Determining Forest Duff Water Content Using a Low-Cost Standing Wave Ratio Sensor

Forest duff (fermentation and humus) water content is an important parameter for fire risk prediction and water resource management. However, accurate determination of forest duff water content is difficult due to its loose structure. This study evaluates the feasibility of a standing wave ratio (SW...

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Main Authors: Xiaofei Yan, Yajie Zhao, Qiang Cheng, Xiaoliang Zheng, Yandong Zhao
Format: Article
Language:English
Published: MDPI AG 2018-02-01
Series:Sensors
Subjects:
Online Access:http://www.mdpi.com/1424-8220/18/2/647
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author Xiaofei Yan
Yajie Zhao
Qiang Cheng
Xiaoliang Zheng
Yandong Zhao
author_facet Xiaofei Yan
Yajie Zhao
Qiang Cheng
Xiaoliang Zheng
Yandong Zhao
author_sort Xiaofei Yan
collection DOAJ
description Forest duff (fermentation and humus) water content is an important parameter for fire risk prediction and water resource management. However, accurate determination of forest duff water content is difficult due to its loose structure. This study evaluates the feasibility of a standing wave ratio (SWR) sensor to accurately determine the forest duff water content. The performance of this sensor was tested on fermentation and humus with eight different compaction levels. Meanwhile, a commercialized time domain reflectometry (TDR) was employed for comparison. Calibration results showed that there were strong linear relationships between the volumetric water content (θV) and the SWR sensor readings (VSWR) at different compaction classes for both fermentation and humus samples. The sensor readings of both SWR and TDR underestimated the forest duff water content at low compacted levels, proving that the compaction of forest duff could significantly affect the measurement accuracy of both sensors. Experimental data also showed that the accuracy of the SWR sensor was higher than that of TDR according to the root mean square error (RMSE). Furthermore, low cost is another important advantage of the SWR sensor in comparison with TDR. This low-cost SWR sensor performs well in loose materials and is feasible for evaluating the water content of forest duff. In addition, the results indicate that decomposition of the forest duff should be taken into account for continuous and long-term water content measurement.
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spelling doaj.art-4c029471af224b509aed078c12d0db1e2022-12-22T04:22:50ZengMDPI AGSensors1424-82202018-02-0118264710.3390/s18020647s18020647Determining Forest Duff Water Content Using a Low-Cost Standing Wave Ratio SensorXiaofei Yan0Yajie Zhao1Qiang Cheng2Xiaoliang Zheng3Yandong Zhao4School of Technology, Beijing Forestry University, Beijing 100083, ChinaSchool of Technology, Beijing Forestry University, Beijing 100083, ChinaCollege of Information and Electrical Engineering, China Agricultural University, Beijing 100083, ChinaSchool of Technology, Beijing Forestry University, Beijing 100083, ChinaSchool of Technology, Beijing Forestry University, Beijing 100083, ChinaForest duff (fermentation and humus) water content is an important parameter for fire risk prediction and water resource management. However, accurate determination of forest duff water content is difficult due to its loose structure. This study evaluates the feasibility of a standing wave ratio (SWR) sensor to accurately determine the forest duff water content. The performance of this sensor was tested on fermentation and humus with eight different compaction levels. Meanwhile, a commercialized time domain reflectometry (TDR) was employed for comparison. Calibration results showed that there were strong linear relationships between the volumetric water content (θV) and the SWR sensor readings (VSWR) at different compaction classes for both fermentation and humus samples. The sensor readings of both SWR and TDR underestimated the forest duff water content at low compacted levels, proving that the compaction of forest duff could significantly affect the measurement accuracy of both sensors. Experimental data also showed that the accuracy of the SWR sensor was higher than that of TDR according to the root mean square error (RMSE). Furthermore, low cost is another important advantage of the SWR sensor in comparison with TDR. This low-cost SWR sensor performs well in loose materials and is feasible for evaluating the water content of forest duff. In addition, the results indicate that decomposition of the forest duff should be taken into account for continuous and long-term water content measurement.http://www.mdpi.com/1424-8220/18/2/647standing wave ratioforest duffvolumetric water contentcompaction
spellingShingle Xiaofei Yan
Yajie Zhao
Qiang Cheng
Xiaoliang Zheng
Yandong Zhao
Determining Forest Duff Water Content Using a Low-Cost Standing Wave Ratio Sensor
Sensors
standing wave ratio
forest duff
volumetric water content
compaction
title Determining Forest Duff Water Content Using a Low-Cost Standing Wave Ratio Sensor
title_full Determining Forest Duff Water Content Using a Low-Cost Standing Wave Ratio Sensor
title_fullStr Determining Forest Duff Water Content Using a Low-Cost Standing Wave Ratio Sensor
title_full_unstemmed Determining Forest Duff Water Content Using a Low-Cost Standing Wave Ratio Sensor
title_short Determining Forest Duff Water Content Using a Low-Cost Standing Wave Ratio Sensor
title_sort determining forest duff water content using a low cost standing wave ratio sensor
topic standing wave ratio
forest duff
volumetric water content
compaction
url http://www.mdpi.com/1424-8220/18/2/647
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AT yajiezhao determiningforestduffwatercontentusingalowcoststandingwaveratiosensor
AT qiangcheng determiningforestduffwatercontentusingalowcoststandingwaveratiosensor
AT xiaoliangzheng determiningforestduffwatercontentusingalowcoststandingwaveratiosensor
AT yandongzhao determiningforestduffwatercontentusingalowcoststandingwaveratiosensor