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| dc.contributor.author | Amera, Wendale | |
| dc.date.accessioned | 2020-06-12T07:07:41Z | |
| dc.date.available | 2020-06-12T07:07:41Z | |
| dc.date.issued | 2019-06 | |
| dc.identifier.uri | http://hdl.handle.net/123456789/11042 | |
| dc.description.abstract | The aim of this study was to estimate the actual evapotranspiration using soil water balance method and the remote sensing-based SEBS model at Koga irrigation Scheme. First, the soil water balance method was conducted in 60 ha irrigation block. Field work was carried out in the study area for ground truth collection including irrigation and soil moisture content. Irrigation water entered to the block was measured at each inlet using floating method of discharge measurement and TDR instrument was applied for measuring soil moisture content at three selected sites. After collecting these parameters, water balance approach is conducted to estimate the actual evapotranspiration. Second, spatial and temporal variations of actual evapotranspiration for Koga irrigation scheme was estimated using surface energy balance system (SEBS) model. The study has utilized four cloud free MODIS (TERRA) level 1B images for the dry irrigation seasons. the ILWIS software has been was used for developing the energy balance model. In the preprocessing phase the MODIS raw data has been converted to reflectance and radiance, brightness temperature is estimated, water vapor is estimated using ratio techniques and the atmospheric correction in the visible and NIR band is done using SMAC model. After these, the biophysical parameters for SEBS model are estimated. Then evapotranspiration and energy fluxes are estimated from the combination of these data sets with meteorological data. The study reveals that there is a satisfactory correlation (r2 = 0.521) between the water balance and the FAO-PM evapotranspiration during the time of observations. Results have showed that in study irrigation block at the irrigation season water balance yields actual ET values that range from 3.82 to 10.22 mm day-1, though the highest value is extremely overestimated. At the same season, SEBS model gives mean ET values range from 3.789 to 4.665 mm day-1. Undertaken comparative analysis showed that SEBS model overestimate ET value than FAO-PM. SEBS model obtained proxy values with FAO-PM on both daily (r2= 0.852) and monthly (r2= 0.643) scale. | en_US |
| dc.language.iso | en | en_US |
| dc.subject | Engineering Hydrology | en_US |
| dc.title | Estimation of Actual Evapotranspiration Using Soil Water Balance Method and Surface Energy Balance System Model At Koga Irrigation Scheme, Ethiopia | en_US |
| dc.type | Thesis | en_US |
