Estimation of Herbaceous Fuel Moisture Content Using Vegetation Indices and Land Surface Temperature from MODIS Data
The monitoring of herbaceous fuel moisture content is a crucial activity in order to assess savanna fire risks. Faced with the difficulty of managing wide areas of vegetated surfaces, remote sensing appears an attractive alternative for terrestrial measurements because of its advantages related to t...
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doaj-cb668398369943509fb1bafd53a6333c2020-11-24T22:20:23ZengMDPI AGRemote Sensing2072-42922013-05-01562617263810.3390/rs5062617Estimation of Herbaceous Fuel Moisture Content Using Vegetation Indices and Land Surface Temperature from MODIS DataRasmus FensholtBienvenu SambouChristelle HélyCheikh MbowMomadou SowThe monitoring of herbaceous fuel moisture content is a crucial activity in order to assess savanna fire risks. Faced with the difficulty of managing wide areas of vegetated surfaces, remote sensing appears an attractive alternative for terrestrial measurements because of its advantages related to temporal resolution and spatial coverage. Earth observation (EO)-based vegetation indices (VIs) and the ratio between Normalized Difference Vegetation Index (NDVI) and surface temperature (ST) were used for assessment of herbaceous fuel moisture content estimates and validated against herbaceous data collected in 2010 at three open savanna sites located in Senegal, West Africa. EO-based estimates of water content were more consistent with the use of VI as compared to the ratio NDVI/ST. Different VIs based on near-infrared (NIR) and shortwave infrared (SWIR) reflectance were tested and a consistent relationship was found between field measurements of leaf equivalent water thickness (EWT) from all test sites and Normalized Difference Infrared Index (NDII), Global Vegetation Moisture Index (GVMI) and Moisture Stress Index (MSI). Also, strong relationships were found between fuel moisture content (FMC) and VIs for the sites separately; however, they were weaker for the pooled data. The correlations between EWT/FMC and VIs were found to decrease progressively as the woody cover increased. Although these results suggest that NIR and SWIR reflectance can be used for the estimation of herbaceous water content, additional validation from an increased number of study sites is necessary to study the robustness of such indices for a larger variety of savanna vegetation types.http://www.mdpi.com/2072-4292/5/6/2617herbaceous moisture contentvegetation indicesland surface temperatureremote sensingMODISSenegal |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Rasmus Fensholt Bienvenu Sambou Christelle Hély Cheikh Mbow Momadou Sow |
spellingShingle |
Rasmus Fensholt Bienvenu Sambou Christelle Hély Cheikh Mbow Momadou Sow Estimation of Herbaceous Fuel Moisture Content Using Vegetation Indices and Land Surface Temperature from MODIS Data Remote Sensing herbaceous moisture content vegetation indices land surface temperature remote sensing MODIS Senegal |
author_facet |
Rasmus Fensholt Bienvenu Sambou Christelle Hély Cheikh Mbow Momadou Sow |
author_sort |
Rasmus Fensholt |
title |
Estimation of Herbaceous Fuel Moisture Content Using Vegetation Indices and Land Surface Temperature from MODIS Data |
title_short |
Estimation of Herbaceous Fuel Moisture Content Using Vegetation Indices and Land Surface Temperature from MODIS Data |
title_full |
Estimation of Herbaceous Fuel Moisture Content Using Vegetation Indices and Land Surface Temperature from MODIS Data |
title_fullStr |
Estimation of Herbaceous Fuel Moisture Content Using Vegetation Indices and Land Surface Temperature from MODIS Data |
title_full_unstemmed |
Estimation of Herbaceous Fuel Moisture Content Using Vegetation Indices and Land Surface Temperature from MODIS Data |
title_sort |
estimation of herbaceous fuel moisture content using vegetation indices and land surface temperature from modis data |
publisher |
MDPI AG |
series |
Remote Sensing |
issn |
2072-4292 |
publishDate |
2013-05-01 |
description |
The monitoring of herbaceous fuel moisture content is a crucial activity in order to assess savanna fire risks. Faced with the difficulty of managing wide areas of vegetated surfaces, remote sensing appears an attractive alternative for terrestrial measurements because of its advantages related to temporal resolution and spatial coverage. Earth observation (EO)-based vegetation indices (VIs) and the ratio between Normalized Difference Vegetation Index (NDVI) and surface temperature (ST) were used for assessment of herbaceous fuel moisture content estimates and validated against herbaceous data collected in 2010 at three open savanna sites located in Senegal, West Africa. EO-based estimates of water content were more consistent with the use of VI as compared to the ratio NDVI/ST. Different VIs based on near-infrared (NIR) and shortwave infrared (SWIR) reflectance were tested and a consistent relationship was found between field measurements of leaf equivalent water thickness (EWT) from all test sites and Normalized Difference Infrared Index (NDII), Global Vegetation Moisture Index (GVMI) and Moisture Stress Index (MSI). Also, strong relationships were found between fuel moisture content (FMC) and VIs for the sites separately; however, they were weaker for the pooled data. The correlations between EWT/FMC and VIs were found to decrease progressively as the woody cover increased. Although these results suggest that NIR and SWIR reflectance can be used for the estimation of herbaceous water content, additional validation from an increased number of study sites is necessary to study the robustness of such indices for a larger variety of savanna vegetation types. |
topic |
herbaceous moisture content vegetation indices land surface temperature remote sensing MODIS Senegal |
url |
http://www.mdpi.com/2072-4292/5/6/2617 |
work_keys_str_mv |
AT rasmusfensholt estimationofherbaceousfuelmoisturecontentusingvegetationindicesandlandsurfacetemperaturefrommodisdata AT bienvenusambou estimationofherbaceousfuelmoisturecontentusingvegetationindicesandlandsurfacetemperaturefrommodisdata AT christellehely estimationofherbaceousfuelmoisturecontentusingvegetationindicesandlandsurfacetemperaturefrommodisdata AT cheikhmbow estimationofherbaceousfuelmoisturecontentusingvegetationindicesandlandsurfacetemperaturefrommodisdata AT momadousow estimationofherbaceousfuelmoisturecontentusingvegetationindicesandlandsurfacetemperaturefrommodisdata |
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