California Supplemental (CSE) Practice Exam

Surface Roughness B is best characterized by which type of terrain?

1. Open areas with less than 30-foot tall structures

2. Flat, unobstructed areas

3. Urban and suburban areas with closely spaced obstructions

4. Water surfaces outside hurricane-prone regions

The correct answer is: Urban and suburban areas with closely spaced obstructions

Surface Roughness B is characterized by urban and suburban areas with closely spaced obstructions due to the presence of multiple man-made structures, such as buildings, walls, and other installations that disrupt the flow of wind. This type of terrain creates a roughness that affects how winds behave and influence meteorological observations. In urban areas, the various heights and distances between buildings create a complex flow pattern that is markedly different from flat and open areas. Closely spaced obstructions lead to turbulence and a more variable wind profile, which is critical to consider in meteorological modeling and applications. The other options represent terrain types that would not provide the same level of roughness. Open areas or flat unobstructed locations would present minimal wind resistance, while water surfaces outside hurricane-prone regions have smoothness that allows winds to flow with less interruption. Thus, the unique characteristics of urban and suburban environments contribute to the definition of Surface Roughness B.