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Accueil du site → Master → Etats Unis → 2014 → Evaluation of a surface energy balance method based on optical and thermal satellite imagery to estimate root-zone soil moisture

COLORADO STATE UNIVERSITY (2014)

Evaluation of a surface energy balance method based on optical and thermal satellite imagery to estimate root-zone soil moisture

Alburn, Nathan E.

Titre : Evaluation of a surface energy balance method based on optical and thermal satellite imagery to estimate root-zone soil moisture

Auteur : Alburn, Nathan E.

Université de soutenance : COLORADO STATE UNIVERSITY

Grade : Master of Science (MS) 2014

Résumé
Various remote-sensing methods are available to estimate soil moisture, but few address the fine spatial resolutions (e.g., 30 m grid cells) and root-zone depth requirements of agricultural and other similar applications. One approach that has been previously proposed to estimate fine-resolution soil moisture is to first estimate the evaporative fraction from an energy balance that is inferred from optical and thermal remote-sensing images (e.g., using the ReSET algorithm) and then estimate soil moisture through an empirical relationship to evaporative fraction. A similar approach has also been proposed to estimate the degree of saturation. The primary objective of this study is to evaluate these methods for estimating soil moisture and degree of saturation, particularly for a semiarid grassland with relatively dry conditions. Soil moisture was monitored at twenty-eight field locations in southeastern Colorado with herbaceous vegetation during the summer months of three years. In-situ soil moisture and degree of saturation observations are compared with estimates calculated from Landsat imagery using the ReSET algorithm. The in-situ observations suggest that the empirical relationships with evaporative fraction that have been proposed in previous studies typically provide overestimates of soil moisture and degree of saturation in this region. However, calibrated functions produce estimates with an accuracy that may be adequate for various applications. The estimates produced by this approach are more reliable for degree of saturation than for soil moisture, and PREVIEW iii the method is more successful at identifying temporal variability than spatial variability in degree of saturation for this region

Mots clés : Root-zone, Remote-sensing, Applied sciences, Semiarid grassland, Remote sensing, Civil engineering, Arkansas valley, Degree of saturation, Soil sciences, Evaporative fraction, Biological sciences, Earth sciences, Hydrologic sciences

Présentation (Gradworks)

Page publiée le 13 mars 2015, mise à jour le 24 décembre 2017