Response of tidal creek networks and tidal connectivity to coastal squeeze of saltmarshes in the southern Bohai Bay

ABSTRACT

Coastal squeeze of saltmarshes (CSS) has substantially eliminated valuable intertidal habitats and worsened local tidal hydrological environment by disintegrating tidal creek networks and losing tidal connectivity (TC). In this study, we explored the process response of creek network structure and TC to CSS dynamics, taking the southern Bohai Bay of China as a case study area. With the Landsat series data and ArcGIS spatial analysis, the morphological and structural evolution of tidal creek systems were quantified by four parameters: creek order, creek length, creek branch point, and network catchment area. Also, the TC was assessed and visualised based on a geostatistical connectivity method. It was found that low-order small creeks were more sensitive and vulnerable to CSS and the creek network would face disintegration when about 50% of the saltmarsh squeeze degree occurred, which has been observed as a crucial threshold. In the seaward direction, the CSS process has led to the continuous replacement of high TC areas by low TC areas, greatly altering the original natural TC pattern. Revealing the relationship between CSS and creek network structure and TC will allow a further understanding of the degradation of intertidal ecosystems, and will promote their ecological and hydrological restoration.

KEYWORDS:

• Coastal squeeze
• saltmarsh
• tidal creek
• tidal connectivity
• sea level rise

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was financially supported by the National Natural Science Foundation of China [grant number 31901155] and the key special project for introduced talents team of Southern Marine Science and Engineering Guangdong Laboratory [grant number GML2019ZD0402].