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Titolo:
Modeling the roughness properties of artificial soil clods
Autore:
Dong, ZB; Fryrear, DW; Gao, SY;
Indirizzi:
Chinese Acad Sci, Desert Res Inst, Lanzhou 730000, Gansu, Peoples R China Chinese Acad Sci Lanzhou Gansu Peoples R China 730000 su, Peoples R China USDA ARS, Big Spring, TX 79720 USA USDA ARS Big Spring TX USA 79720USDA ARS, Big Spring, TX 79720 USA
Titolo Testata:
SOIL SCIENCE
fascicolo: 12, volume: 164, anno: 1999,
pagine: 930 - 935
SICI:
0038-075X(199912)164:12<930:MTRPOA>2.0.ZU;2-8
Fonte:
ISI
Lingua:
ENG
Soggetto:
AERODYNAMIC ROUGHNESS; WIND; EROSION; RIDGES;
Keywords:
soil clods; aerodynamic roughness; surface roughness; prediction model;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Agriculture,Biology & Environmental Sciences
Citazioni:
20
Recensione:
Indirizzi per estratti:
Indirizzo: Dong, ZB Chinese Acad Sci, Desert Res Inst, 260,W Donggang Rd, Lanzhou 730000, Gansu, Peoples R China Chinese Acad Sci 260,W Donggang Rd Lanzhou Gansu Peoples R China 730000
Citazione:
Z.B. Dong et al., "Modeling the roughness properties of artificial soil clods", SOIL SCI, 164(12), 1999, pp. 930-935

Abstract

Knowledge of the aerodynamic roughness length (Z(0)) resulting from management practices that include soil clods, vegetation, and ridges is essentialto describing their protective roles in wind erosion. The usual method of obtaining Z(0) from a logarithmic wind profile has limited accuracy becausethe probes used to measure wind profiles do not reveal well the subtle characteristics of the very near-surface airflow. To evaluate the roughness properties of soil clods in this study, Z(0) is derived by direct measurementof the drag on cloddy surfaces. Z(0) values, in response to different windvelocities and artificial soil clod coverage, were obtained in a wind tunnel. Z(0) was found to be the function of both clod coverage and wind velocity increasing with clod coverage by a function of Z(0) = a + bS(c)lnS(c)(R-2 > 0.81, P < 0.001) and decreasing with wind velocity by a function of Z(0) = c + d exp (-V/k) (R-2 > 0.68, P < 0.001), where S-c and V are clod coverage and wind velocity and a, b, c, d, and k are regression constants. A multivariate predictive equation was developed by regressing Z(0) on S-c and V. The predicted values matched those from the wind tunnel reasonably well (R-2 = 0.92). These results demonstrate a need for distinguishing the concept of aerodynamic roughness that is a dynamic dimension of the interaction between near-surface airflow and surface rougher than that of surface roughness that is dependent exclusively on surface conditions.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 21/09/20 alle ore 04:03:08