GIS analysis of remote sensing data to assess spatial disparities of urban green space and its effect on urban heat islands for strategic, spatial, and health planning purposes : A dissertation submitted in partial fulfilment of the requirements for the Degree of Master at Lincoln University

Abstract

As a response to our international commitments towards the 1992 United Nations Framework Convention on Climate Change, New Zealand has to reduce the transport sector’s emissions via different policy settings, including urban intensification. However, if urban intensification resulted in a diminished urban green space, the urban heat islands effect will be accentuated. Moreover, residents' physical and mental health could deteriorate according to recent literature findings. Such impacts would be relatively higher on disadvantaged and vulnerable communities. Managing urban intensification while also maintaining spatial equity of urban green space necessitates developing an urban green space quantifying tool that detects both private and public green spaces. GIS analysis of remote sensing data from aerial and satellite imagery is explored in this research as a potential solution. This type of analysis is based on the same GIS approach used by the Christchurch City Council to calculate ground imperviousness to predict urban growth. The area of Christchurch’s major urban core was used as the study area subject to the availability of high-resolution aerial imagery. In this study area, the land surface temperature was retrieved from the aerial imagery to predict the urban heat island effect, and a GIS vegetation index analysis was conducted to evaluate the level of greenness following international examples. Results identified neighbourhoods in Christchurch that would be impacted more than the others by unplanned urban intensification after it was integrated with the index of multiple deprivations from Auckland University. Most impacted areas, according to this research, were compared against the prioritised areas for open space interventions that was detected by an accessibility study from the current Public Open Space Strategy of Christchurch City Council 2010-2040. The results could explain the inequitable distribution of urban green space that continues to occur under the currently used approaches and could be used to set a minimum target for urban green space in the newly proposed Natural and Built Environment Act. Simultaneously, the calculated green space per capita represents a suitable approach to assess and prepare our cities for Covid-19 implications; as this partially reflects the amount of private green space, which is most important during lockdowns for households’ social distancing.