MorphEst: An Automated Toolbox for Measuring Estuarine Planform Geometry from Remotely Sensed Imagery and Its Application to the South Korean Coast

Abstract

The rapid advance of remote sensing technology during the last few decades provides a new opportunity for measuring detectable estuarine spatial change. Although estuarine surface area and convergence are important hydraulic parameters often used to predict long-term estuarine evolution, the majority of automated analyses of channel plan view dynamics have been specifically written for riverine systems and have limited applicability to most of the estuaries in the world. This study presents MorphEst, a MATLAB-based collection of analysis tools that automatically measure estuarine planform geometry. MorphEst uses channel masks to extract estuarine length, convergence length, estuarine shape, and areal gain and loss of estuarine surface area due to natural or human factors. Comparisons indicated that MorphEst estimates closely matched with independent measurements of estuarine surface area (r = 0.99) and channel width (r = 0.92) of 39 estuaries along the South Korean coast. Overall, this toolbox will help to improve the ability to solve research questions commonly associated with estuarine evolution as it introduces a tool to automatically measure planform geometric features from remotely sensed imagery.

Impact of Estuarine Dams on the Estuarine Parameter Space and Sediment Flux Decomposition: Idealized Numerical Modeling Study

“…L post , W LT , and W HT based on Landsat views (http://earthexplorer.usgs.gov). L b was derived using the MorphEst automated toolbox (Jung et al., 2021). Data sources ( DS ) for T 1 , T 2 , L pre , and D : 1 = Connell et al.…”

“…Sediments are important in estuaries because sediment flux gradients contribute to the depth and texture of the bed and the overall turbidity of the water column which in turn affects estuarine fisheries and navigability. At present, sediment fluxes are changing in estuaries, as humans have modified the shape of estuaries worldwide through activities such as land reclamation, dredging, and the construction of hard engineering structures (Jung et al., 2021; Wang et al., 2015). Land reclamation and dredging are often carried out to create land area and improve navigability, respectively (Winterwerp & Wang, 2013), while hard engineering structures such as breakwaters, riprap, jetties, and seawalls have been designed to absorb wave energy and stabilize the coast (Davis & Fitzgerald, 2019).…”

“…L post , W LT , and W HT based on Landsat views (earthexplorer.usgs.gov). L b was derived using the MorphEst automated toolbox(Jung et al, 2021). Data sources (DS) for T 1 , T 2 , L pre , and D : 1 = Connell et alStatistics of 10 Selected Estuaries With Estuarine Dams Constructed Within or Near the Salt Intrusion Limit…”

Economic Development Drives Massive Global Estuarine Loss in the Anthropocene

“…We measured land reclamation using the 2020 global land cover data set GlobeLand30 (resolution: 30 × 30 m) (Chen et al, 2015). Here, MorphEst identified land use within areas of ESA loss for each estuary, where reclaimed land represents land that was classified as urban and/or agriculture by the global land cover map (Jung et al, 2021). We then calculated the proportion of land reclamation (i.e., agricultural and urban land) to natural land (i.e., forest, grassland, wetlands, and barren land).…”

“…Although estuaries and their ecosystem services are valued at approximately US$10,000 per hectare (Barbier et al., 2011; Kirwan & Megonigal, 2013), human development has modified estuaries worldwide through deforestation, urbanization, agricultural impoundment, and river flow diversion (Syvitski et al., 2005), where many estuarine tidal flats and wetlands have been converted to vast agricultural and urban areas (Syvitski & Saito, 2007). For example, large‐scale land reclamation projects accounted for 60% of the observed estuarine surface area (ESA) loss in South Korea within the last 30 years (Jung et al., 2021). Although many laws and conservation efforts have been implemented to slow estuarine area loss and the degradation of estuarine ecosystems, developing countries continue to convert estuarine systems to other land use types (Kirwan & Megonigal, 2013; Wang et al., 2014).…”