Long-term variations in water discharge and sediment load of the Pearl River Estuary: Implications for sustainable development of the Greater Bay Area

Abstract

The water discharge and sediment load have been increasingly altered by climate change and human activities in recent decades. For the Pearl River, however, long-term variations in the sediment regime, especially in the last decade, remain poorly known. Here we updated knowledge of the temporal trends in the sediment regime of the Pearl River at annual, seasonal and monthly time scales from the 1950s to 2020. Results show that the annual sediment load and suspended sediment concentration (SSC) exhibited drastically decreased, regardless of water discharge. Compared with previous studies, we also found that sediment load and SSC reached a conspicuous peak in the 1980s, and showed a significant decline starting in the 2000s and 1990s, respectively. In the last decade, however, water discharge and sediment load showed slightly increasing trends. At the seasonal scale, the wet-season water discharge displays a decreasing trend, while the dry-season water discharge is increasing. At the monthly scale, the flood seasons in the North and East Rivers typically occur one month earlier than that in the West River due to the different precipitation regimes. Precipitation was responsible for the long-term change of discharge, while human activities (e.g. dam construction and land use change) exerted different effects on the variations in sediment load among different periods. Changes in the sediment regime have exerted substantial influences on downstream channel morphology and saltwater intrusion in the Greater Bay Area. Our study proposes a watershed-based solution, and provides scientific guidelines for the sustainable development of the Greater Bay Area.

Impacts of river discharge, coastal geomorphology, and regional sea level rise on tidal dynamics in Pearl River Estuary

“…From 1990 to 2015, construction land increased about two times (Liu et al, 2019). Accelerated urbanization resulted in landscape fragmentation (Hu et al, 2021), notorious pollution (Wang and Hao, 2020), hydrological connectivity changes (Shao et al, 2020), and discharge reduction (Horrevoets et al, 2004;Liu et al, 2022), leading to the irreversible structural and functional deterioration of the estuarine ecosystem (Zhang et al, 2010).…”

Evaluation of Wanggu Watershed Carrying Capacity on Water System Indicators in Southeast Sulawesi, Indonesia

“…Sediment resulting from erosion will undergo a deposition process in a place where the flow rate slows down, which is known as the sedimentation process (Arsyad, 2009;Gusarov et al, 2021). The characteristics of the sediment load in the Wanggu watershed have a very serious impact on the sustainability of the waters because it empties into the waters of Kendari Bay where the sedimentation process occurs from the amount of erosion that continues with a large supply of sediment loads from the mainland (Liu et al, 2022;Rogers and Ramos-Scharrón, 2022;Winckler et al, 2023). The results of erosion and sediment load calculations in the Wanggu watershed are presented in Figure 5.…”