PMID- 35062514 OWN - NLM STAT- MEDLINE DCOM- 20220125 LR - 20220128 IS - 1424-8220 (Electronic) IS - 1424-8220 (Linking) VI - 22 IP - 2 DP - 2022 Jan 11 TI - Precise Monitoring of Soil Salinity in China's Yellow River Delta Using UAV-Borne Multispectral Imagery and a Soil Salinity Retrieval Index. LID - 10.3390/s22020546 [doi] LID - 546 AB - Monitoring salinity information of salinized soil efficiently and precisely using the unmanned aerial vehicle (UAV) is critical for the rational use and sustainable development of arable land resources. The sensitive parameter and a precise retrieval method of soil salinity, however, remain unknown. This study strived to explore the sensitive parameter and construct an optimal method for retrieving soil salinity. The UAV-borne multispectral image in China's Yellow River Delta was acquired to extract band reflectance, compute vegetation indexes and soil salinity indexes. Soil samples collected from 120 different study sites were used for laboratory salt content measurements. Grey correlation analysis and Pearson correlation coefficient methods were employed to screen sensitive band reflectance and indexes. A new soil salinity retrieval index (SSRI) was then proposed based on the screened sensitive reflectance. The Partial Least Squares Regression (PLSR), Multivariable Linear Regression (MLR), Back Propagation Neural Network (BPNN), Support Vector Machine (SVM), and Random Forest (RF) methods were employed to construct retrieval models based on the sensitive indexes. The results found that green, red, and near-infrared (NIR) bands were sensitive to soil salinity, which can be used to build SSRI. The SSRI-based RF method was the optimal method for accurately retrieving the soil salinity. Its modeling determination coefficient (R(2)) and Root Mean Square Error (RMSE) were 0.724 and 1.764, respectively; and the validation R(2), RMSE, and Residual Predictive Deviation (RPD) were 0.745, 1.879, and 2.211. FAU - Yu, Xinyang AU - Yu X AD - College of Resources and Environment, Shandong Agricultural University, Tai'an 271018, China. AD - Tropical Research and Education Center/Department of Agricultural and Biological Engineering, Institute of Food and Agricultural Sciences, University of Florida, Homestead, FL 33031, USA. FAU - Chang, Chunyan AU - Chang C AD - College of Resources and Environment, Shandong Agricultural University, Tai'an 271018, China. FAU - Song, Jiaxuan AU - Song J AD - College of Resources and Environment, Shandong Agricultural University, Tai'an 271018, China. FAU - Zhuge, Yuping AU - Zhuge Y AUID- ORCID: 0000-0002-8298-196X AD - College of Resources and Environment, Shandong Agricultural University, Tai'an 271018, China. FAU - Wang, Ailing AU - Wang A AD - College of Resources and Environment, Shandong Agricultural University, Tai'an 271018, China. LA - eng GR - ZR2019MD014/Natural Foundation of Shandong Province/ GR - 2019JZZY010723/Major Science and Technology Projects in Shandong Province/ PT - Journal Article DEP - 20220111 PL - Switzerland TA - Sensors (Basel) JT - Sensors (Basel, Switzerland) JID - 101204366 RN - 0 (Soil) SB - IM MH - China MH - Rivers MH - *Salinity MH - *Soil MH - Unmanned Aerial Devices PMC - PMC8778686 OTO - NOTNLM OT - optimal retrieval model OT - random forest OT - remote sensing OT - soil salinity sensitive parameter OT - support vector machine COIS- The authors declare no conflict of interest. EDAT- 2022/01/23 06:00 MHDA- 2022/01/27 06:00 PMCR- 2022/01/11 CRDT- 2022/01/22 01:02 PHST- 2021/11/06 00:00 [received] PHST- 2022/01/03 00:00 [revised] PHST- 2022/01/08 00:00 [accepted] PHST- 2022/01/22 01:02 [entrez] PHST- 2022/01/23 06:00 [pubmed] PHST- 2022/01/27 06:00 [medline] PHST- 2022/01/11 00:00 [pmc-release] AID - s22020546 [pii] AID - sensors-22-00546 [pii] AID - 10.3390/s22020546 [doi] PST - epublish SO - Sensors (Basel). 2022 Jan 11;22(2):546. doi: 10.3390/s22020546.