Version 1
: Received: 6 April 2020 / Approved: 8 April 2020 / Online: 8 April 2020 (03:51:33 CEST)
How to cite:
Huang, J.J.; Guo, H.; Chen, B.; Guo, X.; Singh, V.P. Retrieval of Non-Optically Active Parameters for Small Scale Urban Waterbodies by a Machine Learning-Based Strategy. Preprints2020, 2020040111. https://doi.org/10.20944/preprints202004.0111.v1
Huang, J.J.; Guo, H.; Chen, B.; Guo, X.; Singh, V.P. Retrieval of Non-Optically Active Parameters for Small Scale Urban Waterbodies by a Machine Learning-Based Strategy. Preprints 2020, 2020040111. https://doi.org/10.20944/preprints202004.0111.v1
Huang, J.J.; Guo, H.; Chen, B.; Guo, X.; Singh, V.P. Retrieval of Non-Optically Active Parameters for Small Scale Urban Waterbodies by a Machine Learning-Based Strategy. Preprints2020, 2020040111. https://doi.org/10.20944/preprints202004.0111.v1
APA Style
Huang, J.J., Guo, H., Chen, B., Guo, X., & Singh, V.P. (2020). Retrieval of Non-Optically Active Parameters for Small Scale Urban Waterbodies by a Machine Learning-Based Strategy. Preprints. https://doi.org/10.20944/preprints202004.0111.v1
Chicago/Turabian Style
Huang, J.J., Xiaolong Guo and Vijay P. Singh. 2020 "Retrieval of Non-Optically Active Parameters for Small Scale Urban Waterbodies by a Machine Learning-Based Strategy" Preprints. https://doi.org/10.20944/preprints202004.0111.v1
Abstract
Water quality retrieval for small urban waterbodies by remote sensing get used to be difficult due to coarse spatial resolution of the remote sensing imagery. The recently launched Sentinel-2 produces imagery with a spatial resolution of 10 m. It provides an opportunity to solve the problem of retrieving water quality for small waterbodies. Additionally, many water management issues also require fine resolution of imagery, e.g. illegal discharge to an urban waterbody. Since illegal discharges are an important issue for urban water management, chemical oxygen demand (COD), total phosphorous (TP), and total nitrogen (TN) were chosen as the target parameters for water quality retrieval in this study. COD, TP and TN, however, are non-optically active parameters. There were limited studies in the past to retrieve these parameters in comparison with optically active parameters, e.g. Chlorophyll-A etc. This study compared three machine learning models, namely Random Forest (RF), Support Vector Regression (SVR), and Neural Networks (NN), to investigate the opportunity to retrieve the above non-optically active parameters. Results showed that R2 of TP, TN, and COD by NN, RF and SVR were 0.94, 0.88, and 0.86, respectively. The performances of water quality retrieval for these non-optically active parameters were significantly improved by the optimized machine learning models. These models hence solved the problem to use remote sensing data to retrieve these non-optically active water quality parameters and provided a new monitoring strategy for small waterbodies. Water quality mapping obtained by Sentinel-2 imagery provided a full spatial coverage of the water quality characterization for the entire water surface. Compared with water samples collecting and testing, it greatly reduced labor cost, reagents cost, and waste treatment cost. It also may help identify illegal discharges to urban waterbodies. The method developed in this research provides a new practical and efficient water quality monitoring strategy in managing water with consideration of environmental sustainability.
Keywords
water quality retrieval; illegal discharges identify; small waterbodies; Sentinel-2; machine learning
Subject
Environmental and Earth Sciences, Environmental Science
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
