Groundwater App to Determine Flow Direction and Gradient          下载免费PDF全文

Derek Morrison  Clyde Munster 《Ground water》2015,53(2):342-346

A computational program, called the groundwater flow calculator, was created to quickly and easily determine the hydraulic gradient and direction of groundwater flow. The groundwater flow calculator automates the hand‐drawn process by Ralph Heath in the U.S. Geological Survey (USGS) Water Supply Paper 2220. In addition, a mobile app was developed to allow this procedure to run on a smart phone for use in the field.  相似文献   

Anomalous Love-wave phase velocities in the Pacific: sequential pure-path and spherical harmonic inversion     

Clyde E. Nishimura  Donald W. Forsyth 《Geophysical Journal International》1985,81(2):389-407

Summary. We have determined the lateral distribution of Love-wave phase velocities in the Pacific for the periods 40, 67, 91 and 125 s. Application of the pure-path and spherical harmonic representation methods indicates that the velocities are primarily a function of the age of the seafloor. A comparison of the results from these two techniques indicates inherent modelling constraints in both methods. The pure-path method is limited by its a priori nature while the spherical harmonic approach is unsuitable in describing sharp lateral velocity gradients. To circumvent these limitations, we propose the sequential application of the pure-path and spherical harmonic methods. The sequential inversion separates the velocity distribution into two separate components; velocity as a function of the age of the oceanic plate and variations superimposed on this relationship. Application of this method demonstrates the presence of velocity anomalies which cannot be modelled by an age–velocity relationship. These anomalies are tentatively correlated with regions of anomalous seafloor depths and/or the presence of active hot-spots. In the central south Pacific, an area with numerous active hot-spots coincides roughly with a region of anomalously slow Love wave velocities. A method for determining the errors associated with the slowness distributions calculated by the spherical harmonic method is presented and provides a means for determining the resolvability of these features.  相似文献   

Regional theory and regionalism: Towards rethinking the regional question     

Clyde Weaver 《Geoforum》1978,9(6):397-413

This article presents an historical review of the evolution of regional planning ideas under the growth pole paradigm, from its beginnings in the early 1950s to the current deluge of criticism. Then the outlines of an alternative approach are suggested, emphasizing what is called territorial development, a concept which focuses on meeting the cultural, political and economic needs of regional population groups — as opposed to urging their functional integration into the broader national and world economy. It is argued that territorial development can only be achieved by arousing the regional communities themselves into seeking selective regional closure and strategic regional advantage through willful community action.  相似文献   

Using the Global Positioning System (GPS) for geodetic positioning   总被引：1，自引：0，他引：1  

John D. Bossler  Clyde C. Goad  Peter L. Bender 《Journal of Geodesy》1980,54(4):553-563

The development of relatively inexpensive satellite receivers in the early 1970's has resulted in cost-effective applications of satellites for a variety of geodetic surveying needs. Currently achievable accuracies range from 10 to 20 centimeters. The NAVSTAR Global Positioning System, now under development by the Department of Defense, incorporates advanced technology which has the potential capability of revolutionizing satellite geodesy. Several concepts for utilizing GPS signals are briefly reviewed, and another concept, called the reconstructed carrier phase method, is described in some detail. This concept is being pursued by the Defense Mapping Agency, National Oceanic and Atmospheric Administration, and the U.S. Geological Survey. These agencies have numerous requirements for accurate positioning. Several prototype receivers are planned to be available for testing in mid-1982. These receivers should be highly portable, consume little power, and obtain base line accuracies of several centimeters in several hours of observation time. However, water vapor radiometers will be needed in order to achieve the full accuracy. Initial simulation results utilizing the reconstructed carrier phase method are included.  相似文献   

Enhanced production of stratospheric OH from methane oxidation at elevated reactive chlorine levels in northern midlatitudes   总被引：1，自引：0，他引：1  

Elizabeth B. Burnett  Clyde R. Burnett 《Journal of Atmospheric Chemistry》1995,21(1):13-41

Examination of odd-hydrogen production and loss processes in the lower stratosphere reveals that the large abundances of midlatitude ClO recently measured requires a reassessment of the OH yield from methane oxidation due to a more rapid initiation of the methane oxidation sequence by atomic chlorine. Using a steady state calculation for OH and an iterative procedure for evaluating odd-hydrogen production from the methane oxidation sequence, we demonstrate that both OH and reactive chlorine are amplified below 25 km. The amplified values of OH and ClO are found to be consistent with recent measurements of ClO concentrations and of OH column abundances.  相似文献   

Interviews of Mongolian herders and high resolution precipitation data reveal an increase in short heavy rains and thunderstorm activity in semi-arid Mongolia     

Clyde E. Goulden  Jerry Mead  Richard Horwitz  Munhtuya Goulden  Banzragch Nandintsetseg  Sabrina McCormick  Bazartseren Boldgiv  Peter S. Petraitis 《Climatic change》2016,136(2):281-295

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Chicxulub impact ejecta from Albion Island, Belize     

Kevin O Pope  Adriana C Ocampo  Alfred G Fischer  Walter Alvarez  Bruce W Fouke  Clyde L Webster  Francisco J Vega  Jan Smit  A.Eugene Fritsche  Philippe Claeys 《Earth and Planetary Science Letters》1999,170(4):275-364

Impact ejecta from the Albion Formation are exposed in northern Belize. The ejecta come from the outer portion of the continuous ejecta blanket of the Chicxulub crater, which is located 360 km to the northwest. The basal unit of the Albion Formation is a 1-m-thick clay and dolomite spheroid bed composed of up to four discrete flows. The clay spheroids are altered impact glass, and the dolomite spheroids are accretionary lapilli. The upper unit is a 15-m-thick coarse diamictite bed containing altered glass, large accretionary blocks, striated, polished, and impacted cobbles, and rare shocked quartz. The abundance of accretionary clasts, evidence for atmospheric drag sorting, and the presence of multiple flows in the Albion Formation indicate that atmospheres play an important role in the formation of the outer portions of continuous ejecta blankets of large craters.  相似文献   

Spatial planning on the North Sea: A case of cross-scale linkages     

Ditte Degnbol  Douglas Clyde Wilson 《Marine Policy》2008

The North Sea Regional Advisory Council (NSRAC) is the main forum through which fisheries interests are involved in Marine Spatial Planning (MSP) on the North Sea. The NSRAC is a relatively new and fragile forum involving various stakeholders. MSP confronts this group with a series of broader issues such as inter alia wind farms, transportation, and marine protected areas. The spatial focus involves both a reduction and a multiplication of the levels of geographical scale at which information for management must be resolved. The ongoing development of these institutions provides lessons about facilitating the evolution of cross-scale institutional linkages that strengthen adaptive, eco-system-based management.  相似文献   

Lightning flash mensuration using video from the space shuttle Columbia (STS‐32)     

David E. Pitts  Clyde A. Sapp  Otha H. Vaughan Jr. 《国际地球制图》2013,28(1):61-68

Abstract

Environmental data are often utilized to guide interpretation of spectral information based on context, however, these are also important in deriving vegetation maps themselves, especially where ecological information can be mapped spatially. A vegetation classification procedure is presented which combines a classification of spectral data from Landsat‐5 Thematic Mapper (TM) and environmental data based on topography and fire history. These data were combined utilizing fuzzy logic where assignment of each pixel to a single vegetation category was derived comparing the partial membership of each vegetation category within spectral and environmental classes. Partial membership was assigned from canopy cover for forest types measured from field sampling. Initial classification of spectral and ecological data produced map accuracies of less than 50% due to overlap between spectrally similar vegetation and limited spatial precision for predicting local vegetation types solely from the ecological information. Combination of environmental data through fuzzy logic increased overall mapping accuracy (70%) in coniferous forest communities of northwestern Montana, USA.  相似文献   

The Question, “But Is It Geography?”—Revisited or Are There Criteria for Establishing the Geographic Content of Topics?     

Clyde E. Browning 《The Professional geographer》1974,26(2):137-139

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