POINT PATTERN ANALYSIS AND REMOTE SENSING TECHNIQUES APPLIED TO EXPLAIN THE FORM OF THE URBAN HEAT ISLAND.

摘要

The relationship between the form of the Urban Heat Island (UHI) and the pattern and quantity of urban vegetation was investigated. Although, earlier empirical studies have investigated the relationship between land-use and the form of the UHI, an explicit description of surface types and their spatial arrangement was sought in order to explain a greater amount of the variance in the UHI. The effect of surface type patterns on the energy budget of urban spaces has been suggested throughout the literature.;A digitized NASA CIR (1:120,000 scale) photograph provided the data base for the determination of pattern and quantity of vegetation in a spatial unit. An IR/G spectral ratio was utilized to classify 10,000 pixels, depicting a 600 m x 600 m ground scene, to vegetated and non-vegetated cells on a computerized vegetation map. By repeatedly sampling the map (5000x) with a 5 cell x 5 cell quadrat a number of measures of the arrangement (pattern), as well as the quantity, of vegetation in each of the 34 spatial units was obtained using Quadrat Analysis.;The UHI was found to exhibit a characteristic form depending on the length of urbanized surface air traveled over before being sampled. The magnitude of the UHI was most sensitive to nighttime meteorological conditions.;A methodology utilizing Remote Sensing and Quadrat Analysis was developed to describe the pattern and quantity of vegetation in 600 m x 600 m spatial units. A linear combination of variables, describing the distance from non-developed countryside, pattern of vegetation, quantity of vegetation, and meteorological conditions, explained 84% of the temporal and spatial variability of the Syracuse, N.Y. UHI for nine nights at 34 sampling stations.