The role of superficial geology in controlling groundwater recharge in the weathered crystalline basement of semi-arid Tanzania

Study region: Little Kinyasungwe River Catchment, central semi-arid Tanzania. Study focus: The structure and hydraulic properties of superficial geology can play a crucial role in controlling groundwater recharge in drylands. However, the pathways by which groundwater recharge occurs and their sensitivity to environmental change remain poorly resolved. Geophysical surveys using Electrical Resistivity Tomography (ERT) were conducted in the study region and used to delineate shallow subsurface stratigraphy in conjunction with borehole logs. Based on these results, a series of local-scale conceptual hydrogeological models was produced and collated to generate a 3D conceptual model of groundwater recharge to the wellfield. New hydrological insights for the region: We propose that configurations of superficial geology control groundwater recharge in dryland settings as follows: 1) superficial sand deposits act as collectors and stores that slowly feed recharge into zones of active faulting; 2) these fault zones provide permeable pathways enabling greater recharge to occur; 3) ‘windows’ within layers of smectitic clay that underlie ephemeral streams may provide pathways for focused recharge via transmission losses; and 4) overbank flooding during high intensity precipitation events increases the probability of activating such permeable pathways. These conceptual models provide a physical basis to improve numerical models of groundwater recharge in drylands, and a conceptual framework to evaluate strategies (e.g., Managed Aquifer Recharge) to artificially enhance the availability of groundwater resources in these regions

Lambros Couloubaritsis, Mythe et philosophie chez Parménide

DNA Barcoding to combat Wildlife Crime Workshop May, 2016Poaching for both meat and trophy has always been a major challenge in conservation history. Illegal trade in wildlife and its products affect the survival of magnitude number of species. The population of rhinos and elephants for instance has declined in recent years as a result of escalation in organized trade in their products. This has necessitated many states to take active measures to protect their biodiversity in recent years.However, wildlife criminals (poachers and traffickers) continue to develop new ways to circumvent detection and prosecution. Crime investigators on the other hand fail to hold these criminals responsible with confidence due to lack of reliable forensic tools admissible in courts of law. The prosecutors try to prove that the suspects have committed crimes on wildlife but fail because criminals tried to remove overtindicative morphological features specific to poached animals. Over the recent years, this illegal wildlife poaching has turned into being a highly profitable business worldwide with remarkably low risks as trials of illegal wildlife traffickers are rare, largely because law enforcement officers, prosecutors, and judicial systems typically consider such crime a low priority. Large volumes of wildlife including those already at risk are being illegally poached and traded and if this trend is unabated it threatens future survival of some key species in East Africa region and beyond. To overt these challenges scientists are racing in arms to develop highly sensitive, accurate and high throughput DNA based techniques to mitigate these challenges. One of the leading examples of this development is the institution of a standardized global DNA- based barcode identification system which provides a simple, universal tool for the identification of wildlife species and their products.DNA barcoding has now become an accepted and commonly used method for species identification practiced by taxonomists, ecologists, forensic scientists and other researchers. A Google-supported Barcode of Wildlife Project (BWP) hosted by the Smithsonian Institution in Washington,successively initiated these initiatives in Kenya since 2012. Recently, BWP as expanded these training and technical assistance to new participants in Tanzania through the recently funded USAID-PEER project since 2015. The new participating institutions are Sokoine University of Agriculture (SUA) and Tanzania Wildlife Institute (TAWIRI

Participatory involvement of farming communities and public sectors in determining malaria control strategies in Mvomero District, Tanzania

No Abstract

The role of superficial geology in controlling groundwater recharge in the weathered crystalline basement of semi-arid Tanzania

Study region Little Kinyasungwe River Catchment, central semi-arid Tanzania. Study focus The structure and hydraulic properties of superficial geology can play a crucial role in controlling groundwater recharge in drylands. However, the pathways by which groundwater recharge occurs and their sensitivity to environmental change remain poorly resolved. Geophysical surveys using Electrical Resistivity Tomography (ERT) were conducted in the study region and used to delineate shallow subsurface stratigraphy in conjunction with borehole logs. Based on these results, a series of local-scale conceptual hydrogeological models was produced and collated to generate a 3D conceptual model of groundwater recharge to the wellfield. New hydrological insights for the region We propose that configurations of superficial geology control groundwater recharge in dryland settings as follows: 1) superficial sand deposits act as collectors and stores that slowly feed recharge into zones of active faulting; 2) these fault zones provide permeable pathways enabling greater recharge to occur; 3) ‘windows’ within layers of smectitic clay that underlie ephemeral streams may provide pathways for focused recharge via transmission losses; and 4) overbank flooding during high intensity precipitation events increases the probability of activating such permeable pathways. These conceptual models provide a physical basis to improve numerical models of groundwater recharge in drylands, and a conceptual framework to evaluate strategies (e.g., Managed Aquifer Recharge) to artificially enhance the availability of groundwater resources in these regions

Patient's dissatisfaction with the public and private laboratory services in conducting HIV related testing in Tanzania

<p>Abstract</p> <p>Background</p> <p>Patient's satisfaction with both private and public laboratory services is important for the improvement of the health care delivery in any country.</p> <p>Methods</p> <p>A cross-sectional survey was conducted in 24 randomly selected health facilities with laboratories that are conducting HIV related testing, in Mainland Tanzania. The study assessed patient's satisfaction with the laboratory services where by a total of 295 patients were interviewed.</p> <p>Results</p> <p>Of data analyzed for a varying totals from 224 to 294 patients, the percentage of dissatisfaction with both public and private laboratory services, ranged from 4.3% to 34.8%, with most of variables being more than 15%. Patients who sought private laboratory services were less dissatisfied with the cleanness (3/72, 4.2%) and the privacy (10/72, 13.9%) than those sought public laboratory service for the same services of cleanness (41/222, 18.5%) and privacy (61/222, 27.5%), and proportional differences were statistically significant (X²= 8.7, p = 0.003 and X²= 5.5, p = 0.01, respectively). Patients with higher education were more likely to be dissatisfied with privacy (OR = 1.8, 95% CI: 1.1–3.1) and waiting time (OR = 2.5, 95% CI: 1.5 – 4.2) in both private and public facilities. Patients with secondary education were more likely to be dissatisfied with the waiting time (OR = 5.2; 95%CI: 2.2–12.2) and result notification (OR = 5.1 95%CI (2.2–12.2) than those with lower education.</p> <p>Conclusion</p> <p>About 15.0% to 34.8% of patients were not satisfied with waiting time, privacy, results notification cleanness and timely instructions. Patients visited private facilities were less dissatisfied with cleanness and privacy of laboratory services than those visited public facilities. Patients with higher education were more likely to be dissatisfied with privacy and waiting time in both private and public facilities.</p

Leprosy post-exposure prophylaxis with single-dose rifampicin

_Objective:_ Leprosy post-exposure prophylaxis with single-dose rifampicin (SDRPEP) has proven effective and feasible, and is recommended by WHO since 2018. This SDR-PEP toolkit was developed through the experience of the leprosy postexposure prophylaxis (LPEP) programme. It has been designed to facilitate and standardise the implementation of contact tracing and SDR-PEP administration in regions and countries that start the intervention. _Results:_ Four tools were developed, incorporating the current evidence for SDRPEP and the methods and learnings from the LPEP project in eight countries. (1) th

Uncertainity reduction in climate and hydrological models predictions at catchment scale in the upper great Ruaha river sub-basin, Tanzania

A thesis 2019Water resources have become scarce in most tropical areas of Tanzania due to climate change. Any changes to the hydrological cycle may have significant effects on the water resources in the river basins of Tanzania. The impact of climate change on water resources in Tanzania have been studied using General Circulation Models (GCM) which run at low spatial resolutions of 100-300 km. The resolution is too coarse to provide useful information about climate change impact in small catchments as many physical processes which control local climate e.g.; vegetation, hydrology, topography is not fully parameterized and hence results on uncertainty in model prediction. The main aim of this research was to quantify the uncertainty in model predictions for the Mbarali River Sub-catchment of the Upper Great Ruaha River Sub-basin in the Rufiji River Basin, Tanzania. Three research objectives were analyzed; the first objective was to evaluate the performance of the Coordinated Regional Downscaling Experiment Regional Climate Model (CORDEX, Regional Climate Models) in simulating rainfall characteristics of the Mbarali River Sub catchment. The area weighted average method was used to calculate the average rainfall from the CORDEX RCMs and from ERA-Interim reanalysis over the entire Mbarali River sub-catchment. Comparison between rainfall data from CORDEX RCMs and ERA-Interim reanalysis was done to test the ability of the CORDEX RCMs to reproduce the annual cycles, interannual variability, annual total and trends of rainfall as presented by the ERA-Interim reanalysis. The second objective assessed the impact of climate change on hydrological characteristics using the Soil and Water Assessment Tool (SWAT) model. The ability of the SWAT model to simulate catchment processes was assessed through a calibration and validation process, which was a key factor in reducing uncertainty and increasing user confidence in its predictive abilities. The SWAT model was driven by high resolution climate simulations for historical climate condition (1971-2000) as well as future climate projections (2011-2040, 2041-2070 and 2071-2100) for two Representative concentration Pathways (RCPs): RCP 4.5 and RCP 8.5. Furthermore, Ensemble of RCMs was applied into SWAT to simulate water resources availability and the results were compared with individual models (HIRHAM5, CCLM4, RACMO22T, RCA4). The Rainfall and Temperature data were obtained from the selected four CORDEX RCMs driven by three different General Circulation Models (GCMs). Inverse Distance Weight Average (IDWA) was used to interpolate model gridded climate simulation to the location of weather station. The third objective assessed the impacts of land use and land cover change on the hydrology using integration of remote sensing data, QGIS and SWAT model. The land use and land cover (LULC) maps for three window period snapshots, 1990, 2006 and 2017 were created from Landsat TM and OLI_TIRS. Supervised classification was used to generate LULC maps using the Maximum Likelihood Algorithm and Kappa statistics for assessment of accuracy. The findings of the first objective are that CORDEX RCMs were able to capture well the seasonal and annual cycles of rainfall. However, they underestimated the amount of rainfall in March, April and May (MAM) and overestimated in October, November and December (OND) respectively. CORDEX RCMs reproduce interannual variation of rainfall. The source of uncertainties was revealed when the same RCMs driven by different GCMs and when different RCMs driven by the same GCM in simulating rainfall. It was found that the error and biases from RCMs and driving GCMs contribute roughly equally. Overall, the evaluation found reasonable (although variable) model capability in representing the mean climate, interannual variability and rainfall trends.The results suggest that CORDEX RCM is suitable in simulating rainfall, maximum temperature and minimum temperature. The findings of the second objective showed that SWAT model simulated stream flow and water balance components differently when two different RCMs were forced by the same GCMs as well as when the same RCMs were forced by different GCMs. The differences are related to the formulation of the RCMs themselves. For example, RACMO22T and HIRHAM5 driven with the same GCM (ICHEC-EARTH) simulate different amount of stream flows, surface runoff, water yield and groundwater yield in historical (1971–2000) as well as in present century (2011-2040), mid-century (2041- 2070) and end century (2071-2100). Ensemble RCMs projected decrease in stream flows by 13.67% under RCP 8.5. However annual rainfall was shown to increase in averages by 1.62% under RCP 4.5 and by 1.96% for RCP 8.5 relative to the 1177.1mm of the baseline period (1971-2000). The results also showed that, temperature will slightly increase relative to the baseline during present century (2011-2040) for RCP 4.5 and RCP 8.5. The ensemble average project that the minimum temperature will increase by 14% (1.9 0 C) under RCP 8.5 and maximum temperature by 7.68% (1.8 o C) under RCP 4.5 The findings of the third objective showed that there were significant changes in land use and cover for the three-time periods (1990, 2006 and 2017). The cultivated land and built up area increased from 25.69% in 1990 to 31.53% in 2006 and 43.57% in 2017 compared to other land classes. Increase of cultivated land and built up area led to decrease in forest cover. Forests occupied 7.54% in 1990, but decreased to 5.51% in 2006 and 5.23% in 2017. This decrease in forest cover has resulted in increased surface runoff for the same periods (2006-2017). The increase in surface runoff in the study area could be attributed to deforestation and poor land husbandry, where during land preparation much of the vegetation is cleared, hence decreasing canopy interception and allowing water to drain off. Also, poor farming practices including cultivation on hillslopes without soil conservation, reducing soil compaction, hence allowing more water to drain as surface runoff. The calibrated SWAT model using the three different land use and land cover change of 1990, 2006 and 2017 indicate that during the wet season, the mean monthly flow increased by 1.48% relative to the 28.09 m 3 /s of the baseline 1990 while during the dry season, the mean monthly flow decreased by 16.7% relative to the 0.20 m 3 /s baseline flow. Assessment of the impacts of land use and land cover changes on catchment water balance component revealed that surface runoff increased by 3.9% in 2006 and 9.01% in 2017 while groundwater contribution to stream flow decreased by 6.3% and 12.86% in 2006 and 2017, respectively. The decrease in stream flow could also be attributed to abstraction of water for irrigation activities upstream of the Igawa gauge station. The findings of the study may help basin water officers, planners in water sector and agriculture sector in addressing uncertainty in policy and decision-making specifically when preparing strategies and adaptations plans for river catchment. The science used in this study can be applicable to another river basin in Tanzanian in a climate change impact study

Uncertainity reduction in climate and hydrological models predictions at catchment scale in the upper great Ruaha river sub-basin, Tanzania

A Thesis 2019Water resources have become scarce in most tropical areas of Tanzania due to climate change. Any changes to the hydrological cycle may have significant effects on the water resources in the river basins of Tanzania. The impact of climate change on water resources in Tanzania have been studied using General Circulation Models (GCM) which run at low spatial resolutions of 100-300 km. The resolution is too coarse to provide useful information about climate change impact in small catchments as many physical processes which control local climate e.g.; vegetation, hydrology, topography is not fully parameterized and hence results on uncertainty in model prediction. The main aim of this research was to quantify the uncertainty in model predictions for the Mbarali River Sub-catchment of the Upper Great Ruaha River Sub-basin in the Rufiji River Basin, Tanzania. Three research objectives were analyzed; the first objective was to evaluate the performance of the Coordinated Regional Downscaling Experiment Regional Climate Model (CORDEX, Regional Climate Models) in simulating rainfall characteristics of the Mbarali River Sub catchment. The area weighted average method was used to calculate the average rainfall from the CORDEX RCMs and from ERA-Interim reanalysis over the entire Mbarali River sub-catchment. Comparison between rainfall data from CORDEX RCMs and ERA-Interim reanalysis was done to test the ability of the CORDEX RCMs to reproduce the annual cycles, interannual variability, annual total and trends of rainfall as presented by the ERA-Interim reanalysis. The second objective assessed the impact of climate change on hydrological characteristics using the Soil and Water Assessment Tool (SWAT) model. The ability of the SWAT model to simulate catchment processes was assessed through a calibration and validation process, which was a key factor in reducing uncertainty and increasing user confidence in its predictive abilities. The SWAT model was driven by high resolution climate simulations for historical climate condition (1971-2000) as well as future climate projections (2011-2040, 2041-2070 and 2071-2100) for two Representative concentration Pathways (RCPs): RCP 4.5 and RCP 8.5. Furthermore, Ensemble of RCMs was applied into SWAT to simulate water resources availability and the results were compared with individual models (HIRHAM5, CCLM4, RACMO22T, RCA4). The Rainfall and Temperature data were obtained from the selected four CORDEX RCMs driven by three different General Circulation Models (GCMs). Inverse Distance Weight Average (IDWA) was used to interpolate model gridded climate simulation to the location of weather station. The third objective assessed the impacts of land use and land cover change on the hydrology using integration of remote sensing data, QGIS and SWAT model. The land use and land cover (LULC) maps for three window period snapshots, 1990, 2006 and 2017 were created from Landsat TM and OLI_TIRS. Supervised classification was used to generate LULC maps using the Maximum Likelihood Algorithm and Kappa statistics for assessment of accuracy. The findings of the first objective are that CORDEX RCMs were able to capture well the seasonal and annual cycles of rainfall. However, they underestimated the amount of rainfall in March, April and May (MAM) and overestimated in October, November and December (OND) respectively. CORDEX RCMs reproduce interannual variation of rainfall. The source of uncertainties was revealed when the same RCMs driven by different GCMs and when different RCMs driven by the same GCM in simulating rainfall. It was found that the error and biases from RCMs and driving GCMs contribute roughly equally. Overall, the evaluation found reasonable (although variable) model capability in representing the mean climate, interannual variability and rainfall trends. The results suggest that CORDEX RCM is suitable in simulating rainfall, maximum temperature and minimum temperature. The findings of the second objective showed that SWAT model simulated stream flow and water balance components differently when two different RCMs were forced by the same GCMs as well as when the same RCMs were forced by different GCMs. The differences are related to the formulation of the RCMs themselves. For example, RACMO22T and HIRHAM5 driven with the same GCM (ICHEC-EARTH) simulate different amount of stream flows, surface runoff, water yield and groundwater yield in historical (1971–2000) as well as in present century (2011-2040), mid-century (2041- 2070) and end century (2071-2100). Ensemble RCMs projected decrease in stream flows by 13.67% under RCP 8.5. However annual rainfall was shown to increase in averages by 1.62% under RCP 4.5 and by 1.96% for RCP 8.5 relative to the 1177.1mm of the baseline period (1971-2000). The results also showed that, temperature will slightly increase relative to the baseline during present century (2011-2040) for RCP 4.5 and RCP 8.5. The ensemble average project that the minimum temperature will increase by 14% (1.9 0 C) under RCP 8.5 and maximum temperature by 7.68% (1.8 o C) under RCP 4.5 The findings of the third objective showed that there were significant changes in land use and cover for the three-time periods (1990, 2006 and 2017). The cultivated land and built up area increased from 25.69% in 1990 to 31.53% in 2006 and 43.57% in 2017 compared to other land classes. Increase of cultivated land and built up area led to decrease in forest cover. Forests occupied 7.54% in 1990, but decreased to 5.51% in 2006 and 5.23% in 2017. This decrease in forest cover has resulted in increased surface runoff for the same periods (2006-2017). The increase in surface runoff in the study area could be attributed to deforestation and poor land husbandry, where during land preparation much of the vegetation is cleared, hence decreasing canopy interception and allowing water to drain off. Also, poor farming practices including cultivation on hillslopes without soil conservation, reducing soil compaction, hence allowing more water to drain as surface runoff. The calibrated SWAT model using the three different land use and land cover change of 1990, 2006 and 2017 indicate that during the wet season, the mean monthly flow increased by 1.48% relative to the 28.09 m 3 /s of the baseline 1990 while during the dry season, the mean monthly flow decreased by 16.7% relative to the 0.20 m 3 /s baseline flow. Assessment of the impacts of land use and land cover changes on catchment water balance component revealed that surface runoff increased by 3.9% in 2006 and 9.01% in 2017 while groundwater contribution to stream flow decreased by 6.3% and 12.86% in 2006 and 2017, respectively. The decrease in stream flow could also be attributed to abstraction of water for irrigation activities upstream of the Igawa gauge station. The findings of the study may help basin water officers, planners in water sector and agriculture sector in addressing uncertainty in policy and decision-making specifically when preparing strategies and adaptations plans for river catchment. The science used in this study can be applicable to another river basin in Tanzanian in a climate change impact study