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To eliminate cloud and atmosphere-affected pixels, the compositing of multi temporal remote sensing data sets is done by selecting the maximum vale of the normalized different vegetation index (NDVI) within a compositing period. The NDVI classifier, however, is strongly affected by surface type and anisotropic properties, sensor viewing geometries,...

Seasonal herbaceous vegetation production on Senegal's native rangelands exhibits high spatial and temporal variability. This variability can be monitored using normalized difference vegetation index (NDVI) data computed from 1-km resolution Advanced Very High Resolution Radiometer (AVHRR) image data. Although annual fluctuations in rainfall account for some of the variability,...

Many of the physical processes being studied by global change researchers are affects by land surface topography and consequently topographic data are an important requirement for these investigations. Remotely sensed data, especially those that will be collected by the instruments of the Earth Observing System, require significant correction to...

Physical characteristics and persistence of macrohabitat used by different life stages of Sonora chub (Gila ditaenia) were determined by repeatedly measuring distinct reaches in Sycamore Creek, Santa Cruz County, Arizona, in 1990 and 1991. At the beginning of summer drought, habitats occupied by adult Sonora chub were deeper and larger...

The U.S. Geological Survey (USGS) has a database of side-looking airborne radar (SLAR) images of a significant part of the continental United States. These images provide a regional view of terrains and should be an aid to better understanding image data of satellite synthetic aperture radar (SAR) and other...

Crater Lake caldera (8 × 10 km), formed 6845 years B. P. (14C age) during the climactic eruption of the volcanic edifice known as Mount Mazama, is intermediate in size between small calderas associated with central vent eruptions and large calderas that have ring fracture vent systems. Our quantitative study...

Within eastern Kentucky, organic petrographic and geochemical data indicate a southeastwards increase in maturation of the Cleveland Shale Member of the Ohio Shale (Devonian-Mississippian). Reflectance levels of dispersed organic material in the Cleveland Shale increase from 0.5% in the outcrop belt in central Kentucky, to slightly over 1.0% in Pike...

In coal samples, published recommendations based on statistical methods suggest 100 measurements are needed to estimate the mean random vitrinite reflectance (Rv−r) to within ±2%. Our survey of published thermal maturation studies indicates that those using dispersed organic matter (DOM) mostly have an objective of acquiring 50 reflectance measurements. This...

The inorganic geochemistry and mineralogy of three cores from the Anderson-Dietz 1 coal bed, a 15.2-m-thick subbituminous coal bed in the Tongue River Member (Paleocene) of the Fort Union Formation, were examined (1) to determine if the cores could be correlated by geochemical composition alone over a total distance of...

No abstract available....

Precise resolution of the timing of igneous activity is crucial to understanding the dynamic processes associated with continental rifting. Mafic intrusive rocks constitute a major portion of the exposed 1100 Ma (Keweenawan) Midcontinent Rift system in northeastern Minnesota; however, prior to this study, geochronological data were insufficient to allow rigorous...

Walnut Creek National Wildlife Refuge-Prairie Learning Center (Walnut Creek or the Refuge) is one of the newest additions to the National Wildlife Refuge System, which consists of over 480 units throughout the United States operated by the U.S. Department of the Interior, Fish and Wildlife Service (the Service). Located...

Rainfall runoff samples were collected from streets, parking lots, roofs, driveways, and lawns. These five source areas are located in residential, commercial, and industrial land uses in Madison, Wisconsin. Solids, phosphorus, and heavy metals loads were determined for all the source areas using measured concentrations and runoff volumes estimated by...

Effects of pH and hydrophobicity on attachment and detachment of PRD-1 and MS-2 in three different sandy soils were investigated in a series of laboratory-column experiments. Concentrations of the lipid-containing phage PRD-1 decreased 3–4 orders of magnitude during passage through the 10–15-cm-long columns. Attachment of the lipid-containing phage PRD-1 was...

The effect of physical variability upon the relative transport behavior of microbial-sized microspheres, indigenous bacteria, and bromide was examined in field and flow-through column studies for a layered, but relatively well sorted, sandy glaciofluvial aquifer. These investigations involved repacked, sieved, and undisturbed aquifer sediments. In the field, peak abundance of...

Evapotranspiration from bare soil and phreatophytes is a principal mechanism of groundwater discharge in arid and semiarid regions of the midwestern and western United States including the Great Basin. The imbalance between independent estimates of groundwater recharge from precipitation and of groundwater discharge based on estimates of groundwater evapotranspiration leads...

Chapman’s (1910) Pseudocythere funafutiensis from 1924m off Funafuti, western Pacific is redescribed and illustrated together with additional Pleistocene and Recent material from the Coral and Tasman seas. A new paradoxostomatid genus, Glyphidocythere, is described to accommodate it and two other species yet to be formally described from the Banda Sea,...

In the southwestern New Jersey Coastal Plain, four drill holes contain continuous neritic sedimentation across the Paleocene/Eocene boundary (calcareous nannofossil Zone NP 9/NP 10 boundary). Significant lithologic and biotic changes occur in these strata near the top of the Paleocene. Global warming, increased precipitation, and other oceanographic and climatic events...

Ground data from the Central Plains Experimental Range in northeast Colorado and Landsat satellite images of that area acquired in August 1989, June 1990, and September 1990 were used to evaluate the level of association that can be expected from a univariate model relating spectrally derived vegetation indices (difference, ratio,...

In 1991 the Trinity River Basin National Water-Quality Assessment (NAWQA) will include assessments of surface-water and ground-water quality. Initial efforts have focused on identifying water-quality issues in the basin and on the environmental factors underlying those issues. Physical characteristics described include climate, geology, soils, vegetation, physiography, and hydrology. Cultural characteristics...

Industrial phosphate esters, both triaryl and alkyl aryl phosphate esters, are used as fire resistant hydraulic fluids and as fire retardant plasticizers (Lapp 1976). Hydraulic fluids probably represent the largest contribution of phosphate ester compounds released into the environment. Lapp (1976) estimated that 65 to 70 percent of all phosphate...

Two chronic toxicity tests were conducted in which Daphnia magna were either continuously or intermittently exposed to bromoxynil octanoate (BO; as Buctril®) for 28 d. In the intermittent exposure test, daphnids were exposed to daily pulses of BO with 24-h mean concentrations equal to those in the continuous...

Pseudomonas cepacia G4 degrades trichloroethylene (TCE) via a degradation pathway for aromatic compounds which is induced by substrates such as phenol and tryptophan. P. cepacia G4 5223 PR1 (PR1) is a Tn5 insertion mutant which constitutively expresses the toluene ortho-monooxygenase responsible for TCE degradation. In groundwater microcosms, phenol-induced strain G4...

No abstract available ...

No abstract available....