Evaporation Estimation of Rift Valley Lakes: Comparison of Models

Authors

Assefa M. Melesse, Department of Earth and Environment, Florida International UniversityFollow
Wossenu Abtew, South Florida Water Management District
Tibebe Dessalegne, BEM Systems Inc.

Date of this Version

12-1-2009

Document Type

Article

Abstract

Evapotranspiration (ET) accounts for a substantial amount of the water flux in the arid and semi-arid regions of the World. Accurate estimation of ET has been a challenge for hydrologists, mainly because of the spatiotemporal variability of the environmental and physical parameters governing the latent heat flux. In addition, most available ET models depend on intensive meteorological information for ET estimation. Such data are not available at the desired spatial and temporal scales in less developed and remote parts of the world. This limitation has necessitated the development of simple models that are less data intensive and provide ET estimates with acceptable level of accuracy. Remote sensing approach can also be applied to large areas where meteorological data are not available and field scale data collection is costly, time consuming and difficult. In areas like the Rift Valley regions of Ethiopia, the applicability of the Simple Method (Abtew Method) of lake evaporation estimation and surface energy balance approach using remote sensing was studied. The Simple Method and a remote sensing-based lake evaporation estimates were compared to the Penman, Energy balance, Pan, Radiation and Complementary Relationship Lake Evaporation (CRLE) methods applied in the region. Results indicate a good correspondence of the models outputs to that of the above methods. Comparison of the 1986 and 2000 monthly lake ET from the Landsat images to the Simple and Penman Methods show that the remote sensing and surface energy balance approach is promising for large scale applications to understand the spatial variation of the latent heat flux.

Comments

Originally published in Sensors; licensee MDPI, Basel, Switzerland.

Creative Commons License

This work is licensed under a Creative Commons Attribution 3.0 License.

Recommended Citation

Melesse, A.M.; Abtew, W.; Dessalegne, T. Evaporation Estimation of Rift Valley Lakes: Comparison of Models. Sensors 2009, 9, 9603-9615.