Combining Multispectral Imagery with in situ Topographic Data Reveals Complex Water Level Variation in China’s Largest Freshwater Lake

Wu, Guojun; Liu, Yuanbo

doi:10.3390/rs71013466

Cited by 18 publications

(10 citation statements)

References 59 publications

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“…This result was consistent with former studies [31,57]. During the retreating period, the water level decreases slowly from south to north, with water levels dropping first in the southern parts of Poyang Lake and a water level gradient reappearing in the main lake body of the lake [58]. Different from the rising period, the slope of grassland area change decreased with the declining water levels due to the distribution pattern of wetland vegetation in Poyang Lake (Figure 7).…”

Section: Relations Between Grassland Area and Water Levelsupporting

confidence: 82%

“…The slope increased from north to south as follows: Xingzi (coefficient of x 2 equals to −16.21), Duchang (coefficient of x 2 equals to −19.08), Tangyin (coefficient of x 2 equals to −31.99), and Kangshan (coefficient of x 2 equals to −96.98). During the retreating period, the water level decreases slowly from south to north, with water levels dropping first in the southern parts of Poyang Lake and a water level gradient reappearing in the main lake body of the lake [58]. Different from the rising period, the slope of grassland area change decreased with the declining water levels due to the distribution pattern of wetland vegetation in Poyang Lake (Figure 7).…”

Section: Relations Between Grassland Area and Water Levelmentioning

confidence: 99%

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Spatial–Temporal Dynamics of Wetland Vegetation Related to Water Level Fluctuations in Poyang Lake, China

Tan

Jiang

2016

Water

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Hydrological properties are driving forces of wetland systems. The influence of water level fluctuations on vegetation distribution is of growing interest as wetlands are increasingly disturbed by climate change and intensive human activity. Based on time series MODIS (Moderate Resolution Imaging Spectroradiometer) imagery from 2000 to 2012, we investigated the spatial-temporal dynamics of wetland vegetation in Poyang Lake using a combined Sen's slope and Mann-Kendall (MK) test approach, and explored their correlations with water level fluctuations in different hydrological periods. The results showed that more than 34% of wetlands at lower elevations of Poyang Lake had experienced an increasing trend in the enhanced vegetation index (EVI), whereas EVI in about 11% of the wetlands at higher elevations decreased significantly. Responses of grassland area extracted from MODIS EVI were found to be more sensitive to water level fluctuations in the southern lakes. The change rate of grassland area decreased with the rising water level during the rising period, but increased with the rising water level during the retreating period. Correlations between grassland area and water level were much weaker in the dry period. In addition, we found fluctuations of the main water body had negligible effect on grassland area since the water level at Xingzi station was below 14 m. These results provide new insights for predicting future changes of wetland vegetation influenced by the ongoing threats from climate change and human activity, and form a foundation for ecosystem management of Poyang Lake.

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Section: Relations Between Grassland Area and Water Levelsupporting

confidence: 82%

Section: Relations Between Grassland Area and Water Levelmentioning

confidence: 99%

Spatial–Temporal Dynamics of Wetland Vegetation Related to Water Level Fluctuations in Poyang Lake, China

Tan

Jiang

2016

Water

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“…Other researchers studied variations in bottom topography across Poyang Lake through quantification of erosion and deposition patterns between 1998 and 2010. These studies indicate that the lake's boundary and bathymetry have remained stable in the last two decades ( Wu and Liu, 2015;Zhu et al, 2014 ).…”

Section: Poyang Lake Basin Morphologymentioning

confidence: 94%

Dramatic variations in emergent wetland area in China's largest freshwater lake, Poyang Lake

Mei

Dai

Fagherazzi

et al. 2016

Advances in Water Resources

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a b s t r a c tFreshwater wetlands are important ecosystems experiencing rapid degradation around the world. As much as 64% of world's wetland area has been lost since 1900; the situation is even more serious in Asia, where land reclamation and anthropogenic modifications of rivers are increasing the rate of wetland disappearance. In this study, we provide a first complete estimation of daily Emergent Wetland Area (EWA) in Poyang Lake, China's largest freshwater lake, from 1955 to 2012. A wavelet analysis indicates a strong periodicity in the monthly EWA time series with two oscillations having a period of 12 and 60-72 months, respectively. A dramatic increase in mean annual EWA is detected since 2003, when the Three Gorges Dam (TGD) was completed, mainly due to the seasonal drying of 1078 km 2 of wetlands in October. It is found that the timing of wetland emergence during the dry season has been anticipated of one month, from November to October, since the establishment of TGD. It is argued that a significant increase in wetland exposure and an observable shift in the seasonal timing of flooding and drying will seriously degrade the wetland system and threaten the endangered migratory birds that inhabit it unless effective countermeasures are implemented.

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“…Merging zonal flood information with topography can reveal complexities in water surface dynamics [12,13] and in local flow connectivity [14], which are difficult to observe with flood imagery or maps alone. Integrating satellite data with models can lead to significant improvements in the latter, especially for large scale flood hydrology and hydrodynamics, as illustrated by Pinel et al [15] in the Amazon Basin and by Jung and Jasinski [16] in the Atchafalaya Basin.…”

Section: Overview Of Contributionsmentioning

confidence: 99%

Preface: Remote Sensing in Flood Monitoring and Management

Schumann

2015

Remote Sensing

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This Special Issue is a collection of papers studying the use of remote sensing data and methods for flood monitoring and management. The articles contributed span a wide range of topics and present novel processing techniques, review methods and discuss limitations, and also report on current capabilities and outline emerging needs. This preface provides a brief overview of the content.Keywords: flood hazard and risk; satellite imagery; altimetry; digital elevation model; hydrodynamics ScopeFloods can be mapped and monitored with remotely sensed data acquired by aircraft and satellites, or even from ground-based platforms. The sensors and data processing techniques that exist to derive information about floods are numerous. Instruments that record flood events may operate in the visible, thermal and microwave range of the electromagnetic spectrum. Due to the limitations posed by adverse weather conditions during flood events, active radar is invaluable for monitoring floods; however, if a visible image of flooding can be acquired, retrieving useful information from this is often more straightforward.Apart from providing direct information about flooding, remote sensing data can also be integrated with flood models (via model calibration or validation, and data assimilation techniques) or provide floodplain topography data to augment the amount and type of information available for efficient flood management. There have been notable studies on integrating remotely sensed data with flood modeling since the late 1990s and there is now a general consensus among space agencies to strengthen the support that satellite missions can offer. This trend has stimulated more research in this area, and significant progress has been achieved in recent years in fostering our understanding of the ways in which remote sensing can support flood monitoring and management.This Special Issue presents a collection of work on current efforts to aid advancing flood monitoring and management through remotely sensed data. The following section gives a brief overview of the large variety of papers contributed to this Special Issue, presenting the use of remote sensing data and methods in flood research and applications. Overview of ContributionsThe variety of high quality research and application studies published in this Special Issue is large and I only provide a brief overview here. I encourage the reader to refer to the entire Special Issue to gain insight into the current state-of-the-art methods employed in remote sensing for flood monitoring and management.The contributed articles cover local to global scale applications and range across a number of fields (e.g., disaster management and societal impact, flood forecasting, rainfall-runoff modeling, A number of papers in this Special Issue also demonstrate that much is to be gained from combining satellite flood maps with digital elevation models (DEMs) and also distributed process models. Merging zonal flood information with topography can reveal complexities in water surf...

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Combining Multispectral Imagery with in situ Topographic Data Reveals Complex Water Level Variation in China’s Largest Freshwater Lake

Cited by 18 publications

References 59 publications

Spatial–Temporal Dynamics of Wetland Vegetation Related to Water Level Fluctuations in Poyang Lake, China

Spatial–Temporal Dynamics of Wetland Vegetation Related to Water Level Fluctuations in Poyang Lake, China

Dramatic variations in emergent wetland area in China's largest freshwater lake, Poyang Lake

Preface: Remote Sensing in Flood Monitoring and Management

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