HIGH-RESOLUTION URBAN MORPHOLOGY DATA FOR URBAN WIND FLOW MODELING

The application of urban forestry methods and technologies to a number of practical problems can be further enhanced by the use and incorpor ation of localized, high resolution wind and temperature fields into t heir analysis methods. The numerical simulation of these micrometeorol ogical fields will represent the interactions and influences of urban structures, vegetation elements, and variable terrain as an integral p art of the dynamics of an urban domain. Detailed information of the na tural and-man-made components that make up the urban area is needed to more realistically model meteorological fields in urban domains. Simu lating high resolution wind and temperatures over and through an urban domain utilizing detailed morphology data can also define and quantif y local areas where urban forestry applications can contribute to bett er solutions. Applications such as the benefits of planting trees for shade purposes can be considered, planned, and evaluated For their imp act on conserving energy and cooling costs as well as the possible rec onfiguration or removal of trees and other barriers for improved airfl ow ventilation and similar processes. To generate these fields, a wind model must be provided, as a minimum, the location, type, height, str uctural silhouette, and surface roughness of these components, in orde r to account for the presence and effects of these land morphology fea tures upon the ambient airflow. The morphology of Sacramento, CA has b een characterized and quantified inconsiderable detail primarily for w ind flow modeling, simulation, and analyses, but can also be used for improved meteorological analyses, urban forestry, urban planning, and other urban related activities. Morphology methods previously develope d by Ellefsen are applied to the Sacramento scenario with a high resol ution grid of 100 m x 100 m. The Urban Morphology Scheme defines Urban Terrain Zones (UTZ) according to how buildings and other urban elemen ts are structured and placed with respect to each other. The urban ele ments within the 100 m x 100 m cells (one hectare) are further describ ed and digitized as building height, building footprint (in percent), reflectivity of its roof, pitched roofer flat, building's long axis or ientation, footprint of impervious surface and its reflectivity, footp rint of canopy elements, footprint of woodlots, footprint of grass are a, and footprint of water surface. A variety of maps, satellite images , low level aerial photographs, and street level photographs are the r aw data used to quantify these urban properties. The final digitized m orphology database resides in a spreadsheet ready for use on ordinary personal computers. Published by Elsevier Science Ltd.