Remote Sensing of Floodpath Lakes and Wetlands: A Challenging Frontier in the Monitoring of Changing Environments

Monitoring of changing lake and wetland environments has long been among the primary focus of scientific investigation, technology innovation, management practice, and decision-making analysis. Floodpath lakes and wetlands are the lakes and associated wetlands affected by seasonal variations of water level and water surface area. Floodpath lakes and wetlands are, in particular, sensitive to natural and anthropogenic impacts, such as climate change, human-induced intervention on hydrological regimes, and land use and land cover change. Rapid developments of remote sensing science and technologies, provide immense opportunities and capacities to improve our understanding of the changing lake and wetland environments. This special issue on Remote Sensing of Floodpath Lakes and Wetlands comprise featured articles reporting the latest innovative research and reflects the advancement in remote sensing applications on the theme topic. In this editorial paper, we review research developments using state-of-the-art remote sensing technologies for monitoring dynamics of floodpath lakes and wetlands; discuss challenges of remote sensing in inventory, monitoring, management, and governance of floodpath lakes and wetlands; and summarize the highlights of the articles published in this special issue

Extraction of Spatial and Temporal Patterns of Concentrations of Chlorophyll-a and Total Suspended Matter in Poyang Lake Using GF-1 Satellite Data

Poyang Lake is the largest freshwater lake in China. Its ecosystem services and functions, such as water conservation and the sustaining of biodiversity, have significant impacts on the security and sustainability of the regional ecology. The lake and wetlands of the Poyang Lake are among protected aquatic ecosystems with global significance. The Poyang Lake region has recently experienced increased urbanization and anthropogenic disturbances, which has greatly impacted the lake environment. The concentrations of chlorophyll-a (Chl-a) and total suspended matter (TSM) are important indicators for assessing the water quality of lakes. In this study, we used data from the Gaofen-1 (GF-1) satellite, in situ measurements of the reflectance of the lake water, and the analysis of the Chl-a and TSM concentrations of lake water samples to investigate the spatial and temporal variation and distribution patterns of the concentrations of Chl-a and TSM. We analyzed the measured reflectance spectra and conducted correlation analysis to identify the spectral bands that are sensitive to the concentration of Chl-a and TSM, respectively. The study suggested that the wavelengths corresponding to bands 1, 3, and 4 of the GF-1 images were the most sensitive to changes in the concentration of Chl-a. The results showed that the correlation between the reflectance and TSM concentration was the highest for wavelengths that corresponded to band 3 of the GF-1 satellite images. Based on the analysis, bands 1, 3, and 4 of GF-1 were selected while using the APPEL (APProach by ELimination) model and were used to establish a model for the retrieval of Chl-a concentrations. A single-band model that was based on band 3 of GF-1 was established for the retrieval of TSM concentrations. The modeling results revealed the spatial and temporal variations of water quality in Poyang Lake between 2015 and 2016 and demonstrated the capacities of GF-1 in the monitoring of lake environment

Pemanfaatan Citra Landsat 8 Multitemporal Untuk Pemetaan Muatan Padatan Tersuspensi Pada Muara Sungai Serayu Jawa Tengah

Alih fungsi lahan pada kawasan Dieng, Kabupaten Wonosobo berdampak pada peningkatan jumlah muatan padatan tersuspensi (MPT) pada muara sungai. Penelitian ini bertujuan untuk: (1) mengkaji kemampuan saluran citra Landsat 8 OLI untuk pemetaan distribusi MPT pada muara Sungai Serayu melalui analisis regresi (2) memetakan variasi dan mengkaji pola distribusi MPT pada muara Sungai Serayu. Metode yang digunakan dalam mengestimasi MPT di muara sungai Serayu adalah analisis regresi liniear antara variabel saluran Landsat 8 OLI dan data MPT aktual. Variabel saluran Landsat 8 OLI yang sesuai untuk memetakan konsentrasi MPT adalah penisbahan antara saluran hijau dan saluran biru atau B3/B2 dengan kesalahan standar yang dihasilkan ± 4,59 mg/l untuk setiap nilai piksel yang diestimasi. Distribusi MPT 2013 sampai 2015 cenderung mengarah ke perairan tenggara muara Sungai Serayu akibat kondisi hidrodinamika seperti pasang surut, arus permukaan dan fenomena upwelling. Pola distribusi MPT cenderung fluktuatif namun terjadi penurunan konsentrasi dari tahun ketahun

PEMANFAATAN CITRA LANDSAT 8 MULTITEMPORAL UNTUK PEMETAAN MUATAN PADATAN TERSUSPENSI PADA MUARA SUNGAI SERAYU JAWA TENGAH

Alih fungsi lahan pada kawasan Dieng, Kabupaten Wonosobo berdampak pada peningkatan jumlah muatan padatan tersuspensi (MPT) pada muara sungai. Penelitian ini bertujuan untuk: (1) mengkaji kemampuan saluran citra Landsat 8 OLI untuk pemetaan distribusi MPT pada muara Sungai Serayu melalui analisis regresi (2) memetakan variasi dan mengkaji pola distribusi MPT pada muara Sungai Serayu. Metode yang digunakan dalam mengestimasi MPT di muara sungai Serayu adalah analisis regresi liniear antara variabel saluran Landsat 8 OLI dan data MPT aktual. Variabel saluran Landsat 8 OLI yang sesuai untuk memetakan konsentrasi MPT adalah penisbahan antara saluran hijau dan saluran biru atau B3/B2 dengan kesalahan standar yang dihasilkan ± 4,59 mg/l untuk setiap nilai piksel yang diestimasi. Distribusi MPT 2013 sampai 2015 cenderung mengarah ke perairan tenggara muara Sungai Serayu akibat kondisi hidrodinamika seperti pasang surut, arus permukaan dan fenomena upwelling. Pola distribusi MPT cenderung fluktuatif namun terjadi penurunan konsentrasi dari tahun ketahun

Multidecadal Remote Sensing of Inland Water Dynamics

Remote sensing approaches to measuring inland water dynamics date back more than 50 years. These approaches rely on the unique spectral properties of different waterbodies to delineate surface extents and estimate optically active water quality parameters. Until recently, inland water remote sensing focused largely on localized study domains due to limitations in modelling methods, computing power, and data access. Recent advances in these areas have created novel opportunities for data-driven-multidecadal remote sensing of inland waters at the landscape scale. Here, I highlight the history of inland water remote sensing along with the dominant methodologies, water quality constituents, and limitations involved. I then use this background to contextualize three macroscale inland water remote sensing studies of increasing complexity. The first combines field measurements with remotely sensed surface water extents to identify the impacts of small-scale gold mining in Peru. Our results suggest that mining is leading to synergistic increases in lake area and mercury loading that are significantly heightening exposure risk for people and wildlife. I move from measuring lake extents in Peru to measuring lake color in over 26,000 lakes across the United States. This analysis shows that lake color seasonality can be generalized into five distinct phenology groups that follow well-known patterns of algae growth and succession. The stability of a given lake (i.e. the likelihood it will move from one phenology group to another) is tied to lake and landscape level characteristics including climate and population density. Finally, I move from simple parameters such as quantity and color to estimating multidecadal changes in water clarity in U.S. lakes. I show that lake water clarity in the U.S. has increased by an average of 0.52 cm yr-1 since 1984, largely as a result of extensive U.S. freshwater pollution abatement measures. In combination, these three studies highlight that data intensive remote sensing approaches are expanding the capabilities of inland water remote sensing from local to global scales, and that macroscale remote sensing of inland waters reveals trends and processes that are unobservable using field data alone.Doctor of Philosoph

Remote Sensing of the Aquatic Environments

The book highlights recent research efforts in the monitoring of aquatic districts with remote sensing observations and proximal sensing technology integrated with laboratory measurements. Optical satellite imagery gathered at spatial resolutions down to few meters has been used for quantitative estimations of harmful algal bloom extent and Chl-a mapping, as well as winds and currents from SAR acquisitions. The knowledge and understanding gained from this book can be used for the sustainable management of bodies of water across our planet