Abstract:
Application of remote sensing (RS) and geographic information system (GIS) techniques in
hydrology is today one of the most effective approaches for possible dam site selection. Digital
elevation models (DEMs) as well as layers produced by RS and GIS provide a solid geospatial
data foundation, which is suitable for selecting the possible dam sites for hydro power stations.
The study aimed to demonstrate the use of remote sensing and geographic information system in
dam site selection within the context of a catchment scale. Google Earth and Enhanced Thematic
Mapper Plus (ETM+) from LANDSAT 7 were used to acquire the satellite imageries of the
possible areas. Using high resolution imageries from the Advanced Space borne Thermal
Emission and Reflection Radiometer (ASTER 30m), a Digital Elevation Model (DEM) was
developed with Surfer 8 to characterise the catchment area. ArcGIS 10.0 was used to develop the
flow direction, flow length and flow accumulation maps. The flow direction, flow accumulation
and flow length maps were combined with land use map to produce the major and mini hydro
power dam maps with the use of map algebra in ArcGIS 10.0 software. The results shows that
the areas with main hydro-power stations are areas that are closest to the main prominent rivers
with their several tributaries and are located on low relief while areas with mini hydro-power
stations are far away from the main rivers. The study area has three prominent rivers (Rivers
Ogbese, Owena and Ose) and their several tributaries (Rivers Ala, Elegbin and Ureje). The
results also shows that the areas in red colour represents the areas that are suitable for major
hydro-power stations while the areas in yellow colour represent the areas that are suitable for
mini hydro-power stations. The used of remotely sensed data and ArcGIS 10.0 software provide
an effective approach to develop accurate possible dam sites with a minimum amount of time,
effort, and cost. This approach creates easily read and accessible charts and maps that facilitate
the identification of possible areas and also can be used effectively in planning. |
