Archaeological Survey Design, Units of Observation, and the Characterization of Regional Variability

2007 ◽  
Vol 72 (2) ◽  
pp. 322-333 ◽  
Author(s):  
Alan P. Sullivan III ◽  
Philip B. Mink II ◽  
Patrick M. Uphus
Keyword(s):  
Survey Design ◽  
Grand Canyon ◽  
Active Management ◽  
Archaeological Survey ◽  
Regional Variability ◽  
Mapping Unit ◽  
Near Surface ◽  
Northern Arizona ◽  
Research Priority ◽  
Kaibab National Forest

It is generally presumed that intensive survey yields reliable representations of regional archaeological variability. We evaluate this assumption with an analysis of the results of two intensive surveys of the same terrain in the Upper Basin, a heavily forested upland ecosystem located south of Grand Canyon National Park in Kaibab National Forest, northern Arizona. By comparing differences between the results of site-based surveys with those of mapping-unit-based surveys, we demonstrate that units of observation have a profound effect on how archaeological landscapes and their variability are characterized and interpreted. In addition, results of four analyses of survey data show that the archaeological resource inventories created by the application of these two different units of observation cannot be reconciled. We suggest that because some units of observation may be more appropriate for certain problems and for different kinds of surface and near-surface archaeological records, additional studies of the effects of units of observation on characterizing the archaeological content of the same terrain should become a research priority in survey archaeology. Without such studies, the identification of archaeologically sensitive areas, particularly those that necessitate active management and vigilant protection on public lands, will be underdetermined, thereby placing those heritage properties at risk.

scholarly journals Artificial Project Time Horizons In The Absence Of Discounting: The Case Of Canyon Forest Village

2011 ◽  
Vol 8 (1) ◽  
pp. 115-122
Author(s):  
Dennis Foster ◽  
Craig Bain
Keyword(s):  
Environmental Impact ◽  
Grand Canyon ◽  
Forest Service ◽  
National Forest ◽  
Environmental Impact Statement ◽  
Time Value Of Money ◽  
Northern Arizona ◽  
Time Value ◽  
Kaibab National Forest ◽  
Value Of Money

In the summer of 1997, the Kaibab National Forest released the Draft Environmental Impact Statement for Tusayan Growth. This report analyzed various scenarios involving the transfer of National Forest land at the boundary of the Grand Canyon National Park to a private developer, in exchange for private inholdings scattered throughout the Kaibab National Forest in northern Arizona. The resulting private development was to be called Canyon Forest Village, and would include hotels, visitor facilities, private housing, community facilities and a transportation center for tourists accessing the Grand Canyon. The proposed build out of Canyon Forest Village (CFV) was to take place from 1999 to 2010. Consequently, the Forest Service analysis used that time frame as the basis for calculating the economic impacts CFV would be expected to have on local economies in the northern Arizona region. The Draft Environmental Impact Statement (EIS) concluded that overall growth in demand for lodging in northern Arizona would be robust over those years, and that CFV would have no net negative impacts. The results of the Draft EIS were sharply contested during the public comment phase, and, in the summer of 1998, a Supplement to the Draft Environmental Impact Statement for Tusayan Growth was issued. This document used a different modeling procedure and changed its primary focus to two, smaller, CFV proposals, involving only 900 and 1,270 hotel rooms. The Supplement did conclude that there would be some negative impacts to the communities surrounding Grand Canyon. The results of the Supplemental Draft EIS were also contested during the public comment phase following its release, although a year later, in the summer of 1999, the Forest Service issued a Final EIS and adopted the CFV proposal for 1,270 rooms. One peculiarity of the Forest Service reports, throughout this process, was the failure to identify an explicit discount rate of interest in order to identify costs and benefits in terms of their present value. While EIS documentation has been required for many years, the obvious focus is on purely environmental concerns and the analyses tend to be based on scientific findings. The inclusion of a socioeconomic analysis necessitates a careful accounting of benefits and costs. While this EIS is not the first to include an explicit accounting of economic benefits and costs, it may serve as a harbinger of more reporting of this type. Unless those with an appreciation of the discounting process, especially economists and accountants, are included in these analyses, present values may be employed only on an erratic basis, making the results of such reports difficult, if not impossible, to adequately interpret. This article applies basic and commonly accepted time value of money principles to an EIS report. Although an economic analysis was provided as part of the report, the time value of money was ignored. In order to present a viable economic impact, these basic financial tenants must be employed. The authors used basic time value of money principles with reasonable discount rates. The result is that impacts could be as much as six times greater than the values given by the Forest Service, representing upwards of one hundred and fifty million dollars.

scholarly journals Re-evaluation of exotic gravel and inverted topography at Crooked Ridge, northern Arizona: Relicts of an ancient river of regional extent

Geosphere ◽  
2020 ◽  
Vol 16 (2) ◽  
pp. 533-545
Author(s):  
Ivo Lucchitta ◽  
Richard Holm
Keyword(s):  
Grand Canyon ◽  
San Juan ◽  
East Side ◽  
San Juan Mountains ◽  
Northern Arizona ◽  
Geomorphic Features ◽  
San Juan River ◽  
Kaibab Plateau ◽  
Very High ◽  
Satisfactory Manner

Abstract An ancient drainage, named Crooked Ridge river, is unique on the Colorado Plateau in extent, physiography, and preservation of its alluvium. This river is important for deciphering the generally obscure evolution of rivers in this region. The ancient course of the river is well preserved in inverted relief and in a large valley for a distance of several tens of kilometers on the Kaibito Plateau–White Mesa areas of northern Arizona. The prominent landform ends ∼45 km downstream from White Mesa at a remarkable wind gap carved in the Echo Cliffs. The Crooked Ridge river alluvium contains clasts of all lithologies exposed upstream from the Kaibito Plateau to the San Juan Mountains in Colorado, so we agree with earlier workers that Crooked Ridge river was a regional river that originated in these mountains. The age of Crooked Ridge river cannot be determined in a satisfactory manner. The alluvium now present in the channel is the last deposit of the river before it died, but it says nothing about when it was born and lived. Previous research attempted to date this alluvium, mostly indirectly by applying a sanidine age obtained ∼50 km away, and directly from six sanidine grains (but no zircon grains), and concluded that Crooked Ridge river was a small river of local significance, because the exotic clasts were interpreted to have been derived from recycling of nearby preexisting piedmont gravels; that its valley was not large; and that it only existed ca. 2 Ma. Our proposition in 2013 was that Crooked Ridge river came into being in Miocene and possibly Oligocene time, which is when the very high San Juan Mountains were formed, thus giving rise to abundant new precipitation and runoff. To address some of this ambiguity, we examined all available evidence, which led us to conclude that several of the interpretations by previous researchers are not tenable. We found no evidence for a preexisting piedmont from which the Crooked Ridge river exotic clasts could be recycled. Furthermore, the principal advocate of the piedmont discounted it in a later publication. Tributaries to Crooked Ridge river in the White Mesa area contain no exotic clasts that could have been derived from a local clast-rich piedmont; only the Crooked Ridge river channel contains exotic clasts. So, we conclude that Crooked Ridge river was the principal stream, that it was of regional significance, that it was headed in the San Juan Mountains, and that it existed long before it died, perhaps as early as Oligocene time, until it was captured by the San Juan River, maybe ca. 2 Ma. West and downstream from The Gap, no deposits or geomorphic features attributable to the Crooked Ridge river have been preserved, but we infer that the river joined the Colorado and Little Colorado paleorivers somewhere on the east side of the Kaibab Plateau, and then crossed the plateau along a paleovalley that approximated the present alignment of the eastern Grand Canyon. West of the Kaibab Plateau, the combined rivers perhaps flowed in a northwest-trending strike valley to an as-yet-unknown destination.

Making seismic monitoring work in a complex desert environment — 4D processing

2019 ◽  
Vol 38 (8) ◽  
pp. 637-645 ◽  
Author(s):  
Robert Smith ◽  
Emad Hemyari ◽  
Andrey Bakulin ◽  
Abdullah Alramadhan
Keyword(s):  
Survey Design ◽  
Signal To Noise Ratio ◽  
Time Lapse ◽  
Seismic Monitoring ◽  
Carbonate Reservoir ◽  
Acquisition System ◽  
Desert Environment ◽  
Near Surface ◽  
Different Seasons ◽  
Processing Techniques

Seismic monitoring of an onshore carbonate reservoir in a desert environment has been achieved for the first time. Optimizing data repeatability was key to detecting the weak 4D (time-lapse) signal resulting from a fluid-injection program, which was achieved through a combination of specialized survey design, careful acquisition, and dedicated 4D processing. The hybrid acquisition system utilized buried geophones, which significantly reduced 4D noise caused by variability in the near-surface environment. Despite the extensive acquisition efforts, time-lapse processing is an essential component of achieving highly repeatable data. A fit-for-purpose workflow was developed to reduce the remaining 4D noise using a combination of parallel and simultaneous processing. Processing steps leading to the largest improvement in reflection signal-to-noise ratio, such as noise attenuation, amplitude balancing, and supergrouping, produced the largest reduction in 4D noise. Outstanding final migrated data repeatability has been achieved, comparable to levels reported for the more favorable permanent marine systems. However, the need to use surface sources results in a seasonal imprint on data repeatability, which hinders the interpretation of surveys acquired during different seasons. In the absence of a fully buried acquisition system, advanced processing techniques such as surface-consistent matching filters may be required to resolve these variations.

Depth and properties of freshwater export from the Greenland Ice Sheet modulated by ice-ocean processes

2020 ◽  
Author(s):  
Donald Slater ◽  
Fiamma Straneo
Keyword(s):  
Large Scale ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Regional Variability ◽  
Near Surface ◽  
Fjord Circulation ◽  
Ocean Reanalyses ◽  
Freshwater Export ◽  
Ocean Processes

<p>Freshwater export from the Greenland Ice Sheet to the surrounding ocean has increased by 50% since the early 1990s, and may triple over the coming century under high greenhouse gas emissions. This increasing freshwater has the potential to influence both the regional and large-scale ocean, including marine ecosystems. Yet quantification of these impacts remains uncertain in part due to poor characterization of freshwater export, and in particular the transformation of freshwater around the ice sheet margin by ice-ocean processes, such as submarine melting, plumes and fjord circulation. Here, we combine in-situ observations, ocean reanalyses and simple models for ice-ocean processes to estimate the depth and properties of freshwater export around the full Greenland ice sheet from 1991 to present. The results show significant regional variability driven primarily by the depth at which freshwater runoff leaves the ice sheet. Areas with deeply-grounded marine-terminating glaciers are likely to export freshwater to the ocean as a dilute mixture of freshwater and externally-sourced deep water masses, while freshwater from areas with many land-terminating glaciers is exported as a more concentrated mixture of freshwater and near-surface waters. A handful of large glacier-fjord systems dominate ice sheet freshwater export, and the vast majority of freshwater export occurs subsurface. Our results provide an ice sheet-wide first-order characterization of how ice-ocean processes modulate Greenland freshwater export, and are an important step towards accurate representation of Greenland freshwater in large-scale ocean models.</p>

Target-oriented optimized survey design and quantitative comparison for 3D electrical resistivity tomography

2020 ◽  
Author(s):  
Lincheng Jiang ◽  
Gang Tian ◽  
Bangbing Wang ◽  
Amr Abd El-Raouf
Keyword(s):  
Electrical Resistivity ◽  
Electrical Resistivity Tomography ◽  
Survey Design ◽  
Quantitative Comparison ◽  
Data Set ◽  
Resistivity Tomography ◽  
Near Surface ◽  
Target Set ◽  
Survey Designs

<p>In recent decades, geoelectrical methods have played a very important role in near-surface investigation. The most widely used of these methods is electrical resistivity tomography (ERT). Regardless of the forward and inversion algorithms used, the original data collected from a survey is the most important factor for quality of the resulted model. However, 3D electrical resistivity survey design continues to be based on data sets recorded using one or more of the standard electrode arrays. There is a recognized need for the 3D survey design to get better resolution using fewer data. Choosing suitable data from the comprehensive data set is a great approach. By reasonable selecting, better resolution can be obtained with fewer electrodes and measurements than conventional arrays. Previous research has demonstrated that the optimized survey design using the 'Compare R' method can give a nice performance.</p><p>This paper adds target-oriented selection and modified the original 'Compare R' method. The survey design should be focused on specific target areas, which need a priori information about the subsurface properties. We select electrodes and configurations as the target set by the comprehensive set firstly which meets the requirements of the target area. The number of measurements and electrodes is much less than the comprehensive set and the model resolution matrix takes less time to calculate. At the next step for rank, we calculate the sensitivity matrix of the target set only once and then calculate the contribution degree of each measurement separately from it. The time of iterative calculation of the resolution matrix when measurements set changing is less than the original method.</p><p>The traditional method of evaluating RMS is not appropriate for comparing the quality of collected data by different survey designs. SSIM (structural similarity index) gives more reliable measures of image similarity better than the RMS. The curves of SSIM values in three dimensions and the average SSIM are given as quantitative comparisons. Besides, the frequency of electrodes utilized given to guides on selecting the highest used electrodes. Finally, the curves of the average relative resolution S and the number of electrodes as the number of measurements increase are given, which proves the method works effectively.</p><p>The results show the significance of using target-oriented optimized survey design, as it selects fewer electrodes and arrays than the original CR method. Also, it produces better resolution than conventional arrays and takes less calculation time. 3D SSIM, frequency of electrodes used, the relationship between average relative resolution, number of electrodes and number of measurements, these quantitative comparison methods can effectively evaluate the data collected in various survey designs.</p>

scholarly journals Extent and duration of Antarctic surface melting

1994 ◽  
Vol 40 (136) ◽  
pp. 463-475 ◽  
Author(s):  
H. Jay Zwally ◽  
Stephen Fiegles
Keyword(s):  
Surface Melting ◽  
Summer Temperature ◽  
Katabatic Wind ◽  
Regional Variability ◽  
Near Surface ◽  
Ice Shelves ◽  
Microwave Brightness Temperature ◽  
Melt Index ◽  
Air Temperatures ◽  
The Antarctic

Abstract The extent and duration of surface melting on the Antarctic ice shelves and margins of the Antarctic ice sheet are derived from satellite passive-microwave data for 1978–87. The occurrence of surface melting in daily maps of Tb is indicated by a marked increase in microwave brightness temperature (Tb), which is caused by moisture in the near-surface firn. Tb increases of more than 30 deg above the annual-mean Tb are chosen to indicate melting. Most Antarctic surface melting occurs during December and January. The observed melting is correlated with regional air temperatures, but some melt patterns also appear to be related to katabatic-wind effects. The correlations suggest that the surface melting in Antarctica increases about 3.5 × 106 d km2 per degree of summer temperature increase. The surface-melt index (duration times area of melting) calculated for Antarctica is 24 × 106 d km2, averaged over nine summers. The observed inter-annual and regional variability is large. Surface melting was most extensive during the 1982/83 summer (36 × 106 d km2) and least extensive during the 1985/86 summer (15 × 106d km2). The data indicate a decline in surface melting over the 9 years, but meaningful inferences regarding trends in surface melting are precluded by the large inter-annual variability.

scholarly journals Student midwives’ knowledge, skills and competency in relation to the active management of the third stage of labour: A correlational study

Curationis ◽  
2020 ◽  
Vol 43 (1) ◽  
Author(s):  
Fungai Muzeya ◽  
Hester Julie
Keyword(s):  
Survey Design ◽  
Maternal Mortality Ratio ◽  
The Self ◽  
Active Management ◽  
Knowledge And Skills ◽  
The Third ◽  
Third Stage ◽  
Mortality Ratio ◽  
Quantitative Descriptive ◽  
Descriptive Survey

Background: Lesotho has been experiencing health challenges as indicated by its high maternal mortality ratio of 620 per 100 000 live births for the year 2010, which has been linked to its limited human resources.Objectives: The knowledge and skills of final-year student nurse-midwives related to the active management of the third stage of labour were determined.Method: A quantitative, descriptive survey design was used to conduct this study with 99 final-year midwifery students at four nursing schools in Lesotho using stratified sampling. The structured questionnaire collected data on the knowledge and self-reported competency. Subsequently, the controlled cord traction marks, extracted from the objective structured clinical examination (OSCE), were compared to the self-reported competency of these midwifery students using R software version 3.4.0.Results: The mean score for knowledge and the OSCE was 73.8% (n = 99) and 77.2% (n = 99), respectively. The majority of respondents (95.2%, n = 99) rated themselves highly in terms of the active management of the third stage of labour competency. There was no correlation between the self-reported competency and knowledge (r = 0.08, p = 0.4402), and self-reported competency and OSCE scores (r = −0.004, p = 0.01).Conclusion: The high mean scores for the knowledge and the OSCE indicate that the theoretical component of the curriculum on the active management of the third stage of labour was effective in equipping final-year midwifery students with knowledge and skills to carry out this competency.

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