Changes of the displacement height and roughness length of maize during a growing season

• Published in: Agricultural and forest meteorology Vol. 42; no. 1; pp. 53 - 62
• Main Authors: Jacobs, Adrie F.G, Van Boxel, John H
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.01.1988; Oxford Elsevier; New York, NY
• Subjects: Agricultural and forest climatology and meteorology. Irrigation. Drainage; Agricultural and forest meteorology; Agronomy. Soil science and plant productions; AIR TEMPERATURE; Biological and medical sciences; Biometrics, statistics, experimental designs, modeling, agricultural computer applications; CANOPY; COUVERT; Crop climate. Energy and radiation balances; CUBIERTA DE COPAS; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Generalities. Biometrics, experimentation. Remote sensing; MICROCLIMA; MICROCLIMAT; MICROCLIMATE; TEMPERATURA DEL AIRE; TEMPERATURE DE L'AIR; VENT; VIENTO; WINDS; ZEA MAYS; Monocotyledones; Cultivated field; Correlation; Zea mays; Europe; Roughness; Growing season; Quantization; Wind velocity; Aerodynamics; Vegetation effect; Air flow; Netherlands; Gramineae; Seasonal variation; Aerodynamic parameter; Angiospermae; Parameter; Spermatophyta; Plant cover; Height; Fodder crop; Phytoclimate
• ISSN: 0168-1923; 1873-2240
• DOI: 10.1016/0168-1923(88)90066-4

Variations in the displacement height (d) and roughness length (z0) of a maize crop were investigated through a growing season. A programme of measurement from which the wind profile, the Richardson gradient number and the turbulent fluxes of heat and momentum were estimated, was carried out. Two techniques were combined to obtain unique values for d and z0: the log-profile fitting technique and the eddy correlation technique. Throughout the growing season, the displacement height appeared to correlate very well (r = 0.98) with the height (H) of the canopy. A mean value for d/H was 0.75. The roughness length was strongly correlated with the difference between the canopy height and the displacement height. A mean value of 0.26 for z0/(H − d) was found (r = 0.86). If the ratio d/H was fixed, the roughness length did not show any clear dependence on wind speed or thermal stability.