Research on Hyperspectral Inversion of Soil Organic Carbon in Agricultural Fields of the Southern Shaanxi Mountain Area

Rapidly obtaining information on the content and spatial distribution of soil organic carbon (SOC) in farmland is crucial for evaluating regional soil quality, land degradation, and crop yield. This study focuses on mountain soils in various crop cultivation areas in Shangzhou District, Shangluo Cit...

Full description

Saved in:
Bibliographic Details
Main Authors: Yunhao Han, Bin Wang, Jingyi Yang, Fang Yin, Linsen He
Format: Article
Language:English
Published: MDPI AG 2025-02-01
Series:Remote Sensing
Subjects:
Online Access:https://www.mdpi.com/2072-4292/17/4/600
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850082000941088768
author Yunhao Han
Bin Wang
Jingyi Yang
Fang Yin
Linsen He
author_facet Yunhao Han
Bin Wang
Jingyi Yang
Fang Yin
Linsen He
author_sort Yunhao Han
collection DOAJ
description Rapidly obtaining information on the content and spatial distribution of soil organic carbon (SOC) in farmland is crucial for evaluating regional soil quality, land degradation, and crop yield. This study focuses on mountain soils in various crop cultivation areas in Shangzhou District, Shangluo City, Southern Shaanxi, utilizing ZY1-02D hyperspectral satellite imagery, field-measured hyperspectral data, and field sampling data to achieve precise inversion and spatial mapping of the SOC content. First, to address spectral bias caused by environmental factors, the Spectral Space Transformation (SST) algorithm was employed to establish a transfer relationship between measured and satellite image spectra, enabling systematic correction of the image spectra. Subsequently, multiple spectral transformation methods, including continuous wavelet transform (CWT), reciprocal, first-order derivative, second-order derivative, and continuum removal, were applied to the corrected spectral data to enhance their spectral response characteristics. For feature band selection, three methods were utilized: Variable Importance Projection (VIP), Competitive Adaptive Reweighted Sampling (CARS), and Stepwise Projection Algorithm (SPA). SOC content prediction was conducted using three models: partial least squares regression (PLSR), stepwise multiple linear regression (Step-MLR), and random forest (RF). Finally, leave-one-out cross-validation was employed to optimize the L4-CARS-RF model, which was selected for SOC spatial distribution mapping. The model achieved a coefficient of determination (R<sup>2</sup>) of 0.81, a root mean square error of prediction (RMSEP) of 1.54 g kg<sup>−1</sup>, and a mean absolute error (MAE) of 1.37 g kg<sup>−1</sup>. The results indicate that (1) the Spectral Space Transformation (SST) algorithm effectively eliminates environmental interference on image spectra, enhancing SOC prediction accuracy; (2) continuous wavelet transform significantly reduces data noise compared to other spectral processing methods, further improving SOC prediction accuracy; and (3) among feature band selection methods, the CARS algorithm demonstrated the best performance, achieving the highest SOC prediction accuracy when combined with the random forest model. These findings provide scientific methods and technical support for SOC monitoring and management in mountainous areas and offer valuable insights for assessing the long-term impacts of different crops on soil ecosystems.
format Article
id doaj-art-320342e69f6849a3b4368f77a8d1ac98
institution DOAJ
issn 2072-4292
language English
publishDate 2025-02-01
publisher MDPI AG
record_format Article
series Remote Sensing
spelling doaj-art-320342e69f6849a3b4368f77a8d1ac982025-08-20T02:44:36ZengMDPI AGRemote Sensing2072-42922025-02-0117460010.3390/rs17040600Research on Hyperspectral Inversion of Soil Organic Carbon in Agricultural Fields of the Southern Shaanxi Mountain AreaYunhao Han0Bin Wang1Jingyi Yang2Fang Yin3Linsen He4Shaanxi Key Laboratory of Land Consolidation, School of Land Engineering, Chang’an University, Xi’an 710054, ChinaCommand Center of Natural Resources Comprehensive Survey, China Geological Survey, Beijing 100055, ChinaShaanxi Key Laboratory of Land Consolidation, School of Land Engineering, Chang’an University, Xi’an 710054, ChinaShaanxi Key Laboratory of Land Consolidation, School of Land Engineering, Chang’an University, Xi’an 710054, ChinaShaanxi Key Laboratory of Land Consolidation, School of Land Engineering, Chang’an University, Xi’an 710054, ChinaRapidly obtaining information on the content and spatial distribution of soil organic carbon (SOC) in farmland is crucial for evaluating regional soil quality, land degradation, and crop yield. This study focuses on mountain soils in various crop cultivation areas in Shangzhou District, Shangluo City, Southern Shaanxi, utilizing ZY1-02D hyperspectral satellite imagery, field-measured hyperspectral data, and field sampling data to achieve precise inversion and spatial mapping of the SOC content. First, to address spectral bias caused by environmental factors, the Spectral Space Transformation (SST) algorithm was employed to establish a transfer relationship between measured and satellite image spectra, enabling systematic correction of the image spectra. Subsequently, multiple spectral transformation methods, including continuous wavelet transform (CWT), reciprocal, first-order derivative, second-order derivative, and continuum removal, were applied to the corrected spectral data to enhance their spectral response characteristics. For feature band selection, three methods were utilized: Variable Importance Projection (VIP), Competitive Adaptive Reweighted Sampling (CARS), and Stepwise Projection Algorithm (SPA). SOC content prediction was conducted using three models: partial least squares regression (PLSR), stepwise multiple linear regression (Step-MLR), and random forest (RF). Finally, leave-one-out cross-validation was employed to optimize the L4-CARS-RF model, which was selected for SOC spatial distribution mapping. The model achieved a coefficient of determination (R<sup>2</sup>) of 0.81, a root mean square error of prediction (RMSEP) of 1.54 g kg<sup>−1</sup>, and a mean absolute error (MAE) of 1.37 g kg<sup>−1</sup>. The results indicate that (1) the Spectral Space Transformation (SST) algorithm effectively eliminates environmental interference on image spectra, enhancing SOC prediction accuracy; (2) continuous wavelet transform significantly reduces data noise compared to other spectral processing methods, further improving SOC prediction accuracy; and (3) among feature band selection methods, the CARS algorithm demonstrated the best performance, achieving the highest SOC prediction accuracy when combined with the random forest model. These findings provide scientific methods and technical support for SOC monitoring and management in mountainous areas and offer valuable insights for assessing the long-term impacts of different crops on soil ecosystems.https://www.mdpi.com/2072-4292/17/4/600soil organic carbonmountain areahyperspectral inversionZY1-02D satelliteremote sensing
spellingShingle Yunhao Han
Bin Wang
Jingyi Yang
Fang Yin
Linsen He
Research on Hyperspectral Inversion of Soil Organic Carbon in Agricultural Fields of the Southern Shaanxi Mountain Area
Remote Sensing
soil organic carbon
mountain area
hyperspectral inversion
ZY1-02D satellite
remote sensing
title Research on Hyperspectral Inversion of Soil Organic Carbon in Agricultural Fields of the Southern Shaanxi Mountain Area
title_full Research on Hyperspectral Inversion of Soil Organic Carbon in Agricultural Fields of the Southern Shaanxi Mountain Area
title_fullStr Research on Hyperspectral Inversion of Soil Organic Carbon in Agricultural Fields of the Southern Shaanxi Mountain Area
title_full_unstemmed Research on Hyperspectral Inversion of Soil Organic Carbon in Agricultural Fields of the Southern Shaanxi Mountain Area
title_short Research on Hyperspectral Inversion of Soil Organic Carbon in Agricultural Fields of the Southern Shaanxi Mountain Area
title_sort research on hyperspectral inversion of soil organic carbon in agricultural fields of the southern shaanxi mountain area
topic soil organic carbon
mountain area
hyperspectral inversion
ZY1-02D satellite
remote sensing
url https://www.mdpi.com/2072-4292/17/4/600
work_keys_str_mv AT yunhaohan researchonhyperspectralinversionofsoilorganiccarboninagriculturalfieldsofthesouthernshaanximountainarea
AT binwang researchonhyperspectralinversionofsoilorganiccarboninagriculturalfieldsofthesouthernshaanximountainarea
AT jingyiyang researchonhyperspectralinversionofsoilorganiccarboninagriculturalfieldsofthesouthernshaanximountainarea
AT fangyin researchonhyperspectralinversionofsoilorganiccarboninagriculturalfieldsofthesouthernshaanximountainarea
AT linsenhe researchonhyperspectralinversionofsoilorganiccarboninagriculturalfieldsofthesouthernshaanximountainarea