Junfeng Zhu

Dr. Junfeng Zhu


Research Focus & Metrics

Academic Career Length

22Years (2005-Present)

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

Representative Publications

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26 July 2005 in Water Resources Research
Verified
Journal Article
Closed access
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JZJunfeng Zhu
Junfeng Zhu
TYTian-Chyi Jim Yeh
Tian-Chyi Jim Yeh

2 September 2005 in Water Resources Research
Verified
Journal Article
Closed access
PDF file
CWCheng‐Mau Wu
Cheng‐Mau Wu
TYTian-Chyi Jim Yeh
Tian-Chyi Jim Yeh
JZJunfeng Zhu
Junfeng Zhu
TLTim Hau Lee
Tim Hau Lee
NHNien‐Sheng Hsu
Nien‐Sheng Hsu
ASAlbert Folch Sancho
Albert Folch Sancho

18 July 2007 in Water Resources Research
Verified
Journal Article
Closed access
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Salvatore StrafaceSalvatore Straface
Salvatore Straface
TYT.‐C. J. Yeh
T.‐C. J. Yeh
JZJunfeng Zhu
Junfeng Zhu
STS. Troisi
S. Troisi
CLC. H. Lee
C. H. Lee

1 February 2016 in Journal of Hydrology
Verified
Journal Article
Closed access
JZJunfeng Zhu
Junfeng Zhu
WPWilliam P. Pierskalla
William P. Pierskalla

1 September 2020 in Journal of Hydrology
Verified
Journal Article
Closed access
JZJunfeng Zhu
Junfeng Zhu
ANAdam M. Nolte
Adam M. Nolte
NJNathan Jacobs
Nathan Jacobs
MYMing Ye
Ming Ye

15 February 2022 in Earth and Space Science
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Journal Article
Open access
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MRMuhammad Usman Rafique
Muhammad Usman Rafique
JZJunfeng Zhu
Junfeng Zhu
NJNathan Jacobs
Nathan Jacobs
Sinkholes are the most abundant surface features in karst areas worldwide. Understanding sinkhole occurrences and characteristics is critical for studying karst aquifers and mitigating sinkhole‐related hazards. Most sinkholes appear on the land surface as depressions or cover collapses and are commonly mapped from elevation data, such as digital elevation models (DEMs). Existing methods for identifying sinkholes from DEMs often require two steps: locating surface depressions and separating sinkholes from non‐sinkhole depressions. In this study, we explored deep learning to directly identify sinkholes from DEM data and aerial imagery. A key contribution of our study is an evaluation of various ways of integrating these two types of raster data. We used an image segmentation model, U‐Net, to locate sinkholes. We trained separate U‐Net models based on four input images of elevation data: a DEM image, a slope image, a DEM gradient image, and a DEM‐shaded relief image. Three normalization techniques (Global, Gaussian, and Instance) were applied to improve the model performance. Model results suggest that deep learning is a viable method to identify sinkholes directly from the images of elevation data. In particular, DEM gradient data provided the best input for U‐net image segmentation models to locate sinkholes. The model using the DEM gradient image with Gaussian normalization achieved the best performance with a sinkhole intersection‐over‐union (IoU) of 45.38% on the unseen test set. Aerial images, however, were not useful in training deep learning models for sinkholes as the models using an aerial image as input achieved sinkhole IoUs below 3%.