A simple two‐parameter model for scaling hillslope surface runoff          下载免费PDF全文

Gary J. Sheridan  Philip J. Noske  Patrick N.J. Lane  Owen D. Jones  Christopher B. Sherwin 《地球表面变化过程与地形》2014,39(8):1049-1061

The objective of this research was to develop and parameterise a physically justified yet low‐parameter model to quantify observed changes in surface runoff ratios with hillslope length. The approach starts with the assumption that a unit of rainfall‐excess runoff generated at a point is a fraction β of precipitation P (m) which travels some variable distance down a slope before reinfiltrating, depending on the local rainfall, climate, soils, etc. If this random distance travelled Y is represented by a distribution, then a survival function will describe the probability of this unit of runoff travelling further than some distance x (m). The total amount of per unit width runoff Q (m²) flowing across the lower boundary of a slope of length λ (m) may be considered the sum of all the proportions of the units of rainfall excess runoff integrated from the lower boundary x = 0 to the upper boundary x = λ of the slope. Using these assumptions we derive a model Q(λ) = βPμλ/(μ + λ), (μ > 0, 0 ≤ β ≤ 1, λ ≥ 0) that describes the change in surface runoff with slope length, where μ (m) is the mean of the random variable Y. Dividing both sides of this equation by Pλ yields a simple two‐parameter equation for the dimensionless hillslope runoff ratio Q_h(λ) = βμ/(μ + λ). The model was parameterised with new rainfall and runoff data collected from three replicates of bounded 2 m wide plots of four different lengths (0.5, 1.0, 2.0 and 4.0 m) for 2 years from a forested SE Australian site, and with 32 slope length–runoff data sets from 12 other published studies undertaken between 1934 and 2010. Using the parameterised model resulted in a Nash and Sutcliffe statistic between observed and predicted runoff ratio (for all data sets combined) of 0.93, compared with –2.1 when the runoff ratio was fixed at the value measured from the shortest plot. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

Seismic activity in the region of northwest bohemia     

Vladimír Tobyáš  Reinhard Mittag 《Studia Geophysica et Geodaetica》1992,36(3):207-214

Summary The seismic activity of the region is analysed on the basis of the recent microseismic and former macroseismic observations. Only microearthquakes in the narrow magnitude range of 0–1.2 were monitored during 1982–1988. The mean annual frequencies are of the same order as the figures extrapolated from the magnitude-frequency relationship obtained for earthquakes in the magnitude range 2.4–4.5 which occurred in the region before 1910. The recent stress release is very low but its annual average of 7 × 10 ³ J ^1/2 is close to the annual average of 23×10 ³ J ^1/2 of long-term macroseismic observations.  相似文献   

Electrical conductance of sediments overlying the basement of the Czech Republic     

Oldřich Praus  Marta Tobyášová 《Studia Geophysica et Geodaetica》1992,36(2):161-167

Summary The data of borehole resistivity logs were collected, analysed, classified and a contour map of electrical conductance of the sedimentary complex overlying the crystalline basement of the Czech Republic was computer-generated. The map contributes to estimating the distortion fields produced by conductance variations in the surface layer. Information on the basement relief is also obtained from the contour map patterns.  相似文献   

Astatism of a pendulum seismometer with a vertical plane of oscillation     

Vladimír Tobyáš  Reviewer J. Buben 《Studia Geophysica et Geodaetica》1977,21(3-4):306-315

Summary Formulae are derived for computing the coefficient of astatism of a seismometer, the pendulum of which, oscillating in the vertical plane, has its equilibrium position in general deflected from the horizontal plane. An ideal linear system with a zero and non-zero theoretical initial length of the spring is considered. These solutions include as special cases seismometers of vertical seismographs.  相似文献   

Seismic equipment for the investigation of microtremors     

Tobyáš  Vladimír 《Studia Geophysica et Geodaetica》1957,1(1):101-105

Studia Geophysica et Geodaetica - В настоящей статье...  相似文献   

Sensitivity of the Gs 12 gravity meter to vibrations     

Vladimír Tobyáš  Karel Diviš  Reviewer Z. Šimon 《Studia Geophysica et Geodaetica》1980,24(4):333-347

nuaa m¶rt;ua u mam unmauaumaGs 12 No. 129 a uauu ¶rt;uana amm 0.02–30. a uu a uau nam auu au u auma naamauma a mua ma u n¶rt;a mumm a ¶rt;uu ¶rt;ama ammau uu .  相似文献   

Saharan air outbreaks over the tropical North Atlantic     

Joseph M. Prospero  Toby N. Carlson 《Pure and Applied Geophysics》1980,119(3):677-691

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The effect of vibrations on the accuracy of measurements with a CG-2 gravimeter     

Karel Diviš  Vladimír Tobyáš  Reviewer M. Pick 《Studia Geophysica et Geodaetica》1974,18(2):199-204

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Reaction of linear gravimetric measuring systems to disturbances of equilibrium state     

Jiří Trešl  Reviewer V. Tobyáš 《Studia Geophysica et Geodaetica》1985,29(1):32-43

Summary The reaction is studied of measuring systems of quartz gravity meters to external disturbances. The actual elastic system is approximated by a model of a linear oscillator with one degree of freedom. The appropriate differential equation of motion is solved for some of the typical shapes of determinate and random disturbance input signals. The result represents expressions which describe the time behaviour of the output signals.

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Short-period seismographs at průhonice in seismological practice     

Vladimír Tobyáš  Libuše Ruprechtová  Jaroslava Plomerová  Reviewer A. Zátopek 《Studia Geophysica et Geodaetica》1983,27(3):241-247

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