Effect of vegetation and waterbody on the garden city concept: An evaluation study using a newly developed city, Putrajaya, Malaysia

Abstract

The garden city concept was adopted in the development of a new tropical city, Putrajaya, aimed at mitigating the effect of urban thermal modification associated with urbanisation, such as urban heat island (UHI). WRF/Noah/UCM coupled system was used to estimate the urban environment over the area and the individual thermal contributions of natural land use classes (vegetation and waterbody). A control experiment including all land use types describing the urban conditions of Putrajaya city agreed well with the observations in the region. A series of experiments was then conducted, in which vegetation and waterbody were successively replaced with an urban land use type, providing the basis for an assessment of their respective effect on urban thermal mitigation. Surface energy components, 2-m air temperature (T2m) and mixing ratio (Q2m), relative humidity (RH) and UHI intensity (UHII) showed variations for each land use class. Overall, an increase in urban surfaces caused a corresponding increase in the thermal conditions of the city. Conversely, waterbody and vegetation induced a daily reduction of 0.14 and 0.39 °C of T2m, respectively. RH, UHI and T2m also showed variations with urban fractions. A thermal reduction effect of vegetation is visible during mornings and nights, while that of water is minimally shown during daytime. However, during nights and mornings, canopy layer thermal conditions above waterbody remain relatively high, with a rather undesirable effect on the surrounding microclimate, because of its high heat capacity and thermal inertia.

Impact of Urban Climate Landscape Patterns on Land Surface Temperature in Wuhan, China

“…Since the influence of patch geometry is limited, mitigation strategies integrating the surrounding environment should be considered for the Heavy Industry landscape. Previous researchers report that similar to vegetation, urban waterbodies can reduce the temperature of the ambient environment [40], and waterbody geometry significantly influences cooling capacity [41]. Consistently, our regression result shows that patch cooling intensity of Water is affected by CAI, AREA, and ECON, and 57.4% of cooling intensity variation can be explained by the regression model (Table 5).…”

Influence of Urban Agglomeration Expansion on Fragmentation of Green Space: A Case Study of Beijing-Tianjin-Hebei Urban Agglomeration

“…The study of green space began in the 19th century in Britain. Since it plays an important role in protecting the urban ecological environment [47] and influencing urbanization, green space has become a hot research topic and concept in the field of urban space research since the 21st century [48,49]. Scholars have carried out research on the concept definition, ecological function and service value, pattern characteristics, and environmental effects of green space [50,51].…”

Mapping the Changes in Urban Greenness Based on Localized Spatial Association Analysis under Temporal Context Using MODIS Data

“…Vegetation supports sustainable urban development [7,13]. As the principal component in the garden city concept (GCC), vegetation was found to have a consistent cooling effect on the canopy layer temperature in some tropical cities [14]. Due to the migration of population from remote rural areas to cities, the impact of human activities on urban land use is expected to intensify [9,15].…”