Development of the GCOM-C global ET_index estimation algorithm

• TASUMI Masahiro

  Department of Forest and Environmental Sciences, Faculty of Agriculture, University of Miyazaki

• KIMURA Reiji

  Arid Land Research Center, Tottori University

• ALLEN Richard G.

  Water Resources Engineering, University of Idaho

• MORIYAMA Masao

  Graduate School of Engineering, Nagasaki University

• TREZZA Ricardo

  Water Resources Engineering, University of Idaho

Bibliographic Information

Other Title

• Development of the GCOM-C global ETindex estimation algorithm

Abstract

Freshwater resources management has become a primary global issue. Improved management of agricultural water is important because agriculture is the dominant user of fresh water. Estimation of evapotranspiration (ET) using satellite imagery is regarded as an effective tool for improving agricultural water management.<br>　This paper presents the progress made in the development of a global Evapotranspiration-Index (ET_index) estimation algorithm that is applicable to Global Change Observation Mission-Climate (GCOM-C) satellite observation. The algorithm computes an ET-related indicator that is termed the ET_index. The primary input data are thermal observation data from the satellite and near-surface wind speed data from a global climate model. The ET_index is equivalent to the crop coefficient, which has been applied widely for agricultural and irrigation water management around the globe. As a result, the ET_index maps have congruency with traditional agricultural water management methodologies, although the application targets of the ET_index are not limited to irrigation or agriculture.<br>　The algorithm estimates the ET_index by analyzing the relative position of actual surface temperature between two extreme surface conditions (wet and dry conditions). Estimation of the wet and dry surface temperatures is a key component of the algorithm. The developed model represents the wet and dry surface temperatures with less than 1°C bias and less than 6°C random error in Shenmu, China. The simple structure of the algorithm is designed to process global data with limited computational load. The final product is a 16-day, cloud-free global ET_index map having spatial resolution equal to that of GCOM-C thermal observation. Daily actual ET is estimated from the global ET_index map using local or global weather datasets that include cloudy and rainy days.

Journal

• Journal of Agricultural Meteorology

  Journal of Agricultural Meteorology 72 (2), 85-94, 2016

  The Society of Agricultural Meteorology of Japan

Keywords

• Crop coefficient
• Evapotranspiration
• GCOM-C
• Surface temperature
• Water management

Details

• CRID: 1390282679645250176
• NII Article ID: 130005156596
• NII Book ID: AN00200732
• DOI: 10.2480/agrmet.d-15-00022
• ISSN: 18810136
• ISSN: 00218588
• NDL BIB ID: 027374236
• Web Site: http://id.ndl.go.jp/bib/027374236
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I027374236
• Web Site: https://www.jstage.jst.go.jp/article/agrmet/72/2/72_D-15-00022/_pdf
• Text Lang: en
• Data Source:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
• Abstract License Flag: Disallowed