45
– to provide a reference system for cities which lack a monitoring network but
intend to deploy one;
– to demonstrate a prototype for a new monitoring system that is already
operational.
Any city operating measurement sites for UHI detection is strongly encouraged
to adopt these recommendations to its measurement and evaluation systems in order
to obtain better coverage of UHI phenomena over the city.
2.3 Planning a Representative Urban Climate Station
Network
The simple classification of measuring sites contains categories for urban, downtown, suburban, and rural sites. For correct and precise heat island evaluation, far
more detailed descriptions of urban areas are necessary, as Stewart and Oke’s
method (2012) suggests applying. Local Climate Zones were introduced for characterizing the building and vegetation structures of a compact urban region.
Stewart and Oke formally defined Local Climate Zones (LCZs) as regions of
uniform surface cover, structure, material, and human activity that span hundreds of
meters to several kilometers in the horizontal scale. The LCZ system comprises 17
zone types at the local scale (100–1000 m). Each type is unique in its combination
of surface structure, cover, and human activity. Classification can be made on the
basis of built-up area (10 classes) and types of land cover (7 classes). Classification
of sites into appropriate LCZs requires basic metadata and surface characterization.
The zone definitions provide a standard framework for reporting and comparing
field sites and their climate observations.
LCZs are a widely used classification system (Unger et al. 2011). It provides
useful information for
– defining UHI magnitude,
– establishing comparable values originating from different sites,
– modeling climate and analyzing temperature,
– detecting features that influence microclimates.
– Determination of LCZs means defining urban areas characterized by the same
structure, a similar built-up ratio, and relatively similar building heights (Balázs
et al. 2009). Bordering is essential for finding ideal and representative sites for
urban climate observation(Unger et al. 2011). Typically, a “three-step process” is
suggested by Stewart and Oke (2012) “to users when classifying field sites into
LCZs” (p. 1889):
“Step 1: Collect site metadata. Users must collect appropriate site metadata to
quantify the surface properties of the source area (as defined in Step 2) for a
temperature sensor. This is best done by a visit to the field sites in person to
survey and assess the local horizon, building geometry, land cover, surface
wetness, surface relief, traffic flow, and population density […]. If a field visit
is not possible, secondary sources of site metadata include aerial photographs,
2 Urban Heat Island Gold Standard and Urban Heat Island Atlas
– to provide a reference system for cities which lack a monitoring network but
intend to deploy one;
– to demonstrate a prototype for a new monitoring system that is already
operational.
Any city operating measurement sites for UHI detection is strongly encouraged
to adopt these recommendations to its measurement and evaluation systems in order
to obtain better coverage of UHI phenomena over the city.
2.3 Planning a Representative Urban Climate Station
Network
The simple classification of measuring sites contains categories for urban, downtown, suburban, and rural sites. For correct and precise heat island evaluation, far
more detailed descriptions of urban areas are necessary, as Stewart and Oke’s
method (2012) suggests applying. Local Climate Zones were introduced for characterizing the building and vegetation structures of a compact urban region.
Stewart and Oke formally defined Local Climate Zones (LCZs) as regions of
uniform surface cover, structure, material, and human activity that span hundreds of
meters to several kilometers in the horizontal scale. The LCZ system comprises 17
zone types at the local scale (100–1000 m). Each type is unique in its combination
of surface structure, cover, and human activity. Classification can be made on the
basis of built-up area (10 classes) and types of land cover (7 classes). Classification
of sites into appropriate LCZs requires basic metadata and surface characterization.
The zone definitions provide a standard framework for reporting and comparing
field sites and their climate observations.
LCZs are a widely used classification system (Unger et al. 2011). It provides
useful information for
– defining UHI magnitude,
– establishing comparable values originating from different sites,
– modeling climate and analyzing temperature,
– detecting features that influence microclimates.
– Determination of LCZs means defining urban areas characterized by the same
structure, a similar built-up ratio, and relatively similar building heights (Balázs
et al. 2009). Bordering is essential for finding ideal and representative sites for
urban climate observation(Unger et al. 2011). Typically, a “three-step process” is
suggested by Stewart and Oke (2012) “to users when classifying field sites into
LCZs” (p. 1889):
“Step 1: Collect site metadata. Users must collect appropriate site metadata to
quantify the surface properties of the source area (as defined in Step 2) for a
temperature sensor. This is best done by a visit to the field sites in person to
survey and assess the local horizon, building geometry, land cover, surface
wetness, surface relief, traffic flow, and population density […]. If a field visit
is not possible, secondary sources of site metadata include aerial photographs,
2 Urban Heat Island Gold Standard and Urban Heat Island Atlas