Land and water resources, historical changes, and dune criticality : Mustang and North Padre Islands, Texas

Accompanied by 1 foldout plate -- Plate 1 : Land and water resources, Mustang and north Padre Islands, TexasUT Librarie

Digital Compilation of Submerged Lands Sediment Textures, Sediment Geochemistry, and Washover Areas of the Texas Coast

This report summarizes the methods used by the Bureau of Economic Geology (BEG) to produce electronic files of sample locations, sediment textures, and geochemical analyses for about 6,700 sediment samples collected from the Submerged Lands of Texas, including all coastal bays, estuaries, lagoons, and the inner continental shelf extending 10.3 mi into the Gulf of Mexico. Active washover areas and other potential sites of oil invasion along the Texas Gulf shore were also mapped and digitized for inclusion in the Texas Natural Resources Inventory (NRI) ARC/INFO geographic information system (GIS). The major categories of the NRI program addressed by this project include 1.2a2 (sediment metals), 1.2a9 (sediment grain size), 1.2a10 (sediment total organic carbon), 1.7e (sediment percent sand), and 2.6e(c) (morphology of washover areas). The primary results of the project were electronic files containing the locations and attributes of surficial sediments and washover areas of the following seven coastal regions: Beaumont-Port Arthur (Sabine Lake), Houston Galveston (Galveston Bay), Bay City-Freeport, Port Lavaca (Matagorda Bay), Corpus Christi (Corpus Christi Bay), Kingsville (upper Laguna Madre), and Brownsville-Harlingen (lower Laguna Madre). These seven regions cover the entire Texas coast and include all of the NRI highest priority areas.Bureau of Economic Geolog

Conceptual information processing: A robust approach to KBS-DBMS integration

Integrating the respective functionality and architectural features of knowledge base and data base management systems is a topic of considerable interest. Several aspects of this topic and associated issues are addressed. The significance of integration and the problems associated with accomplishing that integration are discussed. The shortcomings of current approaches to integration and the need to fuse the capabilities of both knowledge base and data base management systems motivates the investigation of information processing paradigms. One such paradigm is concept based processing, i.e., processing based on concepts and conceptual relations. An approach to robust knowledge and data base system integration is discussed by addressing progress made in the development of an experimental model for conceptual information processing

Decline of Submerged Vegetation in the Galveston Bay System: Chronology and Relationships to Physical Processes

The Galveston Bay complex of Texas ranks as the 7th largest estuary in the USA, including 143,000 ha (about 554,000 acres) of open water and approximately 93,000 ha (230,000 acres) of wetlands, of which about 48,000 ha (about 118,000 acres) are marshes and swamps. These habitats support finfish and shellfish populations, which annually account for 28 percent of the total Texas commercial bay fisheries landings, 67 percent of the Texas oyster harvest (averaging 3.6 million pounds), and 30 percent of blue crab and shrimp harvests. This production is sustained by a combination of high freshwater inflows from the Trinity-San Jacinto Rivers, nutrient cycling dynamics of bay wetlands, and nursery grounds afforded by shallow-water habitats. Despite its inherent natural resource value, Galveston Bay has been heavily impacted by shoreline industrial and municipal development, excess inputs of pollutants and wastewater discharges, channelization, dredging projects, subsidence, and alterations in bay-water circulation dynamics. Degradation of the bay-system's water quality has increased to the point that over 38 billion gallons a day of waste effluents are discharged into the bay and its tributaries. A decline of approximately 90 percent in bay submerged vascular vegetation (SV) since 1956 (when aerial photographs indicate approximately 2,070 ha -- 5,120 acres) is an alarming environmental impact because of the loss in fisheries nursery habitat. The disappearance of this valuable subtidal habitat has received widespread attention with the recent designation of Galveston Bay as a national estuary by the EPA National Estuary Program. Review of the chronological sequence of SV habitat loss has been recommended to help determine critical factors threatening estuarine habitats and to design management solutions for restoration of impacted SV habitat.Bureau of Economic Geolog

Decline of submerged vegetation in the Galveston Bay system: chronology and relationships to physical processes

The Galveston Bay complex of Texas ranks as the 7th largest estuary in the USA, including 143,000 ha (about 554,000 acres) of open water and approximately 93,000 ha (230,000 acres) of wetlands (Diener 1975), of which about 48,000 ha (about 118,000 acres) are marshes and swamps (Fisher et al. 1972). These habitats support finfish and shellfish populations which annually account for 28 percent of the total Texas commercial bay fisheries landings, 67 percent of the Texas oyster harvest (Avg. 3.6 million pounds), and 30 percent of blue crab and shrimp harvests (NOAA 1989). This production is sustained by a combination of high freshwater inflows from the Trinity-San Jacinto Rivers, nutrient cycling dynamics of bay wetlands, and nursery grounds afforded by shallow-water habitats. Despite its inherent natural resource value, Galveston Bay has been heavily impacted by shoreline industrial and municipal development, excess inputs of pollutants and wastewater discharges, channelization, dredging projects, subsidence, and alterations in bay-water circulation dynamics. Degradation of the bay-system's water quality has increased to the point that over 38 billion gallons a day of waste effluents are discharged into the bay and its tributaries (NOAA 1989). A decline of approximately 90 percent in bay submerged vascular vegetation (SV) since 1956 (when aerial photographs indicate approximately 2,070 ha -- 5,120 acres: Fisher et al. 1972) is an alarming environmental impact (NOAA 1989) because of the loss in fisheries nursery habitat. The disappearance of this valuable subtidal habitat has received widespread attention with the recent designation of Galveston Bay as a national estuary by the EPA National Estuary Program (NOAA 1989). Review of the chronological sequence of SV habitat loss has been recommended to help determine critical factors threatening estuarine habitats and to design management solutions for restoration of impacted SV habitat. We have completed a study, which examines major regions of Galveston Bay where submerged halophytes have declined since the 1950's and compares them with nearby remaining sites where plants still persist. The approach involved compilation and analysis of active processes and hydrologic data, which could affect distribution and abundance of rooted estuarine plants. After the SV distribution at different time periods was mapped, physical and hydrologic factors were analyzed in an attempt to establish the processes contributing to impacts on SV habitats. This report is part of a study funded by the Texas Parks and Wildlife Department and Texas Water Development Board with funds allocated by the Texas Legislature for comprehensive studies of the effects of freshwater inflows on the bays and estuaries of Texas.Bureau of Economic Geolog

Determining Recent Sedimentation Rates of the Trinity River, Texas

Replacement of wetlands by water and flats in the lower alluvial valley and delta of the Trinity River suggests that relative sea-level rise and reductions in sediment supply have rendered the fluvial-deltaic system incapable of maintaining sufficient elevation to prevent its submergence. The Trinity River transports the greatest load of suspended sediment of all rivers emptying into Texas bays (Longley, 1992a), and therefore, it has the greatest potential for delivering enough sediment to offset subsidence.Bureau of Economic Geolog

Colorado River Diversion Project Reconnaissance Work to Establish Monitoring Stations in Matagorda Bay Near the Mouth of the Colorado River

Fifteen monitoring stations were established in the eastern arm of Matagorda Bay, west of the Colorado River Delta, in the area where the river is to be diverted by the U.S. Army Corps of Engineers (see fig. 1). All stations shown on figure 1 were located by triangulation, and their positions were recorded with respect to features existing on nautical chart 11319 or with respect to features located and plotted on the chart during the field survey. Twenty-foot sections of 2.5-inch PVC pipe were driven into the sediments at eight stations (see table 1) to mark selected deep-water and bay-center sites. The PVC pipes extend about 3 ft above the water. Six cedar posts, 2 inches in diameter by 6 ft long, were placed on land at strategic locations along the bayward side of Matagorda Peninsula. The locations of the posts were confirmed with reference to aerial photographs and were plotted on the nautical chart. The posts were used as reference markers to locate bay-margin sampling sites. The tops of the PVC pipes and fence posts were painted and flagged with orange fluorescent paint and tape. Because the sampling stations were also located by triangulation using more permanent navigation aids such as water tanks, radio antennas, houses, and bay markers, they can be relocated should the PVC pipes or cedar posts be removed.Bureau of Economic Geolog

Determining Recent Sedimentation Rates of the Lavaca-Navidad River System, Texas

Replacement of wetlands by water and barren flats in the lower alluvial valley and delta of the Lavaca River suggests that relative sea-level rise and possible reductions in sediment supply have rendered the Lavaca-Navidad fluvial-deltaic system incapable of maintaining sufficient elevation to prevent its submergence. The Lavaca-Navidad River System transports a significant load of suspended sediment (Longley, 1992a) and therefore should have the potential for delivering enough sediment to offset subsidence and submergence.Bureau of Economic Geolog

Sedimentation in Fluvial Deltaic Wetlands and Estuarine Areas, Texas Gulf Coast

Deltaic and associated riverine deposits near the mouths of rivers that discharge into estuaries along the Texas coast are the sites of extensive salt, brackish, and fresh-water marshes that are essential components of biologically productive estuarine systems. These bay-head depositional features are constructed primarily by fluvial sediments, sediments transported and deposited by the major rivers that enter estuarine waters. The loss of over 10,000 acres of wetlands in alluvial and deltaic areas of the Neches (White and others, 1987) and San Jacinto Rivers (White and others, 1985) emphasized the need to examine in more detail the processes that establish and maintain, as well as degrade, these important natural resources along the Texas coast.Bureau of Economic Geolog