Coastal Hydrology
# Peculiar Dynamics: The Impact of Sea Level Rise on Coastal Hydrology
The rising volume of the world's oceans, a particularly alarming consequence of climate change, is reshaping coastal hydrology in peculiar and dramatic ways. Particularly, the residence time of water in coastal systems, the amount of time a molecule of water resides within a particular area before exiting, is changing. This change, along with the altering of usual coastal features, has far-reaching impacts on the natural and human-managed systems that reside in these areas.
Take, for instance, the Gold Coast and other similar coastal cities. As sea levels rise, the coast's capacity to handle oceanic inflow diminishes. The once reliable barriers - embankments, buffers of islands and islets, and even man-made structures - are cracking under the pressure of the increased volume of water. The rise in sea level reshapes the coastal landscape, corrugating the shoreline and depositing sediment in new areas.
The altered coastline impacts the hydrology of connected water bodies. The English Channel and the Bering Strait, for example, are seeing changes in their currents, impacting both upstream and downstream riverways. The upstream portions of rivers, even those as far as the headwaters, are experiencing increased salinity, turning freshwater brooks and streams into brackish tributaries.
The increase in saline water upstream can miscalculate the residency of water molecules within the system. In the Gulf Stream, a critical oceanic current, warmer, saltier water is pushed farther north than historically noted, altering the maritime climate and ecology of regions far from the coast.
Moreover, the deflation of barrier systems such as offshore platforms and embankments also leads to increased sedimentary deposition in areas like the seabed and oceanic trenches. This deposit of sediment, coupled with the rising oceanic basin, is transforming the ocean floor, creating new underwater landscapes which alter the direction and speed of ocean currents.
The impact of sea-level rise on hydrology isn't limited to the surface. Subterranean rivers and thermal springs, hidden players in the water cycle, are also affected. Changes in pressure and volume at the surface can cause underground rivers to redirect, or worse, dry up completely.
These transformations in coastal hydrology are undeniable proof of our rapidly changing world. As we navigate these changes, it is paramount to calculate and understand these shifts. Only then can we prepare our dwellings, towns, and cities for the new era of hydrological dynamics. Despite the challenges ahead, our resilience and resourcefulness can help us adapt, ensuring our continued residency on this beautiful, yet ever-changing planet.
