Design of an urban monitoring network based on Local Climate Zone mapping and temperature pattern modelling

The recently developed Local Climate Zones (LCZ) classification system was initially not designed for mapping, but to classify temperature observation sites. Nevertheless, as a need arose to characterize areas based on their distinct thermal climate, utilizing LCZ classes for mapping was a logical step. The objectives of this study were (1) to develop GIS methods for the calculation of different surface parameters required for LCZ classification; (2) to identify and delineate the LCZ types within the study area using the calculated parameters; and (3) to select re presentative station sites for an urban monitoring network utilizing both the mapped LCZs and the modelled mean annual temperature surplus pattern in Szeged, Hungary. The study used remotely sensed data, maps and GIS databases of the city and its surroundings. The basic area of calculation was the lot area polygon, consisting of a building and its close vicinity. Adjoining polygons classified with identical or similar parameters were merged to obtain LCZs of appropriate size. As a result, 6 built LCZ types were distinguished in the studied urban area. The temperature pattern in the city was provided by an empirical model. The siting of stations took both the LCZ map and the modelled temperature pattern into account. The lampposts onto which the stations were to be mounted were determined by field surveys. The bias between the temperature pattern interpolated from the 24 stations and the initially estimated distribution by the model was found to be small. LCZ mapping is the first step in the development of urban climate maps (UCMs) that carry information on the spatial distribution and magnitude of the heat stress (thermal loads) and on the ventilation ability (dynamical potential) of different urban areas.