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R.K. Gabrysch

Publications and source records attributed to R.K. Gabrysch.

22 records · Page 2Linked to original sources
USGS1976

Land-surface subsidence in the area of Moses Lake near Texas City, Texas

Removal of water, oil, and gas from the subsurface in Harris and Galveston Counties has caused declines in fluid pressures, which in turn have resulted in subsidence of the land surface. Subsidence of the land surface at Moses Lake in due principally to the removal of ground water in adjacent areas. Significant subsidence of the land surface at Moses Lake began after 1900, and as much as 1.8 feet of subsidence had occurred in the ara by 1973. Probable future subsidence was calculated by two methods for two loading situations. In the first loading situation, the artesian head in the middle Chicot aquifer, in the Alta Loma Sand (Rose, 1943), and in the Evangeline aquifer would continue to decline at respective rates of 1, 3, and 3 feet per year until 1980 and then cease. In the second loading situation, the artesian head in the middle Chicot aquifer, in the Alta Loma Sand, and in the Evangeline aquifer would continue to decline at respective rates of 1, 3, and 3 feet per year until 1990 and then cease.

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USGS1974

Land-surface subsidence in the Houston-Galveston region, Texas

The pumping of large amounts of ground water in the Houston-Galveston region, Texas, has resulted in water-level declines of as much as 200 feet (61 metres) in wells completed in the Chicot aquifer and as much as 325 feet (99 metres) in wells completed in the Evangeline aquifer during 1943-73. The maximum annual rates of decline for 1943-73 were 6.7 feet (2.0 metres) in the Chicot aquifer and 10.8 feet (3.3 metres) in the Evangeline aquifer. During 1964-73, the maximum rates were 10 feet (3.0 metres) in the Chicot and 17.8 feet (5.4 metres) in the Evangeline. The declines in artesian pressures have resulted in pronounced regional subsidence of the land surface. The center of subsidence is at Pasadena, where as much as 7.5 feet (2.3 metres) of subsidence occurred between 1943 and 1973. More than 1.0 foot (0.3 metre) of subsidence occurred at Pasadena between 1906 and 1943. The maximum amount of subsidence during 1964-73 was about 3.5 feet (1.1 metres). In the southern part of Harris County, about 55 percent of the subsidence is a result of compaction in the Chicot aquifer. The area in which subsidence is 1 foot (0.3 metre) or more has increased from about 350 square miles (906 square kilometres) in 1954 to about 2,500 square miles (6,475 square kilometres) in 1973. Estimates of subsidence are based on the amount of water-level decline, the thickness of the clay, and the compressibility of the clay. At Seabrook, it is estimated that for each 1 foot (0.3 metre) of average water-level decline, 1 foot (0.3 metre) of clay would compact 0.000031 foot (0.00094 centimetre). At Seabrook, for 1 foot (0.3 metre) of water-level decline, 0.0248 foot (0.756 centimetre) of subsidence would occur. Planned use of surface water instead of ground water will probably result in some recovery of artesian pressures. If pressure recovery occurs the rate of subsidence should decrease substantially in the more critical areas.

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USGS1974

Land-surface subsidence in the area of Burnett, Scott, and Crystal Bays near Baytown, Texas

Removal of water, oil, and gas from the subsurface in Harris County has caused declines in fluid pressures, which in turn have resulted in subsidence of the land surface. Subsidence in the area of Burnett, Scott, and Crystal Bays near Baytown is becoming critical because much of the area is now subject to inundation by high tides. Production of oil and gas from the Goose Creek Field on the southeast edge of Baytown had caused as much as 3.25 feet (1 meter) of subsidence by 1925. The subsidence due to oil and gas production is restricted to the area of production and has not extended to the area of Burnett, Scott, and Crystal Bays. Withdrawals of water from large-capacity industrial wells, which resulted in declines in artesian pressure, began about 1918. As much as 280 feet (85.3 meters) of artesian-head decline has occurred in the Evangeline aquifer, and as much as 320 feet (97.5 meters) of artesianhead decline has occurred in the Alta Lorna Sand of Rose (1943). Significant subsidence of the land surface probably began about 1920 or later and as much as 8.2 feet (2.5 meters) of subsidence had occurred in the area by 1973. The study of subsidence in the area of the three bays included the collection of undisturbed clay samples for laboratory analyses, collection of water-level records, and installation and monitoring of pressure transducers in clays and of observation wells in sands. Probable future subsidence was calculated for two loading situations. Case I provided that the artesian head in both the Alta Lorna Sand and Evangeline aquifer would continue to decline at a rate of 6 feet (1.8 meters) per year until 1980 and then cease. Case II provided that artesian head in the Alta Lorna Sand would continue to decline at a rate of about 6 feet (1.8 meters) per year until about 1995, when the potentiometric surface would reach the top of the Alta Lorna Sand. The artesian head in the Evangeline aquifer would also decline about 6 feet (1.8 meters) per year until 1995. The ultimate subsidence expected for the assumed conditions of case I and case II is 11.4 feet (3.47 meters) and 15.1 feet (4.60 meters), respectively. However, only 1.4 feet (0.43 meter) of subsidence below present land surface would occur if artesian heads were maintained at their present levels. To halt subsidence in the near future, artesian head must be increased, either by decreasing pumpage or by repressurization by artificial recharge.

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