13 research outputs found

    An assessment of the impact of climate change on plant species richness through an analysis of the Normalised Difference Water Index (NDWI) in Mutirikwi Sub-catchment, Zimbabwe

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    This study assesses the effects of climate change on vegetative species diversity exploring the usefulness of the Normalised Difference Water Index (NDWI) in predicting spatio-temporal diversity variations. The relationship between species richness and climatic variables of rainfall and temperature is explored based on species data collected from the field over a 3 year period and climate data collected from four local weather stations. Relationship between NDWI and species diversity indices is examined to confirm the usefulness of Remote Sensing in predicting vegetative diversity. The resultant predictive model was used to estimate changes in species richness over a 27 year period (1987-2014). The species diversity data was then regressed with climatic data for the same period. The results show a significant (P<0.05) correlation between species diversity and the two climatic variables. The results also indicate that there is a significant positive (P=0.0001; α=0.05; R2=0.565) relationship between species richness and NDWI. This implies that the NDWI is essential when assessing changes in species diversity over time. The Mann Kendall test revealed a decrease, though not statistically significant, in the rainfall received within the catchment over the period and significant variability. The minimum and maximum temperatures over the period were significantly increasing. These changes in climate variables were matched with a decrease in species richness. Some species tend to be succumbing to the environmental changes influenced by climate change resulting in their changes in phenology, abundance and distribution

    Impact of climate change on vegetative species diversity in Masvingo Province, Zimbabwe

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    Vegetative species diversity is under threat from environmental pressures, particularly climate change. As the impacts of climate change vary from place to place, response of vegetative species diversity to a changing climate also vary depending on geographical location. The response of vegetative species diversity under dry conditions in Zimbabwe is not well known. This study assessed the impact of climate change on vegetative species diversity under semiarid conditions of Masvingo province in Zimbabwe. This was achieved by determining climate change trends over a period of forty years (1974-2014), and examining the relationship between vegetative species diversity and spatially interpolated climate data. The absence of historical diversity data prompted the use of remote sensing to enable the assessment of spatial and temporal changes. Thus, the Normalised difference vegetation index (NDVI) was used to assess vegetative species diversity changes after establishing a positive relationship between species diversity and NDVI. The mixed methods research design was used as the strategy of inquiry. The non-aligned block sampling design was used as the sampling framework from which 198 sampling points were identified. Meteorological data obtained from Zimbabwe Meteorological Services Department (ZMSD) and the National Climate Data Centre (NCDC) were used for climate change analysis. Data collected through image analysis, direct observations, questionnaire surveys and interviews were used to assess the impact of climate change on vegetative species diversity. Results indicate that all temperature and precipitation variables have significant (p<0.05) trends over the period under study. However, the trend for seasonal total precipitation was not significant but declining. The significant trends indicate that climate change occurred over the period under study. 93% of the respondents confirmed having experienced the climate change phenomenon. Results also show a significant relationship between climate elements (precipitation and temperature) and vegetative species diversity represented by Shannon Weaver Index (H). More so, there is a positive relationship between NDVI and H. Vegetative species diversity represented by NDVI decreased over the period under review. The results indicate that climate change has contributed to the decrease of vegetative species diversity in Masvingo province, thus it is a force behind many other factors contributing to biodiversity loss.College of Agriculture and Environmental SciencesPh. D. (Environmental Sciences

    Seasonality, Mass Vaccination and critical policy evaluation on Global Exit Strategy of COVID-19 crisis

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    There is a strong coordinated effort by vaccination groups all over the world to put an end to the current crisis of COVID-19. Now sufficient data are available to analyse and compare some results to explore the aftereffects of vaccination. Some influence variables on transmissions of the disease were discussed e.g., mass vaccination, lockdown and seasonality. Most studies covered here are up to the beginning of July 2022, while some analyses focused on the earlier period of mass vaccination. Well established, simple statistical techniques to evaluate results were presented those used open data sources of authoritative bodies. Some comparisons between vaccinated vs. unvaccinated were also discussed based on data from UK Government Health Security Agency (UHSA). In terms of mass vaccination, adverse reactions after vaccination received attention, as health and safety issues of the general public are of prime importance. Apart from direct side effects, the secondary effect of mass vaccination needs attention too. After the initiation of the vaccination programme, almost all countries experienced a sudden surge in transmission and most countries had to impose strict lockdown measures. Many countries, with a low prevalence of disease, suddenly showed a steep jump and some countries even followed a synchronized pattern between the rate of transmissions and the variation of vaccine doses. Time series analyses and bar diagram presentations were able to capture those features. In that context, fast mutation of the virus and new variants after mass vaccination and possible mechanisms/consequences were also attended. To understand the effect of seasonality, similarities between COVID-19 and the seasonal Flu are discussed for Europe and US to gain useful insight. Using time series analyses and spatial plots of regional temperature composites we showed, like Flu, seasonality played a dominant role in transmissions of COVID-19 in the Europe. Regulations of vaccine dose and policy implication were explored too. From 22nd December 2021, global vaccine doses were reduced substantially, which followed a dramatic reduction in cases and thereafter deaths with around one month's lag between each. As strong dependency on seasonality is noticed in certain countries and observing that regulation of vaccine doses has roles in modulating the transmission with certain lags, globally as well as regionally, our results have policy implications for the management of COVID. Debating, questioning and criticism are always the foundation of great science and the major pillars of its progress. Following that objective, it is an effort to explore pragmatically, supported by scientific analyses, areas relating to the effectiveness of the COVID-19 vaccine and the exit strategy via the pathway of vaccination

    Climate Change Response Strategies and Implications on Sustainable Development Goals in Mutirikwi River Sub-Catchment of Zimbabwe

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    Sub-catchment level water sector response strategies to climate change in Zimbabwe have not been adequately analyzed to determine their impact and connectedness with the Sustainable Development Goals (SDGs). In this study, the mixed methods research design is used to examine the implications of water sector climate change response strategies (CCRS) on SDGs in Mutirikwi sub-catchment in Masvingo, Zimbabwe. Results show that the climate is changing, with a statistically significant (p = 0.031; α = 0.05) increase in the annual mean temperature and a declining rainfall trend, though not statistically significant (p=0.753; α = 0.05). Views from local communities and stakeholders confirm the existence of climate change. There is a deluge of response strategies to the changing climate, including borehole drilling, roof rainwater harvesting, surface storage, water reuse and water transfers. These strategies have directly contributed to the achievement of SDG 6 (Clean Water and Sanitation), SDG 11 (Sustainable Settlements), and SDG 13 (Climate Action). They have also indirectly contributed to the achievement of SDG 3 (Health), SDG 5 (Gender), SDG 9 (Infrastructure) SDG 12 (Sustainable Consumption) and SDG 15 (Life on Land). The study concludes that there is an inextricable link between CCRS and SDGs. However, implementation of the response strategies is riddled with challenges that are threatening the sustainability matters. There is a need to design community-driven response mechanisms synergized with national and international climate adaptation initiatives to ensure sustainability of the strategies through guaranteed policy and resource support from the national government and non-governmental agencies

    Climate Change Response Strategies and Implications on Sustainable Development Goals in Mutirikwi River Sub-Catchment of Zimbabwe

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    Sub-catchment level water sector response strategies to climate change in Zimbabwe have not been adequately analyzed to determine their impact and connectedness with the Sustainable Development Goals (SDGs). In this study, the mixed methods research design is used to examine the implications of water sector climate change response strategies (CCRS) on SDGs in Mutirikwi sub-catchment in Masvingo, Zimbabwe. Results show that the climate is changing, with a statistically significant (p = 0.031; α = 0.05) increase in the annual mean temperature and a declining rainfall trend, though not statistically significant (p=0.753; α = 0.05). Views from local communities and stakeholders confirm the existence of climate change. There is a deluge of response strategies to the changing climate, including borehole drilling, roof rainwater harvesting, surface storage, water reuse and water transfers. These strategies have directly contributed to the achievement of SDG 6 (Clean Water and Sanitation), SDG 11 (Sustainable Settlements), and SDG 13 (Climate Action). They have also indirectly contributed to the achievement of SDG 3 (Health), SDG 5 (Gender), SDG 9 (Infrastructure) SDG 12 (Sustainable Consumption) and SDG 15 (Life on Land). The study concludes that there is an inextricable link between CCRS and SDGs. However, implementation of the response strategies is riddled with challenges that are threatening the sustainability matters. There is a need to design community-driven response mechanisms synergized with national and international climate adaptation initiatives to ensure sustainability of the strategies through guaranteed policy and resource support from the national government and non-governmental agencies

    Interfacing vector-borne disease dynamics with climate change : implications for the attainment of SDGs in Masvingo city, Zimbabwe

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    This study used a mixed-methods research design to examine the sensitivity of vector-borne disease (VBD) patterns to the changes in rainfall and temperature trends. The research focused on malaria in Masvingo Province, Zimbabwe. The study interfaced the climate action, health and sustainable cities and communities with sustainable development goals (SDGs). Historical climate and epidemiological data were used to compute the correlations and determine the possible modifications of disease patterns. Clustered random and chain-referral sampling approaches were used to select study sites and respondents. Primary data were gathered through a questionnaire survey (n = 191), interviews and focus group discussions, with Mann– Kendal trend tests performed using XLSTAT 2020. The results show a positive correlation between malaria prevalence rates and temperature-related variables. A decline in precipitation-related variables, specifically mean monthly precipitation (MMP), was associated with an increase in malaria prevalence. These observations were confirmed by the views of the respondents, which show that climate change has a bearing on malaria spatial and temporal dynamics in Masvingo Province. The study concludes that climate change plays a contributory role in VBD dynamics, thereby impeding the attainment of the 2030 Agenda for Sustainable Development, especially SDG 3, which deals with health. The study recommends further research into appropriate adaptation mechanisms to increase the resilience of rural and urban communities against the negative transmutations associated with weather and climatic pressures
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