35 research outputs found
Recommended from our members
Delineation of Irrigated Land Using Landsat Imagery
The High Plains test site (fig. 1) is one of five areas selected in the State of Texas as part of the Applications System Verification and Transfer (ASVT) Project of the Texas Natural Resources Information System (TNRIS). This test site was chosen because the Texas Department of Water Resources (TDWR) needed timely information regarding water usage for irrigation in northwest Texas. The Test Plan for this project (Finley and Baumgardner, 1981) identified three objectives for the study of this test site: (1) identification of irrigated cropland, (2) definition of the spectral signature of drought-stressed vegetation, and (3) identification of broad crop categories. This report presents the results of work on the first objective, identification of irrigated cropland.Bureau of Economic Geolog
Recommended from our members
Origin of the "Cup and Saucer"
The "Cup and Saucer" feature, named due to its resemblance to those utensils (W. J. Brown, 1980, personal communication), is located in southern Mitchell County, Texas. It is situated on private property but can be easily observed about 400 ft (122 m) east of State Highway 163 between Sterling City and Colorado City, 3.4 mi (5.4 km) north of the intersection of that highway with FM2183. The feature lies on the eastern edge of the Hyman NE quadrangle (scale 1:24,000, 7.5-minute series, U.S. Geological Survey, topographic maps), 0.75 mi (1.2 km) south of Beals Mountain. The feature will be described according to the following conventions. The "saucer" portion, which dips concentrically toward the center, will be referred to as the "lower ring." The "cup" portion, located in the center of the saucer, will be called the "core." The outcrops south of the lower ring, also capped by rocks dipping toward the core, will be referred to as the "outer ring."
This feature, long assumed to be a meteorite crater, exhibits characteristics that argue for another explanation. Firstly, the lower ring is capped with massive sandstone rocks that dip only gently (3°30' to 14°10') toward the core, which would not likely result from a violent meteorite impact. Secondly, abundant black stones scattered on the upper surface of the saucer are cemented with iron oxide but are neither fragments of a meteorite nor fused by the heat of an impact. Instead, they appear to be concretions formed in the vadose zone when the ring was still buried by younger sediments and the local water table was higher. Thirdly, if this feature were an ancient impact structure, the core would be composed of breccia created by the meteorite impact. However, the core is composed of friable fine-grained sandstone, volcanic ash, and fluvial gravels, none of which are brecciated.Bureau of Economic Geolog
Recommended from our members
Relationship Between Radar Lineaments, Geologic Structure and in Situ Stress in East Texas
Radar-based lineaments in East Texas and northwest Louisiana were studied to determine their relationship to surficial and subsurface geologic structure and to in situ stress. For all lineament data, two significant azimuths of vector sums were defined: 325° and 37°. The northwest trend has the same orientation as the mean direction of wellbore elongations in the Schuler Formation throughout the East Texas Basin. However, this trend is significantly different from the 344° orientation of wellbore elongation in the overlying Travis Peak Formation. These results suggest a complex relationship between subsurface stress and the northwest lineament trend. The northeast lineament trend does not coincide with the orientation of any known stress or regional structure and may be an artifact of radar illumination direction. Unlike a previous regional study based on smaller-scale Landsat data, no consistent correlation between surficial or subsurface structure and lineament density was discovered. However, high values of lineament density occur preferentially on outcrops of the Sparta and Leeches Formations. These results suggest that either most radar lineaments smaller than Landsat lineaments are manifestations of unmapped subregional or local structures or most radar lineaments are surficial phenomena, unrelated either to subsurface geologic structure or to stress.Bureau of Economic Geolog
Recommended from our members
Geomorphic Processes of the Texas Panhandle
Joints are fractures in a rock that exhibit no detectable displacement between one face of the fracture and the other. Previous work on the origin of joints has determined different mechanisms to explain fracturing. Some researchers have explained joints in terms of their relationship to tectonic deformation and major structural elements (Harris and others, 1960; Price, 1966; Stearns and Friedman, 1972). Others have shown that joints may develop independently from tectonic deformation and that joints may form in sedimentary rocks early in their history (Parker, 1942; Hodgson, 1961; Price, 1966; Cook and Johnson, 1970). Price (1974) investigated the development of joints and stress systems in undeformed sediments during the accumulation of a sedimentary series, its downwarping and subsequent uplift, and accompanying de-watering of the sediments. Joints can also result from unloading due to erosion (Chapman, 1958). The formation of joints in sedimentary rocks is dependent on three factors (Hobbs, 1967): (1) physical properties of both the fractured rock bed and the surrounding rock beds; (2) thickness of the rock bed; and (3) degree of tectonic deformation of the beds.Bureau of Economic Geolog
Recommended from our members
The Feasibility of Using Digitally Processed Landsat Data to Determine Coastal Inundation Frequency
The purpose of this feasibility study was to determine if Landsat data could be used to determine the level and frequency of inundation of Texas' coastal areas. The presence of seawater is an important criterion in the legal definition of a coastal wetland. Seawater is defined by the Coastal Wetland Acquisition Act 33.231, Subchapter G, as water with a concentration of 1/20 of one percent or more by weight of total dissolved inorganic salts. To adequately define a coastal wetland, it is necessary to know which coastal areas are covered by seawater at times other than, and in addition to, during storms or hurricanes. This preliminary research effort was limited to the use of Landsat computer-compatible tapes (CCTs) on hand at the Texas Natural Resources Information System (TNRIS) for which Band 5 transparencies or prints were also available. Two study areas (see fig. 1) were selected that had different land/water boundaries on Landsat images from different dates (see figs. 2, 3).Bureau of Economic Geolog
Recommended from our members
Geomorphology of the Hueco Bolson in the Vicinity of the Proposed Low-Level Radioactive Waste Disposal Site, Hudspeth County, Texas
The Fort Hancock study area is located 40 mi (65 km) southeast of El Paso, Texas, in the Hueco Bolson on an alluvial slope between the Diablo Plateau and the Rio Grande. The study area spans the drainage divide between Alamo and Camp Rice Arroyos. Since deposition of bolson fill ceased, the arroyos have incised, cutting down to expose the Fort Hancock and Camp Rice Formations in their floors and valley walls.
Quaternary strata younger than the Camp Rice Formation underlying the study area can be divided into four units: a basal gravel, a middle sand, a petrocalcic horizon (Stage IV), and an upper sand. The petrocalcic horizon is interpreted to be the upper surface of the Madden Gravel, and, on the basis of its dense, laminated character, took 25,000 to 75,000 years to form. These Quaternary sediments range in thickness from 20 to 60 ft (6 to 18 m), thinning to the southwest across the study area and toward the edges of arroyos.Bureau of Economic Geolog
Recommended from our members
Test Plan for Remote Sensing Information Subsystem Products Test Site 1 (Coastal)
This plan outlines the map products to be generated from Landsat imagery, airborne multispectral scanner imagery, and aerial photography of a test site on the Texas coast. The objectives of producing these maps are:
To determine the methodology necessary for developing each type of product.
To designate the size, scale, level of detail, and final format of each map within an initial phase of development of remote sensing products.
To designate specifications for the generation of equivalent products from aerial photography to be used in comparison evaluations.
The map products and data analysis procedures described here are based on:
Objectives outlined in the Applications System Verification and Transfer (ASVT) Project Plan (McCulloch and McKain, 1978).
State agency coastal information needs and listings of possible products developed in conjunction with the User Advisory Group.
The Remote Sensing Information Subsystem (RSIS) Level I Design and Design Review documents.
As such, the descriptions contained herein are primarily conceptual and are derived from only limited hands-on experience with Landsat imagery and digital image processing hardware and software. Present time schedules call for the software required for full analysis of data over the Coastal Test Site to be available in early 1981.Bureau of Economic Geolog
Recommended from our members
Annotated Bibliography of Techniques for Image Enhancement and Interpretation in Remote Sensing
The purpose of this annotated bibliography is to provide the user of the Remote Sensing Information Subsystem (RSIS) with brief descriptions of recent research techniques of image enhancement and their applications to specific image interpretation problems. Table 2 of the May 1979 ASVT/RSIS Technical Report entitled "Functional Design Narrative Descriptions" listed digital image processing requirements of the RSIS. The references in this bibliography were chosen because they describe these processing requirements. The format of that table was modified slightly and used as the outline for Section One of this bibliography.
The bibliography is not intended to be an exhaustive compilation of all pertinent articles. Such a collection would be outdated as soon as it was printed. It does, however, contain a broad sampling of the recent remote sensing literature. We tried not to include multiple references to the same technique, but some repetition was necessary in order to fully describe some procedures of image enhancement and interpretation.Bureau of Economic Geolog
Recommended from our members
Outline of Basic Procedures for Remote Sensing Information Subsytem (RSIS) Analysis of Landsat Data
This document outlines basic procedures for analyzing Landsat data using the Remote Sensing Information Subsystem (RSIS), prepared for the Texas Natural Resources Information System and dated November 1980.
The outline includes procedures for Reflectance Data Display and Classified Data Display. It provides detailed steps for various tasks such as locating areas of interest, running histogram processors, setting up display tapes, analyzing data, and creating look-up tables. Additionally, it covers the use of software tools like LARSYS Histogram Processor, ISOCLS Processor, and CLRTAB.
The document includes tables and figures illustrating channel data, radiance values, and color assignments. It also includes appendices detailing RSIS runstreams and ISOCLS procedures.
Overall, it's a comprehensive guide for utilizing RSIS to analyze Landsat data for various applications related to natural resource management and geology.Bureau of Economic Geolog
Recommended from our members
Definition of Optimum Isocls Parameters for RSIS Interactive Data Anaylsis , Texas Coastal Applications Test Site
Data tapes for a specified window are processed through a program called ISOCLS (Iterative Self-Organizing Clustering). The user supplies several input parameters, including the spectral distance between clusters (DLMIN) and the maximum standard deviation for the values within a cluster (STDMAX). The purpose of this study was to vary these two parameters and analyze the differences in images produced from the same data.Bureau of Economic Geolog