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Accueil du site → Doctorat → Australie → 2001 → Monitoring regional moisture availability using AVHRR data : its application for drought assessment

Australian National University (2001)

Monitoring regional moisture availability using AVHRR data : its application for drought assessment

McVicar, Timothy Richard.

Titre : Monitoring regional moisture availability using AVHRR data : its application for drought assessment

Auteur : McVicar, Timothy Richard

Université de soutenance : Australian National University

Grade : Doctor of Philosophy (PhD) 2001

Résumé partiel
The objective of this research is to improve decision making for drought assessment. One of the underlying issues with current methods for assessing drought is that the regional measures are spatially uncertain due to using spatially isolated measurements as the basis of the decision making process. In this research the development of an objective method is based heavily on remotely sensed data, and other environmental data, which allow drought and its impacts to be assessed. Drought assessment involves far more than measurements of moisture availability, plant condition or measures of rainfall effectiveness. However, the provision of consistent and objective indices and measurements is basic to drought monitoring and assessment. An underlying ethos when developing the information system has been that only readily available data be used. This means that the approach developed here is suited to application for all Australia, and other continents. In this thesis improvements to the information available for objective drought assessment and monitoring are developed by creating a time series of hydroecologic indicators though making novel use of remotely sensed data. Remote sensing offers spatially dense geophysical measurements of the Earth’s surface, which can be linked to process models, to regionally estimate the moisture availability (m„), the ratio of actual to potential evapotranspiration. This mapping of ma is achieved by linking daytime thermal and reflective measurements from the AVHRR sensor, with meteorological data, through a resistance energy balance model to generate the Normalised Difference Temperature Index (NDTI). The opportunity to use daytime thermal remote sensing was identified from a comprehensive review of previous literature using remotely sensed data for drought assessment.

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