Article
Geography, Physical
Jilin Men, Xi Chen, Xuejiao Hou, Jingyi Tian, Qingjun Song, Liqiao Tian
Summary: In this study, a novel water classification and spectral scoring system (OC_3S) was developed based on global in situ hyperspectral data. OC_3S classified water types into 30 classes and provided detailed information on the optical properties of different water classes. The system performed well in capturing high-quality Rrs data with little loss of data volume.
ISPRS JOURNAL OF PHOTOGRAMMETRY AND REMOTE SENSING
(2023)
Article
Environmental Sciences
Elena N. Korchemkina, Daria V. Kalinskaya
Summary: This study utilizes a large array of field and satellite data for the northeastern part of the Black Sea to show the numerical differences between surface-level and satellite measurements of atmospheric parameters. It proposes an additional correction algorithm that significantly reduces the discrepancy between in situ and retrieved remote sensing reflectance in the Black Sea, especially in short-wave spectral bands.
Article
Remote Sensing
Jun Chen, Xianhui Dou, Xianqiang He, Min Xu, Xinyue Li, Delu Pan
Summary: Remote sensing reflectance (R (rs)) and inherent optical properties (IOPs) conversions are crucial for accurate satellite measurements of biogeochemical products. Traditional conversions using quadratic polynomial functions with model parameters (G (x = 0,1)) are limited by spatial and temporal variability. To address this, we developed two neural network models (NNG (x = 1,2)) to calculate G (x) from R (rs) spectrum and improve the accuracy of R (rs)-IOPs conversions. Our evaluations show that the NNG (x) models outperform existing models in this conversion. Furthermore, we find that G (x) values vary significantly globally, particularly in oligotrophic gyres, coastal waters, and high latitude oceans, which can lead to large uncertainties in IOPs retrievals for China's coastal regions. Our results suggest that accurate pixel-level G (x) values can enhance the quality of global ocean IOPs data.
INTERNATIONAL JOURNAL OF REMOTE SENSING
(2023)
Article
Environmental Sciences
Jianwei Wei, Menghua Wang, Karlis Mikelsons, Lide Jiang, Susanne Kratzer, Zhongping Lee, Tim Moore, Heidi M. Sosik, Dimitry Van der Zande
Summary: This study reports a new water class product for global waters from VIIRS, which divides the ocean, coastal, and inland waters into 23 water classes using a hyperspectral scheme. The results show that these water classes are distinguishable by their distinct bio-optical and biogeochemical properties, and the accuracy of the water class products is validated globally.
REMOTE SENSING OF ENVIRONMENT
(2022)
Article
Environmental Sciences
Rodrigo Hernandez-Moresino, Gabriela N. Williams, Antonela Martelli, Elena S. Barbieri
Summary: The study assessed the dynamics of phytoplankton in a seasonal frontal system in the San Jose Gulf and neighbouring shelf waters. Differences in bio-optical properties between eastern and western domains of the system were observed, with vertically mixed waters showing a strong phytoplankton bloom and vertically stratified waters displaying early and long-lasting blooms. The optical parameters of these systems were complex, with a strong correlation between satellite chlorophyll-a and phytoplankton absorption in outer shelf waters but a weaker correlation in the gulf's waters.
MARINE ENVIRONMENTAL RESEARCH
(2022)
Article
Environmental Sciences
Huizeng Liu, Xianqiang He, Qingquan Li, Susanne Kratzer, Junjie Wang, Tiezhu Shi, Zhongwen Hu, Chao Yang, Shuibo Hu, Qiming Zhou, Guofeng Wu
Summary: The study proposes a hybrid approach for estimating UV Rrs from visible bands and evaluates its performance using in situ and satellite data, showing high accuracy in both clear open ocean and optically complex waters. The model-estimated UV Rrs may improve the accuracy of absorption coefficients in semi-analytical IOPs algorithm, indicating great potential for reconstructing UV Rrs data and enhancing IOPs retrieval for historical satellite sensors.
REMOTE SENSING OF ENVIRONMENT
(2021)
Article
Environmental Sciences
Ryan E. O'Shea, Nima Pahlevan, Brandon Smith, Emmanuel Boss, Daniela Gurlin, Krista Alikas, Kersti Kangro, Raphael M. Kudela, Diana Vaiciute
Summary: This article presents a method for the simultaneous estimation of biogeochemical parameters and optical properties from hyperspectral satellite imagery of globally distributed inland and coastal waters. By training a machine learning model called Mixture Density Networks, the uncertainty in the retrieval results can be greatly reduced. The application of this model is of great importance for future hyperspectral missions.
REMOTE SENSING OF ENVIRONMENT
(2023)
Article
Engineering, Civil
Jiafeng Xu, Ying Zhao, Heng Lyu, Huaiqing Liu, Xianzhang Dong, Yunmei Li, Kai Cao, Jie Xu, Yangyang Li, Huaijing Wang, Honglei Guo
Summary: In this study, an optimal optical indicator for estimating Chla/TSM was found and a semianalytical algorithm was proposed. The algorithm showed favorable performance in inland waters and had higher estimation accuracy compared to other algorithms.
JOURNAL OF HYDROLOGY
(2022)
Article
Engineering, Aerospace
Pravin Jeba Dev, Gejo Anna Geevarghese, R. Purvaja, R. Ramesh
Summary: Field spectroscopy data play a crucial role in comparing, calibrating, and validating remote sensing data. However, there are challenges and limitations in the measurement of benthic reflectance in shallow water coastal ecosystems. This paper focuses on the theory, concepts, and measurement techniques of in-vivo sensing of benthic reflectance in shallow water environments.
ADVANCES IN SPACE RESEARCH
(2022)
Article
Engineering, Electrical & Electronic
Yinghui Sun, Wei Wu, Xiaobo Shen, Zhen Cui
Summary: In this article, a novel method MvIGH is proposed for remote sensing image retrieval (RSIR), which captures latent similarities among RS images to achieve better performance, and is able to adaptively learn weights of each view to characterize their contribution.
IEEE JOURNAL OF SELECTED TOPICS IN APPLIED EARTH OBSERVATIONS AND REMOTE SENSING
(2021)
Article
Environmental Sciences
Aline de M. Valerio, Milton Kampel, Vincent Vantrepotte, Nicholas D. Ward, Jeffrey E. Richey
Summary: Optical water types (OWTs) in the Lower Amazon region were identified using field data acquired from 2014 to 2017, showing strong seasonal variability. Four OWTs were identified, each associated with specific bio-optical and biogeochemical environments. Further classification of Sentinel-3 images using the identified OWTs as reference showed differences between the Amazon River and clearwater tributary OWTs.
Article
Environmental Sciences
Barbara Lednicka, Maria Kubacka, Wlodzimierz Freda, Kamila Haule, Dariusz Ficek, Maciej Sokolski
Summary: This research investigates the possibility of using multi-parameter algorithms in the Pomeranian lakes, comparing them with algorithms used in the coastal waters of the Southern Baltic Sea. The results show that the multi-parameter algorithms developed for the Southern Baltic Sea can be applied to measure water quality in the Pomeranian lakes.
Article
Engineering, Electrical & Electronic
Jun Chen, Wenting Quan, Hongtao Duan, Qianguo Xing, Na Xu
Summary: Accurately estimating intrinsic optical properties (IOPs) is crucial for understanding long-term global climate change effects on aquatic ecosystems. The study utilized a combination of near-infrared and visible wavelength bands to adjust the IOPs data processing system, resulting in more effective IOPs estimation for oceanic and inland waters. The near-infrared band played a significant role in retrieving IOPs from highly turbid waters and removing residual errors in satellite remote sensing data.
IEEE JOURNAL OF SELECTED TOPICS IN APPLIED EARTH OBSERVATIONS AND REMOTE SENSING
(2021)
Article
Environmental Sciences
Darya V. Kalinskaya, Anna S. Papkova
Summary: This study investigates the atmospheric correction of satellite optical data and proposes an additional correction algorithm. The research findings highlight the numerical differences between atmospheric parameters measured at different levels and their relationship with the differences in in situ and satellite remote-sensed reflectance.
Article
Astronomy & Astrophysics
M. Lo Prejato, D. McKee
Summary: A spectral deconvolution model (SDM) is introduced for estimating the concentrations of chlorophyll, colored dissolved organic material (CDOM), and non-biogenic mineral suspended solids (MSS) in water. The SDM utilizes spectral information to estimate these parameters and shows better performance and adaptability compared to other methods.
EARTH AND SPACE SCIENCE
(2023)
Article
Environmental Sciences
Shengqiang Wang, Jun Lv, Junwei Nie, Deyong Sun, Hanwei Liang, Zhongfeng Qiu, Wei Yang
Summary: This study developed a new approach to directly derive euphotic zone depth (Z(eu)) from remote sensing data in the Bohai Sea and Yellow Sea. Seasonal variations in Z(eu) were observed, with higher levels in summer and lower levels in winter, possibly influenced by changing concentrations of total suspended matter.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Marine & Freshwater Biology
Takehiko Fukushima, Bunkei Matsushita
Summary: By analyzing long-term limnological data, this study identified thresholds for phosphorus and nitrogen limitations in phytoplankton production, as well as the predominant roles of TP' and TN' in chlorophyll a levels under specific P and N limitation conditions. The study also discussed factors influencing nutrient use efficiency.
Article
Biodiversity Conservation
Jan-Peter George, Wei Yang, Hideki Kobayashi, Tobias Biermann, Arnaud Carrara, Edoardo Cremonese, Matthias Cuntz, Silvano Fares, Giacomo Gerosa, Thomas Grunwald, Niklas Hase, Michael Heliasz, Andreas Ibrom, Alexander Knohl, Bart Kruijt, Holger Lange, Jean-Marc Limousin, Denis Loustau, Petr Lukes, Riccardo Marzuoli, Meelis Molder, Leonardo Montagnani, Johan Neirynck, Matthias Peichl, Corinna Rebmann, Marius Schmidt, Francisco Ramon Lopez Serrano, Kamel Soudani, Caroline Vincke, Jan Pisek
Summary: Leaf Area Index (LAI) serves as a key ecological indicator for describing canopy structure and modeling energy exchange between atmosphere and biosphere. While LAI of the forest overstory can be accurately assessed via remote sensing, LAI of the forest understory (LAI(u)) remains challenging to obtain and has been largely ignored in ecological studies. Research on retrieval methodologies for understory LAI demonstrates significant correlation between different methods, but biases depending on the LAI scale are observed.
ECOLOGICAL INDICATORS
(2021)
Article
Limnology
Takehiko Fukushima, Fajar Setiawan, Luki Subehi, Muh Fakhrudin, Endra Triwisesa, Aan Dianto, Bunkei Matsushita
Summary: The ecology of a lake is largely influenced by mixing processes, especially in tropical oligomictic lakes where convection plays a key role in vertical mixing. Through surveys on Lakes Maninjau and Singkarak, the study identified variations in convection events in different seasons and years, shedding light on their impact on the distribution of organisms and chemicals.
Article
Environmental Sciences
Anastazia Daniel Msusa, Dalin Jiang, Bunkei Matsushita
Summary: This study improved a Z(SD) estimation algorithm based on a new underwater visibility theory. The algorithm was shown to have significant improvement in accuracy compared to the original algorithm, as demonstrated by simulated and in situ data. The algorithm was further evaluated using imaging spectrometer images, with promising results in estimating Z(SD) for different optical water types.
Article
Green & Sustainable Science & Technology
Darshana Athukorala, Ronald C. Estoque, Yuji Murayama, Bunkei Matsushita
Summary: This study examined the impacts of urbanization on the natural landscape and ecosystem services of the MMNL in Sri Lanka, revealing a significant decrease in ecosystem service value due to loss of mangrove and marshland from urban expansion. The results suggested that an ecological protection scenario could help decrease the potential future changes in the ESV of the MMNL compared to a business-as-usual scenario, making it a more desirable option for sustainability.
Article
Multidisciplinary Sciences
Takehiko Fukushima, Tatsumi Kitamura, Bunkei Matsushita
Summary: The study investigated the impact of extreme rainfall events (EREs) on lake water quality, finding that the effects depend on factors such as rainfall magnitude, season, and distance from inflow rivers. The highest correlations were found between water quality indicators and rainfall amount in the 10 days before sampling days, with different thresholds of rainfall amount representing different sources of water during EREs and potential changes in the lake's primary production state. These findings emphasize the importance of considering various factors in assessing the effects of EREs on lake water quality.
SN APPLIED SCIENCES
(2021)
Article
Environmental Sciences
Zhaoxin Li, Wei Yang, Bunkei Matsushita, Akihiko Kondoh
Summary: This study proposes a machine learning algorithm, the enhanced random forest regression (ERFR), combined with the theory-based primary production model (TPM), to estimate primary production in aquatic ecosystems. The ERFR outperforms conventional algorithms and captures the variability of key parameters better. The results demonstrate the potential utility of the TPMERFR in assessing global primary production.
REMOTE SENSING OF ENVIRONMENT
(2022)
Article
Environmental Sciences
Chunyang Wang, Yingjie Zhang, Xifang Wu, Wei Yang, Haiyang Qiang, Bibo Lu, Jianlong Wang
Summary: The paper focuses on the transformation of resource-exhausted urban land and proposes a residual-intelligent module network for improved classification accuracy. The study analyzed the land use changes in Jiaozuo city from 1993 to 2020 and found significant shifts in land use types, driven by policies, social development, and economic restructuring. The findings provide important scientific reference for land use planning and sustainable development in resource-exhausted cities.
Article
Environmental Sciences
Hiroyuki Arai, Takehiko Fukushima, Yuichi Onda
Summary: This study analyzed the changes and migration of radiocesium concentrations in sediments and suspended solids in Lake Kasumigaura following the Fukushima nuclear accident in 2011. The results showed that the radiocesium concentration decreased due to riverine input and atmospheric deposition, but remained relatively high. Furthermore, the difference in input between different rivers into the lake is gradually decreasing.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2022)
Article
Limnology
Takehiko Fukushima, Fajar Setiawan, Luki Subehi, Dalin Jiang, Bunkei Matsushita
Summary: In this study, we measured the vertical distributions of water quality indicators in Lake Toba and observed increasing water temperature profiles. Shoaling of hypolimnetic DO-deficient waters was observed in both basins, except during a specific period in the south basin where the zero DO layer deepened. The study found that the minimums of electric conductivity (EC25) corresponded to the maximums of DO in the north basin, and there were significant negative correlations between DO and EC25 in both basins. The results suggest the flow of hypolimnetic water from the south basin to the north basin and the influence of worse water quality near the bottom of the strait on the behavior of DO and EC25.
Article
Environmental Sciences
Takehiko Fukushima, Bunkei Matsushita, Michiaki Sugita
Summary: This study constructed a prediction model to assess the decadal water temperature changes observed at the center of Lake Kasumigaura in Japan. The model incorporated the effects of meteorological and limnological parameters on water temperature changes, and showed good performance in predicting water temperature for several years. The results demonstrated that increases in air temperature and solar radiation raised water temperature, while increases in wind velocity and turbidity lowered water temperature.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Environmental Sciences
Thuy Thi Phuong Vu, Tien Dat Pham, Neil Saintilan, Andrew Skidmore, Hung Viet Luu, Quang Hien Vu, Nga Nhu Le, Huu Quang Nguyen, Bunkei Matsushita
Summary: A pixel-based algorithm and the Google Earth Engine platform were used to monitor the dynamics of mangroves in three provinces along the northern coast of Vietnam from 1990 to 2022. The study found that the mangrove area in these provinces showed fluctuations over time, with an overall increase in recent years. The restoration programs and policies implemented by the Vietnamese government and local authorities were identified as key drivers of this increase.
Article
Chemistry, Analytical
Rossi Hamzah, Bunkei Matsushita
Summary: In this study, a method combining daytime and nighttime satellite data was developed to estimate the impervious surface area percentage (ISA%) in Indonesian watersheds. The method was used to generate ISA% distribution maps from 2003 to 2021 and assess the health status of Indonesian watersheds. The results showed that 88% of Indonesian watersheds remained without impact in 2021, indicating a relatively healthy condition. However, there was a significant increase in total ISA from 2003 to 2021, particularly in rural areas, suggesting potential negative trends in the future without proper watershed management.
Article
Biodiversity Conservation
Licong Liu, Jin Chen, Miaogen Shen, Xuehong Chen, Ruyin Cao, Xin Cao, Xihong Cui, Wei Yang, Xiaolin Zhu, Le Li, Yanhong Tang
Summary: We propose a novel method for remotely sensing alpine grasslines and determining their positions, which is of great importance for investigating the response of alpine grasslands to climate change.
GLOBAL CHANGE BIOLOGY
(2023)