America's Most Vulnerable Coastal Communities
Natural versus anthropogenic mechanisms of erosion along the upper Texas coast
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Published:January 01, 2009
Galveston Island and Bolivar Peninsula have experienced a well-documented history of shoreline and bay shoreline change ranging from +3.63 m/yr to −1.95 m/yr. By integrating core, Light detection and ranging (LIDAR), and coastal change data, we develop a sand budget that attempts to quantify long-term sand sources (e.g., fluvial sand cannibalization through transgression) and sinks (washover fans, offshore sand bodies, and flood-tidal deltas). These results are then considered in light of anthropogenic influences (e.g., beach-nourishment projects, coastal engineering structures, and dredging operations) in an attempt to relate natural versus human influence on coastal change. Our findings suggest that hurricane washover (Galveston Island = 0.4 m/100 yr; Bolivar Peninsula varies from 0.154 m/100 yr to 0.095 m/100 yr) and offshore sand deposits are minimal long-term sand sinks. Flood-tidal deltas, however, appear to be major locations for natural sand sequestration. We also conclude that damming of rivers has had minimal impact on the upper Texas coast, although hard structures, such as the Galveston seawall and its groins, have exacerbated erosion along a shoreline that is currently sand starved. The impact of hard structures has mainly been one of trapping sand in locations where that sand would not have naturally accreted. Sand supply is minimal, so understanding and developing a better sand budget for the Texas coast are vital to sustainability.
- beach nourishment
- coastal sedimentation
- construction
- deltas
- dredging
- erosion
- floods
- fluvial features
- Galveston County Texas
- Galveston Island
- geologic hazards
- Gulf Coastal Plain
- human activity
- hurricanes
- land use
- landform evolution
- laser methods
- lidar methods
- littoral erosion
- radar methods
- remote sensing
- rivers
- sediment supply
- sedimentation
- shorelines
- storms
- Texas
- United States
- Bolivar Peninsula
- tidal deltas