Global potential for the growth of fresh groundwater resources with large beach nourishments

Abstract

Whether a coastal area is suitable for beach nourishments and can induce a growth in fresh groundwater resources depends on the appropriateness of the intended site for beach nourishments, and the attainable growth in fresh groundwater resources. In this study we presume that all eroding sandy beaches are suitable for large beach nourishments, and focus on the impact of these nourishments on fresh groundwater in various coastal settings. The growth in fresh groundwater resources – as a consequence of the construction of a beach nourishment – was quantified with 2-D variable-density groundwater models, for a global range in geological parameters and hydrological processes. Our simulation results suggest that large beach nourishments will likely lead to a (temporary) increase of fresh groundwater resources in most settings. However, for a substantial growth in fresh groundwater, the coastal site should receive sufficient groundwater recharge, consist of sediment with a low to medium hydraulic conductivity, and be subject to a limited number of land-surface inundations. Our global analysis shows that 17% of shorelines may consist of erosive sandy beaches, and of these sites 50% have a high potential suitability. This shows a considerable potential worldwide to combine coastal protection with an increase in fresh groundwater resources.

Natural Variability and Warming Signals in Global Ocean Wave Climates

“…Long‐term variations of wave climate affect a wide range of activities and processes in which wave hydrodynamics play an essential role, such as port operability (Izaguirre et al., 2020), wave energy resources (Fairley et al., 2020), marine and coastal ecosystems (Fraser et al., 2018; Odériz, Gómez, et al., 2020), and water quality (Erftemeijer et al., 2012; Huizer et al., 2019). Furthermore, changes in wave run‐up may significantly increase the risk of coastal erosion (Luijendijk et al., 2018; Ranasinghe, 2016; Toimil et al., 2020) and flooding (Kirezci et al., 2020; Melet et al., 2018).…”

Coastal Wave Extremes around the Pacific and Their Remote Seasonal Connection to Climate Modes

“…Wind-generated ocean surface waves represent the principal driver of open littoral vulnerability over a wide range of scales including long interannual timescales [1]. In particular, coastal breaking waves have been shown to contribute significantly to extreme coastal water-level episodes and associated flooding and erosion [2][3][4][5][6], therefore strongly impacting littoral socio-economic systems and human activities, e.g., coastal infrastructures' maneuverability [7], energy resources [8], marine/mangrove ecosystems [9,10], water quality [11,12], aquaculture, and oil industries [13,14].…”

Shoreline retreat and beach nourishment are projected to increase in Southern California

“…Artificial nourishment is established as a soft coastal management adaptation to changing and fluctuating hydroclimatic conditions 33 . Nourishment practices synergize economic activities such as tourism by preserving a suitable beach width and agriculture by restoring water quality in coastal aquifers 34 . Although nourishment is often considered eco-friendly for beach restoration and protection, it also negatively impacts its ecosystem's sustainability 35 .…”