributed to the error is the different spatial and temporal resolutions between the two datasets. NDVI had a pixel resolution of 250m while evapotranspiration had a resolution of 3km. At the same time, the temporal resolution for the NDVI data was twice monthly while evapotranspiration had a temporal resolution of 10 day averages.Keywords: Grads, CDO, Pearson product moment correlation, Scatter plots NDVI, Evapotranpiratio

Evaluation of urbanization influences on urban temperature of Nairobi City,Kenya

Developing countries are becoming more urbanized leading to modification on climate over the cities. Proper urban atmospheric planning and management are thus fundamental for cities’ sustainability. Urban weather and climate therefore needs continuous monitoring to offer accurate, reliable and timely update of any significant changes. This study examined the long term modification of temperature by urbanization utilizing decadal population data, monthly maximum and minimum temperature and land surface albedo for forty years. The data were subjected to homogeneity test using Short-Cut Bartlett test method that showed both maximum and minimum temperature increasing, though insignificant. Urbanization is evidenced by the reducing land surface albedo and increasing population. The study revealed the influence of urbanization on urban climate. The increase in temperatures is harmful to human comfort. Practical approaches, such as increasing the urban for-est cover and a proper planning of the cities,have been suggested to help prevent further modification of weather and urban climate by urbanization. The findings of this work are thus important for multi-sectoral use in the Kenyan cities

Bio-prospecting of Medicinal Bio-resources from the Kenyan Biodiversity: Reflections on Governance as the Missing Link - A Review Article

Medicinal biodiversity has since times immemorial served as one of the richest sources of bio-prospecting leading to the discovery of novel drugs for mankind globally. However, in Kenya, despite the Country being known to be a mega biodiversity hotspot, bio-prospecting has not been very successful mainly due to lack of effective institutional and legal frameworks. This article reviews the policy and legislation instruments governing medicinal biodiversity in Kenya in order to identify their weaknesses and strengths and come up with recommendations for effective economic exploitation of the Country’s’ mega diverse resource. The methodology employed was a qualitative content analysis of relevant biodiversity legislations in Kenya. Results reveal that there has been governance gaps as far as bio-prospecting activities in Kenya are concerned which has rendered the Country’s mega biodiversity vulnerable to bio-piracy at the expense of the poor  local communities who are the traditional knowledge owners. There is need to review the current pieces of legislation on medicinal biodiversity and work towards developing a strong National bio-prospecting policy together with an implementation plan. These are important to inform the overall national development agenda, in tandem with Vision 2030. Some of the policies were found out dated and rather obsolete and not serving the current interests and ambitions of the Country. There is therefore a need to revisit the policy and legislative instruments because they will continue frustrating bio-prospecting activities.  Moreover, we recommend the creation of a National Institute to coordinate and harmonize the legislations and National policies on medicinal biodiversity to seal loopholes, avoid conflicts and contradictions being experienced in the current legislative and policy frameworks. Keywords: Bio-prospecting; Bio-piracy; Governance; Kenya; Medicinal biodiversity DOI: 10.7176/JHMN/60-05 Publication date:March 31st 201

Spatial-Temporal Characteristics of Past and Projected Climate Over Dairy Production Zones: A Case of Nandi County, Kenya

Climate change is regarded as a significant global environmental threat. This study assesses downscaled projections of climate change over dairy production regions (Nandi County) of Kenya using Rossby Centre Regional Atmospheric Model (RCA4) outputs driven by the eight (8) coordinated regional Downscaling Experiment (CORDEX) models. Climate baseline period (1971-2000) was used to evaluate CORDEX model performance against different sources of precipitation and temperature observations. Graphical and statistical approaches which correlation; Mann-Kendall test and nonparametric Sen’s method were used to assess the trends in both past and future climate. Spatial analysis involved mapping of climate variables. Assessment of the skill of CORDEX models shows significant bias in the individual models in simulating precipitation. However, maximum and minimum temperatures performed well based on both individual and ensemble based outputs. CORDEX model outputs were comparable to observations, and either overestimated or underestimated the climate. Past and projected precipitation remains bimodal and highly variable (increasing/decreasing) in both space and time. Positive change between baseline and projected temperatures were noted for RCP45 and RCP85. As a response to the effects of climate variability and change, adoption of climate smart agricultural technologies is necessary to ensure that smallholder farmers put adequate measures to adapt and mitigate impact of climate change Keywords: Precipitation; temperature; climate; projections; CORDEX DOI: 10.7176/JEES/10-6-06 Publication date:June 30th 202

Forage Monitoring and Prediction Model for Early Warning Application over the East of Africa Region

Rangelands dominate arid and semi-arid lands of the Greater Horn ofAfrica (GHA) region, whereby pastoralism being the primary source oflivelihood. The pastoral livelihood is affected by the seasonal variabilityof pasture and water resources. This research sought to design a grid-basedforage monitoring and prediction model for the cross-border areas of theGHA region. A technique known as Geographically Weighted Regressionwas used in developing the model with monthly rainfall, temperature,soil moisture, and the Normalized Difference Vegetation Index (NDVI).Rainfall and soil moisture had a high correlation with NDVI, and thusformed the model development parameters. The model performed wellin predicting the available forage biomass at each grid-cell with March-May and October-December seasons depicting a similar pattern but witha different magnitude in ton/ha. The output is critical for actionable earlywarning over the GHA region’s rangeland areas. It is expected that thismode can be used operationally for forage monitoring and prediction overthe eastern Africa region and further guide the regional, national, sub-national actors and policymakers on issuing advisories before the season

First molecular phylogenetic insights into the evolution of Eriocaulon (Eriocaulaceae, Poales)

Eriocaulon is a genus of c. 470 aquatic and wetland species of the monocot plant family Eriocaulaceae. It is widely distributed in Africa, Asia and America, with centres of species richness in the tropics. Most species of Eriocaulon grow in wetlands although some inhabit shallow rivers and streams with an apparent adaptive morphology of elongated submerged stems. In a previous molecular phylogenetic hypothesis, Eriocaulon was recovered as sister of the African endemic genus Mesanthemum. Several regional infrageneric classifications have been proposed for Eriocaulon. This study aims to critically assess the existing infrageneric classifications through phylogenetic reconstruction of infrageneric relationships, based on DNA sequence data of four chloroplast markers and one nuclear marker. There is little congruence between our molecular results and previous morphology-based infrageneric classifications. However, some similarities can be found, including Fyson’s sect. Leucantherae and Zhang’s sect. Apoda. Further phylogenetic studies, particularly focusing on less well sampled regions such as the Neotropics, will help provide a more global overview of the relationships in Eriocaulon and may enable suggesting the first global infrageneric classification

Savanna fire and the origins of the 'underground forests' of Africa

1. The origin of fire-adapted lineages is a long-standing question in ecology. Although phylogeny can provide a significant contribution to the ongoing debate, its use has been precluded by the lack of comprehensive DNA data. Here we focus on the ‘underground trees’ (= geoxyles) of southern Africa, one of the most distinctive growth forms characteristic of fire-prone savannas. 2. We placed geoxyles within the most comprehensive dated phylogeny for the regional flora comprising over 1400 woody species. Using this phylogeny, we tested whether African geoxyles evolved concomitantly with those of the South American cerrado and used their phylogenetic position to date the appearance of humid savannas. 3. We found multiple independent origins of the geoxyle life-form mostly from the Pliocene, a period consistent with the origin of cerrado, with the majority of divergences occurring within the last 2 Ma. When contrasted with their tree relatives, geoxyles occur in regions characterized by higher rainfall and greater fire frequency. 4. Our results indicate that the geoxylic growth form may have evolved in response to the interactive effects of frequent fires and high precipitation. As such, geoxyles may be regarded as markers of fire-maintained savannas occurring in climates suitable for forests.Government of Canada through Genome Canada and the Ontario Genomics Institute (2008-OGI-ICI-03), the International Development Research Centre (IDRC), Canada and the University of Johannesburg.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1469-81372015-10-31hb201

Simulation of Decadal Precipitation over Nairobi in Kenya

In investigating Kenya rainfall variability and its relationship to other climatic elements it has become imperative to analyze the irregularly distributed rainfall events in time. To meet this requirement, this study used a stepwise regression technique. The study seeks to improve existing rainfall monitoring and prediction in Nairobi. Monthly rainfall data was fitted to several mathematical functions. The best mathematical model which best simulated the March-May (MAM) and October -December (OND) seasonal rainfall over the three stations of analysis was chosen using a stepwise regression technique. The value of R-squared for the best fit was computed to show the percentage of rainfall information that is explained by the variation in the independent (time) variable. From the results obtained, the stepwise regression technique selected the fourth degree polynomial as the best fit for analyzing the March-May (MAM) and October -December (OND) seasonal rainfall data set. Solar cycle period of ten (10) years was employed to get the fourth degree polynomial variables. Hence from the study, it can be deducted that the 4th degree polynomial function can be used to predict the peak and the general pattern of seasonal rainfall over Nairobi, with acceptable error values.  This information can be used in the planning and management of water resources over Nairobi. The same information can be extended to other areas

TOWARD OPTIMIZING BREWER ZENITH SKY TOTAL OZONE MEASUREMENTS AT THE ITALIAN STATIONS OF ROME AND ISPRA

A ''sky chart'' program for optimizing Brewer zenith sky total ozone measurements at Rome Station is developed. It is applied to total ozone data at the Rome station, obtained by both direct Sun and zenith sky methods for the period May 1991 to March 1993, to compute new polynomial coefficients used in the calculation of the zenith sky total ozone values. These new coefficients are then utilized by the program to compute new zenith sky total ozone values. The percentage differences between (1) the zenith sky measurements computed using the old coefficients and direct Sun ozone data and (2) the direct Sun and the zenith sky total ozone values obtained using the new coefficients are presented. The new coefficients are also applied to some zenith sky (ZS) ozone data of Ispra. The results of the comparison between new ZS and old ZS values with respect to the corresponding DS measurements are presented. The new coefficients give more optimized zenith sky total ozone values than the old ones