TY - JOUR
T1 - Sea-level-rise-induced threats depend on the size of tide-influenced estuaries worldwide
AU - Leuven, J.R.F.W.
AU - Pierik, H.J.
AU - van der Vegt, M.
AU - Bouma, T.J.
AU - Kleinhans, M.G.
PY - 2019/11/4
Y1 - 2019/11/4
N2 - The effects of sea-level rise on the future morphological functioning of estuaries are largely unknown because tidal amplitudes will change due to combined deepening of the estuary mouth and shifting amphidromic points at sea. Fluvial sediment supply is also globally decreasing, which hampers infilling necessary to maintain elevation relative to sea level. Here we model 36 estuaries worldwide with varying sizes, shapes and hydrodynamic characteristics, and find that small shallow estuaries and large deep estuaries respond in opposite ways to sea-level rise. Large estuaries are threatened by sediment starvation and therefore loss of intertidal area, particularly if tidal amplitude decreases at the mouth. In contrast, small estuaries face enhanced flood risks and are more sensitive to tidal amplification on sea-level-rise-induced deepening. Estuary widening can partly mitigate adverse effects. In large estuaries, expanded intertidal areas increase tidal prism and available erodible sediment for adaptation, whereas it slightly reduces tidal amplification in small estuaries.
AB - The effects of sea-level rise on the future morphological functioning of estuaries are largely unknown because tidal amplitudes will change due to combined deepening of the estuary mouth and shifting amphidromic points at sea. Fluvial sediment supply is also globally decreasing, which hampers infilling necessary to maintain elevation relative to sea level. Here we model 36 estuaries worldwide with varying sizes, shapes and hydrodynamic characteristics, and find that small shallow estuaries and large deep estuaries respond in opposite ways to sea-level rise. Large estuaries are threatened by sediment starvation and therefore loss of intertidal area, particularly if tidal amplitude decreases at the mouth. In contrast, small estuaries face enhanced flood risks and are more sensitive to tidal amplification on sea-level-rise-induced deepening. Estuary widening can partly mitigate adverse effects. In large estuaries, expanded intertidal areas increase tidal prism and available erodible sediment for adaptation, whereas it slightly reduces tidal amplification in small estuaries.
U2 - 10.1038/s41558-019-0608-4
DO - 10.1038/s41558-019-0608-4
M3 - Article
SN - 1758-678X
VL - 9
SP - 986
EP - 992
JO - Nature Climate Change
JF - Nature Climate Change
IS - 12
ER -