The Effect of Land use/cover change on Biomass Stock in Dryland Areas of Eastern Uganda. A case study of Olio Sub-county in Soroti District

Drylands occupy 44% of Uganda’s land surface and provide livelihood to a cross-section of both rural and urban folks. However in the face of population pressure, drylands are increasingly in the path of conversion and degradation. This study therefore, performed an assessment of the effect of land use/cover change on biomass stock in olio sub-county from 1973 to 2001. A series of systematically corrected Orthorectified Landsat imageries of 1973, 1986 and 2001 obtained from the Landsat website were used. The images were analysed using  unsupervised approach in Integrated Land and Water Information System version 3.3 and validated using field observations and historic memories of village elders. Findings indicate that land use/cover change is driven by small-scale farming. Between 1973-1986 significant declines were identified among small-scale farming (23.2%), grasslands (8.7%) and large scale-farming (9.9%). Further, declines were also registered between 1986-2001 in Bushland (12.1%), woodlands (13.9%) and wetlands (8.2%) while dramatic gains were registered in small-scale farming by 19.4%. These declines led to losses in the available biomass stock by 2001 within bushlands, wetlands and woodlands loosing 29.1 million tons, 669.1 metric tons and 87.3 million tons respectively. We conclude that small-scale farming by resource poor farmers is rapidly transforming the vegetation landscape. Therefore, there is need for increased use of remote sensing and GIS to quantify change patterns at local scales for essential monitoring and assessment of land use and or/cover change effects and human interference on the landscape. @JASEMJ. Appl. Sci. Environ. Manage. December, 2010, Vol. 14 (4) 101 - 10

Genetic structure of Anopheles gambiae populations on islands in northwestern Lake Victoria, Uganda

BACKGROUND: Alternative means of malaria control are urgently needed. Evaluating the effectiveness of measures that involve genetic manipulation of vector populations will be facilitated by identifying small, genetically isolated vector populations. The study was designed to use variation in microsatellite markers to look at genetic structure across four Lake Victoria islands and two surrounding mainland populations and for evidence of any restriction to free gene flow. METHODS: Four Islands (from 20–50 km apart) and two surrounding mainland populations (96 km apart) were studied. Samples of indoor resting adult mosquitoes, collected over two consecutive years, were genotyped at microsatellite loci distributed broadly throughout the genome and analysed for genetic structure, effective migration (Nem) and effective population size (Ne). RESULTS: Ne estimates showed island populations to consist of smaller demes compared to the mainland ones. Most populations were significantly differentiated geographically, and from one year to the other. Average geographic pair-wise FST ranged from 0.014–0.105 and several pairs of populations had Ne m < 3. The loci showed broad heterogeneity at capturing or estimating population differences. CONCLUSION: These island populations are significantly genetically differentiated. Differences reoccurred over the study period, between the two mainland populations and between each other. This appears to be the product of their separation by water, dynamics of small populations and local adaptation. With further characterisation these islands could become possible sites for applying measures evaluating effectiveness of control by genetic manipulation

VEGETATION BIOMASS PREDICTION IN THE CATTLE CORRIDOR OF UGANDA

Pastoralists in Sub-Saharan Africa face complex problems notably frequent and severe droughts. This study was conducted in the cattle corridor of Uganda, a largely semiarid area to estimate the likely vegetative biomass production under the 2O71-2100 projected rainfall conditions. Spatio-temporal pattern of vegetative biomass production were determined by analysis of the seasonal variation of Normalised Difference Vegetation Index (NDVI) for 10 years from 2001-2010. A biomass relationship was established between the NDVI and the Standardised Precipitation Index (SPI); and used to project the period 2071-2100 NDVI using downscaled rainfall for the cattle corridor. A change trajectory performed on the annual means revealed the highest increase in vegetation in 2008 (0.031) and decrease in 2009 (-0.022). The SPI revealed two main droughts that were established to have occurred in the years of 2004 - 2005 and 2008-2009. The wettest year was 2003 and corresponded with the increase in NDVI. A strong positive correlation of rainfall and vegetation was established (r=0.99). Precipitation has influenced vegetative biomass in the cattle corridor as there is a positive correlation between precipitation and the vegetative biomass production. Secondly, vegetation is likely to be concentrated in areas that will have high precipitation in 2070-2100, such as Luwero and the districts south of it of the cattle corridor compared to those in the north of the cattle corridor of Uganda.Les \ue9leveurs en Afrique Sub-saharienne se confrontent aux probl\ue8mes complexes notamment les s\ue9cheresses fr\ue9quentes et plus graves. Cette \ue9tude a \ue9t\ue9 men\ue9e dans le corridor du b\ue9tail de l\u2019ouganda, une r\ue9gion largement semi-aride pour estimer la production susceptible de biomasse v\ue9g\ue9tale sous les conditions pluviom\ue9triques projet\ue9es en 2071-2100. Le mod\ue8le spatio-temporel de production de biomasse v\ue9g\ue9tale a \ue9t\ue9 d\ue9termin\ue9 par l\u2019analyse de la variation saisonni\ue8re de l\u2019Indice de V\ue9g\ue9tation par Diff\ue9rence Normalis\ue9e (NDVI) pendant 10 ans dans l\u2019intervalle de temps 2001-2010. Une relation de biomasse a \ue9t\ue9 \ue9tablie entre l\u2019indice de v\ue9g\ue9tation NDVI et l\u2019indice de pr\ue9cipitations normalis\ue9 (SPI), et elle est utilis\ue9e pour projeter le NDVI de la p\ue9riode 2071-2100 en utilisant les pr\ue9cipitations \ue0 \ue9chelle r\ue9duite pour le corridor du b\ue9tail. Une trajectoire de changement effectu\ue9e sur les moyennes annuelles a r\ue9v\ue9l\ue9 la plus forte augmentation de la v\ue9g\ue9tation en 2008 (0.031) et une diminution en 2009 (-0.022). Le SPI a r\ue9v\ue9l\ue9 deux principales s\ue9cheresses qui ont \ue9t\ue9 \ue9tablies pour avoir eu lieu dans les ann\ue9es 2004 - 2005 et 2008-2009. L\u2019ann\ue9e la plus humide \ue9tait 2OO3 et correspondait \ue0 une augmentation de l\u2019indice de v\ue9g\ue9tation NDVI. Une forte corr\ue9lation positive entre les pr\ue9cipitations et la v\ue9g\ue9tation a \ue9t\ue9 \ue9tablie (r = 0.99). Les pr\ue9cipitations ont influenc\ue9 la biomasse v\ue9g\ue9tale dans le corridor du b\ue9tail, car il existe une corr\ue9lation positive entre les pr\ue9cipitations et la production de la biomasse v\ue9g\ue9tale. Deuxi\ue8mement, la v\ue9g\ue9tation est susceptible d\u2019\ueatre concentr\ue9e dans les zones qui auront de fortes pr\ue9cipitations en 2070-2100, comme Luwero et les districts du Sud de celui-ci du corridor du b\ue9tail par rapport \ue0 ceux dans le nord du corridor du b\ue9tail de l\u2019ouganda

Towards the empowered commuter : exploring information behaviour of informal public transport users

Papers presented virtually at the 41st International Southern African Transport Conference on 10-13 July 2023.Information is emerging as one of the key dimensions of mobility, and as an important lever through which sustainable access can be promoted in Sub-Saharan African (SSA) cities. Information acts as an enabler of transport, by allowing travellers to make informed decisions on whether, when, and how they travel. The lack of information can also act as a barrier to accessing desired services, with consequences for the attainment of equity and human development goals. Little is known about what information passengers need and how they find and use information. This paper reports on a qualitative mixed-methods study to explore information behaviour amongst informal transport passengers in Tshwane, South Africa. We use the theory and methods of information science (with information behaviour as a subdiscipline) to provide a lens for the investigation. We collected mobility data through travel diaries, user-submitted photos of the travel context and voice messages to explain these, and in-depth individual interviews combined with drawings of situations where respondents used information and its sources (called information horizon mappings). The drawings and interviews revealed the information-poor environment within which informal transport operates, and the strong reliance on other people as well as tacit embedded knowledge for gaining access to information. The paper concludes by offering directions for further research around digital information

Willingness to pay for COVID-19 mitigation measures in public transport and paratransit in low-income countries

In order to combat the spread of COVID-19, various measures were taken in most countries to make public transit and paratransit safer. These additional measures, which include restrictions on number of passengers, provision of hand sanitisers and face coverings, and more frequent cleaning, add to the costs of operations or reduce profitability. The resulting financial pressure on the transport operators raises an important question on who pays for these additional measures. In most countries, this has been covered by one-time government bailouts to operators or strategies to increase fare, the latter of which directly affects the users. However, even without these interventions, there could be a demand and as such willingness to pay (WTP) for some of these intervention measures from the consumers concerned about safety. Knowing such WTP will not only help operators set their fare, but also help the governments decide the appropriate bailout needed. This paper addresses the issue by estimating the user's willingness to pay for selected COVID-19 mitigation measures in public transport and paratransit (motorcycle taxis) using survey data collected from two cities in low-income countries as case studies – Kampala, Uganda and Dhaka, Bangladesh. For public transport, these measures are - (1) social distancing (passenger loading at half capacity), and (2) mandatory hand sanitisation and increased cleaning of surfaces, while for paratransit, they are - (1) provision of a transparent shield between the rider and the passenger, and (2) provision of cleaned helmets at the start of each trip. The study analyses stated preference data using the utility maximisation framework and finds that the implementation or provision of COVID-19 mitigation measures improves the attractiveness of the associated public transport or paratransit alternatives, and transport users make trade-offs between safety and cost when making travel decisions. We find positive willingness to pay for all four mitigation measures, suggesting potential existence of a market for these measures. We also find that the typical mode choice factors such as costs, travel time and convenience became less important during the pandemic and the safety measures became more important considerations

Longitudinal evaluation of aflatoxin exposure in two cohorts in south-western Uganda

Aflatoxins (AF) are a group of mycotoxins. AF exposure causes acute and chronic adverse health effects such as aflatoxicosis and hepatocellular carcinoma in human populations, especially in the developing world. In this study, AF exposure was evaluated using archived serum samples from human immunodeficiency virus (HIV)-seronegative participants from two cohort studies in south-western Uganda. AFB1-lysine (AFB-Lys) adduct levels were determined via HPLC fluorescence in a total of 713 serum samples from the General Population Cohort (GPC), covering eight time periods between 1989 and 2010. Overall, 90% (642/713) of the samples were positive for AFB-Lys and the median level was 1.58 pg mg(-1) albumin (range = 0.40-168 pg mg(-1) albumin). AFB-Lys adduct levels were also measured in a total of 374 serum samples from the Rakai Community Cohort Study (RCCS), across four time periods between 1999 and 2003. The averaged detection rate was 92.5% (346/374) and the median level was 1.18 pg mg(-1) albumin (range = 0.40-122.5 pg mg(-1) albumin). In the GPC study there were no statistically significant differences between demographic parameters, such as age, sex and level of education, and levels of serum AFB-Lys adduct. In the RCCS study, longitudinal analysis using generalised estimating equations revealed significant differences between the adduct levels and residential areas (p = 0.05) and occupations (p = 0.02). This study indicates that AF exposure in people in two populations in south-western Uganda is persistent and has not significantly changed over time. Data from one study, but not the other, indicated that agriculture workers and rural area residents had more AF exposure than those non-agricultural workers and non-rural area residents. These results suggest the need for further study of AF-induced human adverse health effects, especially the predominant diseases in the region

Population structure of the malaria vector Anopheles moucheti in the equatorial forest region of Africa

<p>Abstract</p> <p>Background</p> <p><it>Anopheles moucheti </it>is a major malaria vector in forested areas of Africa. However, despite its important epidemiological role, it remains poorly known and insufficiently studied. Here, levels of genetic differentiation were estimated between different <it>A. moucheti </it>populations sampled throughout its distribution range in Central Africa.</p> <p>Methods</p> <p>Polymorphism at ten microsatellite markers was compared in mosquitoes sampled in Cameroon, the Democratic Republic of Congo and an island on Lake Victoria in Uganda. Microsatellite data were used to estimate genetic diversity within populations, their relative long-term effective population size, and the level of genetic differentiation between them.</p> <p>Results</p> <p>All specimens collected in Tsakalakuku (Democratic Republic of Congo) were identified as <it>A. m. bervoetsi </it>while other samples consisted of <it>A. m. moucheti</it>. Successful amplification was obtained at all microsatellite loci within all <it>A. m. moucheti </it>samples while only six loci amplified in <it>A. m. bervoetsi</it>. Allelic richness and heterozygosity were high for all populations except the island population of Uganda and <it>A. m. bervoetsi</it>. High levels of genetic differentiation were recorded between <it>A. m. bervoetsi </it>and each <it>A. m. moucheti </it>sample as well as between the island population of <it>A. m. moucheti </it>and mainland populations. Significant isolation by distance was evidenced between mainland populations.</p> <p>Conclusion</p> <p>High levels of genetic differentiation supports complete speciation of <it>A. m. bervoetsi </it>which should henceforth be recognized as a full species and named <it>A. bervoetsi</it>. Isolation by distance is the main force driving differentiation between mainland populations of <it>A. m. moucheti</it>. Genetically and geographically isolated populations exist on Lake Victoria islands, which might serve as relevant field sites for evaluation of innovative vector control strategies.</p

The terrain of urbanisation process and policy frameworks: A critical analysis of the Kampala experience

Kampala is urbanising in an unplanned manner, but without a clear picture of the underlying dynamics. The city is characterised by lack of proper zoning of economic activities and construction of physical infrastructure without regard to subsequent spatial quality and environmental conservation. Consequently, there are sharp differences in residential standards where expensive housing and luxury flats co-exist with shanty towns and informal settlements, with about 60% of the city’s population living in unplanned informal settlements and often faced with challenges of unemployment. The unprecedented increase in the urban population in Kampala and the prospects for further increases in the near future have economic and social implications concerning employment, housing, education and health, among others. Understanding the nature of the dynamics of the growth or decline of cities like Kampala helps planners to support the processes that lead to harmonious urban development and to deal with the negative consequences of urban growth. This paper reflects the urbanisation dynamics explaining Kampala’s urbanisation process with the view to analysing the implications for an alternative urban policy framework. It argues that the conditions that have allowed the situation to exist have serious policy implications which require the need for an integrated policy framework that can be used to effectively prevent or halt Kampala’s unplanned urbanisation while promoting planned urbanisation. Induced by the migration and lack of information, understanding urban dynamics is crucial to the development of urban policies that can effectively ensure that further urban changes occur in a systematic and satisfactory manner. The current urban process in developing countries like Uganda is associated with poverty, environmental degradation and population demands that outstrip service capacity

Utilisation des ressources en eau et implications pour la sécurité humaine dans le bassin du lac Victoria en Afrique de l'est

International audienceThis synthesis/review paper attempts to explore water resource use issues in the Lake Victoria Basin [LVB] andwhat implications these would have on human security in the basin. Use was made of both primary and secondary datato analyse: (1) water resource use issues and their implication for human security, and (2) existing initiatives/ policies/ programmesin water resources management to improve human security. Anecdotal evidence suggests that the LVB is facedby an array of stressors operating in combination, including hydrological and climate change (reduced amounts of rainfall,unpredictability of rainfall seasons, shifts in rainfall distribution patterns), discharge of waste materials (municipal and industrialwastes); intense resource extraction and fisheries depletion; political uncertainty; land use and cover change [increasingurban and de-vegetated catchments] and increased pollution loading [horticultural and industrial]. How thesestressors impact on the water resources in the context of global changes is still unclear in the LVB. The paper argues that increasingstress from global change in the basin will lead to further degradation and dwindling of the vital water resource basethat would have serious implications for human security. Innovative and strategic water resources management approachessuch as incentive/financing mechanisms (PES), information/education/research and development, command and controlmeasures (penalties for inappropriate use) at different governance scales are therefore required to protect the integrity oftrans-boundary basins like the LVB.Dans cette synthèse les auteurs examinent les questions soulevées par l’exploitation de la ressource en eaudans le bassin du lac Victoria (LVB), en Afrique de l’est. Les auteurs s’intéressent principalement à l’impact sur la vie humaine,notamment sur la survie et la sécurité et surtout l’impact sur les moyens d’existence.En Afrique, le stress hydrique concerne les pays qui manquent d’eau mais aussi les régions où il y a abondance.Les changements climatiques exacerbent la situation et les activités humaines et naturelles ont un effet sur tous les secteursdu cycle de l’eau. Parmi les menaces principales pour les êtres humains on peut citer la pollution et la pénurie d’eau.Les auteurs enquêtent sur les ressources en eau que représente le LVB. Ils examinent l’impact des changements climatiquessur les ressources en eau, ainsi que ce que cela implique pour la sécurité environnementale. Ils voient commentassurer l’utilisation efficace de l’eau à l’avenir. Ils analysent ensuite les moyens disponibles pour une gestion proactivedes ressources en eau et la promotion du développement durable de l’eau dans cette région africaine. La gestion du lacet les activités humaines du passé continuent à influer sur les stratégies de management actuelles et toute solution proposéedoit prendre en compte les tensions et les conflits potentiels entre les différents pays, riverains et acteurs, à savoir,la Tanzanie, le Kenya, l’Ouganda, le Burundi et le Rwanda.Situé à 1100 m au-dessus du niveau de la mer, le lac Victoria est le plus grand lac d’eau douce en Afrique. Alimentépar une quinzaine de fleuves principaux et drainé par le Nil blanc, c’est aussi une région importante de zones humides.Une population de 30 millions de personnes habite le bassin et le PIB annuel est estimé à environ 30 milliards dedollars. L’urbanisation se développe et la densité de la population riveraine s’accroit de façon très importante. Les eauxdu lac sont exploitées comme source d’eau potable, de nourriture, d’énergie, d’irrigation, pour le transport, comme sitede rejet pour les eaux usées et pour certains déchets. Des données récentes démontrent l’eutrophisation du lac. À la finde 2012, la capacité en hydroélectricité créée par les eaux du Nil qui quittent le lac augmentera à 450 MW.Les sources principales de stress environnemental - dans le lac, dans la zone littorale, dans le bassin et au-delàdu bassin - mènent à une dégradation de l’écosystème du LVB et ont un effet négatif sur l’économie de la région et surles moyens d’existence des populations lacustres. On s’inquiète donc pour la détérioration de la qualité de l’eau, pourl’augmentation de la pollution et de l’eutrophisation et pour l’impact des changements climatiques mondiaux sur lesressources en eau. L’existence des populations lacustres est donc fragilisée.Le niveau des eaux du lac varient naturellement, mais depuis plus d’une décennie on observe une baisse généraledu niveau ce qui occasionne des pertes en tout genre notamment pour les transporteurs, les pêcheurs et pour l’hydroélectricité.Les pays riverains reconnaissent que la bonne gestion des eaux du lac est donc cruciale pour l’économiede la région, pour la protection de la biodiversité et les zones humides ainsi que pour le maintien de l’intégrité environnementaledu LVB.Au coeur des ces préoccupations se trouve la sécurité humaine. Dans un avenir proche on estime qu’il ne seraplus possible de soutenir une population en croissance permanente. Les mauvaises pratiques en agriculture et en élevagemais aussi dans les forêts sont en partie responsables des menaces pour la sécurité humaine. La qualité de l’eau sedétériore et bientôt elle ne sera plus potable; le manque d’eau pour la production agricole qui est la source de conflitsentre différents acteurs conduirait à des pénuries d’alimentation. Le manque d’eau est ainsi source de tensions dans lebassin tout comme l’excès d’eau quand la région n’arrive pas à gérer la précipitation excessive et les inondations. Ces dernièressont en grande partie imputables à l’activité humaine (déforestation, perte de la couche végétale (terre arable),conversion des zones humides…). La contamination de l’eau affecte la santé des populations directement : pollution industrielle, eaux usées non traitées, déchets agricoles et prolifération de la biomasse algale qui mène à la disparitiondes poissons et à la destruction de l’habitat aquatique. Des tensions et des conflits au niveau de l’état, de la région, voireau niveau de chaque foyer aggravent les menaces qui pèsent sur la sécurité sanitaire et économique de la populationnotamment entre les acteurs en amont et en aval du bassin. La présence de barrages et l’inconstance de la précipitationajoutées à une surextraction importante de l’eau exacerbent la situation politique et économique. La santé publique estmenacée par une combinaison de facteurs qui favorisent l’apparition de maladies contagieuses ou de maladies véhiculéespar l’eau. Les auteurs identifient les stratégies pour une gestion optimale de l’eau du LVB et préconisent essentiellementune gestion raisonnée de la ressource qui dépasse les frontières nationales. Ils prônent le recours aux organismes internationauxpour la résolution amicale des conflits. En conclusion ils déplorent l’héritage post-impérial et l’existence de structures colonialistes mises en place pour servir une élite urbaine qui perdure