. Figure 3. Shrimp boat sunk in Pass Cavallo (September 1997) Tidal prism is defined as the product of bay water-surface area and the tidal range, typically the spring tidal range. Harwood (1973) concluded that the cross-sectional area of Pass CavaUo decreased after the Colorado River delta eliminated the water-surface area of East Matagorda Bay from the bay system because of the decrease in tidal prism. Her conclusion was based on estimates of the tidal prism and the cross-sectional areas of Pass CavaUo as interpreted from navigation charts and a sateUite photograph (for the year 1971). She U
. Figure 3. Shrimp boat sunk in Pass Cavallo (September 1997) Tidal prism is defined as the product of bay water-surface area and the tidal range, typically the spring tidal range. Harwood (1973) concluded that the cross-sectional area of Pass CavaUo decreased after the Colorado River delta eliminated the water-surface area of East Matagorda Bay from the bay system because of the decrease in tidal prism. Her conclusion was based on estimates of the tidal prism and the cross-sectional areas of Pass CavaUo as interpreted from navigation charts and a sateUite photograph (for the year 1971). She Usts six dates from 1856 to 1971 for which survey data were available for study. By 1971, the discharge through Pass Cavallo had decreased as compared to estimates from earUer dates. With diversion of the Colorado River back to Matagorda Bay in 1992, this cause for a reduction in flow out of the bay was eliminated. More significantly, the discharge through Pass Cavallo has decreased because the Matagorda Ship Channel (MSC) opened in September 1963, as also noted by Harwood (1973). Ward (1982) compared measured tidal prisms of Pass Cavallo and the MSC available from 1959 to 1976 and showed that the MSC had already capmred half the tidal prism by 1976 (Van de Kreeke 1985). Measurements made in the present study, as described in Chapter 3, show that three-fourths of the discharge or prism now goes through the MSC. Pass Cavallo is closing, a situation considered in a physical model Chapter 1 Background and Problem Statement
Size: 2725px × 1834px
Photo credit: © The Bookworm Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcollectionamer, bookcollectionbiodiversity, bookleafnumber15
