Estuaries & Coasts
Estuaries and coastal environments experience the combined influences of river discharge, tides, storm surge, waves, sediment processes, and sea-level change. In the GGBI Framework, estuarine and coastal applications highlight how upstream and coastal drivers interact—and how portfolios of Green, Grey, Blue, and Intelligent elements support resilience.
Estuaries & Coasts in the GGBI Framework
Estuaries and coastal systems lie at the downstream end of watersheds and the upstream edge of the ocean. They integrate signals from both directions. The GGBI Framework helps clarify how:
- River discharge and tidal forcing interact to shape water levels and currents.
- Storm surge and waves propagate inland and interact with infrastructure.
- Wetlands and marshes influence flood attenuation, sediment processes, and ecology.
- Shoreline structures modify nearshore hydrodynamics and sediment transport.
- Sea-level rise alters estuarine circulation, salinity, and inundation patterns.
These environments are especially sensitive to climate variability, extreme events, and upstream land- and water-management decisions.
Representative Settings & Processes
Tidal Rivers & Channels
Transitional zones where river-driven flows meet tidal forcing, influenced by bottom friction, geometry, salinity, winds, and upstream–downstream gradients.
Estuaries & Bays
Partially mixed or stratified systems that respond to river inflows, tides, winds, and basin geometry, and host critical ecological and biogeochemical processes.
Coastal Shorelines
Dynamic zones shaped by waves, longshore transport, coastal storms, sea-level change, and human interventions such as seawalls, breakwaters, and nourishment.
Wetlands & Marshes
Intertidal vegetated areas that provide habitat, wave attenuation, nutrient cycling, and floodwater storage—and are sensitive to sediment supply and sea-level rise.
Interactions Across the GGBI Domains
Estuarine and coastal challenges often require combinations of:
- Green elements: wetlands, living shorelines, coastal marsh restoration, and upland GI that influence flows and sediment delivery.
- Grey elements: levees, seawalls, breakwaters, tidal gates, surge barriers, navigation channels, and shoreline stabilization structures.
- Blue elements: tides, storm surge, waves, salinity, stratification, and sediment dynamics that shape estuarine and coastal behavior.
- Intelligent elements: monitoring networks, hydrodynamic and morphodynamic models, forecasting systems, and tools for evaluating adaptation under sea-level rise and changing storm patterns.
The GGBI Framework emphasizes how these elements reinforce or constrain each other across spatial and temporal scales.
Sea-Level Rise, Extreme Events, & Coastal Resilience
Estuaries and coasts face increasing risks from sea-level rise, stronger storms, and changing wave climates. Applications within the GGBI Framework can support:
- Evaluation of storm-surge pathways and coastal flooding.
- Assessment of shoreline change and sediment budgets.
- Analysis of salinity intrusion and estuarine circulation under future conditions.
- Design and evaluation of hybrid Green–Grey interventions.
- Development of long-term coastal adaptation strategies.
Resilience planning benefits from linking hydrodynamics, geomorphology, ecosystems, and infrastructure considerations.
Connections to Other GGBI Domains
- Green domain – wetlands, marshes, and upland GI
- Grey domain – coastal structures and flood protection
- Blue domain – estuarine and coastal processes
- Intelligent domain – models, monitoring, and forecasting