Estimating Actual Evapotranspiration using the SEBAL Model for the Atankwidi and Afram Catchments in Ghana
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Date
2012-01
Journal Title
Journal ISSN
Volume Title
Publisher
International Journal of Applied Agricultural Research
Abstract
Evapotranspiration (ET) monitoring has important implications on global and
regional climate modelling. It is important for the hydrological cycle and
assessment of environmental stress that affects ecosystems. Accurate
measurement and estimation of ET is a basic input in computing water balance
and to estimate water availability and requirements. Most methods for ET
computation can only provide point estimates of ET for a specific location and
fails to provide ET on a regional scale and makes it inadequate for proper
water resource management. In this study, the Surface Energy Balance
Algorithm for Land (SEBAL) model is used to estimate actual
evapotranspiration (ETa) for different land use/cover types (closed woodlands,
gallery forests, open woodlands, farmlands, water bodies, barelands, rocky
areas and built-up areas) for the Atankwidi and Afram catchments in the Volta
Basin of Ghana. It was found that the SEBAL model can successfully estimate
and distinguish ETa among different land use/cover types in the two
catchments. SEBAL estimates of ETa varied from 1.4 to 7.30 mm/day across
the different land use/cover types. The range of CVs for ETa was 5−75%
across the different land use/cover types for the two catchments. The results
confirms SEBAL is an appropriate algorithm for estimating ETa using satellite
images in catchments similar to that of the study areas, where few or no
ground measurements are available.
Description
This article is published in International Journal of Applied Agricultural Research
Keywords
Evapotranspiration, Landsat, Land use, Remote sensing, SEBAL, Model
Citation
International Journal of Applied Agricultural Research, Volume 6 Number 2 (2011) pp. 177-193