Department of Geography and Environmental Sciences

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The quaternary stratigraphy and environments of Olduvai gorge - Tanzania, based on fossil soils and related dating
(VRIJE UNIVERSITEIT BRUSSEL, 2000) Kafumu, Peter .D.
This study reports research results and interpretations based on field geological-stratigraphical- litological-palaeosol sequential studies of Tertiary-Quaternary deposits of Olduvai Gorge (main work), Manonga-Wembere Valley and Holili, (annex work) localities in Tanzania. It is also based on laboratory studies (micromorphology, mineralogy, geochemistry and magnetic susceptibility). Special emphasis is placed on the study of palaeosol levels frequently found in these sedimentary sequences. Geology and stratigraphy In all the three areas, Pliocene-Pleistocene sediments are laid down unconformable on a Precambrian basement complex. A huge unconformity exists between the Precambrian rocks (granite, quartzite and gneiss) and the Pliocene-Pleistocene sediments. The basement is a remnant planation surface, which was formed at the beginning of the Tertiary, often represented by isolated granite kopjes, quartzite and gneiss inselbergs and hills sticking out from the present plain level. In Olduvai Gorge the study revisits the stratigraphy and reveals numerous sediments and palaeosol levels (not earlier reported). These levels and beds are within the earlier recognized general Bed I, II, III, IV, Masek and Ndutu Beds. Bed I (2.2Ma - 1.75Ma) contains at least 43 lithological (clay, sands, gravel, mudstone, limestone and marls) units including palaeosol levels. Bed II (1.75Ma - 1.15Ma) is also a zone of abundant geological depositional environments composed of clay, sand-gravel bed complexes, tuff (ash fall or ash flow), limestone and palaeosol levels. Bed III (1.15Ma - 0.6Ma) is a complex volcano-sedimentary depositional environment marked by lacustrine marly sequences, clay layers, sand-gravel beds and calcarenaceous sediments itercalated by red-brown palaeosol levels. Bed IV and Masek Beds (0.6Ma - 0.4Ma) are not distinguishable in the field and therefore grouped together and names adapted from previous workers. The zone contains about 4 palaeo-Vertisols each developed on a clay layer. Ndutu Bed (0.2Ma and younger) is represented by a series of 7 palaeo-Vertisol levels (similar to the ones in Masek Beds), mudstone, claystone and limestone from bottom to top. Gravel and sand beds across the profile have the highest magnetic susceptibility (MS) values compared to clay, marls, calc-sediments or tuff lithologies. Magnetic susceptibility values of palaeosol levels in sandy units are usually lower than the background values of the sand layers. Palaeosols that developed on clay units have higher MS record than the clay background values. The general MS pattern shows an increasing trend across the stratigraphy from older to younger units. The mineralogical signatures also reflect the general stratigraphical characterization. The lower (Bed 1 and Lower Bed II) stratigraphical unit show higher clay minerals and carbonate concentrations, the middle (Bed II and Bed III) indicate slightly low clay minerals and carbonates abundance and the upper parts of the profile (Masek/Bed IV) show higher concentrations of clay and carbonate minerals. Based on field and some micromorphological studies 57 palaeosol levels are mapped. They are grouped into (a) Red-brown to dark gray palaeosols which are probably palaeo-Alfisols or Ultisols, occur in Upper Bed I, Middle Bed II and Bed III. (b) Olive to gray palaeo-vertisols (Bed I, Masek and Ndutu Beds), (c) Palaeo-Andisols found in Bed I and Bed II are observed to develop on ash fall/flow tuffs and (d) Palaeo-Aridisols are gray to olive palaeosol levels, seem to have developed on sand levels mainly in upper Bed II. Red to brown palaeosols (AlfisoIs/UItisols?) are slightly richer in FeO-Fe2O3 and MnO values than other palaeosol levels. Total soil silica/sesquioxide mole ratios of both palaeo-Alfisols and palaeo-Vertisol resemble modern Alfisols and Vertisols. Micromorphological studies indicate that gray-olive palaeosols (Vertisols, Aridisols and Andisols) contain numerous calcite nodules, calcite coatings/hypocoatings and infillings with rare Fe-Mn hydr(o)xide coatings and nodules. Clay coatings are rare or absent. They commonly show a granostriated or monostriated b-fabric and porphyric c/f related distribution of the basic components. The red-brown and dark gray palaeo-Alfisols contain multiple micromorphological features (red-yellow clay coatings and clay coating fragments, Fe-Mn oxide nodule and coatings with some calcite coatings and in-fillings) that are usually seen, imprinted on one another. Palaeo- Aridsols are regarded to be formed in semi-arid palaeoclimates, while palaeo-Vertisols were formed in alternating wet and dry conditions of the Pleistocene Epoch. The red to brown palaeo- Alfisols are assumed to have developed during wet/humid palaeoclimates in Olduvai Gorge during the Pleistocene. The Manonga-Wembere Valley geology comprises of Pliocene-Pleistocene lacustrine gravel, sands and calcareous-clay deposits and Holocene mbuga clays and alluvial sand. The micromorphology of palaeosol levels from Manonga-Wembere Valley show strong clay illuviation of red to yellow clay coating and clay coating fragments with Fe-Mn (hydr)oxide coatings. The clay coating fragments occur as accumulation of oriented clay-coating fragments in a red to yellow groundmass resembling clay illuviation fronts found in present day warm and humid (Meditterranean) climates. -Manonga-Wembere Valley palaeosol levels are therefore assumed to represent a wet and humid climate and environment during the Pliocene-Pleistocene times. Kaolinite and illite clay minerals together with gibbsite and some zeolites (analcime and stilbite) dominate the mineralogy of these palaeosol levels. The geology and stratigraphy of Holili begins with the Precambrian basement rocks and then covered by lava flows (basalt) of the Kilimanjaro volcanic episode. Then a soil (palaeosol) developed on the basalt. The landscape (palaesol) was finally covered in succession by tuffaceous mudstone and calcareous tuffaceous grit. A hominid tool, fossil leaf impressions of angiosperm dicotyledon flowering plants and animal remains (tooth, horn and canon bone) were recovered in Holili Pleistocene deposits. Palaeoclimatic and palaeoenvironmental variability The palaeoclimatic and palaeoenvironmental variability in Olduvai Gorge, Manonga- Wembere and Holili localities as deduced from facies, magnetic susceptibility, mineralogy, geochemistry, micromorphology and palaeosol occurrences and cyclicities seem to be linked to the global causes of climatic changes. 400ka Gravel beds cyclicity (at about 2.2Ma, 1.76Ma, 1.4Ma, l.OOMa 0.65Ma and 0.2Ma), 40Ka and lOKa palaeosol cyclicity are observed in Olduvai Gorge. The climatic variability of Olduvai Gorge during the Quaternary is found to correlate with that of Greece (Mediterannean). This is evidence that the climate of Olduvai Gorge during the Quaternary also followed global trends. In Olduvai Gorge hominids and other animal fossil remains are frequently found on palaeosols levels or closely associated to palaeosol levels. Long periods of 400Ka marked by gravel bed complexes are generally wet periods. Gravel bed complexes that mark significant short periods of drought in this study are correlated to FAD and LAD of Australopithecus boisei, Homo habilis and Homo erectus hominid species in Olduvai Gorge. Likewise in Manonga-Wembere Valley and Holili deposits animal fossil remains occurrences are associated to palaeosol levels. Future research For future research a complete micromorphological study of all possible palaeosol levels will be helpful in discerning more the climatic variability. Future hominid search would be more successful if palaeosol levels were mapped and followed over long distances. New Ar-Ar dating of the basalt and tuff in Manonga-Wembere Valley and Holili areas would provide better age estimates of the deposits.
Analytical methods for Cyhalofop-butyl and its metabolites in Soil and water
(China academic journal electronic publishing house, 2001) Mwalilino, Jilisa K; L i, Zhao; Guonian, Zhu; Yingxu, Chen
A relatively simp le and less expensive m ethod is p ropo sed fo r the determ ination of cyhalofop2butyl (XDE2537) and its m etabo lites: R2(+ ) 222[ 42(22fluo ro242 cyanophenoxy) phenoxy ] p ropano ic acid (AC ID ); R2(+ ) 222[42 (42 carboxyl222fluo ro242 cyanophenoxy) phenoxy ] p ropano ic acid ( D IAC ID ); and 22[42(42carbamoyl222 fluo rophenoxy) phenoxy ] p ropano ic acid (AM IDE). Conversion of the parent compound to its arylöalkylöo r halide derivative fo r determ ination by GC w as found unnecessary. O nly HPLC w as used and under gradient elution all the four compounds separated w ell. Good recoveries w ere obtained w ith the fo rtified so il and w ater samp les. Low pH w as impo rtant fo r the extraction of the four components
Response of gstase and L iver esterase in goldf ish (Ca rra sius aura tus) and topmouth gudegon (Pseudora sboraparva ) after sublethal exposure to cyhalofop-butyl and profur ite-am in ium
(Chinese journal of pesicide science, 2002) ZHU, Guo-nian; Hui ming, WU; Mwalilino, Jilisa K.; Shao-nan, L I
Investigations w ere carried to assess the sublethal effects of a herbicide clincher ( 100 EC) containing cyhalofop2butyl [ 100 g (a. i) ·L - 1 ] as the active ingredient and the insecticide p rofurite2am inium [ 78% SP, 780 g (a. i) ·kg - 1 ] on liver esterases and hepatic glutath ione2S 2transferase (GST ) in go ldfish (Carassius au ratus) and topmouth gudgeon (P seud orasbora p arva). GST w as found to be induced in bo th go ldfish and topmouth gudgeon by the p rofurite2am inium at concentration of 0. 234 m g·L - 1 . Clincher bo th at concentration of 1 and 2 m g·L - 1 caused GST induction in topmouth gudgeon. The m ixture of clincher and p rofurite2am inium had the h ighest effect in topmouth gudgeon 722. 3 nmo l· (m in - 1·m g - 1 p ro tein ) w ith a po ssible indication of additive toxicity. L iver esterases w ere induced by bo th clincher (1 and 2m g·L - 1 ) and p rofurite2am inium (0. 117 and 0. 234m g·L - 1 ) in go ldfish. In topmouth gudgeon liver esterases w ere induced by p rofurite2am inium but inh ibited by clincher. It is suggested that the two bio transfo rm ation enzym es m ay be directly o r indirectly affected by the tested chem icals and that there are differences betw een them
Household waste recovery and recycling: a case study of Kigoma-Ujiji, Tanzania
(Inderscience Enterprises Ltd, 2003) Shams, Shahriar; Ibrahimu, Chikira
Management of waste in most developing countries has become important for most of the cities as they try to curb and control city growth and urbanisation. The general norm where waste management had been the sole duty of municipalities has proved not to work due to lack of funds, public participation, political will and awareness. This paper looks at the general problems faced in household waste recovery and recycling, with a case study from Tanzania. A process scheme that consists of public participation, costs, social acceptance, economic benefits, and hygiene is considered. The overall conclusion is that there is a need for government commitment and general involvement of the public. The setting up of recycling industries will also ease the situation and at the same time create employment for the people.
The biological importance of the Eastern Arc Mountains of Tanzania and Kenya
(Elsevier, 2006-10) Burgess, N.D.; Butynski, T.M.; Cordeiro, N.J.; Doggart, N.H.; Fjeldså, J.; Howell, K.M.; Kilahama, F.B.; Loader, S.P.; Lovett, J.C.; Mbilinyi, B.; Menegon, M.; Moyer, D.C.; Nashanda, E.; Perking, A.
The Eastern Arc Mountains are renown in Africa for high concentrations of endemic Received 17 June 2005 species of animals and plants. Thirteen separate mountain blocks comprise the Eastern Received in revised Arc, supporting around 3300 km 2 of sub-montane, montane and upper montane forest, less form 29 June 2006 than 30% of the estimated original forested area. At least 96 vertebrate species are endemic, Accepted 8 August 2006 split as follows: 10 mammal, 19 bird, 29 reptile and 38 amphibian species. This includes Available online 12 October 2006 four endemic or nearly endemic species of primate – the Sanje Mangabey, the Iringa Red Colobus, the Mountain Galago and the new Kipunji monkey that forms its own monotypic Keywords: genus. A further 71 vertebrate species are near-endemic. At least 800 vascular plant species Biodiversity conservation are endemic, almost 10% of these being trees. These endemics include the majority of the Eastern Arc Mountains species of African violet – Saintpaulia, a well-known flowering plant in Western households. Protected areas An additional 32 species of bryophytes are also endemic. Many hundreds of invertebrates Diversity are also likely to be endemic, with data for butterflies, millipedes and dragonflies indicating Endemism potential trends in importance. Seventy-one of the endemic or near-endemic vertebrates are threatened by extinction (8 critical, 27 endangered, 36 vulnerable), with an additional seven wide ranging threatened species. Hundreds of plant species are also threatened
Environmental and human health risks of mercury released from artisanal gold mining in Tanzania
(Ghent University, 2008) Chibunda, Raphael Tihelwa
Artisanal gold mining is one of the major sources of mercury (Hg) contamination in Tanzania. Whilst the gold extraction process (known as amalgamation) is a simple technology, it is potentially very harmful to the environment and can contaminate air, soil, rivers and lakes with mercury. High levels of environmental mercury can cause harm to organisms living in the various environmental compartments. Also the health of the miners and other people living within the contaminated area may be adversely affected through inhalation of mercury vapour, direct contact with mercury, through eating Hg contaminated fish and other food items, or through ingesting Hg contaminated water. The Mugusu mine, which is privately owned by Chipaka family, is one of the active artisanal gold mines in Geita district, Tanzania. The current status of mercury use, environmental contamination and the potential risks of Hg to humans and the environment at the Mugusu mine arc not well understood. This doctoral study aimed at using the Mugusu mine as a model to asses the risks of Hg use in artisanal gold mining in Tanzania. In this thesis, the current status of mercury use and environmental contamination at Mugusu mine was established. The knowledge and perception of miners about the possible effects of mercury to the environment and human health were explored using structured questionnaire and focused group discussion. Based on chemical analysis and ecotoxicity testing the possible ecological effects to the aquatic ecosystem of wastes released from artisanal mine was studied. The potential health risk to humans was assessed by estimating mercury exposure of women residing in a fishing village near Mugusu mine through fish consumption. Concentrations of mercury in muscle and liver tissues of free grazing cattle and scavenging domestic fowl in gold mining centres were determined and used to assess the potential contribution of this exposure route to the Hg intake. Additionally, a total diet study approach was used to estimate the dietary mercury intake of people living and working in the Mugusu village. Finally, through head hair monitoring we established the current exposure of mercury to artisanal gold miners at the Mugusu mine. This study identified that intensive use of mercury in gold extraction and the associated environmental pollution is occurring at Mugusu mine. The current mining practice involves excavation of gold rich ore by using hand hoes, chisels and sledge hammers. After removing the mineralized bearing material, the ore is grinded in the ball mills and soil concentrate is recovered in sluice boxes which are lined with sisal sacks or any other fibre materials. The soil concentrate obtained is subsequently amalgamated with mercury to trap fine gold from the ore pulp. A piece of cloth is used to squeeze off excess mercury’ by twisting it and leaving behind the amalgam. Once the amalgam is obtained it is burned in open air to release Hg. Retorts arc not used, neither is any other form of protection against mercury contamination and/or exposure. Most miners lack knowledge on the possible environmental and human health problems associated with mercury release and exposure. Amalgamation mainly takes place adjacent to the river Mabubi that in turn drains into Lake Victoria, thus potentially contaminating Lake Victoria resources. Results from the present study show that use of mercury in gold mining contaminates nearby water resources and soils. To perform an exploratory’ environmental risk assessment, selected environmental compartments were studied. Analysis of water and sediment samples collected from the river Mabubi demonstrated that Hg concentrations in sediment and water decreased towards the river mouth. The highest concentrations of Hg in sediment (2.3 pg g’1 dw) were measured three kilometres downstream of the mine. As in previous studies in the Lake Victoria goldfields, we showed that the distribution of Hg in river sediments away from the mine is relatively restricted. Probably Fe-rich laterites and seasonal swamps act as natural barriers restricting the movement of Hg downstream into the Lake Victoria. The soil samples collected near the mine contained up to 1.2 pg g’1 dw. In the ecotoxicity assessment, sediments collected up to six kilometres downstream of Mugusu mine significantly reduced survival and growth of the African catfish (Clarias gariepinus). The calculated 5 day-LCso value (larval survival) was 1.75 pg Hg g'1 dw (95% CL of 0.72 - 2.53), the 5 day-NOEC for hatching was >2.3 pg Hg g‘‘ dw and that for larval survival and growth was 0.23 pg Hg g1 dw. These results were in agreement with results obtained from laboratory toxicity evaluations using mercury’ spiked artificial sediments and the benthic invertebrate Chirotiomus riparius. Indeed, the emergence of C. riparius midges was significantly delayed at Hg concentrations of 0.93 pg Hg g 1 dw. Mercury affected some life characteristics of C. riparius at concentrations lower than the levels of mercury which have been measured in different artisanal gold mining impacted watersheds in Tanzania. For example, in our assays Hg delayed emergence at concentrations that was 2.5 times lower than those measured three kilometres downstream of the mine in the Mabubi river. Overall, the chemical analysis and the ecotoxicity results from this study indicate that sediments downstream of the mine in the Mabubi river and probably in other artisanal gold mining impacted watersheds in Tanzania pose a risk to aquatic fauna. To assess the risk associated with Hg to the local human population the Hg intake through consumption of Hg contaminated fish, meat and other food types was estimated. Additionally, head hair analysis was done to establish the concentrations of Hg in the body of people living and working in Mugusu gold mining village. Results from the fish consumption survey indicate that, the main fish caught and consumed by the people residing in the Nungwe village that borders the Mugusu mine included nile perch (Lates niloticus), tilapia (Oreochromis niloticus, catfish (Clarias gariepinus), sardine (Rastrineobola argentea), and lung fish (Protopterus aethiopicus). Catfish contained marginally (0.51 ± 0.17 pg g’1 ww) higher concentration of mercury than the WHO safety limit of 0.5 pg Hg g'1 ww; the four other species had Hg levels below this safety limit. Because of high fish intake (144 g/day), the calculated weekly McHg intake in this village (4.0 pg/kg bwt/day) was above the Provisional Tolerable Weekly Intake (PTWI) recommended by WHO/FAO for protection of the unborn child and young children (1.6 pg/kg bwt/weck). On the other hand, the total diet study showed that daily Hg dietary intake for people living and working within the Mugusu mining village exceeded the provisional tolerable daily intake recommended by WHO/FAO for protecting unborn children (15.5 pg/day) by a factor of two. Thus, children born to mothers living in this village arc at risk of intrauterine mercury poisoning. The contribution to overall Hg exposure of meat obtained from cattle and domestic fowl reared in the mining villages was low. Indeed through analysis of muscles obtained from these animals we established that Hg levels in these products were rather low and ranged from 22 to 81 pg/kg ww. These Hg concentrations are far lower than the international safety limits of 500 pg/kg ww. In general, chemical analysis of Hg in head hair collected from people working and living in the Mugusu mining village indicated low exposure. The mean concentration (1.55 ± 2.2 pg g’1 dw) was lower than the warning limit (10 pg Hg g’dw) established by WHO for pregnant women. However, hair obtained from individuals involved in amalgam roasting contained significantly more Hg than those involved in other mining activities. Compared with studies performed ten years ago, the mercury concentrations in the hair of miners at Mugusu mine have slightly increased. In conclusion, this doctoral study has demonstrated that, artisanal gold mining at the Mugusu mine causes contamination of all the environmental compartments which lead to increased risks to the environment and human health. The current level of Hg concentrations in the rivers and streams draining the Mugusu mine into Lake Victoria pose risk to aquatic biota. Based on the survey conducted in this study it is clear that miners lack clear knowledge and understanding of the possible effects of Hg on the environment and human health. Furthermore, based on the current local food consumption pattern and Hg concentrations in different food items it is concluded that there is no risk to the general public but there is a health risk to unborn children. It is therefore recommended that more efforts are made (1) to reduce the use of Hg in gold mining and (2) to educate the miners and surrounding communities on the effects of Hg on the environment and human health.
Environmental degradation and intra household welfare: The case of the Tanzanian rural south Pare highlands
(Wageningen University. Wageningen, 2009) Dimoso, R L
The rural South Pare highlands in Tanzania experience a deteriorating environmental situation. The causes of environmental degradation arc population growth, deforestation, poor fanning techniques, and weak forestry regulatory frameworks. Of particular importance is the disappearance of forests and woodlands. The consequences are declining amounts and reliability of rainfall, lower water levels and loss of biodiversity. Deterioration of environmental resources increases the costs of collecting environmental products, which in many respects have no feasible close substitutes. One of the major components of the increased costs is labour time allocated by household members to collecting environmental products and'or grazing activities. This reallocation of intra-houschold labour resources may have different cl Teets on welfare for different members of a household. Degradation of the local environmental resource base is expected to adversely affect women and children more than men. Furthermore, labour time reallocation may interfere with labour allocated to other agricultural activities in the area. In addition, it could drain much of the time children allocate to schooling activities, which may have negative implications for their school attainment and the quality of their human capital in the long ran. Lastly, intra- houschold labour resource reallocation may influence the subjective welfare and well-being of households. This study presents an empirical analysis of these effects. The analysis is based on cross-sectional data collected in 2006/2007 from households in the Tanzania's rural South Pare highlands. The study was guided by four hypotheses each of which formed the basis of an empirical chapter of the thesis. The first empirical chapter is Chapter 3, in which we investigated whether the deteriorating environmental resources had an 'adverse impact ' on intra-household labour allocation. We applied the neo-classical model of an agricultural household. Io analyse how variations in environmental degradation affect intra-household labour allocation, three types of areas were distinguished: severely-degraded, medium-degraded, and non-degraded environments. Since many individuals spent zero hours on some activities, we corrected for selection bias by using Heckman's two-step selection method. The results show that environmental products collection and/or grazing activities in South Pare were gender biased with husbands specializing in grazing while wives and children specialized in fetching water and fuel wood. Secondly, we found that environmental products collection and/or grazing time by the household members was. almost in all groups and in accordance with gender-biased activity, significantly influenced by the environmental conditions. Thirdly, we noticed that if a spouse or a schoolchild had participated in an intra-household activity, his/her time in the work had a significant impact on the time spent by the other spouse in that particular activity, especially in water and fuel wood fetching for household use. In Chapter 4, we analysed whether environmental degradation led to lower agricultural production and household consumption of home-produced meals prepared from staple food crops, namely, maize, beans, millet and paddy. Since the crop outputs weighed differently, we used the monetary value of their yields as a common scale. The amount of food consumed was expressed in calories per person, per day. The basis of the theoretical framework was a neo-classical model of agricultural household production. We estimated the model with two-stage least squares (2SI.S) to control lor the endogeneity of production and consumption within households. The estimation results of the agricultural production equation show that agricultural output was significantly related to consumption of these crops, environmental degradation conditions, total cropped land, fertilizer application, ox-plough use and total extra-income accrued from other sources minus the monetary value of their own-domestic consumption. With regard to the home-produced meals, the results indicate that their consumption is significantly related to the agricultural output, environmental degradation, household income, and household size. In the final analysis, both descriptive and regression results indicate that there are strong possibilities that environmental degradation is limiting the production and consumption potential in the area and that a limited adoption of agricultural modernization further aggravates this problem. In Chapter 5. we examined whether the school attainment of children m rural primary schools, with respect to their gender, was inversely affected by deteriorating environmental resources. The basis of this analysis were the prior results showing that schoolchildren were involved in the work, supporting their households' livelihoods, including housework, farming, collecting scarce environmental products and/or grazing. This type of child labour frequently led to foregone schooling, which may have critical consequences for educational achievements. Since the grade to age school attainment, our dependent variable, is an ordinal variable, which indicates a ranking of school attainment, we used ordered probit estimation techniques. The results show that the probability of educational attainment at primary school, was found to be significantly associated with age. age-squared, and the mother's secondary education. The formal employment status of the mother at government offices significantly, but differently, affected the probability of educational attainment of both schoolgirls and schoolboys separately, but not in the pooled estimates. The household ethnicity, i.e.. belonging to the Sambaa tribe, significantly decreased the probability of schoolgirls to progress at primary school, as compared with other tribes. Interestingly, in the severely-degraded environment as compared with the non-degraded area, the probability that girls would progress at school decreased significantly. However, the environmental degradation situation neither had significant impact for schoolboys in their educational attainment nor for schoolgirls and schoolboys pooled together. Our basic findings further show that there were other factors (like school erowdedness. illness, bud weather, poor school quality, and school absenteeism due to street vending) that affected the probability of school attainment for the schoolchildren apart from the environmental degradation situation. Reasons for this were twofold, l-'irstly. girls and boys spent, on average, the same number of hours per week in school activities across environmental conditions. Secondly, deteriorating resources like environmental products collection and/or grazing, work at home, and work on the farms, each contributed only marginally to total primary school late entry, negatively affecting the girls only. In Chapter 6. we investigated whether the household subjective economic welfare was inversely affected by deteriorating environmental resources. The first objective of this section was Io study the individual welfare function. We applied a lognormal welfare function of income to analyze the income evaluation question (I EQ). The average estimated values of the want parameter of the individual welfare function, denoting the log-income evaluated al 0.5 on the [0.11 welfare scale, were found to be 4.46 for husbands and 4.39 for wives, corresponding with 86,487 and XU.M(J Tanzanian Shillings, respectively. There amounts of income were evaluated as insufficient on average. The evaluated income was well above the official Government minimum wage in 2006 2007 of 75.340 Tanzanian Shillings per month, suggesting that individuals in South Pare needed an income well above the official monthly minimum wage to experience even an insufficient income. The results of the extended model show that, for both husbands and a wives, the individual welfare parameter significantly increased with an increase in household income, use ol scarce environmental products, namely, fuel wood and waler, and household consumption of the survey crops. Ihe want parameter for husbands alone also increased with education, while the want parameter for wives alone also increased with having an occupation. I aking the ceteris paribus condition, the results show that an increase in the use of these scarce environmental products would obviously lead to higher opportunity costs, which, in turn, would increase the want welfare parameter. This suggested that the individual would need higher income through the exponential of the want parameter to maintain the same welfare level. The second objective of the Chapter 6 was to examine subjective well-being. The results of an ordered probit model showed that subjective well-being was negatively influenced by environmental degradation. That is. living in a medium-degraded area, as compared with a non-degraded environment, significantly decreased the husband's well being. A w ife perceived lower well-being if she happened to live in a severely-degraded place, while a schoolchild fell unhappy living in either a medium or a severely-degraded environment. I he findings in Chapter 3 already described that environmental degradation influenced the burden of labour (thus affecting well-being) differently to each family member depending on the gender of a person. Furthermore, household income had a significant positive influence on the husband's well-being, while the time he spent on domestic chores and the interaction of household size and income reduced his probability of well-being. The well-being of the wife was significantly non-linear in the effect of age. decreasing after the age of 60.5 years. The results further show that the well-being of a wife was also negatively associated with the time she spent on domestic chores and grazing, thus supporting the findings that women in the area associated many of their health problems with their heavy domestic responsibilities. This study is instrumental in understanding the problems of sustainable development, poverty alleviation, environmental policy and the position of women. Policies designed to preserve the natural resource base (e.g., forestry projects) would be recommended in view of long-run benefits. Short-run strategies would include improving production technologies and persuading household members to grow drought-resistant crops. Lastly, policy makers need to devise overall strategics that would stimulate high economic growth rates in both the medium and long term. The findings of this study may be strengthened by the availability of longitudinal data, to reveal a pattern of change in relation to time. This will need a longer period of research.
Groundwater exploitation and hydraulic parameter estimation for a Quaternary aquifer in Dar-es-Salaam, Tanzania.
(Elsevier Ltd, 2009-07-03) Mjemah, Ibrahimu Chikira; Van Camp, Marc; Walraevens, Kristine
The fact that groundwater exploitation has largely increased since 1997 in the Dar-es-Salaam aquifer, calls for a directed attention towards possible problems of aquifer overexploitation that may arise in the near future. Hydraulic parameters are important for developing local and regional water plans as well as developing numerical groundwater flow models to predict the future availability of the water resource. The determination of aquifer parameters through pumping tests has become a standard step in the evaluation of groundwater resource potential. The pumping tests in the study area were con- ducted in August 2004 and August 2005, where 39 boreholes were tested out of 400 visited. In the study area there are over 1300 recorded boreholes drilled by Drilling and Dam Construction Agency (DDCA) by the year 2005. Total groundwater exploitation in the study area was estimated at 8.59 10 6 m 3 /year, based on yield data collected during the 2004–2005 field campaigns. The pumping tests included single- well tests and tests with measurements on the pumping well and at least one observation well. The tests were conducted for 6 h and 30 min. The pump was shut down after 6 h of pumping and the remaining 30 min were used for recovery measurements. The pumping test analysis methods used include: Neuman type curve matching and Walton type curve matching, checked by specific well capac- ity assessment and Thiem–Dupuit/Thiem’s method. The curve-matching results from the aquifer tests show the following parameters: an average transmissivity and hydraulic conductivity of 34 m 2 /d and 1.58 m/d, respectively for the unconfined aquifer; the semi-confined aquifer has an average value of 63 m 2 /d and 2.14 m/d for transmissivity and hydraulic conductivity, respectively. For the case of the storativity, the unconfined aquifer has an average elastic early-time storativity of 0.01, while the lower aquifer has an average storativity of 3 10 4 . Specific well capacity method and Thiem–Dupuit/Thiem’s method confirm results for transmissivity and hydraulic conductivity of the semi-confined aquifer, while values for the unconfined aquifer are somewhat larger (by a factor of 2–3). The hydraulic param- eters calculated appear to reasonably agree with the geological formation of the aquifers, as deduced from borehole descriptions.
Conservation implications of deforestation across an elevational gradient in the Eastern Arc Mountains, Tanzania
(Elsevier, 2009-11) Burgess, Neil D.; Mbilinyi, Boniface; Gereau, Roy E.; Hall, Jaclyn; Lovett, Jon
Deforestation is a major threat to the conservation of biodiversity, especially within global centers of endemism for plants and animals. Elevation, the major environmental gradient in mountain regions of the world, produces a rapid turnover of species, where some species may exist only in narrow elevational ranges. We use newly compiled datasets to assess the conservation impact of deforestation on threatened trees across an elevational gradient within the Eastern Arc Mountains of Tanzania. The Eastern Arc has suffered an estimated 80% total loss in historical forest area and has lost 25% of forest area since 1955. Forest loss has not been even across all elevations. The upper montane zone (>1800 m) has lost 52% of its paleoecological forest area, 6% since 1955. Conversely, the submontane habitat (800–1200 m) has lost close to 93% of its paleoecological extent, 57% since 1955. A list of 123 narrowly endemic Tanzanian East- ern Arc tree taxa with defined and restricted elevational ranges was compiled and analyzed in regard to mountain block locations, elevational range, and area of forest within each 100 m elevational band. Half of these taxa have lost more than 90% of paleoecological forest habitat in their elevational range. When elevational range is considered, 98 (80%) of these endemic forest trees should have their level of extinc- tion threat elevated on the IUCN Red List. Conservation efforts in montane hotspots need to consider the extent of habitat changes both within and across elevations and target conservation and restoration efforts throughout these ecosystems’ entire elevational ranges.
Groundwater vulnerability to petroleum hydrocarbons pollution of quaternary sand aquifer in Dar es Salaam, Tanzania
(The Journal of Building and Land Development., 2010) Mjemah, I. C.; Mato, R.R.A.M.; Thunvik, R.
Groundwater is inherently susceptible to contamination from anthropogenic activities and remediation is very expensive and often impractical. Prevention of contamination is hence critical in effective groundwater management. In this paper, an attempt has been made to assess the aquifer’s vulnerability to petroleum hydrocarbons contamination in Dar es Salaam City, Tanzania. Potential benefit from mapping vulnerability is that it aids in the prioritisation of monitoring boreholes located in high vulnerable area, as well as providing bases for developing appropriate groundwater protection strategies. The DRASTIC model coupled to ArcView-GIS and HSSM model were used in vulnerability assessment. The results from these models have clearly demonstrated that the aquifers in the Dar es Salaam City are likely to be affected from petroleum hydrocarbons, because the pollution sources are located to a moderate and high vulnerability class, which covers about 80% of the Dar es Salaam City. Furthermore, the gasoline estimated arrival time is about 1 year for transport from the ground surface to a water table aquifer at a depth of 7 m. The current situation of petroleum hydrocarbons found in potable water shows very low concentrations (<2.5g/l) compared to the limits of the Tanzania standards of about 0.5 mg/l. However, as the gasoline takes even decade or centuries to migrate through aquifers, the concentrations are likely to increase if no preventive measures are taken.
Integrating the management of the ruaha landscape of Tanzania with local needs and preferences
(University of California, 2010-01) Masozera, M.; Erickson, J.D.; Clifford, D. L.; Coppolillo, P.; Nguvava, M.; Sadiki, H.; Mazet, J. A .K.
ustainable management of landscapes with multiple competing demands requires balancing the diverse preferences and needs of stakeholder groups. Conservation and development organizations have often made unwarranted assumptions about what is desired by, or good for local people without engaging local stakeholders. This study uses conjoint analysis to assess the preferences of representatives from three stakeholder groups—local communities, district government officials, and non-governmental organizations (NGOs)—to identify potential competing conservation and development priorities facing local communities in the Ruaha Landscape of Tanzania. Representatives of local agricultural communities place high importance on investments in farmer’s cooperatives that increase accessibility to supplies, loans, and capacity development. In contrast, district government officials and NGOs perceive investments to improve health, education, and tourism infrastructure as highest priorities for the region. Analysis suggests a need for incorporating issues deemed important by these various groups into a development strategy that aims to promote conservation of the Ruaha Landscape while improving the livelihoods of local communities. To be successful, future projects, whether conservation or development, must reconcile objectives at local to global scales and across sectors.
The potential of hyper-temporal NDVI data to assess vegetation condition and grazing intensity
(International Institute for Geo-information Science and Earth Observation, 2010-02) Hamad, Amina Amri
Land degradation has been reported to be a major environmental problem in Crete for a long time and is largely caused by excessive grazing. Several attempts have been done using satellite images for the purpose of monitoring the effect of excessive grazing on vegetation as a whole and their distribution. These studies lacked the temporal aspects of monitoring grazed lands since they used satellite imagery of one date. This study used 10 years MODIS hyper temporal NDVI images of 16 days temporal resolution to assess vegetation condition and grazing intensity. Grazed areas were classified by vegetation types into 8 groups. Grass Index measured from field was used as a direct estimate of Grazing Index. Seasonal analysis was done where the pixel NDVI value at the peak and at the end of grazing season was compared separately to Grazing Index to assess vegetation conditions. Not only that but also trend analysis was used to assess vegetation conditions, where the slope of 10 years NDVI was compared to the Grazing Index by vegetation types. Assessment of Grazing Intensity was done by comparing the difference of NDVI at the peak and end of grazing season with the Grazing Index. Seasonal analysis showed that at a confidence interval of 0.05 four groups had significant positive relation between the NDVI at a peak of growing season and grazing index and one had a negative relation. Moreover trend analysis revealed that at a confidence level of 0.15 two groups had significant positive and negative relation between slope of 10 years NDVI and grazing index. These analysis indicate that different vegetation types have different response to high grazing intensities. NDVI difference was found to have a positive relation with Grazing Index indicating it is possible to use this method to estimate grazing intensity. Not only that but also R 2 ranged between 25%-87% which means the analysis explained sufficient variability. MODIS hyper temporal NDVI has shown a potential to assess vegetation conditions and grazing intensity however studies should be done more on how to capture the amount of brown biomass this could improve the estimates and monitoring of grazed lands.
Groundwater exploitation and recharge rate estimation of a quaternary sand aquifer in Dar-es-Salaam area, Tanzania
(Springer-Verlag, 2010-09-10) Mjemah, Ibrahimu Chikira; Van Camp, Marc; Martenes, Kristine; Walraevens, Kristine
Dar-es-Salaam City gets water supply from surface water and groundwater. The groundwater is used to supplement surface water supply and has increasingly become a major source of water supply in the city. The study area comprises three major parts: the central coastal plain with quaternary fluvial–deltaic sediments, the deltaic Mio-Pliocene clay-bound sands and gravels in the north- west and southeast and the Lower Miocene fluviatile sandstones of Pugu Hills in the west of the study area. The main objective of this study was to quantify the integrated water balance. The major source of renewable groundwater in the aquifer is rainfall. Hence, the average recharge of 256.2 mm/year (for the year 2006) to the aquifer was estimated using the balance method of Thornthwaite and Mather, which is equal to 99.4 hm 3 /year for the whole alluvial aquifer. This value was balanced with total groundwater abstraction of 8.59 hm 3 /year, baseflow to rivers of 75.7 hm 3 /year and discharge into the sea (15.11 hm 3 /year).
Predicting ecosystems vulnerability under landscape changes in the livingstone mountain ranges in Mbinga district, Tanzania
(Sokoine University of Agriculture, 2011) Makota, Vedast Max
Predicting future conditions of the ecosystems resulting from different human activities is very important in spatial planning for sustainable resources utilisation. This study has developed a spatial decision making supporting system (SDSS) or a model for predicting ecosystems vulnerability under landscape changes in the Livingstone Mountain Ranges in Mbinga District, Tanzania. Various datasets collected through remote sensing and cross-section survey were used in this study. Changes in the spatial extent of the habitats were assessed from remotely sensed data based on land use and cover changes. Variables extracted from remotely sensed data were used to generate parameters and were integrated in the GIS environment to develop the prediction model called, Livingstone Mountain - Conversion of Land Use and Its Effects (LIM-CLUES) Model. Predicted results from the developed model were based on the business as usual and policy scenarios used in this study. The results from the business as usual scenario showed that there would be a continuous decrease in the woodland ecosystem up to the year 2020 mainly at the expense of agro-ecosystem due to livelihood strategies of the local communities in deriving goods and services. Predicted results also showed that there was an increase in the area of cultivated land at the expense of the upland woodland and upland bushland with scattered cropland from year 2005 to 2020. The results also showed that upland cultivation would continue to expand towards the south eastern side up to year 2020. Encroachment would also start to take place in the upland woodlands located in the southern part between the boundaries of Chiwanda (lowland) and Tingi (upland) wards. Likewise, simulated results from the policy scenario showed that upland bushland with scattered cropland category would be extending upwards in Kingerikiti ward between years 2005 and 2010. Upland woodland started to regenerate in the same Kingerikiti ward from year 2005. As a result of this study, a LIM-CLUES model helped to understand factors influencing landscape changes and can be used to project near I ■ future land use trajectories, which are important for targeting spatial management decisions in the study area.
Enhancing protection of Dar es Salaam quaternary aquifer: Groundwater recharge assessment.
(Springer-Verlag, 2011) Mtoni, Y.; Mjemah, I. C.; Van Camp, M.; Walraevens, K.
Water balance for Dar es Salaam Quaternary coastal aquifer (DQCA) was calculated according to the method of Thornthwaite and Mather. Monthly potential evapotranspiration estimates were calculated from 39 years (1971–2009) of routine meteorological data using Penman-Monteith, Thornthwaite, Hargreaves and Hamon methods. Results were compared in order to show possible differences that could be attributed to the methods. Determination of groundwater recharge rates gave a mean value of 184 mm year -1 which is equivalent to 71.39 x 10 6 m 3 year -1 indicating that 16.5% of the long term average annual precipitation of 1114 mm ends up as groundwater recharge. Groundwater abstraction from DQCA was estimated to be 69.3 x 10 6 m 3 year -1 . These results are alarming in two aspects: high abstraction rate and the increasing trend of borehole drilling. Groundwater abstraction which is nearly equal to the amount of the groundwater recharge is far greater than the least conservative sustainable yield calculated at 70% (equivalent to 49.97 x 10 6 m 3 year -1 ).
Nitrate pollution of Neogene alluvium aquifer in Morogoro Municipality, Tanzania.
(International Formulae Group, 2011-02) Kibona, Irene; Mkoma, Stelyus L.; Mjemah, Ibrahimu C.
Concern over nitrate pollution of groundwater in integrated water quality management has been growing recently. The levels of nitrate in wells from septic tanks and urban agriculture with nitrogen fertilizers application may increase the potential groundwater pollution by nitrate. The purpose of this study was to determine the concentrations and spatial distribution of nitrate (NO 3 − ) in groundwater in Morogoro Municipality. Groundwater samples were collected from 20 wells during wet season period in March-April 2010 in 6 wards namely Kihonda, Mji Mpya, Mafisa, Saba Saba, Boma and Kilakala. The spectrophotometer was used to measure the NO 3 − concentration in water samples. The minimum and maximum nitrate levels were 1.4 and 32.5 mg/L respectively in the wards studied with an average of 7.76 mg/L. These results showed that all of the groundwater samples have NO 3 − concentration below the Tanzania Bureau of Standards upper limit value and World Health Organization guideline of 75 mg/l and 50 mg/l respectively. Also, the level of nitrate concentration tend to decrease with depth for most of the places due to the anoxic condition that is available at the higher depth which facilitates the utilization of nitrate by anaerobic microorganisms.
Influence of meteorology on ambient air quality in Morogoro, Tanzania
(International Journal of Enviromental Science., 2011-03) Mkoma, Stelyus L.; Mjemah, Ibrahimu C.
The influence of meteorological parameters on air quality was investigated for a rural background site in Morogoro. Precipitation, temperature, relative humidity and wind speed were measured during wet and dry seasons of 2005 and 2006 period and their relationship with reported mass of particles of aerodynamic diameter smaller than 10 μm (PM10) for the site was assessed. The results show that higher PM10 mass concentrations (45μg/m 3 ) were obtained during the 2005 dry season and the lowest (13 μg/m 3 ) during the 2006 wet season. It is interpreted that reasons for the higher levels of the particulate matter mass in the dry season are due to temperature inversions and absence of rain washdown. The observed particulate matter levels are also affected by the variations in sources strengths and in meteorological conditions such as mixing height, precipitation, relative humidity, wind speed and direction as supported by air mass trajectories.
Saltwater intrusion in the quaternary aquifer of the Dar es Salaam region, Tanzania
(GEOLOGICA BELGICA, 2012) Mtoni, Yohana; Mjemah, Ibrahimu C.; Msindai, Kristoko; Van Camp, Marc; Walraevens, Kristine
A description of the occurrence of the salt water intrusion from seawater close to the coastline of Dar es Salaam Region is presented. The present status of intrusion in two pilot areas located between Mlalakuwa and Msimbazi Rivers (locality I) and Msimbazi and Kizinga Rivers (locality II) is evaluated. The causes, effects, remedial measures and future possibility of intrusion are discussed. An investigation on the hydrodynamics of the phenomenon and analysis of the formations as well as the interfacial transition zone is currently being performed. Water samples from Mikocheni, Oysterbay, Msasani, Masaki and City Centre areas show elevated chloride, sulphate and sodium concentrations. Using Stuyfzand (1986) water classification method, about 60 percent of the samples are classified as fresh-brackish to salt and 30 percent as extremely hard. Groundwater was classified into several categories by subtype, i.e., Sodium-Chloride, Sodium-Bicarbonate, Calcium-Bicarbonate, Magnesium-Bicarbonate, Sodium-Mix and Calcium-Mix. The growing human population in and around the investigated areas has had an adverse impact on the water in the shallow aquifer through, among other factors, indiscriminate abstraction of water without knowledge of the aquifer’s capacity.
Climate characteristics over southern highlands Tanzania
(Scientific Research, 2012) Mbululo, Yassin; Nyihirani, Fatuma
This study was conducted to examine the climate characteristic of southern highland Tanzania (Latitude 6°S - 12°S and Longitude 29°E - 38°E). The study findings reveal that rainfall over the region is linked with SST over the Indian Ocean, where warmer (cooler) western Indian Ocean is accompanied by high (low) amount of rainfall over Tanzania. During wet (dry) years, weaker (stronger) equatorial westerlies and anticyclone (cyclonic) anomaly over the southern tropics act to reduce (enhance) the export of equatorial moisture away from East Africa. The wettest (driest) season was found to be 1978/79 (1999/00) which can be classified as the severely wet (moderate drought). Two different modes of rainfall have been identified at time scale of 1.5 and 6 years which have been associated with the quasi biennial oscillation (QBO) and El Nino Southern Oscillation (ENSO), respectively.
Climate change impacts and adaptation among coastal and mangrove dependent communities: a case of Bagamoyo district
(2012) Mbwambo, J.S; Madalla, D; Zahabu, E; Ndelolia, D; Mnembuka, B; Lamtane, H. A; Mwandya, A. W
The study was done to determine perception, impacts and adaptation of coastal communities towards climate change. A total of three villages and 120 respondents were involved in the study. Both Focus Group Interviews and a structured questionnaire survey were employed for collection of both qualitative and quantitative data. Content and structural functional analysis was used for qualitative data while descriptive and logistic and regression analysis was employed for quantitative data. Results indicates that majority of the community are involved in both fishing and farming activities for both food and cash income. Results indicates further that majority of the respondents are aware of climate change and they perceive the same in relation to unusual rainfall (87.5%), drought (93.3%), floods (74.1%) and increased incidence of pest and diseases (55.8%). It was also found that farmers are coping with food insecurity as a result of declining food stocks and they have also developed adaptation strategies related to farming operations and livelihoods. However, adaptation varies depending on various farm and household factors and in this income, number of plots, extension services and farm size were highly significant and showed strong positive influence on adaptation to climate change. It is concluded that farmers are aware of climate change and have developed both coping and adaptation strategies against climate hazards. Promotion of extension and enhancement of off-farm activities are recommended for enhancing adaptive capacity of the population in the study area.

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