Browsing by Author "Chanda, Dau"

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    Estimation of small reservoir capacities and water demand using sentinel 2a satellite imagery: a case study of Kalomo catchment.
    (University of Dar es Salaam, 2018) Chanda, Dau
    Improving access to water resources for various uses can be enhanced by knowing what is available at any particular time, hence making it easier for policymakers and water resources managers to make informed decisions. This can be made possible through the use of remote sensing and GIS. The objective of this study was to develop a model equation for estimating storage capacities of small reservoirs as a function of their remotely sensed surface areas for Kalomo catchment, Southern Province of Zambia. The Modified Normalized Difference Water Index (MNDWI) was used to map water bodies from Sentinel 2 datasets at a fine resolution of 10m. It involved the downscaling of 20m SWIR Band (Band 11) by using a 10m resolution NIR band (Band 8) as the PAN-like Band. The water bodies were extracted using the Otsu segmentation technique. The surface areas obtained showed no significant difference with those of the Bathymetric Survey at 95% confidence level using the student t test (14) =0.78 and a p value of 0.45. The model equation developed from the power relationship between surface areas and volumes of the 14 small reservoirs studied had a coefficient of determination (R2) of 92% from the regression analysis. Using the model equation small reservoir storage capacity for the month of May 2017 at full supply level was estimated to be 17, 954, 600m3 with a total of 288 small reservoirs mapped. This model equation gives similar results to the model equation developed by Sawunyama for the Limpopo River Basin in Zimbabwe.