Holly Michael's Hydrological, Biological, and Geochemical Linkages in Coastal Wetlands and their response to Climate Change!

Event time and place: ESJ1202 5/3/2024 11:00am

In this talk, Professor Holly Michael of the University of Delaware talked about the many impacts of climate change and sea level rise (SLR). She emphasized the hydrological, biological, and geochemical factors in coastal wetlands and how they respond to climate change. She introduced this of course by acknowledging how climate change has altered the balance of the natural world. All types of water have been hugely affected. She talked about the role of coastal groundwater and how it is “squeezed” between many different uses. One thing that she brought up was that coastal areas have a high population density, so coastal groundwater is contaminated through municipal uses across the coast. Another point that Professor Michael talked about that many people don’t realize is that the ocean is an infinite contaminator. Fresh groundwater naturally flows down towards sea level, and once it reaches the sea or the ocean it becomes contaminated and even unusable. Many people know the main fact that nearly all of the Earth’s water is in its oceans, and Professor Michael does in fact address this. She talked about the geochemical mechanisms that go into the salinization process. For instance, she mentioned lateral intrusion (recharge reduction and pumping), vertical and lateral intrusion (sea level rise), and pure vertical intrusion (ocean surge and flooding). Obviously, all of these hydrology aspects are linked to climate change, and Professor Michael went on to explain how all of these effects have increased due to climate change. Sea levels will only continue to rise and even more usable freshwater will be contaminated. One biological impact that she talked about were ghost forests. These forests full of dead trees are located along coastal wetlands, and can no longer obtain freshwater through their roots, so they die and a barren forest is left in its place. Overall, she talked a lot about the hydrological aspects: surface water, groundwater, salinity, streamflow, soil moisture; and the biological aspects: Plant canopy, vegetation surveys, tree ring data. From this talk, albeit hard to follow as someone who doesn’t know a whole lot about the natural sciences, I was able to relate my understanding of climate change that I’ve learned from SGC correlating the events that the professor talked about to the things we’ve learned so far in SGC.