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Document Estimating reference evapotranspiration using remote sensing and empirical models in a region with limited ground data availability in Kenya

Evapotranspiration is an important component of the hydrological cycle and its accurate quantification is crucial for the design, operation and management of irrigation systems. However, the lack of meteorological data from ground stations is a clear barrier to the proper management of water resources in poor countries, increasing the risks of water scarcity and water conflicts. In the presented study, three temperature based ET models are evaluated in the Taita Hills, Kenya, which is a particularly important region from the environmental conservation point of view. The Hargreaves, the Thornthwaite and the BlaneyeCriddle are the three tested methods, given that these are the most recommended approaches when only air temperature data are available. Land surface temperature data, retrieved from the MODIS/Terra sensor are evaluated as an alternative input for the models. One weather station with complete climate datasets is used to calibrate the selected model using the FAO-56 PenmaneMonteith method as a reference. The results indicate that the Hargreaves model is the most appropriate for this particular study area, with an average RMSE of 0.47 mm d1, and a correlation coefficient of 0.67. The MODIS LST product was satisfactorily incorporated into the Hargreaves model achieving results that are consistent with studies reported in the literature using air temperature data collected in ground stations.

Creator Eduardo Eiji Maeda a, * , David A. Wiberg b , Petri K.E. Pellikka a a Department of Geosciences and Geography, University of Helsinki, Gustaf Hällströmin katu 2, 00014, Helsinki, Finland b Land Use Change and Agriculture Program at the International Institute for Applied Systems Analysis (IIASA), Laxenburg, Austria (email: eduardo.maeda@helsinki.fi)
Publisher Eduardo Eiji Maeda a, * , David A. Wiberg b , Petri K.E. Pellikka a a Department of Geosciences and Geography, University of Helsinki, Gustaf Hällströmin katu 2, 00014, Helsinki, Finland b Land Use Change and Agriculture Program at the International Institute for Applied Systems Analysis (IIASA), Laxenburg, Austria
Type of document Report
Rights Public
File link http://www.helsinki.fi/geo/research/publications/Taita_Hills_publications/Peer_reviewed_articles/Maeda_E_et_al_2011_Estimating%20reference%20evapotranspiration%20using%20remote%20sensing%20.pdf
File link local Maeda_E_et_al_2011_Estimating reference evapotranspiration using remote sensing .pdf (PDF, 1442 Kb)
Source of information @Elsevier 2010
Keyword(s) evapotranspiration, MODIS, remote sensing
Subject(s) AGRICULTURE , HYDRAULICS - HYDROLOGY , INFORMATION - COMPUTER SCIENCES , METHTODOLOGY - STATISTICS - DECISION AID , WATER DEMAND
Relation http://www.emwis.org/topics/fol573816
Geographical coverage Kenya
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