Estimating the Urban Heat Island in Residential Areas in the Netherlands Using Observations by Weather Amateurs

Abstract

A better quantification of the urban heat islands (UHIs) in the Netherlands is urgently needed given the heat stress–related problems in the recent past combined with the expected temperature rise for the coming decades. Professional temperature observations in Dutch urban areas are scarce, however. Therefore, this research explores the use of observations from weather stations that were installed and maintained by weather amateurs. From a set of over 200 stations, suitable and representative data have been selected from 20 stations, using a set of objective selection criteria that are based on metadata. One year of data (January–December 2010) was considered. From these data, estimates have been obtained of the magnitude of the UHI in Dutch low-rise residential areas. A positive relation (linear model with r2 ≈ 0.7) was derived between the summer-averaged UHI and the (neighborhood scale) population density around the observational sites. It was found that the UHI in summer is strongest in nighttime conditions and that it increases with decreasing wind speed, decreasing cloud cover, and increasing sea level air pressure. The summer-averaged UHI was ~0.9°C. During nighttime in a relatively warm 1-month subperiod of the summer, the average UHI was ~1.4°C. During spring and autumn, the UHI was lower than in summer; during winter, no significant UHI was observed. The agreement in results among the different stations and the accordance of the magnitude and variation of the observed UHI with those described in the literature show that automatic observations from weather amateurs can be of sufficient quality for atmospheric research, provided that detailed metadata are available.

Overview of challenges and achievements in the climate adaptation of cities and in the Climate Proof Cities program

“…The intra-urban variability is considerable, indicating that the magnitude of the UHI effect in an urban area is to a large extent determined by local features. This also explains the absence of a clear relationship between UHI intensity and city size (as defined by the number of citizens) found in previous studies [13,14]. This also explains why not only big cities but also smaller towns and large villages in the Netherlands display an urban heat island effect [15].…”

Land surface impacts on precipitation in the Netherlands

“…We find an average and maximum diurnal UHI of 0.4 and 1.3 K respectively. In summer higher UHIs of respectively 0.9 and 2.3 K were measured (Steeneveld et al, 2011;Wolters and Brandsma, 2012). Wolters and Brandsma (2012) however show a clear dependency of UHI intensity on wind speed and measurements of the average UHI in spring are approximately 30% lower than in summer.…”

“…Temperature measurements conducted in the last decade show that urban areas in the Netherlands can be up to 10 K warmer than the surrounding areas (Steeneveld et al, 2011;van der Hoeven and Wandl, 2015;Wolters and Brandsma, 2012). This phenomenon is called the Urban Heat Island (UHI).…”

“…Arnfield, 2003;Oke, 1982;Steeneveld et al, 2011;Theeuwes, 2015;Zhou et al, 2013). In the Netherlands, UHIs over 5°C have been measured despite the relatively small size of Dutch cities (Steeneveld et al, 2011;van der Hoeven and Wandl, 2015;Wolters and Brandsma, 2012). Internationally, there is a large body of literature dealing (mostly) with precipitation enhancement due to urban areas as well (see e.g.…”

“…Our study area is therefore not comparable to the metropolitan areas where previous studies have been conducted. Despte their relatively small size Dutch cities do influence the atmosphere and UHIs over 5°C have been measured (Steeneveld et al, 2011;van der Hoeven and Wandl, 2015;Wolters and Brandsma, 2012). The effects on precipitation have not been investigated however.…”