Characterization of vegetation properties: Canopy modeling of pinyon-juniper and ponderosa pine woodlands; Final report. Modeling topographic influences on solar radiation: A manual for the SOLARFLUX model

摘要

This report is comprised of two studies. The first study focuses on plant canopies in pinyon-juniper woodland, ponderosa pine woodland, and waste sites at Los Alamos National Laboratory which involved five basic areas of research: (1) application of hemispherical photography and other gap fraction techniques to study solar radiation regimes and canopy architecture, coupled with application of time-domain reflectometry to study soil moisture; (2) detailed characterization of canopy architecture using stand mapping and allometry; (3) development of an integrated geographical information system (GIS) database for relating canopy architecture with ecological, hydrological, and system modeling approaches; (4) development of geometric models that simulate complex sky obstruction, incoming solar radiation for complex topographic surfaces, and the coupling of incoming solar radiation with energy and water balance, with simulations of incoming solar radiation for selected native vegetation and experimental waste cover design sites; and (5) evaluation of the strengths and limitations of the various field sampling techniques. The second study describes an approach to develop software that takes advantage of new generation computers to model insolation on complex topographic surfaces. SOLARFLUX is a GIS-based (ARC/INFO, GRID) computer program that models incoming solar radiation based on surface orientation (slope and aspect), solar angle (azimuth and zenith) as it shifts over time, shadows caused by topographic features, and atmospheric conditions. This manual serves as the comprehensive guide to SOLARFLUX. Included are discussions on modeling insolation on complex surfaces, the theoretical approach, program setup and operation, and a set of applications illustrating characteristics of topographic insolation modeling.