College of Environmental Design Professor of Landscape Architecture & Environmental Planning Matt Kondolf and alumnus Pedro J. Pinto (Ph.D LAEP '15) recently published an article comparing and contrasting the environmental changes, framework and implications of two urban estuaries titled, “Evolution of Two Urbanized Estuaries: Environmental Change, Legal Framework, and Implications for Sea-Level Rise Vulnerability.” Published in the November 2016 issue of Water, a journal published by the Multidisciplinary Digital Publishing Institute, the authors consider the similarities and differences between the San Francisco Bay and the Tagus Estuary in Lisbon, Portugal.
Both estuaries share striking similarities in terms of morphology and urban development. The paper further analyzed the development patterns of both estuaries, revealing crucial differences in the extent of shoreline alteration and types of land use that now encroach upon natural estuarine habitat. Through historical map analysis and prior stratigraphic and historical research, Dr. Pinto and Professor Kondolf reconstructed in a GIS environment the evolution of both estuaries over the last millennia and the relative distribution of different classes of land cover.
The paper also discusses the legal frameworks that accompanied this evolution, and how they have influenced the process of wetland reclamation and landfilling. The research team compared the legal history and synchronous patterns of development by compiling historical mapping information and resorting to GIS analysis to explore spatial patterns over time, which allowed researchers to isolate events and decisions that were unique to each of the case studies.
The researchers concluded that while the Tagus Estuary experienced disruption of natural environments for over two millennia, the State was able to keep estuarine lowlands under public control, even though vast areas had been transformed into farmland. Public control could allow wetland migration with rising seas and restoration efforts. The San Francisco Bay, however, was affected by several decades of elevated sediment loads in the 19th century -- which induced rapid wetland expansion -- but virtual cutoff of sediment supply by dams in the 20th century now impairs their ability to accrete. Meanwhile, the Bay Area’s transformation of wetlands into salt ponds, industrial zones and even residential neighborhoods created extensive developed areas at or below sea level, which are vulnerable to even modest rises in sea level.
Read the journal article in full here.