Liem Tran

Dr. Liem Tran

orcid

Research Focus & Metrics

Academic Career Length

20Years (2007-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 February 2016 in Ecological Indicators
Verified
Journal Article
Closed access
LTLiem Tran
Liem Tran


1 November 2018 in Ecological Modelling
Verified
Journal Article
Closed access
WLWanwan Liang
Wanwan Liang
MPMonica Papeş
Monica Papeş
LTLiem Tran
Liem Tran
JGJerome Grant
Jerome Grant
RWRobert Washington-Allen
Robert Washington-Allen
GWGregory Wiggins
Gregory Wiggins


1 January 2020 in Ecological Modelling
Verified
Journal Article
Closed access
AAAdam G. Alsamadisi
Adam G. Alsamadisi
LTLiem Tran
Liem Tran
MPMonica Papeş
Monica Papeş

12 February 2020 in Remote Sensing
Verified
Journal Article
Open access
PDF file
WLWanwan Liang
Wanwan Liang
MAMongi Abidi
Mongi Abidi
LCLuis Carrasco
Luis Carrasco
JMJack McNelis
Jack McNelis
LTLiem Tran
Liem Tran
JGJerome Grant
Jerome Grant
Mapping vegetation species is critical to facilitate related quantitative assessment, and mapping invasive plants is important to enhance monitoring and management activities. Integrating high-resolution multispectral remote-sensing (RS) images and lidar (light detection and ranging) point clouds can provide robust features for vegetation mapping. However, using multiple sources of high-resolution RS data for vegetation mapping on a large spatial scale can be both computationally and sampling intensive. Here, we designed a two-step classification workflow to potentially decrease computational cost and sampling effort and to increase classification accuracy by integrating multispectral and lidar data in order to derive spectral, textural, and structural features for mapping target vegetation species. We used this workflow to classify kudzu, an aggressive invasive vine, in the entire Knox County (1362 km2) of Tennessee (U.S.). Object-based image analysis was conducted in the workflow. The first-step classification used 320 kudzu samples and extensive, coarsely labeled samples (based on national land cover) to generate an overprediction map of kudzu using random forest (RF). For the second step, 350 samples were randomly extracted from the overpredicted kudzu and labeled manually for the final prediction using RF and support vector machine (SVM). Computationally intensive features were only used for the second-step classification. SVM had constantly better accuracy than RF, and the producer’s accuracy, user’s accuracy, and Kappa for the SVM model on kudzu were 0.94, 0.96, and 0.90, respectively. SVM predicted 1010 kudzu patches covering 1.29 km2 in Knox County. We found the sample size of kudzu used for algorithm training impacted the accuracy and number of kudzu predicted. The proposed workflow could also improve sampling efficiency and specificity. Our workflow had much higher accuracy than the traditional method conducted in this research, and could be easily implemented to map kudzu in other regions as well as map other vegetation species.