MODIS EVI and LST Temporal Response for Discrimination of Tropical Land Covers

Bertram Ostendorf,Megan Lewis,Chittana Phompila,Kenneth Clarke

doi:10.3390/rs70506026

Bertram Ostendorf, Megan Lewis

Open Access

https://doi.org/10.3390/rs70506026

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Abstract

MODIS enhanced vegetation index (EVI) and land surface temperature (LST) are key indicators for monitoring vegetation cover changes in broad ecosystems. However, there has been little evaluation of these indices for detecting changes in a range of land covers in tropical regions. In this study, we investigated the characteristics and seasonal responses of LST and EVI for four different land covers in Lao tropical forests: native forest, rubber plantation, mixed wooded/cleared areas and agriculture. We calculated long-term averages of MODIS LST and EVI 16-day time series and compared their monthly transitions over the seven-year period from 2006 to 2012. We also tested whether these indices can be used to classify these four land covers. The findings demonstrate the complex interrelationship of LST and EVI and their monthly transitions for different land covers: they each showed distinctly different intra-annual LST and EVI variations. Native forests have the highest EVI, and the lowest LST throughout the year. In contrast, agricultural areas with little or no vegetation cover have the highest LST. The transition of LST/EVI for the land covers other than native forests showed marked seasonality. Linear discriminant analysis (LDA) showed that there was high overall accuracy of separation of land covers by these indices (86%). The encouraging results indicate that the combined use of MODIS LST and EVI holds promise for improving monitoring of changes in a Lao tropical forest.

Highlights

Vegetation cover changes in tropical regions are among the most significant contributors to global climate change [1,2,3,4]
The 2006–2012 16-day averages and standard deviations of the Moderate Resolution Imaging Spectroradiometer (MODIS) enhanced vegetation index (EVI) and land surface temperature (LST) show the intra-annual responses of the native forest, rubber plantation, mixed wooded/cleared areas and agriculture (Figure 4a–c)
EVI and LST temporal responses for these land covers. Dense vegetation cover such as native forest tends to have the lowest LST and the highest EVI throughout the year compared to the others

Summary

Introduction

Vegetation cover changes in tropical regions are among the most significant contributors to global climate change [1,2,3,4]. These changes have resulted in changes in carbon stock, land degradation and rapid loss of biodiversity [1]. Understanding how ecological systems are changing requires effective monitoring of vegetation changes in space and time [5]. Our knowledge of these changing events and processes can be improved using information from satellite observations. Many studies have suggested that use of additional parameters such as land surface temperature (LST) improves monitoring of land covers [8,9,10]

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Conclusion