Mapping the Rapid Decline of the Intertidal Wetlands of China Over the Past Half Century Based on Remote Sensing

Abstract

Intertidal wetland, located at the interface of the continent and ocean, provides significant support to human society. With China being the largest developing country and the second-biggest economy in the world, the intertidal wetland along its coast has been exposed to climate change and over-exploitation for decades. Despite its ecological and economic significance, the distribution and variation of the intertidal wetland remains unknown. In this study, based on a multi-temporal remote sensing archive accumulated since the 1970s, we detected the dynamics of the intertidal wetland along China's coast, at a spatial resolution of 30 m and a time interval of 20 years, over the course of four decades (1970s-2015). The main objectives of this study lie in (1) examining the distribution of and variation in intertidal wetland extent in temporal and spatial aspects; (2) identifying the main driving force of the intertidal wetland dynamics; and (3) making suggestions for future research and management. The results suggest that the extent of intertidal wetland declined substantially during the last four decades, from 7848 km 2 in the 1970s, to 6017 km 2 in 1995, and finally to 4895 km 2 in 2015. On average, the intertidal wetland was 0.22 km in width along the coast, and about 40% of the extent of intertidal wetland was located along the Jiangsu and Shandong coast in 2015. Width shrinkage was detected to be primarily due to seaward migration of the intertidal wetland as a result of intensive land reclamation for tourism, communication, and transportation, as well as the fishery industry. This study improved our understanding of the vulnerable but valuable transition zone covered by intertidal wetland. A high priority should be given to intertidal wetland conservation and habitat reconstruction with a view to a sustainable future.

Shrinking Habitats and Native Species Loss Under Climate Change: A Multifactorial Risk Assessment of China's Inland Wetlands

“…Third, for natural wetlands, a comprehensive baseline inventory and field monitoring network at the national level have not been established, making it difficult to track and evaluate wetland quality and the effectiveness of wetland conservation efforts. In recent years, the development of large‐scale monitoring techniques (e.g., remote sensing) have availed more and more studies on the dynamics of wetland area (Guo et al., 2017; Song et al., 2020). While climate change does affect the persistence of wetland ecosystems, its short‐term effects reflected by changes in distribution or abundance of wetland species are usually hard to capture on broad scales (Taddeo et al., 2019; Wu et al., 2021).…”

Study on the change monitoring of typical estuarine wetland and its effect on ecological factors in Bohai Rim region, China

“…A study highlights that the population of shorebirds in Austria declines is occurring despite high levels of intertidal habitat protection (Dhanjal-Adams et al, 2016). These findings pointed out that the impact of wetland degradation on the ecological environment was far-reaching and even difficult to change for a while, and it is not easy to achieve protection effect (Song et al, 2020). So that immediate and concerted effort is needed both nationally and internationally to effectively habitat conservation.…”

Modeling the Morphodynamic Response of Estuarine Intertidal Shoals to Sea‐Level Rise

“…Worldwide, intertidal areas are experiencing a notable decline due to anthropogenic impact and climate change (Airoldi & Beck, 2007; Murray et al., 2014, 2019; Song et al., 2020). Pressure sources include urbanization (Lai et al., 2015; MacKinnon et al., 2012), changes in riverine flows and sediment supply (Blum & Roberts, 2009; Jaffe et al., 2007), and sea‐level rise (SLR; Lovelock et al., 2017; Passeri et al., 2015).…”