Browsing by Author "Said, Mateso"

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Climate and anthropogenic footprints implications on the surface and groundwater dynamics on the southern slopes of Mount Kilimanjaro, Tanzania
(NM-AIST, 2021-10) Said, Mateso
Climate and land use/cover changes impact water resources all over the world. This study aimed at developing a conceptual understanding and management of the impacts of present and future climate change and human activities on surface and groundwater resources on the Kikafu-Weruweru-Karanga (KWK) watershed. The methodology includes simulation of the present and prediction of the future hydrological fluxes and streamflow prediction under changing climate and land use/cover. Calibration and validation of the hydrological model, Soil and Water Assessment Tool (SWAT) showed satisfactory performance (Nash-Sutcliffe Efficiency (NSE)) > 0.50). A total of 22 parameters were used, and Curve number for soil moisture condition II, Baseflow alpha-factor, and average slope steepness were the most sensitive parameters. Future climate data for two Representative Concentration Pathway (RCPs) from Regional Atmospheric Climate Model -22T and Climate Limited Area Modeling 4 models were used. Land use/cover (LULC) maps were generated by classifying time-series (1996, 2006, and 2018) satellite images, selected spatial metrics were used to predict the LULC changes for the next decade using 2018 as a base year. Furthermore, the implications of selected staple crops production over the next decade was predicted. Simulated LULC shows expansion in built-up (by 32.55% and agriculture (by 39.52%) areas from 2018 to 2030, and the forest area is projected to shrink by 6.37%. However, the results suggest that farm size plays a minor role in increasing crop production. Expansion in cultivation land and built-up area attributed to the changes in water yield, surface runoff, evapotranspiration (ET), and groundwater flow. Rock-water interaction chiefly controls the groundwater quality in the presence of HCO3 enrichment and mixed CaNaHCO3 water types. The δ2H and δ18O values confirmed that recycled water is the primary recharge means, and glacier melts on Mt. Kilimanjaro sustains downstream water availability during the dry season. Furthermore, temperatures were projected to increase by 0.2ºC/year, and a decrease in precipitation was projected up to 2100 in both highland and lowland areas. The findings suggested the need to intensify the production per unit area rather than expanding the farm size. Also, improving the vegetation cover on the hillside and abandoned land area could help to reduce the direct surface runoff, and floods recurring in the area. The findings of this study are useful to facilitate sustainable water resources management in the watershed and other watersheds with or without modification.
Defluoridation of Water Supplies Using Coconut Shells Activated Carbon: Batch Studies
(IJSR, 2014) Said, Mateso; Machunda, Revocatus
Drinking water with elevated fluoride levels results in serious irreparable health problem that has attained an alarming dimension all over the world, Tanzania being one of the affected countries; techniques have been under study for years. Batch experiments were carried out to determine the effect of various adsorbent factors such as adsorbent dose, initial pH, particle size and contact time on adsorption process. Adsorption efficiency was observed to increase with decrease in particle size, the highest efficiency recorded was 68.2 and 65.9% for field and synthetic water respectively when particle size less than 150μ of coconut shells activated carbon were used. Adsorption was observed to be favoured by pH in acidic range and the maximum efficiency of 58.4% was recorded at pH of 2.0 and particle sizes between 4.18-2.36mm. The pH of the effluent was lowered to acidic range which necessitates further treatment of the effluent or coupling with other materials for pH elevation before use. Adsorption increases with adsorbent dose hence at a smaller influent concentration; the required standard of 1.5mg-F- /l can be met. Equilibrium isotherms have been analysed using Langmuir and Freundlich isotherm models, and both of the models fit to explain the adsorption behaviour of fluoride ions onto Coconut shell activated carbons, during this study it was established that when properly activated; coconut shells can be appropriate for use household filters that could be cost effective in rural areas of Tanzania due its local availability and its colour adsorption property.
Evaluation and Prediction of the Impacts of Land Cover Changes on Hydrological Processes in Data Constrained Southern Slopes of Kilimanjaro, Tanzania
(MDPI, 2021-05-30) Said, Mateso; Hyandye, Canute; Mjemah, Ibrahimu; Komakech, Hans; Munishi, Linus
This study provides a detailed assessment of land cover (LC) changes on the water balance components on data constrained Kikafu-Weruweru-Karanga (KWK) watershed, using the integrated approaches of hydrologic modeling and partial least squares regression (PLSR). The soil and water assessment tool (SWAT) model was validated and used to simulate hydrologic responses of water balance components response to changes in LC in spatial and temporal scale. PLSR was further used to assess the influence of individual LC classes on hydrologic components. PLSR results revealed that expansion in cultivation land and built-up area are the main attributes in the changes in water yield, surface runoff, evapotranspiration (ET), and groundwater flow. The study findings suggest that improving the vegetation cover on the hillside and abandoned land area could help to reduce the direct surface runoff in the KWK watershed, thus, reducing flooding recurring in the area, and that with the ongoing expansion in agricultural land and built-up areas, there will be profound negative impacts in the water balance of the watershed in the near future (2030). This study provides a forecast of the future hydrological parameters in the study area based on changes in land cover if the current land cover changes go unattended. This study provides useful information for the advancement of our policies and practices essential for sustainable water management planning.
Evidence of climate change impacts on water, food and energy resources around Kilimanjaro, Tanzania
(Springer Nature Switzerland AG., 2019-11-08) Said, Mateso; Komakech, Hans; Munishi, Linus; Muzuka, Alfred
This review presents research evidence of climate change and anthropogenic impacts on the slopes of Mt. Kilimanjaro and its implications on water, food and energy production (WFE nexus). While there exist divided scholarly opinions on the impacts of climate change on the Mt. Kilimanjaro glacier, consistent decreases in precipitation amounts are evident throughout the existing literature. The 2050 projections indicate increases in the precipitation amounts by approximately 16–18%. However, it is also stated that there will be a concomitant increase in water deficit of about 71%, 27% and 1% in agriculture, hydropower and livestock production respectively. Despite a large number of researches on impacts of climate and anthropogenic pressure on WFE along Mt. Kilimanjaro slopes, there are still limited long-term, good-quality and high-resolution altitudinal precipitation, temperature records and observation network. Moreover, there is limited information on groundwater recharge areas and their stability under changing environment. It is not clear how the interdependence and interaction between climate change, irrigation, vegetation and river discharges affect groundwater recharge process. Also, there is scarce information on future land use/cover changes. Very limited studies focused on fog water deposition for Mt. Kilimanjaro forest and East Africa, despite its relevance as the water tower of the mountain streams. The review further highlights how both climate and anthropogenic impacts may affect ecosystem services in the region. There is a need for developing adaptive strategies for responding to climate change and anthropogenic impacts on the slopes of Mt. Kilimanjaro now and into the future.
Hydrogeochemical Analysis of Water Quality Dynamics Under Anthropic Activities on the Southern Slopes of Mount Kilimanjaro, Tanzania
(Springer Nature, 2022-07-14) Said, Mateso; Komakech, Hans; Mjemah, Ibrahimu; Lufingo, Mesia; Munishi, Linus; Kumar, Sudhir
Water quality management requires consideration of surface water and groundwater dynamics. This study utilizes hydrogeochemical and isotopic techniques to understand anthropic influences on surface and groundwater resources in the Kikafu–Weruweru–Karanga (KWK) watershed southern slopes of Mount Kilimanjaro. The KWK watershed had two distinct characteristics, i.e., the upper region (above 1000 m.a.m.s.l) with surface water and few groundwater features and the lower part (below 1000 m.a.m.s.l) characterized by most groundwater sources and rivers. Water sampling and analysis were done between July and August 2019; multivariate statistical analysis aided the understanding of analytical findings. The results revealed NaHCO3 enrichment and Mixed CaNaHCO3 water type. The groundwater chemistry is chiefly controlled by aquifer lithology rather than anthropic activities. Stable isotopes show recharge from both regional and local rainfall as traced from the shallow wells. The levels of anthropic pollution indicators such as nitrate, chloride, and sulfate in deep wells are generally low in groundwater than in shallow wells. Anthropic activities such as irrigation, wastewater discharges and severe water abstraction confirmed significant contaminant agents at the dynamic levels. Next to geogenic releases, anthropic pollution as well is affecting groundwater quality in the aquifer. The current findings call for improved monitoring of the groundwater sources to track any changes in quality since there is a potential evolution to an undesirable state for domestic uses.
Plant biomasses for defluoridation appropriateness : unlocking their potentials
(Research Journal in Engineering and Applied Sciences, 2014) Mwakabona, Hezron; Said, Mateso; Machunda, Revocatus; Njau, Karoli
Fluoride and fluorosis are endemic to many countries including Tanzania. Performances of different materials for use in water defluoridation systems have been reported. Some of these materials are; alum, oxides and hydroxide of metals, activated carbon, bone char and plant biomasses. This paper reviews and discusses the performances of selected defluoridation materials such as alum in Nalgonda technique, the oxides and hydroxides of metals (inorganic adsorbents) in ion exchange/adsorption, activated carbon, bone char and plant biomasses in ion exchange/adsorption. More discussion is on the strengths and limitations of these materials in removing fluoride from water. Furthermore, it describes a new approach that will likely enhance the fluoride removal capacity when plant biomasses are used, which involves special arrangement of different plant biomasses in a column. This promises to be of low cost and high performance and thus suitable for both urban and rural communities in developing countries.
Predicting land use/cover changes and its association to agricultural production on the slopes of Mount Kilimanjaro, Tanzania
(Taylor & Francis Online, 2021-01-11) Said, Mateso; Hyandye, Canute; Komakech, Hans; Mjemah, Ibrahimu; Munishi, Linus
Increasing demand for food production results in Land use and land cover (LULC) changes, which afflicts the provision of ecosystem services in high mountain areas. This work used time-series LULC and selected spatial metrics to predict the LULC changes for Kikafu-Weruweru-Karanga (KWK) watershed (on the southern slopes of Mt. Kilimanjaro) for the next decade. LULC maps were generated by classifying time-series satellite images. We further predicted the implications for selected staple crop production over the next decade. The simulated LULC shows expansion in built-up (by 32.55%/27.04 km2) and agriculture (by 39.52%/52.0 km2) areas from 2018 to 2030. These results suggest that urbanization is likely the next biggest threat to water availability and food production. Grasslands and wetlands are expected to decrease by 57.24% and 39.29%, respectively. The forest area is likely to shrink by 6.37%, about 9.82 km2, and 1.26 km2 being converted to agriculture and built-up areas, respectively. However, expansion in agricultural land shows very little increase in staple food crop production records, suggesting that farm size plays a minor role in increasing crop production. Predicting the near future LULC around KWK is useful for evaluating the likelihood of achieving development and conservation targets that are set locally, nationally and internationally.