REMOTE SENSING METHOD FOR LAND COVER CHANGE MONITORING USING LANDSAT MULTI-TEMPORAL DATA (Case study: Tuy Duc and Dak Rap Districts, Dak Nong Province, Central Highlands of Vietnam)

Abstract

In this study, vegetation coverage changes over a 30-year period for the Tuy Duc and Dak R’lap districts,Dak Nong province (central highland of Vietnam) were assessed using remote sensing and Geographic Information Systems (GIS) techniques. 03 Landsat satellite images,including Landsat TM February 13, 1990, Landsat TM February 22, 2005 and Landsat 8 January, 15 2020 were used to calculate the normalized difference vegetation index (NDVI), then assessed the changes in vegetation coverage density. The NDVI differencing method is also used as a change detection method and provides detailed information for monitoring changes in land cover in periods 1990 – 2005, 2005 – 2020 and 1990 – 2020. Analysis of the obtained results showed that the vegetation coverage declined sharply during 1990 – 2005 period,then the vegetation coverage has begun to recover in period 2005 – 2020. From the findings of this study, it can be easily concluded that the Tuy Duc and Dak R’lap areas has lost its valuable vegetation cover both qualitatively and quantitatively.

Assessing forest cover changes in Dak Lak province (Central Highlands of Vietnam) from multi-temporal Landsat data and machine learning techniques

“…In Vietnam, multi-temporal Landsat image data is also used in many studies to assess forest cover changes (Trinh et al, 2020;Vogelmann et al, 2017;Shimizu et al, 2023;Tran et al, 2023). The obtained results show that the forest cover changes are most marked along the relatively narrow interfaces between agricultural and forest areas.…”

“…Meanwhile, the study (Tran et al, 2023) used a series of NDVI index images to evaluate the forest cover changes in Thua Thien Hue province (Central region of Vietnam) from Landsat images for the period 1991 -2022. The NDVI time series calculated from Landsat images for the period 1990 -2018 was also used in the study (Trinh et al, 2020) to evaluate the forest cover quality changes in Dak Nong province (Central Highlands region of Vietnam). In addition, some studies also use multi-temporal Landsat image data to monitor changes in forest cover density and detect forest degradation (Vogelmann et al, 2017) in different areas in Vietnam.…”