Authors / CoAuthors
Lymburner, L. | Ticehurst, C. | Adame, M. F. | Sengupta, A. | Khavei, E. | John Wiley & Sons Ltd
Abstract
Accurate information about the extent, frequency and duration of forest inundation is required to inform ecological, biophysical and hydrological models and enables floodplain managers to quantify the efficacy of flood mitigation/modification activities. Open water classifiers derived from optical remote sensing typically underestimate or fail to detect floodplain forest inundation. This paper presents a new method for detecting forest inundation dynamics using freely available Landsat and Sentinel 2 data, referred to as short-wave infrared mapping under vegetation. The method uses a dynamic threshold that accounts for the additional shortwave infrared reflectance caused by the presence of tree canopies over floodwater. The method is demonstrated at five Ramsar listed River Red Gum floodplain forest wetlands in southeastern Australia. Accuracy assessment based on independent drone imagery from a wide range of vegetated wetlands showed an absolute accuracy of 67%–70% and a fuzzy accuracy of 81%–83%. We found the method is conservative, and underestimates inundation (16%–18%) but very rarely misclassifies dry pixels as inundated (0.3%–0.6%). When compared to river gauge data, the method shows similar trends to an open water classifier (i.e., the area of inundated vegetation increases with increasing river height). The method is conservative compared to lidar-based floodplain inundation models but can be applied wherever cloud-free scenes of Landsat or Sentinel 2 have been acquired, thereby enabling floodplain managers with the ability to quantify changes in inundation dynamics in places/time-periods where lidar is unavailable. <b>Citation:</b> Lymburner, L., Ticehurst, C., Adame, M. F., Sengupta, A., & Kavehei, E. (2024). Seeing the floods through the trees: Using adaptive shortwave infrared thresholds to map inundation under wooded wetlands. <i>Hydrological Processes</i>, 38(6), e15174. https://doi.org/10.1002/hyp.15174
Product Type
document
eCat Id
149155
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Keywords
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- Landsat
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- flood
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- floodplain
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- Sentinel-2
- theme.ANZRC Fields of Research.rdf
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- Surface water hydrologyGeomorphology and earth surface processesHydrology not elsewhere classified
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- Published_External
Publication Date
2024-10-18T04:50:44
Creation Date
2024-01-09T20:00:00
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completed
Purpose
The purpose of the journal article is to inform the broader scientific community (specifically the earth observation community and hydrologists) of the algorithm for mapping water underneath vegetation and enables the quality of the algorithm to be subject to peer review. The paper describes a new method for mapping the extent of inundation underneath tree canopies using Landsat and Sentinel 2 data
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geoscientificInformation
Series Information
Hydrological Processes Volume 38, Issue 6 June 2024 e15174
Lineage
<div>The journal article represents the start of the lineage. The input data sources used are Digital Earth Australia stored surface reflectance products.</div>
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[-54.75, -9.2402, 112.92, 159.11]
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