A three-dimensional (3D) numerical model was developed to investigate the thermodynamic and sediment processes in a subtropical drinking water reservoir. Data-driven models were also established to generate the inflow conditions. The modelling outputs revealed that climatic forces such as storms and winds significantly impact lake stratification and mixing processes. The sediment transport is driven by storm events, during which sediment delivery to the reservoir is dominated by allochthonous flux. The sediments are transported from riverine zones to transition zones and finally to lacustrine zones. It is estimated that sediment accumulation could have reached 100,000 kg during the largest storm event in February 2015.The winds can lead to a strong vertical water cycle, especially at the centre of the reservoir, and strong winds result in bed erosion in shallow regions. The outcomes of this paper benefit future research by providing a modelling approach for understanding the hydrodynamics of lakes and reservoirs under a variable climate, and also the local water utility by providing insights for an improved management of the reservoir of this study. Article Highlights:• Coupled data-driven and numerical model of a shallow water reservoir • Storm and winds have significant impacts on the lake stratification and mixing processes. • Sediment transport dominated by allochthonous flux during storm.• Strong winds result in the bed erosion in shallow regions of the lake.

A good understanding of the physical processes of lakes or reservoirs, especially of those providing drinking water to residents, plays a vital role in water management. In this study, the water circulation and mixing processes occurring in the shallow, subtropical Tingalpa Reservoir in Australia have been investigated. Bathymetrical, meteorological, chemical and physical data collected from field measurements, laboratory analysis of water sampling and an in-situ Vertical Profile System (VPS) were analysed. Based on the high-frequency VPS dataset, a 1D model was developed to provide information for vertical transport and mixing processes. The results show that persistent high air temperature and stable reservoir water depth lead to a prolonged thermal stratification. Analysis indicates that heavy rainfalls have a significant impact on water quality when the dam level is low. The peak value of Dissolved Organic Carbon (DOC) concentration occurred in the wet season, while the specific UV absorbance (SUVA) value decreased when solar radiation increased from spring to summer. The study aims to provide a comprehensive approach for understanding and modelling the water mixing processes in similar lakes with high-frequency data from VPS’s or other monitoring systems.

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Species invasion in salt marsh wetlands is known to disturb the balance of biotic and abiotic ecosystems (e.g., changing material exchange cycles and community structure). However, its influence on the morphological evolution of salt marshes is not yet understood in depth. This study investigates the long-term temporal and spatial distributions of an invasive plant—Spartina alterniflora (S. alterniflora)—and its morphological characteristics in Yangtze Estuary by remote sensing imagery interpretation, tidal creek extraction, regional statistical analysis, and proximity analysis. The invaded site shows an area of S. alterniflora with a 35-fold increase from the start to the end of its initiation phase; it is the second biggest species in the study area. It is found that species invasion not only limited the expansion of native pioneer vegetation but also changed bio-geomorphic feedback loops. With the influence of plant invasion, median tidal creek lengths decreased and the median tidal creek sinuosity ratio remained stable, between 1.06 and 1.07 in the subarea. The method used here is adaptable to other salt marshes. The findings from this study can provide practical guidance for the restoration of native salt marshes in the estuary and thus control the spread of invasive species.

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