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Environmental implications of land-use patterns in the new villages in Tanzania
Department of Geography, University of Dar es Salaam, Dar es Salaam, Tanzania
Agriculture, which dominates most of the African economies, has been the main focus of national development plans of most independent African countries for over two decades. Land policies and reforms of various kinds have been instituted and implemented with the aim of radically improving the performance of the agricultural sector. However, success has been mixed. In most countries, traditional practices and low productivity have persisted despite major reforms and large investments. Where agricultural innovations have been introduced, shortterm successes have often been followed by long-term problems.
The most frequently occurring of such problems is environmental degradation. In practice, many agricultural programmes tend to place a strong emphasis on quantitative increase in production and to be less concerned with qualitative aspects such as resource management and conservation. As a result, the environmental implications of, for example, changes in land use are often overlooked until serious physical deterioration has occurred.
In most parts of Africa there are many examples of environmental deterioration resulting directly or indirectly from changes in land use. This paper highlights some of these environmental implications of land-use changes. It examines the particular case of Tanzania, where a major nationwide resettlement programme was recently undertaken with the aim of transforming agriculture, improving productivity, and raising the standard of living of the people, the majority of whom reside in rural areas.
Resettlement and Villagization
Tanzania adopted the policy of villagization in 1967 as part of a national strategy for development. This policy entailed, among other things, the resettlement of all households outside areas of dense settlements into villages. By 1975, it was estimated that over 75 per cent of the national population was resident in such villages.
This was a dramatic change from the situation in the mid1960s, when it was estimated that 86 per cent of Tanzania's population lived in scattered homesteads, that is, outside villages and towns (Maro and Mlay 1982). Prior to villagization, the system of agriculture practiced in most parts of the country was shifting cultivation. This system permitted farmers to use new lands from time to time and allowed for long periods of fallow. Pastoralists moved from place to place, according to seasonal changes, in order to find adequate pastures for their stocks. As a result, there was generally a balanced adjustment between land-use patterns and the environment, which for the greater part of the country is semiarid, permitting only extensive use.
The villagization policy was the culmination of a long process of searching for the best rural development strategy for Tanzania. During the colonial period and the early years of independence, changes in land use were initially achieved by opening up new areas but retaining traditional agricultural practices. Subsequently, improvement in the agricultural system was considered necessary in order to meet the increasing demand for food and export crops. A transformation approach was therefore proposed whereby modern inputs could be introduced through extension services. Village settlement schemes were established in chosen areas in order to relieve areas with population pressure. This strategy proved to be an expensive undertaking with very limited returns. As a result, it was abandoned after only two and a half years of operation. However, the idea of modernizing the entire agricultural sector was considered a necessary prerequisite for rural development. It was assumed to be the best means by which the welfare and standard of living of the majority of people in rural areas could be improved. Since the majority of the population lived in isolated homesteads, large-scale resettlement was recommended as the first step in the direction of modernization (Nyerere 1967). Resettlement would also provide the basis for concentrating land and human resources, thus minimizing the cost to the Government of providing basic services. At the same time, the benefits of co-operative production and use of modern methods of farming would quickly spread and transform the entire national economy.
Judging from the effects of the implementation of the villagization policy, it seems that major environmental implications of large-scale resettlements were not fully considered before the plan was carried out (Mascarenhas 1979). It was simply assumed that what had prevented nucleated settlements before was the lack of organization and that once this was provided, the benefits of living together in village communities would be more or less automatic.
Generally, the proceeds of settlement were achieved fairly quickly once the Government had decided that all possible methods should be used to move people into villages. After six years (1967-1972) of experimentation with voluntary spontaneous resettlement during which less than 20 per cent of Tanzania's population moved into villages, it took only two years of forced movement (1974-1975) to raise the population living in villages to about 80 per cent, that is, virtually all scattered households were moved into villages (McHenry 1979). Village areas were quickly demarcated, with each village consisting of between 200 to 600 households. Subsequently, attempts were made to set up administrative and organizational structures for each village. Credit facilities, agricultural extension, and other basic services were generally extended to the new villages to enable them to operate as viable socio-economic entities with full legal status.
Land Use Changes Since 1967
The combined effect of resettlement and a rapid population growth (3.1 per cent per annum) over the last two decades has been to change substantially the rural population density in areas previously sparsely populated and thereby to alter patterns of land use.
According to the 1978 Population Census, the average population density for the whole country increased by 42 per cent between 1967 and 1978. Of the four regions which experienced an above average density change, three -Tabora, Rukwa, and Arusha -are some of the most sparsely populated regions in the country (see table 1). The factor which has influenced density change at the regional level is mainly natural increase rather than resettlement, which mostly involved intraregional movement of population. The impact of resettlement on the population density has been felt more at the district and subdistrict levels. Local studies have indicated that over 75 per cent of all movements into villages involved distances of up to 10 kilometres only (Mlay 1981). This suggests that overall, even more drastic density changes have occurred at the local level over much of Tanzania, particularly in areas which were previously sparsely populated.
This concentration of population has had several important effects on land utilization. Foremost, land-use patterns have undergone considerable change. In some areas, land that was once cultivated and under permanent crops was abandoned and allowed to revert to bush when people were moved into villages. Examples of this occur in Mtwara and Coast regions where many cashew nut and coconut farms are covered with bush. In other areas, marginal land which was previously uninhabited or only used for grazing has been closely settled and the natural vegetation has been replaced by food crops such as maize, cassava, and sorghum. Second, where settlements have been established there has been a change from the traditional, extensive use of land to very intensive cultivation and livestock rearing. The establishment of village areas with a central core for dwelling units has increased distances to farms, restricted the traditional practice of shifting cultivation (since all village land is allocated for various uses), and made land a scarce commodity. The greater house-to-field distance has affected the time and energy required to reach fields, the ease of application of inputs such as manure and fertilizer, the ability to protect crops from pests and wildlife, and the cost of transportation of harvests from fields to the village. Hence, in most villages only the land adjacent to the village centre is intensely utilized. Third, with the establishment of permanent settlements, an ongoing competition for land between sedentary agriculturalists and pastoral groups has been intensified. In this struggle there is evidence to show that land that was previously exclusively used for grazing has increasingly been brought under permanent cultivation since villagization, thus pushing livestock keepers to even more marginal lands. The possibility of developing successful mixed farming near or within the village has been reduced to the extent where livestock has had to be moved away from settled areas. This has created in some areas a separation between crop production and livestock development, except in areas where stall feeding is possible (Mascarenhas 1979).
TABLE 1. Regional population density change 1967-1978
Density per sq. km
|Percantage change in density|
|West Lake (Kagera)||23.1||35.5||53 7|
Source: 1978 Population Census: Preliminary Report, Tanzania
Environmental Consequences of Villagization
Inevitably, the large-scale changes in population density and land use have exerted a strong influence on the natural environment. The extent of environmental stress created by villagization can best be appreciated by considering the changes which have taken place in two major ecological zones.
The highland areas of Tanzania constitute about 18 per cent of the national land area but because of their high resource potential they have been densely settled for many years. Currently, they carry about 40 per cent of the population. Rates of population growth in these areas are very high, about 3 per cent per annum, and despite Government efforts there has not been much outmigration. On average the population density is over 75 persons per square kilometre but some areas have densities of over 400 persons per square kilometre.
Environmental stress was evident in the mountain areas long before villagization, and studies of carrying capacity by Moore (1971) and Maro (1975) have indicated that these areas have surpassed their maximum capacity to maintain the rapidly growing population. The movement to villages occurred mainly in the surrounding lowland areas, which had in the past been devoted to wet season cultivation. However, as a consequence of villagization on the lower slopes, there is an increasing encroachment on forested areas for cultivation of cereals and other annual crops which used to be grown in the lowlands. It has been observed in many parts of Tanzania that, in general, forest utilization has traditionally been a plundering operation. Hence, large-scale clearing of forest, often by use of fire, is converting the national forest vegetation into savannah grasslands. Recently, a devastating fire on the slopes of Mount Kilimanjaro destroyed between 10,000 and 20,000 hectares of forest (Darkoh 1980).
This deleterious change in land use has also affected the land which used to be of high fertility. Deforestation has degraded the soils and increased their erodibility. Reduction in infiltration resulting from the destruction of the vegetation cover has caused a fall in the water table and increased the incidence of river flooding in the surrounding plains. Furthermore, the growing demand for arable land on the upper slopes has claimed whatever uncultivated land there used to be. Such land is usually on steep slopes and river banks. It is estimated that over 30 per cent of steep slopes in the mountain areas are being converted into fields. Landslides and mudflows usually start in such cultivated fields carrying away both soil and crop. In a study conducted by Temple and Rapp (1973) in the western Uluguru mountains, it was shown that 47 per cent of cases of landslides occurred in areas under cultivation, 46 per cent in areas under grass, often with old terraces, and only 6 per cent of cases were observed in areas under forest, bush, or rock. Although some forms of traditional soil conservation methods are still practiced, such efforts are negligible because of the rapidity with which the natural vegetation is being depleted. The result is a widespread destruction of the forest environment, including the removal of the soil cover through sheet erosion and gullying.
Lowlands and Plateaux
Lowlands and plateaux cover over 80 per cent of the land area and can be subdivided into two categories:
Together, these areas carry about 50 per cent of the population in medium to low densities.
The occurrence of pockets of low density and surplus land made these areas ideal for large-scale resettlement of the scattered population into villages. However, as in many other similar environments in the tropics, most of the land suitable for agricultural development was already under some form of use (Dasmann 1973). Consequently, the poor location of new settlements on land of inferior quality led to a sharp decline in agricultural production in the years following villagization. Moreover, villagization necessitated the intensification of land use, a practice unfamiliar to most of the people and unsuitable for such fragile environments. The result has been the spread of serious cases of soil erosion and the rapid destruction of the natural vegetation. Where relatively high population densities already existed, such as along the shores of Lake Victoria, villagization has intensified the process of environmental degradation already in operation before resettlement.
However, of greater impact on the environment has been the increased concentration of livestock around the villages, especially in the semi-arid and arid zones. Here, overgrazing is one of the more serious agents of environmental deterioration. It is not always possible to generalize about the effect of grazing for such a large part of the country because pastoral lands vary greatly in type, from semi-arid steppe of the Masailand type to the savannah grasslands of Shinyanga and Mara regions. In the semi-arid and arid areas, overgrazing has led to the destruction of the scanty vegetation, compaction of the soil surface due to trampling, and destruction of the soil structure. This in turn makes the soil more susceptible to erosion and over time converts wet season pasturelands into permanent wasteland or desert. In the better savannah grasslands, where mixed farming is common, the influence of the concentration of population and animals has damaged the natural woodland and productive grasslands and kept their regeneration in check due to constant use. This is particularly noticeable where fires are frequently being used and movement of stock is restricted.
Resettlement has also affected the wildlife ecology. Many of the game sanctuaries and national parks for which Tanzania is famous, such as Serengeti, are found in the semi-arid zone. Until recently, these savannah areas were characterized by large herds of ungulates and other grazers and browsers with their associated predators. The proximity of dense settlements to the game reserves has created a number of environmental hazards. Kurji (1977) lists these as: frequent outbreaks of fire which destroy both vegetation and animals, indiscriminate hunting for trophies, which has caused the near extinction of certain species of game, and a general destruction of the land available for pastures as more and more of this land is taken up for cultivation.
Villagization, Environmental Hazards, and Agricultural Production
Despite these negative impacts of villagization on the environment, initial large-scale movement of populations into villages was in fact carried out in response to specific environmental problems. It was felt that peasants would be better equipped to cope with problems of drought and floods and be better able to raise agricultural production if they lived together in communities than if they were scattered.
If we consider the case of Dodoma region, villagization was introduced at a time when the Government was desperately trying to reach the scattered population with famine relief during a period of extended drought. Dodoma region has a long history of droughts and famine; hence, villagization was seen as a panacea to deal with these problems. With the settlement of populations into villages, boreholes were drilled to provide water for both man and beast. New droughtresistant food crops such as millet varieties were introduced with considerable success. Many of the traditionally seminomadic Wagogo began to settle down to mixed farming and the development of viticulture, which was proving to be an attractive cash crop. In addition, for the first time, more and more villagers were within reach of such services as schools, dispensaries, and food stores.
However, over the last decade, prolonged periods of drought have affected this region, and due to a lack of manpower and funds, basic services have not been maintained. Agricultural production has, as a result, been on a steady decline. In addition, the population density has increased by 50 per cent over the last two decades. Recent livestock densities were estimated by Berry (1976) to be 1.9 hectares per livestock unit in an area where 2.5 hectares per livestock unit is considered the maximum safe density. The result has been the spreading of large tracts of wastelands, bare eroded soils, and gullying, the worst examples of which are the "bad lands" topography of Kondoa district, where innumerable gullies and sand-choked rivers cries-cross newly cultivated fields. A study recently conducted by Mascarenhas (1979) to discover the causes of environmental deterioration in Dodoma has concluded the following:
Changes in the traditional pattern of activity have brought about environmental stress. When a dense settlement is introduced into a fragile environment, pressure is brought to bear on local vegetation. Regeneration of this vegetation was easy when settlement was dispersed and fluid [but] repeated use of land by people who are no longer mobile requires a change in agricultural practices. Increased use of ground water has raised the spectre of a lowered water table, which could be a local disaster if not controlled. But by far the greatest desertification pressures stem from the livestock component of Gogo society. Fixed settlement drastically concentrates animals that once roamed over larger spaces.
Another factor which has limited the capability of villagization to cope with environmental hazards and raise agricultural production is the failure by the local population to adapt to different agricultural practices in the new environment. The case of the resettlement experience in Rufiji district, which has been described in detail by Sandberg (1974), illustrates this. Villagization in the Rufiji district was carried out in response to specific environmental hazards. Traditionally, the Warufiji lived in scattered homesteads on the flood plain and depended on the annual flooding of the Rufiji river to provide silt and water for rice cultivation. However, the floods which made agriculture flourish also caused destruction of homes and fields from year to year. It was decided, therefore, to shift the population to the higher northern banks, into villages. Two major problems resulted from this relocation of the population. Most villagers could not continue to farm on the flood plain because of the increased distance. In any case, cultivation on the flood plain was discouraged because it was feared that many villagers would want to go back to their former homes. The new environment on the higher ground is very different from the one the Warufiji were familiar with. The vegetation is different, the rains erratic, and the soils less fertile. The crops which could be grown, such as cassava, were not popular and wet rice cultivation was not possible. What was required was a gradual change from the old agricultural system practiced in the flood plain which was ecospecific. This change did not happen because of the rush to resettle the population in the shortest possible time before the next floods. The result has been a slow process of adjustment in which famine relief has had to be provided where agricultural production collapsed.
The environmental implications of land use change as illustrated above are not unique to the villagization programme. If villagization is viewed as a component of rural development, as conceived by policymakers and planners in Tanzania, it can be compared in its environmental effects to many other agricultural development projects initiated in the country. Murray-Rust (1973) carried out an in-depth study of one such development project in a catchment area called Kisongo in the rangelands of Northern Tanzania. A water reservoir was constructed at Kisongo in 1960 to provide water for stock and for human consumption in a very dry environment. This area was originally the preserve of the nomadic Masai pastoralists, who maintained an ecological balance by seasonal transhumance movement. However, the completion of the reservoir changed all that. Stock numbers increased and became concentrated on the catchment area. Sedentary cultivators in-migrated from surrounding densely populated areas and settled near the water supply. As a consequence, land use changed dramatically. The area available for grazing began to decline rapidly as more cultivated plots and permanent settlements were established. Overgrazing has become a major cause of sheet and gully erosion, both in the bare pasturelands and along stock routes. By 1975 it was estimated that the water supply would begin to dry up and the carrying capacity of the land would drop to a lower level than before the reservoir was built. The explosion of the cattle population due to overstocking would render the land barren and almost useless to man and beast.
The last, but by no means the least, factor which has had a major influence on agricultural production in villages is location. It has been observed that some of the major environmental problems in the villages stem from locational considerations. In particular, the distance factor has been a great influence on intensity of land use. Thus, in many areas environmental deterioration varies with distance from the village settlement. Evidence of soil exhaustion is more obvious near villages where the land is subject to more frequent and intensive use than farther away. Under the traditional system of shifting cultivation, the settlement would have moved before productivity of the land declined. However, villagization implied permanent settlement within a prescribed village land area. Furthermore, there was a great deal of emphasis on accessible locations, so much so that often roadside sites were preferred even when it was clear that no agricultural activity could be undertaken profitably near the settlement location. In terms of layout, most villages were structured as a concentration of dwellings, like urban settlements. Family plots had, as a result, to be some distance away from the village settlement.
Conclusion and Recommendations
The above-mentioned case studies demonstrate that agricultural development initiatives, whether large-scale national programmes, such as the one undertaken under the villagization policy, or small-scale projects, such as the water reservoir project in Arusha Region, inevitably impinge on the pattern of land use, destabilizing existing agricultural practices and causing major changes in the natural environment.
The human adjustments which are required to develop successful agriculture under changed environmental and demographic conditions brought about by development programmes do not often take place. Hence, environmental deterioration, stagnation, or even decline in yields have continued to be the experience of many agricultural development efforts. In the specific case of villagization in Tanzania, the evidence shows that the whole question of relating demographic change, caused by natural increase and resettlement, to particular ecological conditions did not receive much attention. There seems to have been an implicit assumption that once people were put into villages, development would be automatic.
Many studies of tropical agriculture confirm that, although traditional farming is primitive in its tools and scale of operation, in terms of its agricultural practices, it is the most suited to fragile environmental resources (Knight 1976). These practices were developed over many generations of trial and error and stood the test of time. In the restricted mountainlands and river basin, intensive care of the land resources has maintained high yields. In the savannah plains and plateau, the practice of slash-and-burn shifting cultivation utilizes the great supply of nutrients available in tropical vegetation. Long periods of fallow with short periods of farming allow for vegetation regeneration and recovery of soil fertility. However, rapid rates of population growth and aspirations for an improved standard of living have combined to render such age-long practices ineffective or impracticable. The introduction of development projects, innovative technology, and new agricultural practices has often brought temporary relief, as in the case of villagization. Long-term results have failed to meet expectations, however.
There are many lessons to be learnt from the Tanzanian experience. First is the need to identify possible environmental consequences of changes in land use occasioned by various pressures before they arise. Second, specific solutions to deal with current and future land-use problems should take into consideration those practices with which most farmers are familiar before introducing new ones. Third is the need to monitor development projects designed to meet a specific need with a view to identifying side-effects that may aggravate the original problem.
Too much emphasis has been placed on the fragility of tropical environments, including climatic changes, as the main cause of agricultural decline. Research has shown that different land-use practices have a greater influence on the level of productivity or deterioration of land than the nature of the land resource. For example, Jackson (1977) has shown that differences in soil erosion due to differences in the management of the same soil are greater than the differences in erosion of different soils under the same management. What these lessons suggest is that there is a need to adopt an integrated approach to land-use planning and implementation, backed by research.
In terms of its conceptualization, the villagization policy in Tanzania was intended to be an integrated, holistic approach to rural development. It was a settlement development programme, an agricultural development and resource management programme, as well as a population redistribution strategy. In addition, it was a welfare programme aimed at equitable provision and distribution of welfare and development services. All these objectives were supposed to be interrelated. However, in the implementation, only the welfare aspect was given emphasis. Resettlement was considered to be all that was necessary to achieve the other objectives of villagization. Hardly any research was undertaken prior to implementation and results from past resettlement experiences were rarely considered in launching new operations.
After a review of many of the mistakes committed in the implementation of villagization, some measures for their rectification have been identified. Two of the remedies which are currently being emphasized are: relocation of farmsteads and development of satellite villages. The first remedy involves, where there is surplus land, shifting each household to a sizeable plot of land, usually 3 hectares, in such a way that each farmstead will be surrounded by its farm. This measure has the advantage of reducing the distance to the farm while minimizing the environmental hazards of concentrated settlements. Since the economy of most villages is still dependent on production from household plots rather than the communal farm, this measure has also motivated villagers to adopt land-use management and intensive techniques on their plots, which are within easy reach. To encourage villagers to shift their homes to new sites, loans and credit facilities have been made available for construction of houses. In some regions, building brigades are trained using village youths who are subsequently employed by the village government to construct houses for individual families in the new locations. All these are costly undertakings and there is still some reluctance on the part of people to move yet again. The second remedy has been to encourage the growth of satellite villages, particularly in areas where mixed farming or export crop production require large tracts of land. In such cases, the village settlement is left intact as the permanent residence while temporary settlements are developed away from the village, in areas of extensive farming. These satellite settlements may be seasonally inhabited by part or all of the family labour. This strategy has the obvious advantage of providing the household with a temporary home during peak growing and harvest periods and reducing the travel distance to the farm or pasture land. More time and labour can therefore be devoted to the management of the land. In the long run, such satellite villages may grow to become permanently inhabited and to possess a complete economy of their own, independent of the village from which they sprang.
Both approaches to the problem of concentration of settlements have the added advantage of affording more flexibility in terms of change in agricultural practices and in the introduction of innovation in an integrated manner. Examples from other parts of the world where nucleation has predominated in the past suggest that the present spontaneous tendency is to modify the pattern of rural settlement and land holding in such a manner that the distance separating the farmstead from the lands cultivated is reduced to something in the order of one or two kilometres, if the farmstead is not actually on the farm (Chisholm 1961). However, in the case of Tanzania, achieving an ecologically balanced land-use system will depend on the extent to which the following steps are adopted in the process of adjustment:
In the last analysis, the objective of these measures should be to develop an integrated land-use mix of agriculture and livestock activities which has the greatest returns from different agroecological zones while sustaining the best utilization and conservation of land and water resources.
Barker, D.E. 1979. "The Debate on Rural Socialism in Tanzania.'' In B.U. Mwansasu and C. Pratt, Towards Socialism in Tanzania. Tanzania Publishing House. Dar es Salaam.
Berry, L. 1976. "Dynamics and Process of Change." In C.G. Knight and J.L. Newman, eds., Contemporary Africa: Geography and Change. Prentice-Hall, Englewood Cliffs, N.J.
Chisholm, M. 1961. Rural Settlement and Land Use. Hutchinson University Library, London.
Darkoh, M.N.K. 1980. "Man and Desertification in Tropical Africa." Inaugural Lecture Series. Dar es Salaam University Press, Dar es Salaam.
Dasmann, R.F. et al. 1973. Ecological Principles for Economic Development. John Wiley & Sons, London.
Jackson, l.J. 1977. C/imate, Water and Agriculture in the Tropics. Longman, London.
Knight, C.G. 1976. "Prospects for Peasant Agriculture." In C.G. Knight and J.L. Newman, eds., Contemporary Africa: Geography and Change. Prentice-Hall, Englewood Cliffs, N.J.
Kurji, F. 1977. "Human Population Densities and the Changes around the Conservation Areas of Tanzania." BRALUP Research Paper No. 51. University of Dar es Salaam, Dar es Salaam.
McHenry, D.E. 1979. Tanzania's Ujamea Villages. Institute of International Studies, University of California, Berkeley. Calif.
Maro, P.S. 1975. "Population Growth and Agricultural Change in Kilimanjaro 1920- 1970." BRALUP Research Paper No. 40. University of Dar es Salaam, Dar es Salaam.
Maro, P.S., and W.F.I. Mlay. 1982. "Population Redistribution in Tanzania." In L. Kosinsky and J.l. Clarke, eds., Population Redistribution in Africa. Heinemann, London.
Mascarenhas, A.C. 1977. "Resettlement and Desertification: the Wagogo of Dodoma District, Tanzania." Economic Geography, 53:4.
__________. 1979. "After Villagisation What?" In B.U. Mwansasu and C. Pratt, eds., Towards Socialism in Tanzania. T.P.H., Toronto.
Mlay, W.F.I. 1981. "The Spatial Impact of Decentralisation: Its Significance for Rural Transformation in Tanzania." In H. OkothOgendo, ea., Approaches to Rural Transformation in Eastern Africa. Bookwise, Ltd., Nairobi.
Moore, J. 1971. "Rural Population Carrying Capacities for the Districts of Tanzania." BRALUP Research Paper No. 18. University of Dar es Salaam, Dar es Salaam.
Moss, R.P. 1969. "The Ecological Background to Land Use Studies in Tropical Africa, with Special Reference to the West." In M.F. Thomas and G.W. Whittington, eds., Environment and Land Use in Africa. Methuen, London.
Murray-Rust, D.H. 1973. "Soil Erosion and Reservoir Sedimentation in a Grazing Area West of Arusha, Northern Tanzania." In A. Rapp et al., "Studies of Soil Erosion and Sedimentation in Tanzania." BRALUP Monograph 1. University of Dar es Salaam, Dar es Salaam.
Nyerere, J.K. 1967. Freedom and Socialism. Oxford University Press, Dar es Salaam.
Sandberg, A. 1974. "Socio-economic Survey of Lower Rufiji Flood Plain." BRALUP Research Paper No. 34. University of Dar es Salaam, Dar es Salaam.
Tanzania. 1978. Population Census: Preliminary Report. Dar es Salaam.
Temple, P.H., and A. Rapp. 1973. "Landslides in the Mgeta Area, Western Uluguru Mountains, Tanzania." In A. Rapp et al., "Studies of Soil Erosion and Sedimentation in Tanzania." BRALUP Monograph 1. University of Dar es Salaam, Dar es Salaam.
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