Details

Autor(en) / Beteiligte

• Kent, Christoph W.
• Grimmond, Sue
• Gatey, David
• Hirano, Kohin

Titel

Urban morphology parameters from global digital elevation models: Implications for aerodynamic roughness and for wind-speed estimation

Ist Teil von

• Remote sensing of environment, 2019-02, Vol.221, p.316-339

Ort / Verlag

New York: Elsevier Inc

Erscheinungsjahr

2019

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Urban morphology and aerodynamic roughness parameters are derived from three global digital elevation models (GDEM): Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), Shuttle Radar Topography Mission (SRTM), and TanDEM-X. Initially, each is compared to benchmark elevation data in London (UK). A moving window is used to extract ground heights from the GDEMs, generating terrain models with root-mean-square accuracy of up to 3 m. Subtraction of the ground heights extracted from each GDEM provides roughness-element heights only, allowing for calculation of morphology parameters. The parameters are calculated for eight directional sectors of 1 km grid-squares. Apparent merging of roughness elements in all GDEMs causes height-based parameter underestimation, whilst plan and frontal areas are over- and under-estimated, respectively. Combined, these lead to an underestimation of morphometrically-derived aerodynamic roughness parameters. Parameter errors are least for the TanDEM-X data. Further comparison in five cities (Auckland, Greater London, New York, Sao Paulo, Tokyo) provides basis for empirical corrections to TanDEM-X-derived geometric parameters. These reduce the error in parameters across the cities and for a separate location. Meteorological observations in central London give insight to wind-speed estimation accuracy using roughness parameters from the different elevation databases. The proposed corrections to TanDEM-X parameters lead to improved wind-speed estimates, which combined with the improved spatial representation of parameters across cities demonstrates their potential for use in future studies. •ASTER, SRTM and TanDEM-X elevation data compared to benchmark data in London, UK.•TanDEM-X most like benchmark data (pixel-based, geometric and roughness parameters).•Empirical corrections to TanDEM-X parameters developed from five global cities.•Corrections improve estimation of parameters and for a separate urban location.•Wind-speed estimates with elevation model parameters compared to observations.