Downscaling Seasonal Precipitation Forecasts over East Africa with Deep Convolutional Neural Networks

This study assesses the suitability of convolutional neural networks(CNNs) for downscaling precipitation over East Africa in the context of seasonal forecasting. To achieve this, we design a set of experiments that compare different CNN configurations and deployed the best-performing architecture to downscale one-month lead seasonal forecasts of June–July–August–September(JJAS) precipitation from the Nanjing University of Information Science and Technology Climate Forecast System version 1.0(NUIST-CFS1.0) for 1982–2020. We also perform hyper-parameter optimization and introduce predictors over a larger area to include information about the main large-scale circulations that drive precipitation over the East Africa region, which improves the downscaling results. Finally, we validate the raw model and downscaled forecasts in terms of both deterministic and probabilistic verification metrics, as well as their ability to reproduce the observed precipitation extreme and spell indicator indices. The results show that the CNN-based downscaling consistently improves the raw model forecasts, with lower bias and more accurate representations of the observed mean and extreme precipitation spatial patterns. Besides, CNN-based downscaling yields a much more accurate forecast of extreme and spell indicators and reduces the significant relative biases exhibited by the raw model predictions. Moreover, our results show that CNN-based downscaling yields better skill scores than the raw model forecasts over most portions of East Africa. The results demonstrate the potential usefulness of CNN in downscaling seasonal precipitation predictions over East Africa,particularly in providing improved forecast products which are essential for end users.

The Impacts and Causes of Land Fragmentation on Farm Productivity: Case Review of East African Countries

This report provides an overall assessment of land fragmentation problems in East Africa. Many parts of East Africa have become highly fragmented, putting development systems and activities in these areas at risk of complete collapse. Land fragmentation occurs when land gets converted for agriculture, industrialization, or urbanization, invaded by non-local plants, or enclosed for individual use and by subdividing farmlands into subsequent smaller units called parcels with varying average farm sizes. Fragmentation results from inappropriate agricultural development processes and ineffective land use planning that fails to recognize how farmland is used, and the importance of its interconnected areas. Insecurity of tenure and resource rights are key factors in making this possible. Land fragmentation is one of the key reasons why the ability of most resources in East Africa becomes scarcer, and those remaining become “privatized” by more powerful community members—keen to maintain their access to them. Such individualistic attitudes are new and disadvantage the poorest even further by affecting the traditional customary safety nets and agricultural outputs. Neither the government nor customary governance systems effectively protect resource access for the poorest. This review summary report identifies the key causes, measures, and implications, government interventions, and the common remedies to land fragmentation problems in the East African Countries of Kenya, Uganda, Rwanda, and Tanzania including neighboring Ethiopia, and the Sudan. The findings indicated from 2005 to 2015, the population kept increasing for all the named countries in East Africa with Rwanda and Uganda having a substantial increase in population density. The study review further explores the trend in the performance of agriculture by average farm sizes within the intervals of five years by highlighting their strong linkages and found that the average farm size has declined drastically, especially for Kenya. This can only mean that small farms kept becoming smaller and smaller and that there were more small-scale farmers. The results further depicted that the major and commonly cultivated food crops among the East African countries include maize, sorghum, rice, cassava, sweet potatoes, bananas, Irish potatoes, beans, peas, etc., with maize yields (Mt/ha) in 2003 for Uganda being the highest (1.79 Mt/ha) and the lowest in Rwanda (0.77 Mt/ha) respectively. Therefore, from the review results, recommendations are being made as to how the negative impacts of land fragmentation on agricultural productivity can be reduced or mitigated. One way is by community sensitization and awareness about the importance of land consolidation and its proposition on farm productivity.

Spatio-Temporal Variability of Rainfall and Temperature and Their Effects on Pasture Variability over East Africa: Implication on the Cattle Grazing Areas

Understanding the spatiotemporal variability of climatic parameters and their effects on pasture variability is vital for pasture management interventions over East Africa. The present study aims to assess the spatial-temporal variability of rainfall, temperature and Normalized Difference Vegetation Index (NDVI) (which is being used to assess pasture quality and productivity) over the region, between the period of 1982 and 2019. This study used annual mean values for rainfall, temperature and NDVI which were calculated for the period mentioned above. NDVI was derived from National Oceanic and Atmospheric Administration (NOAA) Global Area Cover (GAC) (NOAA-07-GAC) data. The rainfall data was acquired from the Climate Hazards Group Infrared Precipitation with Station (CHIRPS) while temperature is ERA5 reanalysis data sourced from the European Centre for Medium-Range Weather Forecasts (ECMWF). The study utilized the empirical orthogonal function (EOF) to identify patterns and dominant relationships between the climate variables. The correlation was calculated between rainfall, temperature and NDVI to assess the relationship among them. A non-parametric Mann-Kendall trends test was used to determine whether annual precipitation, temperature and NDVI had statistically increasing or decreasing trend. Results revealed a positive correlation between rainfall and NDVI while a negative correlation between NDVI and temperature. Positive correlation between rainfall and NDVI indicates that pasture health (quality and productivity), will improve accordingly. A negative correlation between temperature and NDVI indicates that pasture health will decrease with increase in temperature while improving with decreasing temperature. Outcome from this study suggests that changes in climatic variables influence the distribution of pasture in East Africa’s cattle grazing areas. The study hence recommends prioritisation of climatic (weather) information during pasture management over East Africa.

The Relationship between Extreme Precipitation Events in East Africa during the Short Rainy Season and Indian Ocean Sea Surface Temperature

The East African short rainy season (October-November-December) is one of the major flood seasons in the East African region. The amount of rainfall during the short rainy season is closely related to the lives of the people and the socio-economic development of the area. By using precipitation data and sea surface temperature data, this study reveals the spatial and temporal variation patterns of extreme precipitation during the East African short rainy season. Key findings include significant rainfall variability, with Tanzania experiencing the highest amounts in December due to the southward shift of the Intertropical Convergence Zone (ITCZ), while other regions receive less than 100 mm. Extreme rainfall events (90th percentiles) are evenly distributed, averaging 2 to 10 days annually. Historical data shows maximum seasonal rainfall often peaks at 15 mm, with frequent occurrences of daily rainfall exceeding 10 mm during OND. Additionally, a positive correlation (0.48) between OND precipitation extremes and Indian Ocean Dipole (IOD) anomalies is statistically significant. These findings highlight the climatic variability and potential trends in extreme rainfall events in East Africa, providing valuable insights for regional climate adaptation strategies.

Potential Driving Systems Associated with Extreme Rainfall across East Africa during October to December (OND) Season 2019

The East African (EA) region highly experiences intra-seasonal and inter-annual variation in rainfall amounts. This study investigates the driving factors for anomalous rainfall events observed during the season of October-November-December (OND) 2019 over the region. The study utilized daily rainfall data from Climate Hazards Group InfraRed Precipitation with Station Data Version 2 (CHIRPSv2) and the driving systems data. Statistical spatiotemporal analysis, correlation, and composite techniques were performed to investigate the teleconnection between OND 2019 seasonal rainfall and global synoptic climate systems. The findings showed that the OND 2019 experienced seasonal rainfall that was twice or greater than its seasonal climatology and varied with location. Further, the OND 2019 rainfall showed a positive correlation with the Indian Ocean Dipole (IOD) (0.81), Nino 3 (0.51), Nino 3.4 (0.47), Nino 4 (0.40), Pacific Decadal Oscillation (PDO) (0.22), and North Tropical Atlantic (NTA) (0.02), while El Nino-Southern Oscillation (ENSO) showed a negative correlation (−0.30). The region was dominated by southeasterly warming and humid winds that originated from the Indian Ocean, while the geopotential height, vertical velocity, and vorticity anomalies were closely related to the anomalous rainfall characteristics. The study deduced that the IOD was the major synoptic system that influenced maximum rainfall during the peak season of OND 2019. This study therefore provided insights on the diagnosis study of OND 2019 anomalous rainfall and its attribution over the EA. The findings of the study will contribute to improvements in forecasting seasonal rainfall by regional climate centers and national meteorological centers within the region.

Climate change risk,resilience,and adaptation among rural farmers in East Africa:A literature review

This study assesses the literature evidence on climate change risk,resilience,and adaptation measures used among rural farmers in East Africa.A systematic literature review was conducted comprising 30 papers from the Web of Science database published during 2000-2022.The results of the literature review showed that climate change risks have direct impacts on agricultural practices,limit rural farmers’resilience,and exacerbate their food insecurity.The most prominent risks are increasingly shorter wet seasons and heat stress,which lead to droughts and food production losses.Responding to climate risks,farmers in East Africa adopt various adaptation strategies such as mixed-and inter-cropping,conservation tillage,early planting,crop diversification,etc.Also,this review summarizes the determinants of climate change adaptation strategy selection by farmers in East Africa,including age,gender,household size,economic status and household assets,landownership and livestock,education and training,etc.Overall,the choice of adaptation strategies to climate change is strongly determined by the gender of household heads,the results of gender as a determinant of adaptation differ greatly between different case studies.Although female-headed households(FHHs)tend to perceive changes in temperature more readily than male-headed households(MHHs),the latter are generally more likely to adopt different adaptation strategies.Despite the resilience and adaptation measures used by rural farmers in East Africa now,improved weather forecasting and early warning systems are needed as a better direction towards the future.

The Inter-Annual Variability of Rainfall Onset and Its Implication on Crop Planting in Selected East Africa Countries

The inter-annual variability of rainfall onset and crop replanting in East Africa (EA) was assessed using daily estimated rainfall data from climate hazard group infrared precipitation (CHIRPS Ver2.0) and monthly Sea Surface Temperature (SST) indices [Indian Ocean Dipole (IOD) and El-Ni?o Southern Oscillation (ENSO) at NINO3.4 region] from the National Center for Environmental Prediction (NCEP) and the National Center for Atmospheric Research (NCAR). The data covered a period of 40 years from1981 to 2020. The methods of cumulative of daily mean rainfall, percentage of onset date departure (PODD), Mann-Kendall (MK) trend test, student t-test, and correlation were applied in the analysis. The results showed that early onset with dry spell (WDS) consideration frequently occurs in Uganda between the first and second dekads of September, while late rainfall onset WDS occurs in the first and second dekads of December over central and Northern Kenya as well as in the Northeastern highlands, parts of the northern coast and unimodal regions in Tanzania. Rainfall onset with no dry spell (WnDS) portrayed an average of 10 days before the occurrence of true onset WDS, with maximum onset departure days (ODD) above 30 days across the Rift Valley area in Kenya and the Northeastern highlands in Tanzania. The high chance of minimum ODD is seen over entire Uganda and the area around Lake Victoria. However, few regions, such as Nakuru (Kenya) Gulu and Kibale (Uganda), and Gitega (Burundi), revealed a slight positive linear trend while others showed negative trend. Significant positive patterns for correlation between onset WDS and SST indices (IOD and NINO 3.4) were discovered in Northern and Northeastern Kenya, as well as areas along the Indian Ocean (over Tanzania’s Northern Coast). Inter-annual relationship between onset dates WDS and IOD (NINO3.4) indices exhibits a high correlation coefficient r = 0.23 (r = 0.48) in Uganda and r = 0.44 (r = 0.36) in Kenya. On the other hand, a negative correlation was revealed over Burundi and Tanzania (over a unimodal region). A high percentage of PODD was observed, ranging from 40% to 70% over the Rift Valley in Kenya and at the Northeastern highlands in Tanzania. However, a strong PODD above 70% was observed over Tanga and the Northern Pwani Region in Tanzania. These findings will help farmers to understand the appropriate time for crop planting, as well as help other socio-economic activities that strongly depend on rainfall.

Enhancement of East African Monsoon Long Rainfall (March to May) Variability from Weekly to Annual Scale by Climatic Extremes

As global warming increasingly affects vulnerable regions such as Central East Africa, it is crucial to understand future changes in rainfall variability to reduce vulnerability. Despite the importance of rainfall variability, it has received less attention compared to changes in mean and extreme rainfall. This study evaluates the amplification of synoptic (weekly) to annual variability of East African Monsoon (EAM) Long Rainfall (March to May) by climatic extremes. Using band-pass filtered daily rainfall data, we found that EAM rainfall variability is anticipated to increase by 20% - 60% across the region under global warming conditions. The majority of the intermodal variability in Long Rain EAM rainfall forecasting is explained by differences in mean rainfall. Our results show that the synoptic variability of Long Rain for EAM rainfall is likely to amplify, resulting in more extreme rainfall events and longer dry spells under global warming. This amplification is attributed to the warming of the Indian Ocean and the associated changes in atmospheric circulation patterns. The projected increase in synoptic to annual variability of Long Rain for EAM rainfall has significant implications for water resources management and agriculture in the region, challenging policymakers to develop adaptive strategies that can mitigate the impacts of these extreme events. This study emphasizes the potential impacts of projected climate changes in rainfall variability on the East African region at all periods and underscores the need for effective adaptation strategies to ensure sustainable development.

Migrated hybrid turbidite-contourite channel-lobe complex of the late Eocene Rovuma Basin, East Africa

Analysis of 3 D seismic data and well log data from the Rovuma Basin in East Africa reveals the presence of a late Eocene channel-lobe complex on its slope.The first two channels,denoted as channel-1 and channel-2,are initiated within a topographic low on the slope but come to a premature end when they are blocked by a topographic high in the northwest region of the basin.New channels migrate southeastward from channel-1 to channel-6 due to the region’s sufficient sediment supply and stripping caused by bottom currents.The primary factors controlling the development of the channel complex include its initial paleo-topographic of seafloor,the property of gravity flows,the direction of the bottom current,and the stacking and expansion of its levees.The transition zone from channel to lobe can also be clearly identified from seismic sections by its pond-shaped structure.At a certain point,thest systems record a transiton from erosive features to sedimentary features,and record a transition from a confined environment to an open environment.Channels and lobes can be differentiated by their morphologies:thick slump-debris flows are partly developed under channel sand sheets,whereas these slump-debris flows are not very well developed in lobes.Well log responses also record different characteristics between channels and lobes.The interpreted shale volume throughout the main channel records a box-shaped curve,thereby implying that confined channel complexes record high energy currents and abundant sand supply,whereas the interpreted shale volume throughout the lobe records an upward-fining shape curve,thereby indicating the presence of a reduced-energy current in a relatively open environment.Within the Rovuma Basin of East Africa,the average width of the Rovuma shelf is less than 10 km,the width of the slope is only approximately 40 km,and the slope gradient is 2°–4°.Due to this steep slope gradient,the sand-rich top sheet within the channel also likely contributes to the straight feature of the channel system.It is currently unclear whether the bottom current has any effect on its sinuosity.

Seasonal Prediction of Summer Precipitation over East Africa Using NUIST-CFS1.0

East Africa is particularly vulnerable to precipitation variability, as the livelihood of much of the population depends on rainfed agriculture. Seasonal forecasts of the precipitation anomalies, when skillful, can therefore improve implementation of coping mechanisms with respect to food security and water management. This study assesses the performance of Nanjing University of Information Science and Technology Climate Forecast System version 1.0(NUISTCFS1.0) on forecasting June–September(JJAS) seasonal precipitation anomalies over East Africa. The skill in predicting the JJAS mean precipitation initiated from 1 May for the period of 1982–2019 is evaluated using both deterministic and probabilistic verification metrics on grid cell and over six distinct clusters. The results show that NUIST-CFS1.0 captures the spatial pattern of observed seasonal precipitation climatology, albeit with dry and wet biases in a few parts of the region. The model has positive skill across a majority of Ethiopia, Kenya, Uganda, and Tanzania, whereas it doesn’t exceed the skill of climatological forecasts in parts of Sudan and southeastern Ethiopia. Positive forecast skill is found over regions where the model shows better performance in reproducing teleconnections related to oceanic SST. The prediction performance of NUIST-CFS1.0 is found to be on a level that is potentially useful over a majority of East Africa.

Quality variations and controlling factors of deepwater submarine-fan reservoirs,Rovuma Basin,East Africa

The mechanisms causing quality variations and key control factors of submarine-fan reservoirs in the gas field X of the Rovuma Basin,East Africa are analyzed based on core and well-log data in this paper.Depositional fabric,lithofacies difference and characteristics of genetic units are the fundamental reasons of reservoir quality variations.In the case of weak cementation,porosity and permeability of submarine-fan reservoirs are controlled by grain sorting and clay content,respectively.Reservoir quality variations for 5 main lithofacies are related to variable depositional fabrics and calcite cementation.Among them,massive medium-coarse sandstones with weak cementation have the highest porosity and permeability,and coarser or finer sandstones have poorer reservoir quality.The existence of bottom current can develop laminated sandstones,improving the pore structure and physical properties greatly.Lithofacies vary among different types,locations and stages of genetic units,and they control the distribution patterns of submarine-fan reservoir quality:the physical properties of channel shaft or lobe main body are better than those of the channel or lobe edge.The sandstone sorting and physical properties are gradually improved from near-source to far-source.When multi-stage sand bodies are superimposed,the sand-mud ratio in the later stage is higher than that in the earlier stage,making the physical properties get better in the later stage.

VARIABILITY OF DIURNAL TEMPERATURE RANGE IN EAST AFRICA DURING 1921-2010

This study investigates the long-term spatiotemporal variability of diurnal temperature range(DTR) in East Africa(EA). The study carries out non-parametric trend analysis of gridded DTR monthly data sourced from Climatic Research Unit(CRU). The DTR exhibits mixed signals in space and time over EA. The DTR correlates negatively with rainfall over EA. Reduction in DTR coincides with the summer season in the northern and southern hemispheres respectively, suggesting the influence of cloud cover on it. There was a non-uniform pattern of DTR changes across the region with time. Lake Victoria basin recorded the highest warming rates. The Indian Ocean coast recorded the least spatiotemporal variability in DTR. A reduction in DTR is evident in the two seasons: hot and cold. The start of the study period; 1921—1930, was the coolest decade in the study period. Most parts of EA recorded negative DTR anomalies in 1961—1970. The overall reduction in DTR throughout the study period highlights the ongoing warming which is a global phenomenon. There remains need for investigating the causation of the observed DTR variability for effective monitoring of the variability in future.

A study of the factors affecting mobile money penetration rates in the West African Economic and Monetary Union (WAEMU) compared with East Africa

According to the 2017 Global Financial Inclusion(Global Findex)database,the average penetration rate of mobile money accounts in East Africa is higher than that of the WAEMU.This study attempts to understand the factors driving the adoption and the use of mobile financial services in the WAEMU compared to East Africa.To achieve this,micro-level data from the 2017 Global Findex database are used to perform probit and multinomial logit estimations.The findings reveal that the same determinants influence the adoption and use of mobile money accounts across the populations of both groups of countries,specifically those related to the least vulnerable social categories(i.e.,males,older,more educated,richer and part of the workforce).Therefore,in comparison to East Africa,the delay in the penetration of mobile money accounts observed in the WAEMU may be attributed to insufficient policies for increasing the awareness of the benefits of mobile financial services.The study recommends that governments in WAEMU countries promote the use of mobile money accounts among the working-age population(adults aged between 25 and 64)through the improvement of individual income level,and the introduction of incentives into the education system to encourage their population to attain higher levels of education.

Determinants of Export Performance in East Africa Countries

The main objectives of this study are to identify and analyze variables which have impact on export performances of seven East Africa countries and suggest possible solutions to improve export performance in East Africa. Usingdata from World Development Indicators database we conducted panel data analysis for the period of 1990-2014.Empirical results show that labor force, industrialization, foreign direct investment, and exchange rate have positiveimpact on export value. On the other hand, inflation has negative impact on export performance while GDP growthis the only variable that does not affect the export value of East Africa countries. Finally, we suggest somerecommendations, including the need of replacing agricultural exports by the industrial export, improving infrastructural facility as well as the quality of human capital and the need of policies for attracting internationalinvestors.

＂Cunning Tactics＂： Indigenous Responses to the Imposition of German Colonial Rule in East Africa

Examinations of the German colonial empire often focus on questions of ideology, metropolitan politics, or seek to address questions related to the ＂special path＂ of German history. All too often, the German invaders are portrayed as omnipotent and intellectually superior to their African allies and opponents. This paper argues for the primacy of ＂events on the ground＂, and instead focuses on the initiative and choices made by local African actors during the protracted conflict between the Germans and the Hehe in German East Africa （modem Tanzania） in the 1890s. During this conflict, African elites sought to maximize their own power, wealth, and prestige by utilizing German resources to their own ends. Overall, this work argues for the centrality of African politics and policy-making during early colonialism.

East Africa’s Quick Killer

HEALTH and politics don’t always mix.In January,as increasing numbers of returnees from North Sudan entered Southern Sudan to vote on a referendum for independence, the World Health Organization(WHO) reported that a major visceral leishmaniasis epidemic was in danger of breaking out.Incidences of the disease - the world’s second deadliest parasitic killer after malaria - had nearly doubled within the span of a month,according to case records from last November. WHO officials speculated that the surge was due to that fact that returnees typically did not have immunity against the disease.

Tectono-Sedimentary Evolution of the Offshore Hydrocarbon Exploration Block 5, East Africa: Implication for Hydrocarbon Generation and Migration

Sedimentary deposits in Block 5, offshore Tanzania basin have been imaged using two-dimensional (2D) seismic data. The seismic data and well data reveal four tectonic units representing different tectonic events in relation to structural styles, sedimentation and hydrocarbon potential evolved in Block 5. Results show that during Early to Late Jurassic, Block 5 was affected by the break-up of Gondwana and the drifting of Madagascar as evidenced by patterns of sediments and structural features. The chaotic and discontinuous reflectors are characteristics features on the sediments pattern indicating a possible transitional setting following the breakup of Gondwana. From the Late Cretaceous, Block 5 sits in more stable subsiding sag as the consequence of the high thermal subsidence. The period displayed continuous parallel reflectors with few markable faults. This was followed by the late post rift sedimentation that occurred after Middle Eocene Unconformity characterized by high wavy and sub parallel reflectors. The evolution of Block 5 through major tectonic events reveals a more complete petroleum system towards the south. Thus, Block 5 responded in both space and time to a complex interplay between tectonics and sedimentation. This indicates that structural styles and associated features are potential control for hydrocarbon generation and migration.

Environmental Challenges Associated with the Development of Socio-Economic Activities in East African Countries Comparative Study with China

This study is presenting a Policy analysis of the related environmental challenges associated with the development of socio-economic activities between China and East African countries. The author thinks that Socio-economic issues and economic development have a direct impact on the environment hence need to be studied for the purpose of policy formulation. This study analysed the policies on environmental issues in China and its five-year economic plan. Furthermore, this study examined what the Chinese government has done about socio-economic activities and what lessons are available for East African countries. Finally, this paper proposed possible solutions for East African countries on environmental challenges associated with the development of socio-economic activities with the potential for combining economic and ecological interests in East Africa. This study can help (potential) Government officers, policymakers, and regulators to assess environmental risks with lessons from China.

Long Term Assessment of Aerosol Radiative Forcing over Selected Sites of East Africa

Atmospheric aerosols have contributed to radiative forcing through direct and indirect mechanisms. Aerosol effects are important in computing radiative forcing estimates for the past, current and future climate. In this study, a comprehensive assessment of regional aerosol radiative forcing, Optical Properties of Aerosol and Clouds (OPAC) model (wavelength range of 0.25 - 4.0 μm) over selected sites in East Africa was done. Aerosol optical properties constituted the inputs of a Radiative Transfer Model (RTM). Op-tical properties investigated included Aerosol Optical Depth (AOD), Single Scattering Albedo (SSA) and Asymmetry Parameter (AP). Aerosol Radiative Forcing (ARF) during the study period at the surface (SFC), top of the atmosphere (TOA) and the atmosphere (ATM) was estimated to be -18.4 ± 1.4 W·m-2, +1.1 ± 0.3 W·m-2 and +19.5 ± 2.5 W·m-2, respectively. This corresponds to an increment in net atmospheric forcing at a heating rate of about 0.55 ± 0.05 K/day (0.41 ± 0.03 to 0.78 ± 0.03 K/day) in the lower troposphere. The study points out the significant role played by atmospheric aerosols in climate modification over the area of study. It is recommended that a further assessment be done in view of uncertainties that may impact on the findings and which were not within the scope of this research.

The statistical prediction of East African rainfalls using quasi-biennial oscillation phases information

A simple correlation method and a quasi-biennial oscillation (QBO)/rainfall composite analysis were used to examine the teleconnections be-tween the seasonal rainfall anomalies of March through May (long-rains) over East Africa and the different QBO phases in the stratospheric zonal winds, and also explore the predictive potential of the long rainy season using infor-mation about the phases of the QBO for the pe-riod 1979-2003. We study the spatial correlation patterns statistically to understand the climatic associations between the equatorial strato-spheric zonal wind and regional rainfall at the interannual time scale. The aim of this analysis is to establish whether this global signal can be employed as predictor variable in the long-range forecasts. Principal component analysis (PCA) is employed in the first instance to reduce the large dimensionality of the predictant (monthly rainfall data), to retain the time series of the principal components (PCs) and to delineate the rain gauge network of East Africa into homo-geneous zones. Spatial patterns of the factor loading were used to delineate East Africa into 11 homogeneous zones.