Short Rainy Season Research Articles

Spatiotemporal climate and vegetation trends, and their relationship: A case of Genale Dawa basin, Ethiopia

Understanding the variability of climate and vegetation, and their relationship in space and time are crucial for agricultural planning, flood risk assessment, and drought monitoring. However, most studies depend on scarce and unevenly distributed climate station datasets in most basins of Ethiopia like the Genale Dawa basin. Detailed climate and vegetation variabilities and their relationship have not well studied in the Genale Dawa basin, which is often affected by recurrent drought. Satellite remote sensing-derived high spatial resolution climate and vegetation data can provide detailed information on climate variability and vegetation changes. This study assessed spatiotemporal variability of temperature, rainfall, and vegetation greenness and their relationship in the Genale Dawa basin. For this study, temperature (minimum and maximum), rainfall data (4 × 4 km) and Moderate Resolution Imaging Spectroradiometer (MODIS) NDVI data (250 × 250 m) were used. Statistical indices like the Mann Kendall (MK) trend test, Coefficient of Variation (CV), Standard Anomaly Index (SAI), Precipitations Concentration Index (PCI), and Pearson correlation techniques were used to examine the trends and variabilities. The result generally indicated increasing trends in rainfall during the dry (“Bega”) season, and maximum and minimum temperatures during Kiremt (Wet season) and annual seasons. Moreover, high rainfall variability in the Dry and Kiremt seasons and low variability of temperature at all timescales were observed in the basin. In addition, anomalies in temperatures (minimum and maximum) and rainfall were observed in the basin during all the timescales. The result further showed a strong correlation of NDVI with rainfall at annual (r = 0.58), dry season (r = 0.9), and the short rainy season (r = 0.7) while weakly correlated at Kiremt (r = 0.31) seasons in the Genale Dawa basin. The result generally showed spatial and temporal variability of climate and vegetation greenness in the Genale Dawa basin, which negatively affects agricultural production, water resource availability, and vegetation growth. Therefore, appropriate management strategies should be implemented to minimize the negative effects.

A review of human dog-bite injuries in Kitui South subcounty, Kenya (2017-2021).

Dog bites continue to be a serious public health issue due to their association with the transmission of rabies virus. In Kenya, there are no studies estimating dog-bite incidence. Annual mortalities resulting from dog-mediated rabies are estimated at 523 (95% confidence interval 134-1100). The main objective of this study was to assess major risk factors associated with dog bites in Kitui South subcounty, Kenya, between 2017 and 2021. We recruited 387 dog-bite patients (cases) and 387 non-bite patients (controls) for the case-control study from the Mutomo Mission Hospital and the Ikutha Level 4 Hospital records. Multivariable logistic regression analysis evaluated the association between risk factors and dog-bite cases. In the final model, pairwise interactions among variables were evaluated. The model fit was evaluated using receiver operating characteristics and area under the curve. The study found that the dog-bite incidence was highest in Kanziko ward in Kitui South subcounty. Fifty-one percent (108 bites) of dog-bite victims were children under 15 years of age, with 53% (N = 68) being men and 36% (N = 77) being bitten on the limbs. Dog bites mostly (44%, N = 93) occurred between October and December (short rainy season). Age group and season were identified as the most significant variables for high dog-bite incidence in Kitui South subcounty. Promotion of responsible dog ownership and reinforcement of dog control policies may prove more effective in reducing dog-bite injuries in Kitui South subcounty.

Assessing Spatio-temporal Variations and Trends of Rainfall over Somalia from 1991 to 2020

This study aims to examine the spatiotemporal variability and rainfall trends over Somalia using the Mann-Kendall (MK) test and Sen’s slope estimator to investigate the trend and magnitude of the rainfall changes and the arithmetic mean and coefficient of variation (CV) to examine the rainfall variability. To achieve this aim, the gridded monthly satellite rainfall datasets from Climate Hazards Group InfraRed Precipitation with Station (CHIRPS) for the period between 1991 and 2020 were used. Results show that annual rainfall generally exhibits bimodal rainfall distribution, March to May (Gu) and September to November (Deyr), though southern coastal regions receive extended Gu rains into July and northwestern regions experience early onset of Deyr rains. The study further showed that a low and moderate degree of inter-annual variability (CV<30%) is observed in most parts of the country, while on a seasonal basis, the short rainy season (Deyr) has a higher rainfall variability (CV>30%) compared to the primary rainy season (Gu) and most regions in the south receiving highest amounts of rainfall experience highest variability (CV>50%) during Deyr season. Furthermore, the trend analysis of the annual rainfall showed a non-significant increasing trend. On a seasonal basis, the trends of Gu rainfall decreased in some regions while trends for the Deyr season increased in most regions. However, rainfall trends observed were not statistically significant throughout the country at a significance level of 0.05.

Urban malaria vector bionomics and human sleeping behavior in three cities in Senegal

BackgroundMalaria is endemic in Senegal, with seasonal transmission, and the entire population is at risk. In recent years, high malaria incidence has been reported in urban and peri-urban areas of Senegal. An urban landscape analysis was conducted in three cities to identify the malaria transmission indicators and human behavior that may be driving the increasing malaria incidence occurring in urban environments. Specifically, mosquito vector bionomics and human sleeping behaviors including outdoor sleeping habits were assessed to guide the optimal deployment of targeted vector control interventions.MethodsLongitudinal entomological monitoring using human landing catches and pyrethrum spray catches was conducted from May to December 2019 in Diourbel, Kaolack, and Touba, the most populous cities in Senegal after the capital Dakar. Additionally, a household survey was conducted in randomly selected houses and residential Koranic schools in the same cities to assess house structures, sleeping spaces, sleeping behavior, and population knowledge about malaria and vector control measures.ResultsOf the 8240 Anopheles mosquitoes collected from all the surveyed sites, 99.4% (8,191) were An. gambiae s.l., and predominantly An. arabiensis (99%). A higher number of An. gambiae s.l. were collected in Kaolack (77.7%, n = 6496) than in Diourbel and Touba. The overall mean human biting rate was 14.2 bites per person per night (b/p/n) and was higher outdoors (15.9 b/p/n) than indoors (12.5 b/p/n). The overall mean entomological inoculation rates ranged from 3.7 infectious bites per person per year (ib/p/y) in Diourbel to 40.2 ib/p/y in Kaolack. Low anthropophilic rates were recorded at all sites (average 35.7%). Of the 1202 households surveyed, about 24.3% of household members slept outdoors, except during the short rainy season between July and October, despite understanding how malaria is transmitted and the vector control measures used to prevent it.ConclusionAnopheles arabiensis was the primary malaria vector in the three surveyed cities. The species showed an outdoor biting tendency, which represents a risk for the large proportion of the population sleeping outdoors. As all current vector control measures implemented in the country target endophilic vectors, these data highlight potential gaps in population protection and call for complementary tools and approaches targeting outdoor biting malaria vectors.Graphical

Dynamics of the transport of total suspended sediments in the Mefou watershed at Nkolbisson-Yaounde

Abstract This study carried out in the Mefou watershed aimed to assess the quantity of suspended solids in suspension. For this study, a water level gauge was installed at the main station at Etoud, four discharge measurements representing the seasons were carried out and water samples were collected. The maximum liquid discharge to the Lake Mefou was 3.92 m3/s observed during the long rainy season, while the minimum observed during the long dry season was 0.58 m3/s. Meanwhile, the maximum solid discharge to the Lake Mefou observed during the short rainy season was 598.8 mg/s and the minimum of 14.85 mg/s was observed in June during the short dry season. It is then evident that the amount of suspended sediments in the river is not proportional to the flow rate. The mobilization of solid particles in the watershed resulted in an annual total flux of 5.74 T/year into the lake reservoir. This result is not yet alarming for the reservoir lifespan but testify to the permanent activity of erosion in this environment caused by the combination of various natural and anthropogenic processes such as climate change and land use activities.

Nature of climate change-induced risks in semi-arid northwestern Ghana: Gauged observations, perceptions of smallholder farmers, and perspectives for livelihood adaptation

Climate variability and impact have been an endemic challenge to smallholder farmers who largely depend on rainy weather for livelihoods in semi-arid north-western Ghana. Many households in semi-arid regions exhibit low levels of adaptive capacity due to ineffective adaptation strategies and poor coping strategies. This study examined (1) trends in gauged rainfall and temperature data spanning the period from 1984 to 2014 and (2) smallholder farmers’ perceptions about yearly cyclical weather, and difficulties associated with climate change adaptations. The study adopted the participatory rural appraisal design using questionnaire, interviews and focus group discussions for collection of data for analysis. Estimated parameters partially supported that yearly temperatures are increasing, whereas annual rainfall is declining, although the latter is not significantly related to the former. Smallholder farmers’ perceptions about changing weather conditions did not corroborate the observed declining annual rainfall trend. These farmers are faced with livelihood-affecting risks during either ‘prolonged dry periods from October to May’ or ‘short annual rainy season from mid-May to September. Therefore, access to climate information and available climate adaptation strategies could improve farming activities and livelihoods of farmers in response to climate change.

Why Eastern Africa was not dry during the 2020 short rainy season despite La Niña and a negative Indian Ocean Dipole: Interplay between the Madden-Julian Oscillation and La Niña in modulating short rain

Why Eastern Africa was not dry during the 2020 short rainy season despite La Niña and a negative Indian Ocean Dipole: Interplay between the Madden-Julian Oscillation and La Niña in modulating short rain

Effect of local climate anomalies on giraffe survival

AbstractWith the rapid pace of global warming, there is an urgent need to understand survival responses to climate, particularly for large mammals that are already experiencing population declines associated with anthropogenic pressures such as poaching and habitat loss. We tested hypotheses about the interactive effects of local climatic anomalies (variations around a long-term mean) and proximity to edge of protected area boundaries on seasonal adult and juvenile survival in a population of 2,385 individually identified giraffes monitored over 8 years in the Tarangire Ecosystem of northern Tanzania. Temperature anomalies were positively correlated with seasonal survival of adult giraffes, suggesting these megaherbivores are adapted to hot conditions. Higher seasonal rainfall anomalies were negatively correlated with both juvenile and adult survival, and greater vegetation greenness was associated with lower adult survival. During seasons of anomalously high rainfall and vegetation greenness, higher parasite and disease abundance, poorer-quality nutrition in forage, and higher predation risk may all play a role in lowering giraffe survival. Furthermore, climate-associated reduction in survival was most pronounced during the short rainy season for adult giraffes living closer to the edge of protected areas, indicating that the influence of climate anomalies may be exacerbated by anthropogenic edge effects such as poaching or livestock keeping. Precipitation in East Africa is projected to increase substantially, with a greater proportion of rain falling during heavy events in the short rainy season, which may threaten persistence of giraffes in one of Earth’s most important landscapes for large mammals.

Rainfall changes perceived by farmers and captured by meteorological data: two sides to every story

Subsistence farmers with high dependency on natural resources are exceptionally vulnerable to rainfall changes. Besides, they are in the front row when it comes to observing these changes. Studies that systematically investigate similarities and differences between measured and perceived rainfall changes are typically limited to trends in rainfall amounts, thereby disregarding changes in extreme events, rainy season durations, and timing. We address this gap by contrasting rainfall changes perceived by subsistence farmers in the Ethiopian highlands with meteorological daily rainfall data derived from the Climate Hazards Group Infrared Precipitation with Stations (CHIRPS). We applied nine distinct metrics for rainfall dynamics, accounting for rainfall variability, including extreme events and changes in the onset and cessation of the two rainy seasons. Farmers perceived increasingly unreliable rainfall for both the short and the long rainy seasons, with later onset and earlier cessation, increasing rainfall intensity, and increasing occurrence of untimely rainfall and droughts. This partially disagrees with the CHIRPS data that indicate most significant rainfall changes for the short rainy season only. Since the early 1980s, this season has been experiencing decreasing rainfall amounts, with high variability between years and an increasingly uncertain – yet delayed – onset. In contrast, the long rainy season experienced little changes in rainfall. Our results point towards changing farmers' water availability and water demand as an explanation for the perceived deteriorating rainfall conditions. As farmers’ perceptions partly diverge from meteorological observations, both data sources should be used complementarily to improve our understanding of climatic change.

A Pulsed-Precipitation Model of Dryland Vegetation Pattern Formation

We develop a model for investigating the impact of rainstorm variability on the formation of banded vegetation patterns in dryland ecosystems. Water input, during rare rainstorms, is modeled as an instantaneous kick to the soil water. The redistribution, from surface water to soil moisture, accounts for the impact of vegetation on infiltration rate and downslope overland flow speed. These two positive feedbacks between water and biomass distributions act on the fast timescales of rain storms. During dry periods, a classic reaction-diffusion framework is used for the slow processes associated with soil water and biomass. This pulsed precipitation model predicts that the preferred spacing of the vegetation bands is determined by the characteristic distance that a storm pulse of water travels overland before infiltrating into the soil. In this way, the vegetation pattern is determined by the fast ecohydrological processes and may be attuned with its dryland precipitation pattern. We demonstrate how this modeling framework, suited for stochastic rain inputs, can be used to investigate possible collapse of a dryland pattern-forming ecosystem under different precipitation patterns with identical low annual mean. Model simulations suggest, for instance, that shorter rainy seasons and greater variability in storm depth may both hasten ecosystem collapse.

Influence of Seasons and Tides on the Distribution of Enteric Protozoa on the Shores of the Atlantic Ocean in Kribi (South Region of Cameroon): Health Risks Related to Bathing

Beaches are major sites of microbiological pollution. Assessment of the abundance of resistant forms of enteric protozoa on these recreational waters is important for the prevention and management of health risks. Based on sedimentation and flotation methods, this study found that Kribi beach waters concentrate considerable amounts of enteric protozoa, which are potentially pathogenic. They include Coccidia (Cryptosporidium sp. and Cyclospora cayetanensis), Amoebae (Endolimax nana, Entamoeba histolytica and Entamoeba coli) and Flagellates (Giardia intestinalis). In general, seasonal changes and tidal cycles have significantly impacted the spread of these parasites along Kribi beaches. Thus, at all sites surveyed (Mpalla, Ngoyè and Mboamanga), maximum protozoan abundances were recorded at low tide and during the rainy seasons. It should also be noted that at each sampling site, significant correlations were recorded between certain protozoa and certain physico-chemical variables (p < 0.05). At Mboamanga, for example, Cryptosporidium sp. and Endolimax nana were positively correlated during the Short Rainy Season with temperature (r = 0.601, p = 0.044 and r = 0.632, p = 0.042). At Mpalla, a positive and significant correlation was observed during the Short Rainy Season between Entamoeba coli and pH (r = 0.605, p = 0.033). The high concentration of resistant forms of these enteric protozoa at Kribi beaches is a real public health threat for bathers. Therefore, in this tourist town, it is urgent to put in place an effective plan for the collection and sustainable treatment of solid and liquid waste, which are the main sources of contamination.

Farmers’ perceptions of climate variability and adaptation strategies in the rural areas of Dire Dawa administration, eastern Ethiopia

Climate variability has significant impact on agricultural production especially in low-income countries where agriculture largely relies on rainfall, but only a few studies explored this issue at local scale. Therefore, this study was conducted to characterize local climate and assess farmers' perceptions and adaptation strategies to climate variability in the rural areas of Dire Dawa administration. Historical rainfall and temperature data (1987–2017) were obtained from National Meteorological Agency (NMA) of Ethiopia, while data of farmers' perceptions and adaptation strategies were collected from a total of 120 household heads through survey questionnaire, key informant interviews and focus group discussions. The results revealed that the area received an average annual rainfall of 568.3 mm with main rainy season (kiremt) contributing 70.7% to annual rainfall. The earliest and latest onset dates of kiremt season were 15th of April and 2nd of August, respectively. The amount of annual and kiremt rainfall totals showed low and medium variability with a coefficient variability (CV) of 18.3% and 27.7%, respectively, whereas short rainy season (belg) rainfall had high variability with a CV of 43.9%. Climate variability perception analysis showed that an overwhelming majority of the respondents (90%) perceived a decrease in the annual rainfall and 91.7% detected an increase in annual average temperature in the study area. Farmers of the study area were well aware of the changes in rainfall and temperature and thus employed a range of adaptation practices. Soil and water conservation practices (100%), off-farm income diversification (63%), planting drought-tolerant varieties (50%) and changing of planting date (45%) were the main adaptation strategies employed in the study area to avert the negative effects of climate variability. The findings imply that the area has been experiencing palpable changes in climate variables during the study period against which farmers exercised multiple adaptation strategies. However, farmers in the area are still face hardship as a result of climate variability which necessitates improving farmers’ resilience through innovative mechanisms and better extension services.

Understanding the Spatial–Temporal Patterns of Floating Islands Impacting the Major Dams of the White Nile

Floating islands in Lake Victoria, the world’s second-largest fresh water lake, disrupt transportation, fisheries, irrigation, and water quality. Despite their impact, the dynamics of these islands remain unexplored. This study investigates island dynamics within the Nalubaale, Kiira, and Bujagali dams in Uganda, exploring the causes of their formation and the subsequent impact on hydropower production. The study collects data of Landsat imagery from 2000 to 2020, CHIRPS precipitation, and Lake Victoria’s water level datasets from 2004, 2010, 2013, 2017, and 2020. The results reveal a strong correlation between precipitation, fluctuating water levels, and floating island formation, with nutrient-rich runoff from municipal waste and agriculture promoting island growth. In addition, rising water levels lead to the dislodging of rocks and soil, contributing to floating island formation, which may manifest with a lag time of up to one month. The analysis shows higher correlations between precipitation, water levels, and floating islands during the long (March–May) and short (September–November) rainy seasons as opposed to drier periods (June–August, December–February). The findings indicate that southeast monsoon winds, which transport floating vegetation, also are essential in influencing island dynamics. Consequently, the major drivers of floating islands in Lake Victoria are identified as precipitation, water level fluctuations and wind variations. Finally, a negative correlation between floating island eutrophication and power production at Kiira and Nalubaale stations suggests that the increased eutrophication caused by the presence of floating islands leads to reduced power output at both Kiira and Nalubaale power stations.

Urea briquettes combined with a fertilizer blend reduces fertilizer costs and improves yields of irrigated rice in Rwanda

AbstractWe evaluated the yield and potential economic impact in Rwanda of replacing the standard lowland rice (Oryza sativa L.) fertilizer recommendation from the current practice of 200 kg NPK 17‐17‐17 ha−1 and 100 kg urea ha−1 with a basal blend of 74 kg diammonium phosphate (DAP), 57 kg potassium chloride (KCl), and deep placement of 112.5 kg urea briquettes ha−1 at 4 weeks after transplanting. Experiments were carried out in nine diverse marshlands across Rwanda in the long and short rainy seasons of 2016, with the two fertilizer treatments and a no‐fertilizer control. Compared to the current practice, the urea deep placement (UDP) package increased yields by 1.08 and 0.84 mt ha−1 in the respective seasons, while at the same time lowering N fertilizer rate by 15 kg ha−1. Average value to cost ratio increased from 1.89 (current recommendation) to 3.16 (UDP recommendation) and would be still greater than 2.0 at six times increase in labor cost. The cost of fertilizer recommendation (fertilizer cost plus application cost) was lower with the UDP package due to replacing 17‐17‐17 with a lower rate of the DAP and KCl combination. The overall average net benefit of US$300 ha−1 was substantial. Should labor cost increase by eight times compared to the current $1.52 per person‐day, UDP would still provide a benefit of $150–$207 ha−1 compared to the current practice. On a national scale, converting to the UDP package recommendation would result in additional 32,000 mt rice and increase farmer revenue by some US$10 million annually.

English

A study was carried out at two sites in Tanzania to assess the effect of different planting densities on growth and yield of five recently released bush bean varieties. The experiment was laid out in a split-plot design in a factorial arrangement with three replications during long and short rainy seasons of 2019/20 and 2020/21. The treatments comprised five bean varieties; TARIBEAN 1, 2, 3, 4 and 5 and five plant population densities; 200000, 222222, 250000, 266666 and 333333 plants/ha. Variables evaluated were plant height, angular leaf spot and common bacterial blight disease scores in leaves, number of pods per plant, number of seeds per pod, hundred seed weight and grain yield. The variables were subjected to ANOVA and means of statistically significant variables to plant density, variety, and environment were analyzed by Tukey HSD test and “which-won-where” view of the GGE biplot. The interaction of factors only affected significantly plant height and yield. Highest grain yield of 1,353 and 1,607 kg/ha were recorded by plant density of 200,000 plants/ha and TARIBEAN 1 variety at Maruku site during short rainy seasons (E2). Therefore, a plant density of 200,000 plants/ha and TARIBEAN 1 variety are recommended in all four environments. Key words: Plant density, bean varieties, grain yield, environment, GGE biplot, “which-won-where”.

Seasonal Transmission Dynamics of Rift Valley Fever in Kilimanjaro Region, Tanzania

Background: Rift Valley Fever (RVF) is a zoonotic disease that affects both animals and humans. Under reporting, misdiagnosis caused by the broad spectrum of symptoms presented by the disease, and limited access to rapid and accurate laboratory confirmation have led to an undefined burden of RVF. Reports are available that show the circulation of the virus during inter-epidemic periods, implying an endemic circulation of RVFV. This study aimed to determine RVFV transmission across annual seasons and demographic factors that are independently associated with exposure to RVFV. Methodology: Repeated serosurveys were performed during the long rainy, short rainy, and dry seasons in Lower Moshi area of Moshi district, Kilimanjaro region from January to December 2020. The goal was to determine seroprevalence against RVFV antibodies in humans and factors associated with seropositivity. Detection of RVF antibody was performed by competitive Enzyme-Linked Immunosorbent Assays (cELISA) using serum samples. Stata statistical software version 15 was used for data analysis. Descriptive statistics was carried out, whereby categorical variables were summarised using frequencies and percentages. Numeric variables were summarised using median and interquartile range. Logistic regression was used to assess factors associated with RVF seropositivity. Results: A total of 446 individuals were involved in the analysis. RVF seroprevalence was highest during rainy season (20.4%) and lowest in the dry season (4%). The overall annual seroprevalence of RVF was 12.8%. Season, participant age, and large number of residents in a given household were found to be significantly associated with RVF seropositivity (p<.05). Conclusion: RVFV demonstrates an endemic circulation in Lower Moshi area of Kilimanjaro region, suggesting the site is a potential RVF hotspot. Based on this study’s findings, we recommend close surveillance of RVF in the study area and other areas with similar ecology in Tanzania as a means of preparedness for future unpredicted RVF outbreaks.

On-farm storage loss estimates of maize in Kenya using community survey methods

Maize is the most important staple in sub-Saharan Africa (SSA), with highly seasonal production. High storage losses affect food security, but good estimations are lacking. A new method using focus group discussions (FGDs) was tested with 121 communities (1439 farmers, 52% women) in Kenya's six maize-growing zones, to estimate the maize losses to storage pests and analyze farmer practices. As control strategies, half of the farmers used chemical pesticides (49%), while hermetic bags (16%) and botanicals (15%) were also popular. Relative loss from weevils in the long rains was estimated at 23%, in the short rains 18%, and annually 21%. Fewer farmers were affected by the larger grain borer (LGB) than by maize weevils: 42% in the long rainy season and 32% in the short rainy season; losses from LGB were also smaller: 19% in the long season, 17% in the short season, and 18% over the year. Total storage loss, from both species combined, was estimated at 36%, or 671,000 tonnes per year. The greatest losses occur in the humid areas, especially the moist mid-altitudes (56%), and with smaller loss in the drylands (20–23%). Extrapolating the point data and overlaying with the maize production map shows the geographic distribution of the losses, with the most important area found around Lake Victoria. FGDs provide convenient and cheap tools to estimate storage losses in representative communities, but a total loss estimate of 36% is higher than is found in other studies, so its accuracy and framing effects need to be assessed. We conclude that storage pests remain a major problem, especially in western Kenya, and that the use of environmentally friendly technologies such as hermetic storage and botanicals needs more attention, both by the public extension service and private agrodealers.

Assessment of the variability of the morphological traits and differentiation of Cucurbita moschata in Cote d’Ivoire

With its predisposition to adapt to different environments, Cucurbita moschata grows well in various ecosystems. It is not a very exigent plant and has an inherent capacity for plasticity that underlies its large variability. An assessment of the accessions of C. moschata in Cote d’Ivoire shows that the plant exhibits large morphological and phenological variability for all the 28 measured traits. There are outliers among most measured traits. Further analysis indicates the emergence of three ecotypes in congruence with the three distinct ecosystems and their respective bioclimatic characteristics. In the savannah region, characterized by a short rainy season followed by a long dry season, a total yearly rainfall of 900 mm, an elevated daily temperature of 29 °C, and a high relative humidity of 80%, the cline of C. moschata is long and thin, with small leaves, small peduncles and small fruits. It has a high growth rate and accelerated phenology. The mountain region has a very long rainy season followed by a short dry season, a total pluviometry of 1400 mm, an average daily temperature of 27 °C and a relative humidity of 69%. The cline of C. moschata in the mountain region is characterized by a delayed flowering and a delayed fruit maturity, large number of small seeds and large fruits. The forest region has a favorable climate for the growth of C. moschata in Cote d’Ivoire. It has two rainy seasons that alternate with two dry seasons of unequal durations, an annual rainfall of 1200 mm, an average daily temperature of 27 °C and a relative humidity of 70%. The cline of C. moschata in that region has a large girth size, large dimensions of the leaves, long peduncles and larger and heavier fruits. The seeds are also large but in small number. It appears that the anatomy and physiology of the clines are differentiated primarily in response to soil water content and availability for the ontogeny of the plant.

Prevalence, seasonal dynamics and associated variables of ixodid tick cattle infestation in Gondar, northwestern Ethiopia

Ticks are ectoparasites that impact the health and productivity in farm animals. They are also important vectors for pathogens transmitted to animals and humans. A cross-sectional study was conducted from November 2018 to April 2019 with the objectives of determining the prevalence, identifying genera and seasonal dynamics of adult ixodid ticks infesting cattle in and around Gondar, northwestern Ethiopia. Pearson Chi-square Test was used to evaluate the association of tick prevalence with explanatory variables. One way analysis of variance was used to compare mean tick density of cattle with the explanatory variables. The overall prevalence of cattle ixodid tick infestation was found to be 65.8% (95% CI = 60.0–71.2%). The effect of breed, sex, age and body condition score on tick prevalence was investigated. However, only the body condition score of study animals was found to have statistically significant effect on the prevalence of tick infestation. Monthly analysis of tick infestation showed statistically significant variation (χ2 = 36.17, p = 0.00) during the study period (November 2018 – April 2019). The highest monthly prevalence was recorded in March (85.0%), and the least in February (42.0%). A comparison of the tick prevalence across seasons showed statistically significant differences (χ = 34.10, p = 0.00), being highest (82.5%) during the short rainy season. During the study period, a total of 3796 adult ixodid ticks were collected from different body regions of the study animals. Three ixodid tick genera were identified, with the genus Rhipicephalus being the most prevalent (n = 2122 (55.9%) of the total adult ticks (3796). The overall mean tick density per host for all genera was 12.78 ticks, with a marked difference in tick density during the three study seasons. The highest MTD was recorded during the short rainy season (MTD = 18.58), (F = 19.71, p < 0.05). The present study has shown that ticks are highly prevalent in the study area. Therefore, an appropriate tick control program should be designed and implemented.

Future Changes in Climate and Hydroclimate Extremes in East Africa

AbstractClimate change is affecting the agriculture, water, and energy sectors in East Africa and the impact is projected to increase in the future. To allow adaptation and mitigation of the impacts, we assessed the changes in climate and their impacts on hydrology and hydrological extremes in East Africa. We used outputs from seven CMIP‐6 Global Climate Models (GCMs) and 1981–2010 is used as a reference period. The output from GCMs are statistically downscaled using the Bias Correction‐Constructed Analogs with Quantile mapping reordering method to drive a high‐resolution hydrological model. The Variable Infiltration Capacity and vector‐based routing models are used to simulate runoff and streamflow across 68,300 river reaches in East Africa. The results show an increase in annual precipitation (up to 35%) in Ethiopia, Uganda, and Kenya and a decrease (up to 4.5%) in Southern Tanzania in the 2050s (2041–2070) and 2080s (2071–2100). During the long rainy season (March–May), precipitation is projected to be higher (up to 43%) than the reference period in Southern Ethiopia, Kenya, and Uganda but lower (up to −20%) in Tanzania. Large parts of Kenya, Uganda, Tanzania, and Southern Ethiopia show an increase in precipitation (up to 38%) during the short rainy season (October–December). Temperature and evapotranspiration will continue to increase in the future. Further, annual and seasonal streamflow and hydrological extremes (droughts and floods) are projected to increase in large parts of the region throughout the 21st century calling for site‐specific adaptation.