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Mapping daily evapotranspiration and dryness index in the East African highlands using MODIS and SEVIRI data

Sun, Z.; Gebremichael, M.; Ardö, Jonas LU and de Bruin, H. A. R. (2011) In Hydrology and Earth System Sciences 15(1). p.163-170
Abstract
Routine information on regional evapotranspiration (ET) and dryness index is essential for agricultural water management, drought monitoring, and studies of water cycle and climate. However, this information is not currently available for the East Africa highlands. The main purpose of this study is to develop (1) a new methodology that produces spatially gridded daily ET estimates on a (near) real-time basis exclusively from satellite data, and (2) a new dryness index that depends only on satellite data and weather forecast data. The methodology that calculates daily actual ET involves combining data from two sensors (MODIS and SEVIRI) onboard two kinds of platforms (Terra - polar orbit satellite and MSG - geostationary orbit satellite).... (More)
Routine information on regional evapotranspiration (ET) and dryness index is essential for agricultural water management, drought monitoring, and studies of water cycle and climate. However, this information is not currently available for the East Africa highlands. The main purpose of this study is to develop (1) a new methodology that produces spatially gridded daily ET estimates on a (near) real-time basis exclusively from satellite data, and (2) a new dryness index that depends only on satellite data and weather forecast data. The methodology that calculates daily actual ET involves combining data from two sensors (MODIS and SEVIRI) onboard two kinds of platforms (Terra - polar orbit satellite and MSG - geostationary orbit satellite). The methodology is applied to the East African highlands, and results are compared to eddy covariance measurements at one site. Results show that the methodology produces ET estimates that accurately reproduce the daily fluctuation in ET but tends to underestimate ET on the average. It is concluded that the synergistic use of the polar-orbiting MODIS data and the geostationary-orbiting SEVIRI data has potential to produce reliable daily ET, but further research is needed to improve the accuracy of the results. This study also proposes an operational new dryness index that can be calculated from the satellite-based daily actual ET estimates and daily reference ET estimates based on SEVIRI data and weather forecast air temperature. Comparison of this index against ground measurements of daily actual ET at one site indicates that the new dryness index can be used for drought monitoring. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Hydrology and Earth System Sciences
volume
15
issue
1
pages
163 - 170
publisher
European Geophysical Society
external identifiers
  • wos:000286723600013
  • scopus:78751524463
ISSN
1607-7938
DOI
10.5194/hess-15-163-2011
project
BECC
language
English
LU publication?
yes
id
c1e69b90-9177-410e-bdb3-2f8af7b71bb4 (old id 1763523)
alternative location
http://www.hydrol-earth-syst-sci.net/15/163/2011/hess-15-163-2011.pdf
http://www.hydrol-earth-syst-sci.net/15/163/2011/
date added to LUP
2011-07-14 10:33:50
date last changed
2017-06-11 03:10:31
@article{c1e69b90-9177-410e-bdb3-2f8af7b71bb4,
  abstract     = {Routine information on regional evapotranspiration (ET) and dryness index is essential for agricultural water management, drought monitoring, and studies of water cycle and climate. However, this information is not currently available for the East Africa highlands. The main purpose of this study is to develop (1) a new methodology that produces spatially gridded daily ET estimates on a (near) real-time basis exclusively from satellite data, and (2) a new dryness index that depends only on satellite data and weather forecast data. The methodology that calculates daily actual ET involves combining data from two sensors (MODIS and SEVIRI) onboard two kinds of platforms (Terra - polar orbit satellite and MSG - geostationary orbit satellite). The methodology is applied to the East African highlands, and results are compared to eddy covariance measurements at one site. Results show that the methodology produces ET estimates that accurately reproduce the daily fluctuation in ET but tends to underestimate ET on the average. It is concluded that the synergistic use of the polar-orbiting MODIS data and the geostationary-orbiting SEVIRI data has potential to produce reliable daily ET, but further research is needed to improve the accuracy of the results. This study also proposes an operational new dryness index that can be calculated from the satellite-based daily actual ET estimates and daily reference ET estimates based on SEVIRI data and weather forecast air temperature. Comparison of this index against ground measurements of daily actual ET at one site indicates that the new dryness index can be used for drought monitoring.},
  author       = {Sun, Z. and Gebremichael, M. and Ardö, Jonas and de Bruin, H. A. R.},
  issn         = {1607-7938},
  language     = {eng},
  number       = {1},
  pages        = {163--170},
  publisher    = {European Geophysical Society},
  series       = {Hydrology and Earth System Sciences},
  title        = {Mapping daily evapotranspiration and dryness index in the East African highlands using MODIS and SEVIRI data},
  url          = {http://dx.doi.org/10.5194/hess-15-163-2011},
  volume       = {15},
  year         = {2011},
}