Abstract
Roughness length is one of the key variables in micrometeorological studies and environmental studies in regards to describing development of cities and urban environments. By utilizing the three dimensions ultrasonic anemometer installed at Mustansiriyah university, we determined the rate of the height of the rough elements (trees, buildings and bridges) to the surrounding area of the university for a radius of 1 km. After this, we calculated the zero-plane displacement length of eight sections and calculated the length of surface roughness. The results proved that the ranges of the variables above are ZH (9.2-13.8) m, Zd (4.3-8.1) m and Zo (0.24-0.48) m.
Highlights
Evaluation of surface roughness over cities is of fundamental parameters in urban areas for many applications, such as air pollution modeling and wind-engineering activities, vertical structures, installing wind turbines and urban planning for vital areas, spatially-varying surface roughness, ground level air quality determination, and environmental pollution
This method yields values of zero-plane displacement value (Zd) at Zo and the latter decline at higher densities beyond single peak [11]
We could calculate the plan area (AP) of roughness elements via aerial image taken from above using Google Earth, with the drawing scale for each block, and taking the averageApin each section
Summary
Evaluation of surface roughness over cities is of fundamental parameters in urban areas for many applications, such as air pollution modeling and wind-engineering activities, vertical structures, installing wind turbines and urban planning for vital areas, spatially-varying surface roughness, ground level air quality determination, and environmental pollution. In atmospheric boundary–layer theory, surface roughness is parameterized through the roughness length (Zo) at which the mean wind speed becomes zero [1]. It is approximately a third of the height of the roughness elements, with values ranging from 0.0001 m for ice or water surface, up to a few meters for large urban areas and 0.1 m for park lands [2]. The change in the surface structure over a certain time will lead to changing micrometeorological parameters such as Reynolds stresses for the mean wind speed profile, and alter the vertical wind shear in both speed and direction
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
