Sand Distribution and Statistical Spatial Characteristics on Pacific Reef Platforms
Abstract
Our long-term goal is to improve understanding of sand distribution, temporal variability, and response to geologic substrate factors on Hawaiian reef platforms within the depth zone from 20 m to the shoreline. We are analyzing patterns of sand distribution on the reef platform, and how they are related to morphology. These patterns and surrounding morphology are best understood using spatial analysis tools emphasizing remote sensing. The work consists of several steps including remote sensing analysis, field work data collection, and spatial analysis. Our top-level goal is to quantify and build a geologic model of the temporal variability and spatial distribution of carbonate sand on fringing reefs. Although waves and currents on fringing reefs mobilize sands they ultimately accumulate under the influence of geologic factors governing hard substrate relief (i.e., karst bathymetry, coral community rugosity, spur and groove development, antecedent topography, etc.). These factors are products of nearshore geologic processes and they exert important controls on the sandy sea floor that work together with dynamic sediment transport processes to determine sand accumulation. We seek to define the relationship between active sand accumulation and reef geologic factors controlling substrate relief. To do this we have implemented a nested scale analysis using image classification and field data. We identify three domains of study defined by spatial scale: 1) fine-scale classification of individual sandy substrate types in localized portions of the reef surface (< 3m resolution), 2) meso-scale spatial relationships between individual sandy substrate classes and their surrounding hard substrate (between 3m and 10m resolution), and 3) coarse-scale statistical distributions and relationships of sandy substrate classes in a test area, and their correlation with geologic factors governing reef substrate.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 29, 2004
- Accession Number
- ADA613081
Entities
People
- Charles H. Fletcher
Organizations
- University of Hawaiʻi System