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Several review studies are found in the areas of geology and geomorphology. These include summaries of the geology of Tanganyika, e.g. Harris 1961 and Quennel et al. 1956 1960; geomorphology and sources of
beach sediment, e.g. Arthurton 1992, 1996; reviews on the coastal erosion problem in Tanzania, e.g. Kaaya 1996, Mruma 1996. There are also a few review studies on climate change. These include Thompson 1965
on the weather of East Africa. Review studies in coastal processes and engineering include those of Dubi 1998 on ocean wave measurement systems and analysis for climate evaluation, Bryceson and Stoemer 1980 on
recommendations for beach erosion control at Silversands Hotel. Schiller and Bryceson also reviewed the problem of beach erosion in the Dar es Salaam area. On resource utilisation, Linden and Lundin 1996 gave a review of
various issues including the status and underlying causes of coastal and marine resources degradation. Recommendations for control of coastal erosion in Tanzania were also given. Pattantyus 1988 reviewed the
problem of beach erosion in the northern parts of Dar es Salaam area.
1.4 RESEARCH METHODOLOGY
Research methodology has been varied depending on the field of study. Field research methods also depend on the parameters being investigated, instrumentation and data analysis tools.
1.4.1 Sampling aspectsparameters
In geology and geomorphology, Cilek 1976 investigated heavy mineral content in Tanzania beach sand deposits. Since beaches are affected by hydrodynamic factors waves, tides and currents, heavy mineral content on beaches
is depends on the coastal processes. Cooke 1974 studied geomorphic features of the Tanga coastal zone and suggested a scheme of alternating sea levels phases in the geologic past. Kaaya and Boenigk 1986 also studied
modes of sedimentation in relation to terrace formation and sea level rise along the Tanzania coastline and only recently, Shaghude and Wannas 1995 put together the sediment distribution and transport in the Zanzibar
channel.
In Climate Change, Dubi 1998 and Lwambuka 1992 evaluated extreme wind speeds and return periods from available wind data. Nieuwolt 1973 investigated the general circulation of the land and sea breezes along the
Tanzanian East Coast. He also studied the effects of these winds, especially the sea breeze on the physiological temperature conditions near the coast. Also, Mwandosya et al. 1998 studied the impact of climate change on the
coastal zone due to the doubling of CO
2
and a sea level rise of 0.5m and 1.0m. In Hydrology, Shayo 1979 studied the best time-discharge relationship of the dam in connection with flood control, agricultural and
hydropower production on the Rufiji river. Temple and Sundborg 1972 studied the water and sediment discharge characteristics of the river and their influence on the morphology and soils of the lower flood plain and delta. In
Hydrography, sampling parameters have included temperature-salinity relationship and distributions, seasonal variations of thermal characteristics and currents in the Zanzibar Channel Harvey, 1977 and Newell, 1957, 1959.
Nearshore bathymetry has been studied by Shaghude 1996 and Dubi and Nyandwi, 1999. On resource utilisation, Mwaiseje 1973 examined ecological parameters such as times of low and high tides, beach profiles,
substrate particle sizes, burrowing forms, flora and fauna; and pattern distribution of animals and plants in Dar es Salaam beaches. Sedimentation rates on corals have been studied by Nzali et al. 1998 while Semesi et al. 1998
studied mangrove and fisheries resources, salt production and tourism. In Coastal Processes, investigated parameters include currents, waves, bathymetry, grain size distribution and profiles Dubi and Nyandwi, 1999;
Hemed, 1987; Lwiza, 1987; Fay, 1992, ocean wave measurement systems and wave parameters Dubi, 1998, sediment transport and optimal design Edet, 1991, Mushala 1978 and Shufaa and Betlem 1996.
1.4.2 Instrumentation and techniques of sampling and data collection
On geology and geomorphology, instrumentation and sources of information have included drills Cilek, 1976, admiralty charts and survey levels Cooke, 1974, aerial photographs Mushala,1978, Shufaa and Betlem, 1996,
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topographic maps, stereoscopes, sieves, diffractometer and bromoform Kaaya and Boenigk, 1986. Techniques of sampling have included air survey, drilling and shallow pits Cilek, 1976. On climate change, instrumentation has
included rotating cup anemometers for measuring wind speeds; theodolite and aerial photos Pethick and Spencer, 1990, General Circulation Models Mwandosya et al., 1998. On hydrology, Temple and Sundborg 1973 used
data collected using gauges and sediment samplers. Shayo 1979 and Chen 1996 mathematical modelling techniques to study river water discharge and sediment load prediction. On resource utilisation studies, Mwaiseje
1973 used automatic level, graduated pole and improvised syringe to study ecological parameters. Nzali et al. 1998 used terracota tiles, steel racks, thermometer, secchi disc, sediment traps and dissecting microscope to
study coral recruitment and sedimentation rates. On coastal processes, instrumentation included self recording current meters RCMs, wave gauges, surveyor’s level, echosounders, and global positioning systems Dubi and
Nyandwi, 1999. Earlier works used drogues, wave staffs and visual observation Lwiza, 1987.
1.4.3 Data analysis methods and procedure
Methods of data analysis varied much the same as the data collection methods. In geology and geomorphology studies, Cilek 1976 used laboratory methods for the separation of heavy minerals from light minerals. The
minerals of heavy fraction were divided into five groups depending upon their electrical and magnetic properties. Kaaya and Boenigk 1986 dried and later sieved clay-free loose sands, while clayey sands were wet sieved using
a whole phi interval from –2 phi to 4 phi. Graphical methods were used to present the cumulative weight percentages. Heavy minerals were separated from light minerals using bromoform. Clay minerals were analysed
using a diffractometer. In Hydrology studies, Temple and Sundborg 1972 used graphical methods and hypsographic analysis methods to present data. In Climate Change studies, probability distribution functions have
been used to evaluate extreme wind speeds and return wind speeds Dubi, 1998 and Lwambuka, 1992.
In Hydrography studies graphical methods have mostly been used while in Coastal Processes, computer and mathematical methods have been used e.g. Dubi and Nyandwi, 1999. In Resource Utilisation, laboratory and
graphical methods have been used to find ecological parameters. Table 2 shows some of the research methodologies applied in different studies.
1.5 Quality, usefulness and reliability of datainformation
