A Machine Learning-Based Approach for Surface Soil Moisture Estimations with Google Earth Engine

Due to its relation to the Earth’s climate and weather and phenomena like drought, flooding, or landslides, knowledge of the soil moisture content is valuable to many scientific and professional users. Remote-sensing offers the unique possibility for continuous measurements of this variable. Especia...

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Main Authors: Felix Greifeneder, Claudia Notarnicola, Wolfgang Wagner
Format: Article
Language:English
Published: MDPI AG 2021-05-01
Series:Remote Sensing
Subjects:
Online Access:https://www.mdpi.com/2072-4292/13/11/2099
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author Felix Greifeneder
Claudia Notarnicola
Wolfgang Wagner
author_facet Felix Greifeneder
Claudia Notarnicola
Wolfgang Wagner
author_sort Felix Greifeneder
collection DOAJ
description Due to its relation to the Earth’s climate and weather and phenomena like drought, flooding, or landslides, knowledge of the soil moisture content is valuable to many scientific and professional users. Remote-sensing offers the unique possibility for continuous measurements of this variable. Especially for agriculture, there is a strong demand for high spatial resolution mapping. However, operationally available soil moisture products exist with medium to coarse spatial resolution only (≥1 km). This study introduces a machine learning (ML)—based approach for the high spatial resolution (50 m) mapping of soil moisture based on the integration of Landsat-8 optical and thermal images, Copernicus Sentinel-1 C-Band SAR images, and modelled data, executable in the Google Earth Engine. The novelty of this approach lies in applying an entirely data-driven ML concept for global estimation of the surface soil moisture content. Globally distributed in situ data from the International Soil Moisture Network acted as an input for model training. Based on the independent validation dataset, the resulting overall estimation accuracy, in terms of Root-Mean-Squared-Error and R², was 0.04 m<sup>3</sup>·m<sup>−3</sup> and 0.81, respectively. Beyond the retrieval model itself, this article introduces a framework for collecting training data and a stand-alone Python package for soil moisture mapping. The Google Earth Engine Python API facilitates the execution of data collection and retrieval which is entirely cloud-based. For soil moisture retrieval, it eliminates the requirement to download or preprocess any input datasets.
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spelling doaj.art-7535e8126f494219b9b0ae750b6b3c002023-11-21T21:36:00ZengMDPI AGRemote Sensing2072-42922021-05-011311209910.3390/rs13112099A Machine Learning-Based Approach for Surface Soil Moisture Estimations with Google Earth EngineFelix Greifeneder0Claudia Notarnicola1Wolfgang Wagner2Institute for Earth Observation, Eurac Research, 39100 Bolzano, ItalyInstitute for Earth Observation, Eurac Research, 39100 Bolzano, ItalyDepartment of Geodesy and Geoinformation, TU Wien, 1040 Vienna, AustriaDue to its relation to the Earth’s climate and weather and phenomena like drought, flooding, or landslides, knowledge of the soil moisture content is valuable to many scientific and professional users. Remote-sensing offers the unique possibility for continuous measurements of this variable. Especially for agriculture, there is a strong demand for high spatial resolution mapping. However, operationally available soil moisture products exist with medium to coarse spatial resolution only (≥1 km). This study introduces a machine learning (ML)—based approach for the high spatial resolution (50 m) mapping of soil moisture based on the integration of Landsat-8 optical and thermal images, Copernicus Sentinel-1 C-Band SAR images, and modelled data, executable in the Google Earth Engine. The novelty of this approach lies in applying an entirely data-driven ML concept for global estimation of the surface soil moisture content. Globally distributed in situ data from the International Soil Moisture Network acted as an input for model training. Based on the independent validation dataset, the resulting overall estimation accuracy, in terms of Root-Mean-Squared-Error and R², was 0.04 m<sup>3</sup>·m<sup>−3</sup> and 0.81, respectively. Beyond the retrieval model itself, this article introduces a framework for collecting training data and a stand-alone Python package for soil moisture mapping. The Google Earth Engine Python API facilitates the execution of data collection and retrieval which is entirely cloud-based. For soil moisture retrieval, it eliminates the requirement to download or preprocess any input datasets.https://www.mdpi.com/2072-4292/13/11/2099soil moistureSentinel-1 SARLandsat-8 optical/thermal datamachine learningcloud-based approachGoogle Earth Engine
spellingShingle Felix Greifeneder
Claudia Notarnicola
Wolfgang Wagner
A Machine Learning-Based Approach for Surface Soil Moisture Estimations with Google Earth Engine
Remote Sensing
soil moisture
Sentinel-1 SAR
Landsat-8 optical/thermal data
machine learning
cloud-based approach
Google Earth Engine
title A Machine Learning-Based Approach for Surface Soil Moisture Estimations with Google Earth Engine
title_full A Machine Learning-Based Approach for Surface Soil Moisture Estimations with Google Earth Engine
title_fullStr A Machine Learning-Based Approach for Surface Soil Moisture Estimations with Google Earth Engine
title_full_unstemmed A Machine Learning-Based Approach for Surface Soil Moisture Estimations with Google Earth Engine
title_short A Machine Learning-Based Approach for Surface Soil Moisture Estimations with Google Earth Engine
title_sort machine learning based approach for surface soil moisture estimations with google earth engine
topic soil moisture
Sentinel-1 SAR
Landsat-8 optical/thermal data
machine learning
cloud-based approach
Google Earth Engine
url https://www.mdpi.com/2072-4292/13/11/2099
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