Utilization of remote sensing and GIS to identify radius of urban cool island for planning open green area in urban area (case study of Yogyakarta)

Abstract

City is a center development of a region that has functions both social and economic. Yogyakarta City is the administrative center of Yogyakarta Special Region province and as educational centers in Indonesia. The complexity of activities that occurring has an impact on the microclimate situation in the region which is called as Urban Heat Island and it will affect the comfort of urban community so that urban area should be arranged especially about microclimate aspects. Open Green Area is one element that can lower the surface temperature. Radius reduction in surface temperature of Open Green Area became the main issue in this research as a basis for determining the location of Open Green Area spaces with an ideal distance interval among Open Green Areas in urban areas. The methods used Split Moving Window Analysis to obtain Land Surface Temperature, Normalized Difference Vegetation Index is transformation to obtain variation of vegetation density, statistic analysis to know LST correlation with NDVI, and buffer analysis to analyze changing of radius temperature. The results show that average surface temperature in Yogyakarta City ranges 25 to 35°C. The value of vegetation density is obtained 0-0,3. Based on the result of correlation between LST and NDVI show that they have correlation value with negative gradient. The higher value of NDVI give impact of LST value in the same location will tend to be low with average value of temperature rise of 0.122°C per 30 meters, then is obtained the ideal distance interval among Open Green Area ranged from 240-260 meters to maintain maximum temperature rise 1 degrees Celsius from the center of Open Green Area. The results of this study can be used as a suggestion to arrange of planning Open Green Area for the Yogyakarta Government.