April 16, 2013 by Dr. G
We all headed back to the conference center (across the street from the hotel) for Day 2 of Coastal Processes & Environments Under Sea-Level Rise. The posters were still available for viewing during and at the end of the day, while the morning and afternoon had 15 talks presented as case studies on the coastal response to accelerated sea-level rise and variations in sediment supply.
Whereas yesterday’s speakers focused heavily on the Gulf of Mexico, today’s talks focused on rivers, delta systems, barrier islands, and overall coastal processes from locations across the globe. I found it extremely valuable to hear about sediment yields on the Yangtze River, the large river discharge along the Ganges-Brahmaputra tidal delta plain, the impact of increasing human activities in Mediterranean deltas, and some fascinating coastal maintenance going on in the Netherlands.
I can’t possibly recap all of the science presented today – in fact, the AGU publication EOS will have an excellent scientific summary in an upcoming issue. But here are my main takeaways from Day 2:
- In east/southeast Asia, delta erosion has been a common feature due to insufficient sediment supply, together with the sea level rise, putting the mega-delats along the western Pacific Ocean at risk of destruction.
- The Asian margin provides the sediment record we need to study sea-level history, not the east coast of the USA (too many transgressions/regressions and reworking of sediments).
- There is an excellent online resource for Global River and Delta Systems Source-to-Sink Information Center.
- Our challenge as coastal geologists is to produce an unbiased measure of deltaic shoreline position and land area through time (need to quantify roles of tides, river discharge, wind and vegetation on the instantaneous position of the “hydrodynamic shoreline”).
- Flooding is not necessarily a bad thing – it is not a disaster for everyone; in fact, flooding is just a part of life in areas such as the Ganges-Brahmaptura tidal delta (agriculture/rice is grown during low waters, and fishing takes place during wet season/high water). This image is an excellent example, drawn by children in Bangladesh for OXFAM’s Climate Change Canvas, that is not a dark/depressing image but shows a community coping/existing in a flood.
- Unless society is willing to abandon deltaic landscapes, engineered diversions that disperse sediment to build land are necessary to counter future land loss.
- Coastal evolution is a balance between accommodation space (relative sea-level rise) and sediment supply. Sea-level rise is not a problem, per se, it depends on sediment budget. In the Dutch coastal system, they are able to successfully get sand from the North Sea (large volume of sand available) to build a sand buffer for coastal renourishment (check out Deltares website and their Sand Motor Mega-Nourishment Experiment).
- With a 16-inch sea-level rise, the runways at San Francisco airport will be submerged.
- One difference between California and the east coast of the USA – once a CA house goes down with a bluff, you can’t rebuild because the bluff is gone. On east coast, we rebuild in the same spot even after a disaster hits, since the land is still there.
- In the Philippines, coastal erosion is prevalent and severe in many places, but it is not yet recognized as a national issue. There is only one geologist in the Philippines working on coastal erosion issues!
Overall, it was really valuable for me to sit through so many presentations about coastal issues in global locations. In my courses, I tend to try very hard to choose local examples to make my courses relevant to all of my non-science majors that are only taking science to satisfy a graduation requirement. I now realize that I am not helping my students see the global connections of all Earth systems by choosing only regional issues and locations. The next time I teach, the world really will be coming to my students!
And, I have to give a shout-out to Steven Goodbred, a faculty member at Vanderbilt University. It was great to see him talk today about his work in Bangladesh. Steve and I met as undergraduate students when we both participated in a semester at the Marine Biological Laboratory in Woods Hole, Massachusetts. Steve was a student at Boston University, and I was a student at the “other BU” – Bucknell University. Steve and I were the only geology majors participating in the Boston University Marine Program (BUMP) that fall semester and took the same classes. Ironically, we then both headed to Florida for graduate school (Steve at University of South Florida, myself at University of Miami-RSMAS). So a note to all of my students – you never know who you may run in to in the future – it is a small world! And seeing Steve reminds me of some of the best lectures, fieldtrips, and research experiences of my undergraduate career.
Oh, and before I forget… I should show an image of my poster! I’m not giving a talk, but instead presenting a poster of the importance of having undergraduate students engage in communicating oceanographic and coastal issues while they are students, even if they are not science majors. All students are voting citizens that read/hear the news and need to be ready to engage in conversations and be actively involved in charting the environmental future of the planet. I’ve had some great conversations with people here at the conference about the projects my students have done – it is a great feeling to know that others (besides myself!) get excited about the impact students can have.
Tomorrow is a big day. It is only half a day of presentations, so we can spend the entire afternoon going on a fieldtrip! More to come….