Browsing by Author "Ssebuggwawo, Vincent"

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    Application of a semi-distributed physically based, hydrologic model using remotely sensed data and GIS (DPHM-RS) to Sezibwa catchment in Uganda.
    (University of Dar es Salaam, 1996) Ssebuggwawo, Vincent
    The main objectives of this study were to investigate if the DPHM-RS model is an effective tool for hydrologic impact studies of land use changes. And also to investigate if the model can effectively use the available spatially distributed, hydrological information retrieved from remotely sensed data and available hydrometeorological data in modelling basin scale hydrologic processes. In the study, daily data for river flows, minimum temperatures, maximum temperatures, sunshine hours, wind speed, relative humidity, rainfall, were processed to the Environment Canada standard format. Spatially distributed data namely, basin mask, slope of each cell in the basin mask, elevation grid, topographic soil index, flow accumulation grid, flow direction grid were derived from the digital elevation model. The leaf areal index for each cell was derived from the NOAA-AVHRR data channel 6. he DPHM-RS has an inbuilt mechanism to automatically optimise its parameters. Optimising the model to R. Sezibwa data failed. Hence the discharge series that resulted from this set of data could not be used for further analysis. In order to investigate if the model can be used to study the impact of land use on the hydrology of the river, sensitivity tests were carried out on the model. Paddle river data was used for this test because the model had previously been optimised for this data set. The paired two sample test was used to test the hypothesis that the mean of the differences in discharge between the Estimated and test discharge were zero. The tests to investigate the sensitivity of the model were carried out by replacing some of the land use parameters with those of other land use classes. The model was found neither suitable for the daily hydrometeorological data nor the spatial data at 1 km resolution and different projections. The model could not sufficiently reflect the land use changes on the resulting discharges. More tests on other catchments were recommended.