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Browsing by Author "Katambara, Zacharia"

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A Fuzzy Inference System for Modelling Streamflow: Case of Letaba River, South Africa.
(Elsevier, 2008-07-10) Katambara, Zacharia; Ndiritu, John
Stream flow modeling of Letaba River in South Africa is complicated by several factors including the existence of dams and other storage structures whose releases are intermittent and based on rules of thumb depending on the irrigation demands and the need to maintain the flow required in the Kruger National park (KNP). The KNP is located about a hundred kilometers downstream of the main storage and water flows through an alluvial aquifer where complex surface–groundwater interactions occur. Farmers abstract water intermittently along the route directly from the river or indirectly from the alluvial aquifer complicating the flow patterns even more. Consequently, the stream flow series in the river shows very little similarity to what would be considered as natural. The actual abstractions are not measured and only monthly estimates of the abstractions currently exist. Like in many other basins in South Africa, stream flow, groundwater level, rainfall and evaporation data in Letaba is sparse and not very reliable. The Takagi–Sugeno fuzzy inference system using subtractive clustering, an approach which is capable of dealing with vague and inadequate information and data has therefore been used to develop a daily stream flow model for Letaba River. In order to take into account the spatial variability and to maximize the use of the available data, the model is applied in a semi-distributed manner consisting of three river reaches. The shuffled complex evolution (SCE-UA) optimizer has been used to calibrate the model. Six years of data from March 2002 to April 2008 has been used for model calibration and verification. To maximize the Nash-Sutcliffe efficiency, the minimum number of clusters required was found to be 10 for 1000 data points in calibration. An analysis of the location of the cluster centers, the coefficients relating the inputs with the simulated stream flow, and the degrees of membership indicates that no single cluster can be associated to the simulation of a specific hydrologic process or component of the stream flow hydrograph (e.g. high flows or low flows). The fuzzy model does not therefore provide any evidence that it is not a pure black box. The Nash–Sutcliffe efficiency results obtained in calibration and verification showed average values of 0.658 and 0.535 with poor values on the first river reach. Very low percent bias values averaging to _0.4% and _2.7% in calibration and verification are obtained highlighting the model’s potential for applications where mass balance considerations are most important.
Adopting the System of Rice Intensification (SRI) in Tanzania: A Review
(Scientific Research, 2013-07-20) Katambara, Zacharia; Kahimba , Frederick C.; Mahoo, Henry F.; Mbungu, Winfred B; Mhenga, Fikiri; Reuben, Paul; Maugo, Muyenjwa; Nyarubamba, Anthony
The demand of water for irrigation purposes in Tanzania outstrips the amount of water available for irrigation and other demands. On the other hand, the demand for more food to feed the growing population is increasing, calling for the need to have technologies and farming practices that ensure more food production while minimizing water uses. Rice is among cereal crops grown in Tanzania, and it can assist in meeting the food demand for the nation. Majority of rice producers in Tanzania and Sub-Saharan Africa (SSA) are subsistence farmers and they practice continuous flooding, a technique that requires much water. In addition to using large amounts of water, the conventional practices of growing paddy using local varieties transplanting process are implemented when seedlings are more than 21 days old, and 3 - 4 seedlings are transplanted in one hole. This practice results in low yields, and low water productivity and water use efficiency. The system of rice intensification (SRI) on the other hand, is a promising new practice of growing paddy rice that has proven to be very effective in saving water and increasing rice yields in many parts of the world. SRI practice is spreading fast and it has been adopted in many countries. The SRI practice has been introduced in Tanzania during the last 3 years as such it is not widely practiced. This paper reviews SRI practice at global, regional and country (Tanzania) level, and evaluates the challenges, opportunities and implications for its adoption in Tanzania. Knowledge gaps at each level have been identified and dis cussed as well as suggestions for researchable areas.
Application of the RUSLE model to estimate sedimentation in the Lwanyo Reservoir in Mbarali District Mbeya– Tanzania
(IWA Publishing, 2025) Moshi, Baraka Moses; Katambara, Zacharia; Lingwanda, Mwajuma
The constant increase in the global population is proportional to the increase in basic human needs associated with environ mental degradation. Sedimentation in water bodies poses socio-economic challenges as it lessens the storage capacities. The RUSLE model expresses the effect of sedimentation in the Lwanyo reservoir sub-catchment. Key factors influencing sedimentation include: maximum erosivity factor (R) is 421.39 (MJ mm ha 1 h 1 yr), the soil erodibility factor (K) is 0.071, the topographic factor (LS) due to catchment topography is 9.086, the vegetation cover and management factor (C) is 0.1045, and the conservation practice factor (P) is 0.14. The RUSLE model estimates soil sediment loss to be 3.977 tonnes/ha/year, as the average annual soil loss for the Lwanyo sub-catchment area is 39.6 km2. This value indicates that for every hectare, the average annual soil loss is 1.004 10 3tonnes/year, with silt as the dominant soil sediment being eroded. If no intervention measures are implemented, the sediment load could reach 119.31 tonnes over 30 years, reducing the reservoir’s storage capacity by 68.177 m3. Reducing human activity in the catchment and promoting afforestation to mitigate sedimentation can help increase soil stability and reduce erosion.
Assessment of Spatial Water Quality Variations in Shallow Wells Using Principal Component Analysis in Half London Ward, Tanzania
(Scientific Research Publishing, 2025-02-21) Matungwa, William; Katambara, Zacharia
Groundwater is a crucial water source for urban areas in Africa, particularly where surface water is insufficient to meet demand. This study analyses the water quality of five shallow wells (WW1-WW5) in Half-London Ward, Tun duma Town, Tanzania, using Principal Component Analysis (PCA) to iden tify the primary factors influencing groundwater contamination. Monthly samples were collected over 12 months and analysed for physical, chemical, and biological parameters. The PCA revealed between four and six principal components (PCs) for each well, explaining between 84.61% and 92.55% of the total variance in water quality data. In WW1, five PCs captured 87.53% of the variability, with PC1 (33.05%) dominated by pH, EC, TDS, and microbial contamination, suggesting significant influences from surface runoff and pit latrines. In WW2, six PCs explained 92.55% of the variance, with PC1 (36.17%) highlighting the effects of salinity, TDS, and agricultural runoff. WW3 had four PCs explaining 84.61% of the variance, with PC1 (39.63%) showing high contributions from pH, hardness, and salinity, indicating geological influences and contamination from human activities. Similarly, in WW4, six PCs ex plained 90.83% of the variance, where PC1 (43.53%) revealed contamination from pit latrines and fertilizers. WW5 also had six PCs, accounting for 92.51% of the variance, with PC1 (42.73%) indicating significant contamination from agricultural runoff and pit latrines. The study concludes that groundwater quality in Half-London Ward is primarily affected by a combination of surface runoff, pit latrine contamination, agricultural inputs, and geological factors. The presence of microbial contaminants and elevated nitrate and phosphate
Assessment of Temporal Variations in Shallow Well Water Quality Using Graphical Analysis and Water Quality Index in Half-London Ward, Tunduma, Tanzania
(Mbeya University of Sience and Technology, 2025-03-01) William, Matungwa; Katambara, Zacharia
Shallow wells are vital for water supply in regions lacking centralised systems, but they are highly susceptible to contamination from anthropogenic activities and natural processes. This study investigated seasonal variations in water quality from five shallow wells in Half London Ward, Tunduma, Tanzania, over a 12-month period to assess biological, chemical, and physical parameters, to identify contamination drivers, and to propose sustainable management solutions. Using WHO and EPA guidelines, monthly water sampling was conducted for 12 months from June 2022 to May 2023. Parameters analysed included Faecal and Total Coliforms, Nitrate, Phosphate, Total Iron, Biological Oxygen Demand (BOD), pH, Electrical Conductivity (EC), Turbidity, Total Dissolved Solids (TDS), and Total Suspended Solids (TSS). The National Sanitation Foundation Water Quality Index (NSFWQI) was employed to classify seasonal variations in water quality. Results revealed significant seasonal trends. Microbial contamination peaked during the rainy season, with shallow well WW3 and WW5 recording faecal coliform levels of 5 CFU/100 ml and total coliforms of 18 CFU/100 ml, exceeding WHO and East African Standards. Phosphate levels in shallow well WW4 and WW5 exceeded the threshold of 2.2 mg/l, attributed to agricultural runoff. Elevated iron concentrations (1.85 mg/l) in WW4 reflected natural geological leaching. BOD and turbidity increased during wet periods due to organic pollutants and sediment influx, while physical parameters such as pH and TDS remained within permissible limits. The NSFWQI ranged from "Excellent" (18.6) in shallow well WW5 during winter to "Medium" (65.4) in shallow well WW3 during summer, highlighting contamination risks from surface runoff and poor land management. The study concludes that rainfall and proximity to pollution sources significantly impact shallow well water quality. It recommends implementing community-driven sanitation measures, protecting shallow wells, and conducting routine monitoring. These findings provide a framework for improving groundwater quality for domestic use in urbanising regions globally.
Characteristics of Rice Produced Under Direct and Indirect SRI Practices in Chimala Area in Mbarali District Tanzania.
(Infinite, 2016) Katambara, Zacharia; Mng’ong’o, Marco; Chambi, Consolatha; Malley, Zacharia
The current status of rice production in Chimala Area in Mbarali is dominated by conventional rice growing practices with limited adoption of the system of rice intensification (SRI), which has been reported of having more advantages. This study evaluated the characteristic of rice produced under SRI and conventional practices in Chimala Area in Mbarali District of Mbeya Region in Tanzania. The evaluation considered the farm management practices, rice yields and the characteristic of the rice grains. The unlevelled characteristics of the farms and the variation of the soil influence the rice yields and the quality of the grains. The transplanting age of the seedling was within the age limit preferred when SRI practices are implemented and the limited water availability for conventional rice growing practice necessitated the intermittent wetting and drying of the rice fields which is preferred for SRI practices. The application of agrochemicals such herbicides limit the aeration of the root system and the development of a healthy roots system. Bird scaring is among the activities which increased the production cost of rice grown under SRI practices. Rice yields under SRI practices where more than 16ton/ha against less than 8ton/ha for conventional rice growing practices. The rice grains grown under SRI practices was observed to be suitable for seeds. With regard to milling, conventionally grown rice produced more good rice (69%) SRI (51%) grown. However, the large percentage of husks (24%) likely suggest that rice grains produced under SRI are more protected and further provide evidence as a good rice seed producing practice. The quality of cooked rice indicate that rice produced under SRI practices has higher aroma and fragrance when compared to that produced under conventional practices. Further studies should consider the effect of the number of seedling per hill, application of herbicide instead of applying push weeder and the suitability of using by-product, rice husks as a source of energy.
Characterizing Hydrological-Sensitive Areas of The Kinyerezi River SubCatchments in Dar Es Salaam, Tanzania Using The Topographic Index Approach.
(IWA Publishing, 2023) Swilla, Livingstone; Katambara, Zacharia; Lingwandaa, Mwajuma
Several areas experience frequent floods due to anthropogenic activities. Among them, is the Dar es Salaam city, which experiences frequent floods along the Msimbazi River, whose flows originate from different tributaries including the Kinyerezi River. This study aims to evaluate the hydrological-sensitive areas of the Kinyerezi River sub-catchments using topographic index values (λ*) that enable the identification of areas with a higher probability of generating surface runoff. A digital elevation model was utilized to delineate the Kinyerezi River sub-catchment characteristics using ArcGIS 10.4. Soil infiltration rates (Ks) on selected open places were determined using a Guelph permeameter. Soil particle size distributions were analyzed and the λ* values were evaluated. The results showed the particle size distribution contains sand and silt-clay ranging from 46 to 84% and 16 to 53%, respectively. The Ks ranged from 0.6 to 7.8 mm/h while the sub-catchment KS3 scored the highest λ* value of about 10.7. Hence, there is a higher probability for generating surface runoff. Sub-catchment KS16 scored the smallest λ* value of 5.7, perceived to generate less surface runoff. Low-impact development practices capable of capturing runoff and enabling infiltration, evaporation, and detention should be employed in sub-catchments with higher λ* values.
Does The System of Rice Intensification A Panacea To Smallholder Rice Farmers? A Case of Mkindo Village Irrigation Scheme in Tanzania
(International Journal of Agriculture Innovation Technology and Globalisation, 2021) Mwidege, Asheri; Katambara, Zacharia
Rice production represents a way of life of the livelihood of majority of smallholder rice farmers constrained with inadequate water for irrigation. However, little information was available on the production pattern of rice for SRI and non-SRI participants. This study investigated whether the SRI practice is a panacea to smallholder farmers of rice at Mkindo village irrigation scheme. Experimental research design and expert sampling plan was employed in which structured interview schedule was used to collect cross sectional data of 100 SRI and non-SRI participants. Descriptive statistics information was obtained using SPSS package. Surveyed findings showed that SRI and non-SRI participants harvested 0.75 to 13.75 tons per ha and 0.5 to 8.0 tons per ha, respectively. It was therefore concluded that SRI technology in rice production is a panacea to smallholder farmers as it leads to high yield. The study recommends on the adopt SRI technology by non-SRI participants to maximise their earnings.
Does the System of Rice Intensification a Panacea to Smallholder Rice Farmers? a Case of Mkindo Village Irrigation Scheme in Tanzania.
(ResearchGate, 2021-01) Mwidege, Asheri; Katambara, Zacharia
Rice production represents a way of life of the livelihood of majority of smallholder rice farmers constrained with inadequate water for irrigation. However, little information was available on the production pattern of rice for SRI and non-SRI participants. This study investigated whether the SRI practice is a panacea to smallholder farmers of rice at Mkindo village irrigation scheme. Experimental research design and expert sampling plan was employed in which structured interview schedule was used to collect cross sectional data of 100 SRI and non-SRI participants. Descriptive statistics information was obtained using SPSS package. Surveyed findings showed that SRI and non-SRI participants harvested 0.75 to 13.75 tons per ha and 0.5 to 8.0 tons per ha, respectively. It was therefore concluded that SRI technology in rice production is a panacea to smallholder farmers as it leads to high yield. The study recommends on the adopt SRI technology by non-SRI participants to maximize their earnings.
Estimation of Extreme Flows in Nkana River to Verify the Adequacy of Naming’ongo Bridge Waterway.
(ScientificResearch, 2012-12-26) Katambara, Zacharia; Msambichaka, Joseph J.; Mkisi, Joseph
The response by the government of Tanzania to food security and poverty alleviation in the Naming’ongo area in Mbozi District has been to develop Naming’ongo irrigation scheme as well as construct a bridge across River Nkana to con- nect the farms and other parts of the district to facilitate a reliable transportation of the produce to the market. The Aus- tralian Water Balance Model was calibrated by using 10 years data from a nearby sub-catchment of Mbarali. The Nam- ing’ongo Sub-catchment was delineated form a 30 m digital elevation model. The observed rainfall was obtained from Mbozi Meteorological station. The study approximated the peak flows in River Nkana for a return period of 50 years to be slight above 560 m3/s. This was considered to be adequate for the proposed structure. The study recommends that when undertaking human activities such as deforestation and cultivation an account for soil and environmental conser- vation should be considered. While it is necessary to establish a monitoring system within the catchment, the designs of future hydraulic structures should incorporate stream flow measuring facilities.
Estimation of Extreme Flows in Nkana River to Verify the Adequacy of Naming’ongo Bridge Waterway.
(Scientific Research, 2013-02-05) Katambara, Zacharia; Msambichaka, Joseph J.; Mkisi, Joseph
The response by the government of Tanzania to food security and poverty alleviation in the Naming’ongo area in Mbozi District has been to develop Naming’ongo irrigation scheme as well as construct a bridge across River Nkana to connect the farms and other parts of the district to facilitate a reliable transportation of the produce to the market. The Australian Water Balance Model was calibrated by using 10 years data from a nearby sub-catchment of Mbarali. The Naming’ongo Sub-catchment was delineated form a 30 m digital elevation model. The observed rainfall was obtained from Mbozi Meteorological station. The study approximated the peak flows in River Nkana for a return period of 50 years to be slight above 560 m3 /s. This was considered to be adequate for the proposed structure. The study recommends that when undertaking human activities such as deforestation and cultivation an account for soil and environmental conservation should be considered. While it is necessary to establish a monitoring system within the catchment, the designs of future hydraulic structures should incorporate stream flow measuring facilities.
Evaluation of Hydropower Potential of Kapologwe Waterfalls for Rural Electrification in Rungwe District, Mbeya Region Tanzania.
(MJRD, 2024-12-05) Mgina, Charles J.; Katambara, Zacharia
Hydropower remains one of the most significant renewable energy sources, accounting for a substantial proportion of global electricity production. In Tanzania, where electricity access is limited, particularly in rural areas, untapped hydropower resources could play a critical role in meeting local energy needs. This study investigates the hydropower potential of the Kapologwe Waterfalls on the Kala River, located in Rungwe District, Mbeya Region. Key factors influencing hydropower generation, including hydraulic head, flow rate, and turbine efficiency, were analyzed using land survey techniques and hydrological modeling. The hydraulic head was measured at 605.15 meters, and flow rates were calculated based on field data, with a design flow of 1.542 m³/s. A Pelton turbine, known for its high efficiency under high-head, low-flow conditions, was selected for the site. The estimated power potential is 7.238 MW, suggesting that the Kapologwe Waterfalls could significantly contribute to localized electrification and reduce reliance on Tanzania’s national grid. This research highlights the feasibility of small-scale hydropower projects in rural Tanzania and their potential to alleviate energy poverty.
Integrated Agricultural Landscape Management: Case Study on Inclusive Innovation Processes, Monitoring and Evaluation in The Mbeya Region, Tanzania.
(SAGE, 2017-06-08) Malley, Zacharia J.; Hart, Abigail; Buck, Louise; Mwambene, Pius L.; Katambara, Zacharia; Mng’ong’o, Marco; Chambi, Consolatha
Integrated landscape management is a process for achieving multiple objectives related to agricultural production, ecosystem conservation, and sustainable natural resource management. These multiple livelihood functions are important features of an agricultural landscape in Mbeya, Tanzania. Due to environmental damage caused by agricultural expansion and charcoal burning, a process called integrated agricultural landscape management (IALM) was implemented to address this problem. This encompassed the identification and involvement of a range of key landscape actors and processes like awareness creation and joint problem analysis, solution framing, learning, planning and implementation of actions, and monitoring and evaluation. A multistakeholder innovation platform was formed for creating a coordination mechanism, common understanding, vision and goals, and networking. Fifty IALM ideas were identified and six selected by the stakeholders. Outcomes of using the IALM process included policy recommendations, joint learning, and innovative actions and were codeveloped, implemented, monitored, and evaluated with the local communities.
Performance evaluation of rainwater harvesting system and strategy for dry season challenge
(IWA Publisher, 2016) Mwamila, Tulinave Burton; Han, Moo Young; Ndomba, Preksedis Marco; Katambara, Zacharia
The extensive application of rainwater harvesting (RWH) projects is inhibited by the challenge posed by the dry seasons. In a case study of Mnyundo Primary School, Tanzania, the performance of the RWH system was eval- uated using a daily water balance model. The methodology is based on defined dry season parameters – no water days (NWDs), rainwater usage ratio (RUR), and water level in local water storages; while the system oper- ational methods involve users adopting either fixed (constant) demand or variable demand (demand varying with respect to available water in the storage tank), throughout the system utilization. Additionally, the cost of instal- ling an RWH system to achieve a substantial reduction of NWDs to zero was calculated. It was established that the existing system cannot achieve zero NWDs under consideration of both operational methods. However, the greater the number of tanks, the lower the NWD, and in the variable demand operational method, better RUR was achieved. For mitigating water shortages in the dry season, the school should adopt RWH in two buildings under the demand scenario (300 demand 900 L/d, for the respective water levels in the storage tanks), yielding 58% RUR. The performance of the system can be improved by monitoring water levels and adhering to demand guide- lines. These are useful strategies for practitioners in water supply.
Positioning Mbeya University of Science and Technology in Tanzania in the Systems of Innovation Perspective.
(Scienetific Research, 2013-10-06) Katambara, Zacharia
The chronological development of universities ranges from the state at which universities are considered to be knowledge accumulators followed by knowledge factories and finally the knowledge hubs. The various national systems of innovations are aligned with the knowledge hubs and it involves a substantial amount of research activities. The newly established Mbeya University of Science and Technology is recognized as a knowledge hub in some particular niches. However, there are a limited number of research activities conducted at the university and this study is an attempt to identify the reasons that limit research activities. Well-structured research questionnaires were designed and distributed to academic staff members and thereafter the respondents were analyzed by using SPSS software package. The lack of knowledge, skills and funds as well as equipment was earmarked as the reason that hindered the research activities. Therefore, resources are required to improve the capabilities of the staff members and the study recommends on the need for deliberate efforts to improve the knowledge of the staff members with respect to research activities.
Quantifying Rooftop Rainwater Harvest Potential: Case of Mbeya University of Science and Technology in Mbeya Tanzania
(Mbeya University of Science and Technology Journal of Research and Development (MJRD), 2013-07-21) Katambara, Zacharia
The advantages that the rooftop rainwater harvesting system has as a source of water supply have been examined. The observed daily rainfall records of 10 years and the current total roof area of the facilities at Mbeya University of Science and Technology as the catchment area were used. Using a water balance model to determine the suitable water use that will cover 100% of the time, the model indicated that for the current roof area a water supply of 120 lts per day can be met when a storage tank whose capacity is 13.5 m3 is installed. When values higher than 120 l/day are simulated, a tank of higher capacity is required to meet the water demand. The study recommends on the necessity of installing rooftop rainwater harvesting system so as to increase the water supply reliability and reduction of cost. The selection of a suitable storage tank capacity should take into consideration the future development plans so as to reduce the construction cost of new storage tank.
Quantifying Rooftop Rainwater Harvest Potential: Case of Mbeya University of Science and Technology in Mbeya Tanzania
(Scientific Research Publishing, 2013) Katambara, Zacharia
The advantages that the rooftop rainwater harvesting system has as a source of water supply have been examined. The observed daily rainfall records of 10 years and the current total roof area of the facilities at Mbeya University of Science and Technology as the catchment area were used. Using a water balance model to determine the suitable water use that will cover 100% of the time, the model indicated that for the current roof area a water supply of 120 lts per day can be met when a storage tank whose capacity is 13.5 m3 is installed. When values higher than 120 l/day are simulated, a tank of higher capacity is required to meet the water demand. The study recommends on the necessity of installing rooftop rainwater harvesting system so as to increase the water supply reliability and reduction of cost. The selection of a suit able storage tank capacity should take into consideration the future development plans so as to reduce the construction cost of new storage tank
Quantifying Suitable Low-Impact Development Practices in Mitigating Runoff Floods for the Kinyerezi River Catchment in Dar Es Salaam, Tanzania.
(IWA Publishing, 2024) Swilla, Livingstone; Katambara, Zacharia; Lingwandaa, Mwajuma
As cities expand, changes in land use increase the runoff quantities. Impermeable catchment areas contribute to peak flows, causing floods in insufficiently capacity river reaches. The rate of urbanization witnessed in the Kinyerezi River catchment in Dar es Salaam has contributed to floods in the Msimbazi River. The low-impact development (LID) practices that include bioreten tion (BR) ponds, rain barrels (RBs), rain gardens (RGs), vegetative swales (VSs), constructed wetlands (CWs), etc., can be utilized to mitigate a portion of the surface runoff. This study aims to quantify the suitable LID practices for the Kinyerezi River catch ment in mitigating a portion of runoff floods. The sub-catchment physical characteristics and soil infiltration rates (Ks) were matched with each LID sitting requirements and later by multi-criteria decision-making (MCDM). The results on matching sub-catchment characteristics and LID sitting requirements indicated that BRs, RBs, VSs, RGs, and CWs were the preferable LIDs while MCDM analysis indicated the BRs, RGs, and RBs more appropriate. The BRs, RGs, and RBs were quantified to be 101, 3,698, and 3,698, respectively, within the catchment. BRs are recommended for catchment use while RBs and RGs are recommended for residential buildings. The RBs have the advantage of promoting water-demanding economic activities.

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